Closed Eye!

The water vapor shows it clearly, the eyewall has closed off now and intensification could become much more rapid. If this trend holds up we could see an eye visible on satellite within 6 hours, just before Gustav makes landfall in southeast/central Louisiana. The green circle indicates the center of circulation of Gustav.

Hurricane Hunters found 952.7, but the dropsonde is not yet in, so we don't know the specific pressure. I am guessing 954 mb, a continued drop in pressure.

Gustav Shows Its Eye

Not on satellite, but on radar! Yes, on the long range radar out of New Orleans you can now see the center of circulation and the eyewall. It won't be long until it make landfall moving at 18 mph. A slow down is expected, and thus why the storm wont hit Louisiana until tomorrow morning.

Another Hurricane Hunter aircraft is entering the center of the storm as I type this, so another update will come shortly.

954.4 mb and now 952.6 mb

Its still strengthening. And the eyewall is getting its act together. It is starting to look like a Category 3 is a certainty, now it will be whether or not Gustav can bottom out before landfall.

Hurricane Hunter Pass

The Hurricane Hunters have found lowest pressure of 957 mb. This confirms that the storm is increasing in strength. The wind speeds have not yet started to increase, but this is not uncommon as often tropical systems reduce their pressure (deepen) before the winds catch up. I would expect the winds to increase in an hour or two. The next Hurricane Hunter mission will likely confirm this.

We should see two Hurricane Hunter planes in the storm at the same time over the next hour or two, so very good data should be available as the system strengthens over the warm Gulf.

Gustav Approaches Northern Gulf

Gustav has been steadily strengthening over the last few hours. Convection has increased on the western and southern sides of the storm, but has not yet developed on the northeastern side. The center of circulation is located near the gray colors in the middle of the highest cloud tops (red colors) on the image below. If this steady intensification continues, Gustav could regain substantial Category 3 winds on the right side. Already upper-level winds support 110 mph, up from the last pass by the Hurricane Hunters, and the center pressure is back down to 960 mb. A second pass is commencing as I write this, so more information should be available very soon.

The storm is still headed on the NHC track, if not just on the east side. I think it is safe to say that it should stay on this track through the rest of its time over water. Afterwards steering currents degrade and the system should drift around in the LA/TX area for a few days. I wouldn't be surprised to see mass flooding in the area.

I will update in a bit with the new Hurricane Hunter information.

11 am EST Update

The 11 am update has come out reporting Gustav with at 962 mb and winds of 120 mph. Where they found the 120 mph is puzzling me. However, I am sure they are doing this so that people along the coast don't think that the risk is reducing. The NHC is still forecasting a major hurricane at landfall. I think we currently have a 105 mph Category 2 Hurricane Gustav rather than the Category 3 the NHC is currently reporting. But, like I said in the last post, the storm is starting to look a bit better in satellite images, and the radar image showed a restructuring southern eyewall. Another 2-4 hours should tell us a lot!

As for the track, the storm still looks to the east or right on the NHC track. The NHC talked about a shift in the models back to the west a bit, which makes sense with a weaker system. However, the models have been to the left all long with this system and the ridge doesn't yet seem to be moving the system. Right now, I think New Orleans (or just to its west/south) gets the worst of this storm, whatever strength it will be at landfall.

Clarification

In my last post, I wasn't saying that the storm shouldn't strengthen, it should....but it is going to have to in the next 12 hours before it reaches a cooler eddy of water in the central Gulf. Right now the storm is actually starting to look like it is strengthening the eyewall on the western side. However, the eastern side still needs work. If it can develop this in the next 3-5 hours, that will give it time to get stronger. The storm is definitely being influenced by these warmer waters right now.

UPDATE:

Hurricane Hunters found central pressure near 960 mb and peak flight level winds of 91 knots. It will be interesting to see what the NHC says in the next update at 11 am EST.

Gustav Weakens

Hurricane Gustav has weakened quite a bit during the night. As it crashed into Cuba Gustav was a Category 4 hurricane with winds of 150 mph, only 6 mph short of a Category 5! However, Cuba disrupted the eye of the hurricane during passage over the island and now Gustav has weakened all the way down to a low Category 3, or possibly now a Category 2. The latest Hurricane Hunter recon pass did not find flight level winds above 100 knots, indicating the surface is somewhere likely between 80-90 knots at best, or between 92-103 mph, or only a weak to moderate Category 2.

Why such the strong weakening? Well, first the passage over Cuba was much worse than expected. Earlier the models and forecasters were thinking Cuba would only reduce the winds a little bit (5-20 mph) and not completely disrupt the eyewall of the storm. Instead, Cuba broke down the eye allowing the pressure to come up from close to 940 mb at landfall to 960 mb now. Also, some shear (10-15 knots) has been influencing the system. Earlier the shear was not a factor because Gustav was located under an anti-cyclone which helped eject mass out of the top of the system, and because strong Category 3-4-5 hurricane eyewalls can protect the center of a storm from shear. Now, however, the eyewall has broken down some and the anti-cyclone did not follow the system into the Gulf. Thus, shear is impacting the storm more, not allowing it to go through rapid intensification while over the loop current. Actually, if this storm doesn't get its act together soon, we might not see more than a weak Category 2 hurricane at landfall, which would be great news!

Another issue that could come into play here is the building ridge to the north of the system. Now that it was weakened, the storm is less likely to plow through the ridge and should feel a bit more of a turn to the west. However, the ridge is now building in a bit weaker and the storm has sped up its arrival. Thus, the balance between these variables should be a wash and the storm looks to make landfall just about where the NHC track places it, to the south of New Orleans moving northwest. This still brings in the greatest surge to the New Orleans area, so any strengthening could lead to levee failures. If the storm stays as weak as it is right now (relatively, of course!) then the levees may hold. However, there are still weak points and it is definitely not the time to be in that city. One good thing, the system weakened as it passed over Cuba, so all the surge it had built up smashed Cuba but didn't continue into the Gulf. Hopefully Cuba was able to get everyone out of harms way.

In the words of a very good forecaster....

NOT GOOD!!!!


I remember when Katrina moved through Miami, diving to the west-southwest in a direction that was unexpected, I said to my friends and current wife: "This is the big one, the one that hits New Orleans." Of course, I wasn't 100% sure at the time and the models were still only starting to trend towards New Orleans, but I could just feel it. That same feeling is starting to get into my head again. Gustav has rapidly strengthened, it has a very symmetrical eye, great outflow, warm waters ahead of it, and nothing (besides a small passage over Cuba) stopping it. This storm has went from a hurricane that we should definitely be worried about, to a storm that can't be messed with.

Hurricane Hunters have found a minimal pressure of 945 mb and peak surface winds of 145 mph. Gustav is only 10 mph away from a Category 5 storm, and the NHC is now predicting it to become a Category 5 storm as it hits Cuba or just afterwards. The storm has consistently been tracking to the east side of the forecast and model tracks. This allowed it to mostly miss the Isle of Youth, not giving the island a real chance to weaken the system. Gustav is also flying right along, faster than most of the models had expected. This forward speed is only allowing it to burst through the ridge and beat the strengthening ridge that will later build as the storm approaches the coast. Things do not look good for the New Orleans area.

I am not going to definitively say this is Katrina 2, but it is starting to look like it. We need to wait an additional 6 hours, letting the storm interact with Cuba, to get an idea of where Gustav might be heading. Wherever Gustav does make landfall though, NO ONE should be within 10 miles of the coast. Be smart and get out of the way.

Gustav Cat 4 strength

Hurricane Hunters just found 943 mb! Western Cuba is about to get pummeled, and the eastern portion of the Isle of Youth is about to take a direct hit...and the storm still has plenty of time to strengthen before it goes over mainland Cuba. Gustav keeps going to the right side of the track, and it is making me a bit worried that things might go east of the NHC track...but we must look at Gustav over the next 6 hours to really get an idea of where it is going. If Gustav stays to the right side of the track through the 11 pm advisory tonight, as it lands in Cuba, then I might shift a bit east.


NWS Update:

000WTNT62 KNHC 301718TCUAT2HURRICANE GUSTAV TROPICAL CYCLONE UPDATENWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072008

120 PM EDT SAT AUG 30 2008

DATA FROM AN AIR FORCE RECONNAISSANCE AIRCRAFT INDICATE THATGUSTAV HAS CONTINUED TO STRENGTHEN AND NOW HAS MAXIMUM WINDSNEAR 145 MPH...230 KM/HR WITH HIGHER GUSTS. THIS MAKES GUSTAV ANEXTREMELY DANGEROUS CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSONHURRICANE SCALE. A SPECIAL ADVISORY WILL BE ISSUED AT ABOUT 200 PMEDT TO MODIFY THE INITIAL AND FORECAST INTENSITIES. THE SPECIALPUBLIC ADVISORY WILL TAKE THE PLACE OF THE INTERMEDIATE PUBLICADVISORY PREVIOUSLY SCHEDULED FOR THAT TIME.

$$FORECASTER KNABB

Gustav Predictions

I still think my landfall location might be OK, primarily because the models often under estimate a building ridge, and thus it should push the storm slightly to the west at the end of the track near Louisiana. Creole, LA is still my pick.



The models are currently in great agreement with a central Louisiana landfall. A few, however, are still hinting at a shift to the west. Many of the GFS ensemble models are even further west, more in line with the UKMET, turning the storm completely around to the southwest near the Louisiana coast. The HWRF also thinks this will happen. So, the building ridge is definitely being picked up by the models, it is just a matter of how strong it will be. I am thinking it will be some sort of blend of the models, pushing it just a bit further west along the LA coast.

Note: Starting position is not even close to current position.

Of course, these are just my thoughts, not the official forecast. It is always best to follow your local law enforcement officials and NHC forecasts. Even if you are in an area that the storm doesn't look like it is heading for, but evacuations are ordered, it is best to evacuate. There is a reason the local officials call for evacuations: To save YOUR life!

Quick Gustav Update

Gustav is now a Major Hurricane with maximum sustained winds of 120 mph and a minimal pressure of 955 mb! The storm has moved a bit east of the NHC track, which isn't too much of a surprise. When a hurricane goes through rapid deepening, it often jogs a bit off of its expected track while organizing its central core. This time Gustav moved a bit to the right, or east. The NHC expects Gustav to go back to its northwestward heading now that it has organized, which is reasonable. However, this little jump to east could end up being a major blow to New Orleans if Gustav does not do a little jump back...

For instance: The NHC tracks currently takes Gustav over the western portion of the Isle of Youth in Cuba. Right now, Gustav looks to track over the eastern portion. If this occurs, and then Gustav stays on a consistent track, a jump the diameter of the Isle of Youth in final position could be in order on the Louisiana coast. That type of jump would bring massive surge into the New Orleans area, which is a major problem.

(NOTE: I don't think this storm will make landfall east of the NHC landfall location...but something to think about.)

Yesterday at this time Gustav was a Tropical Storm with a minimal pressure of 984 mb and winds of 65 mph. In 24 hours the pressure has dropped 31 mb and winds have increased by 60 mph! This is a textbook case of rapid strengthening. In the last three hours alone the pressure dropped 10 mb! It is possible we see Gustav reach Cat 4 status before landfall in Cuba if the center of the storm misses the Isle of Youth and the pressure continues this rapid fall.

Tropical Storm Hanna

Quick Gustav update: Recent recon found 973.4 mb at the center. That's another 2 mb down from the last pass, a drop of 18 mb since this morning when it came off of Jamaica.

Tropical Storm Hanna:

The storm is currently asymmetric, with most of the convection on the eastern side of the storm. A upper-level low has been present to the west of Hanna, creating strong shear on the western side of the system. A substantial burst of convection occurred in Hanna, causing the center of circulation to relocate in this location. However, the shear from the upper-level low has taken a toll even on this burst of convection and the center of circulation is now exposed. An additional burst of convection has occurred in the last hour or so, but it was not as intense as the last burst. The shear will have to reduce for additional development. The red circle indicates the exposed center.

And this upper-level low will weaken as it moves westward away from Hanna, leading to a more conducive environment for development soon. Hanna will be located over warm sea surface temperatures, decent tropical cyclone heat potential waters, in a region of low shear, and under an upper-level anti-cyclone. All of these variables should allow Hanna to develop over the next two days or so into a hurricane. Hanna's environment is not quite as good as Gustav's, so rapid development is less likely.

The ridge that has been currently holding Hanna to the south, keeping her moving westerly will weaken allowing Hanna to move more northwesterly over the next two days. The ridge will restrengthen by the end of day 2 or on day 3, pushing Hanna back southwestward. This is a very unusual path for a tropical cyclone in the tropical Atlantic, so to have so many models picking up on it, it makes it seem like it is likely. The storm will push towards the Bahamas during the next week, likely stalling in the Bahamas or near Cuba. This is when things get tricky. Many of the models pull the storm back north as a trough digs off the eastern coast, others push it through into the Caribbean, and others push it through the Florida Straights into the Gulf of Mexico. At this point it is too difficult to tell what Hanna will do. A strong storm should feel the trough pretty easily, and I am starting to think it will most likely move back to the north. I am thinking eastern Florida and the entire east coast could be at risk from this storm. I do not currently think the Katrina/Rita type track is likely.

The strength is actually a bit easier right now in my opinion. We should see a Cat 1 hurricane in two days pushing towards the Bahamas. It is possible a Cat 2 storm develops if the storm pushes far enough south towards Cuba. From this point, the storm should stall and then pull back northwards as a trough moves towards the system, increasing shear. The storm will likely decrease in strength slightly to a weaker hurricane or strong tropical storm. This will then move up the eastern seaboard. However, this is 5-7 days out, so the models could change substantially over this week.

Hurricane Hunters find 975.2 mb now

Bombing indeed....

Hurricane Gustav Discussion

Hurricane Gustav is currently, per the NHC, a 980 mb hurricane with 75 mph winds to the northwest of Jamaica. The hurricane hunters have found winds up to 90 mph just 24 miles from the center of circulation, which tells me it is within the storms strengthening eyewall. I expect the NHC to up the winds at the 5 pm advisory. Even if they don't, however, this report helps to show that the storm is quickly strengthening and should be near category 2 status as it reaches the Cayman islands.




Gustav is situated in a very favorable environment for strengthening. The system is over the warmest sea surface temperature and tropical cyclone heat potential (TCHP) water in the entire tropical Atlantic. TCHP helps to indicate when rapid, or explosive, strengthening is possible. The waters around Gustav now, and until it reaches the center of the Gulf of Mexico, support rapid strengthening. Upper-level winds are also conducive, with little shear (near 5 knots) and an upper-level anti-cyclone developing over the system. The ridge to the northeast is steering Gustav towards the northwest.



The image above shows the GFS 700 mb forecast 60 hours into the future from the 12Z model run. The red area indicates the ridge that is currently situated through the United States and out into the Atlantic. The purple line indicates a trough that will be digging off of the eastern United States. All of the yellow circles show tropical waves or storms that are forecasted by the GFS model. Gustav is located in the Gulf of Mexico, Hanna off of the Florida coast, and then three more waves are shown in the Atlantic.



The ridge shown in this image is what should steer Gustav to the northwest until Monday. At that time, some of the models then forecast the ridge to build in stronger than the GFS forecast to the north of Gustav as it approaches Louisiana. This would cause Gustav to stall or push towards the west. Below are the models, with the European in red bold, UKMET in yellow bold (which should go a bit further west), and the HWRF in purple bold. As you can see, model trends are starting to indicate that a more western track is looking more likely. However, these models do not develop as deep a system as the GFS or GFDL, which forecast a more eastern landfall in central Louisiana towards New Orleans. A stronger system is much more likely to bust through a developing ridge than a weak system. Thus, the stronger Gustav becomes, the more likely it will make landfall in central Louisiana. However, all I said was more likely, not guaranteed. A stall could occur just as Gustav approaches Louisiana and the storm could move towards the LA/TX border.



Right now I am going to put my forecast track into the area just east (Creole, LA) of the LA/TX border as a Category 3 Hurricane. We should see rapid strengthening as Gustav moves over the Caribbean waters until it reaches Cuba, possibly reaching strong Cat 3 strength. Cuba should weaken the system a bit, and then weak shear should inhibit rapid strengthening over the Gulf of Mexico. The storm may increase back to a strong Cat 3 in the Gulf of Mexico before weakening slightly as it approaches the coast. A Cat 4 is possible either just before Cuba or after, but I do not expect it to hold that strength as it approaches the coast because TCHP waters are not quite as strong in the northern Gulf. We should also see a few eyewall replacement cycles along the way, which could cause strength fluctuations.

Hurricane Gustav Once Again

The Hurricane Hunters have now found surface pressure of 978.4 mb, indicating the pressure has dropped another 5 mb in the last 2 hours. The HH also found surface winds of 80-90 mph, but only in one small area. The NHC has decided to go with 75 mph, at least upgrading the system. The latest votrex message said 980 mb with 90 mph winds! We will likely see stronger winds at the 5 pm advisory, if not updated again before.

Hurricane Hunters and Gustav

The Hurricane Hunters just found a surface pressure of 983 mb and winds of 64 knots, one knot short of hurricane strength. The NHC could go with a 70 mph storm or 75 mph hurricane at the next advisory, depending on what they think is best. I think they will likely go with Hurricane Gustav so the wording sounds more ominous considering the storm will definitely be a hurricane by the time it reaches the Caymans. The Caymans better be ready for a strong Cat 1 at least by the time this storm reaches the islands. The storm has dropped 5 mb in the last 6 hours.

Another update will come later.

Gustav and Hanna.....

I don't like the look of either of these storms right now. The tracks are so ominous, so scary that the thought of what could occur over the next week is not good at all. We are likely to see two major hurricanes traverse through the Gulf over the next week! Think of Ivan and Katrina...and you are fairly close to what is going to occur. Move Ivan a bit west and Katrina a bit east...voila! Not good at all!

I am sorry about the lack of updates, but I had a surprise lengthy visit from a friend from out of town which kept me busy. I will be updating for the next five days continuously until my next 'weekend' Wed-Thurs when I will be going to North Dakota and away from a computer. This might be the best time to take a break considering Gustav should have already made landfall and Hanna will be busy drifting about in the Atlantic near the Bahamas. A quick 5-10 minute update on Gustav and Hanna. A more detailed analysis will come later today.

GUSTAV

Tropical Storm Gustav, which used to be Hurricane Gustav as it plowed into Haiti with 90 mph winds (much stronger than forecasted), is currently moving off of the western edge of Jamaica. Yes, Gustav went northwest into Haiti, took a sharp left turn and move down towards Jamaica and is now moving towards the west or westnorthwest. If we remember back to the models, this type of track was closest to the BAMS as the storm formed. The BAMS was even further south with the future track, but has since corrected and is now in line with all of the other models. Actually, model consistency is VERY good right now for a 5 day track. The models take Gustav westnorthwest through the Caribbean and then turn it northwest into the Gulf over the western edge of Cuba. They then go northwest to about the gulf coast of Louisiana, where they they move west towards Houston over land (take that turn a bit earlier...and Houston is under the gun). Watch out, the models have trended further west with time. This may end up being a Texas storm rather than Louisiana!

Basically the ridge that built over the Bahamas is guiding Gustav on this track. As this ridge breaks down (as Hanna develops into the Bahamas as well) the track of Gustav should move more and more closer to north. However, a second ridge will build in over the south-central US towards just north of the Bahamas in about 5 days. This will begin the push of Gustav back towards the west. The strength of Gustav will generally be determined by the strength of southwesterly shear in the Gulf, which doesn't look to be too much of a destructive factor at the moment. Add 5 knots and a major hurricane could be avoided, but right now I think its a good bet. High sea surface temperatures and tropical cyclone heat potential waters are ahead of the system until it reaches the central Gulf. My guess is we might see the storm go through explosive cyclogenesis, close to a Katrina or Rita development, as it moves over a heat eddy in the Gulf. Hopefully I am wrong, but I wouldn't be surprised. However, the storm should weaken as it moves towards the Gulf coast as TCHP waters decrease. This is NOT a storm to fool around with!

HANNA

Let me state this again....This is NOT a storm to fool around with. Hanna is currently just north-northeast of Puerto Rico, moving northwest. Models have it moving northwest for a day or two and then turning west towards Florida. The storm then looks to stall out as the steering currents subside with the ridge deteriorating in 3-5 days. A second ridge will build in, pushing Hanna southward towards Cuba and the Bahamas. As the ridge strengthens, it will then steer Hanna westward towards southern Florida, possibly right through the straight (European and GFS both go with this solution). Basically, this is a worst case scenario for the Gulf coast, as this track often results in a major hurricane. Right now the European drills this storm into New Orleans....but with this being over a week out, anything is possible. If Hanna takes this track, however, the entire Gulf coast is going to have to be on guard again just a few days after dealing with Gustav. One lucky scenario would be that Gustav uses up a lot of the TCHP waters in the Gulf, thus eliminating the strengthening potential of Hanna. Only problem...the models forecast Hanna to already be a major before it even reaches the Gulf. It is going to be a crazy week to two weeks in the western Tropical Atlantic. And this doesn't even count the eastern Atlantic where we could see another 1-2 storms develop before the Hanna makes landfall.

Note: A few models do pull Hanna out to sea after its stall near the Bahamas. However, I don't think that scenario is as likely because of the strengthening ridge which should push it back westward after the stall.

Tropical Storm Gustav

Ok, its not official yet from the NHC, but it will be in about 15 minutes. The hurricane hunters just found 995.6 mb in the center of the storm, with winds to 59 mph around the center. In my opinion, the NHC will go 995 mb and winds to 55 mph at 2 pm. This storm is wrapping up quickly, and I wouldn't be surprised to see hurricane watches issued for Cuba or even Haiti.


Make that 996 mb at 60 mph! A hurricane before it makes landfall in Haiti seems very possible now, hurricane watches coming.

TD7

TD7 has been officially designated. The track brings it over western Haiti and then along the northern coast of Cuba towards the Keys, close to what I was thinking. The forecast was, of course, low confidence for the NHC. I earlier posted the 6Z model runs with their high divergence...thinking they might get better by 12Z...nope, they got worse. We are going to need another 12-24 hours to really get a handle on where this storm will go in the long term. This may be one of those times when the NHC gets the track completely wrong, but don't blame them. This is an unusual situation.

However, they did go close to the CMC, GFDL, and HWRF which are all reasonably reliable track models. The GFS does not develop the system, so that model can not be used for track. The NOGAPS and European bring the storm north and then northeast, which seems the least likely at this point. However, the European was the first storm to notice that Fay would cross Florida into the Atlantic and then turn back towards the west....so we shouldn't ignore it. This storm will be a good learning experience.

Where Will 94L Go?

That is for you to decide today. I already have my idea, but I would like to hear some of your opinions, and why. Here are the current model tracks:





If you can tell me who is right, you win a cookie! The divergence in the models is amazing, some seeing a weakness which pulls 94L to the north, some seeing a building high which holds 94L south and moves it westward. I wouldn't want to be the NHC right now trying to come up with a forecast when they designate this system a TD/TS later today. The system is looking very well structures right now, and I am not fully sure why it is not a TD. I understand the low level circulation has not completely closed, but it is very strong in all of the quadrants except the southwest. Strong, meaning Tropical Storm winds. I, personally, think they should call it a Tropical Depression right now, keep it as such until it closes off the low, and then bump it to a Tropical Storm, unless wind speeds in it warrant a Tropical Storm classification earlier (for instance, 60 mph winds). But, that's just my opinion. I think 94L will jump TD status (for the 5th time this year!) and become Gustav later today or tonight. Where it goes....you get to tell me. (I will update later today with what I am thinking.)





Fay



Quickly, thought I would post this image from the National Weather Service which Dr. Masters posted on his blog on Weather Underground. It shows how much rain Fay dumped on Florida...amazing!

Addition: Of course, just after I finish this, the Navy says we have TD7. So, I guess it will be called a TD before a TS. However, I don't think it will be long until we have TS Gustav. Because the NHC is going to put out a forecast soon, I thought I would let you know what I am thinking. I think the storm will continue its northwest movement for the next day or two, bringing it very close to mainland Cuba. The weakness created by Fay and the trough moving through the eastern US should allow TD7 to move towards the Keys. After this, it really is a flip-the-coin type of situation. A ridge builds over the gulf/southeast, which will reduce the steering and make it very difficult to pinpoint a track. I wouldn't be surprised to see the NHC track go over Cuba towards the Keys. But with strong model divergence, I expect the NHC to say that it is a low confidence forecast, for both track and strength. Land interaction is going to be a major player.

94L Getting Its Act Together

94L is in one of the classic tropical development stages where it transforms from being part of the ITCZ into a tropical low entity all on its own. The system has been traversing northwestward through the night, has intensified its convection, and developed a more considerable circulation. The circulation is not yet at the surface, at least per QSCAT imagery, but could reach the surface within 24-36 hours at its current development pace. We will likely see the convection wane through the day as the diurnal minimum approaches over water, but with the separation from the ITCZ commencing, a low trying to develop, high pressure building over the system, warm sea surface temperatures, and low shear...development looks very likely at this point. I wouldn't be surprised to see the NHC up the development probabilities to a high chance in the next update or later today (NHC).

Here is the current visible satellite image of 94L:

Do you notice the wave axis? How about the ITCZ convection streamers? It is difficult on a still image, so here is an image that should help you:

The red curved lines help define the wave and are convection along the ITCZ. The Green line is the wave axis (which actually should be tilted the opposite direction, to the south-southeast). The yellow line indicates the storm's motion so far (to the northwest), while the red arrows indicate the present visible rotation, with a guessed low location indicated by the 'L'. 94L is currently moving towards the northwest, breaking off from the ITCZ which is a very important step in tropical development. Once the break is complete, convection will likely wane a bit until the low level circulation is well established. This should occur over the next 24-36 hours as the system approached Hispaniola and Cuba. At that point 94L should have a low level circulation, and I think will be our 7th depression of the season. Considering the potential here with high sea surface temps and low shear, I think 94L could be a 'major' influence in the Caribbean to Mexico...possibly even the Gulf later this week.

94L will continue its northwest track as long as the trough to the north is in place. However, this trough will pull out, allowing another ridge to build in, pushing 94L back west again in 48 hours or so. This should place 94L near Jamaica, or in the heart of the Caribbean Sea. Hopefully Hispaniola or Cuba can do a number on the system, but at this point I am very concerned that we could see a strong hurricane later in the week.

94L and 95L

(NOTE: I would like to apologize for the spacing in this post. The blogger system doesn't want to cooperate and space properly, so this will have to be how it is presented.)

Fay is still the headline story, but the main threats and track are fairly understood at this point. Fay will move westward, possibly over water again today, hold weak tropical storm strength, and then begin dissipation over Mississippi or Louisiana. The storm will produce heavy rainfall through Thursday...at least. This heavy rainfall will lead to flash flooding and river flooding in the areas that receive the heaviest rainfall. However, other tropical stories are currently playing out in the Atlantic, and this update is going to touch on these.

Currently there are two potential tropical systems, 94L (Red circle on water vapor below) and 95L (Blue circle). Each system currently contains robust convection, much more than yesterday, and are in areas of little shear. Both have a weak cyclonic rotation, but no closed surface low. This discussion will go into each system's potential and try to come to some sort of conclusion or prediction.

Water Vapor Imagery (Red: 94L, Blue: 95L)

Current Shear (Low in Tropical Development Region)

850 mb Vorticity (Highest Orange and Yellows)

95L - The Little Guy

Needless to say by the title, I am not quite as worried about this system as 94L. Yes, broad circulation is currently seen on the visible satellite image and convection has increased today, but its location doesn't make me as nervous as 94L's does. It is currently near 20N, 49W which is north of the islands. The system is currently in an area with 5 knots of shear, which is favorable for development, but continued westward motion will march it directly into 30 knot shear, which would destroy the system. The SHIPS model forecasts shear to stay below 10 knots until 72 hrs, where it only briefly brings it to 17 knots and then back to 5 knots. This seems a bit under estimated, considering the high shear environment to the west, which likely explains why the SHIPS strengthens 95L to a 85 knot storm in 120 hours while most models dissipate the system. The trough which is producing the high shear should pull out some, but not completely over the next 120 hours.

Beyond the shear, 95L has to deal with a very dry environment. Dry are is surrounding 95L to the east, north, and west. Even if the storm were to start getting its act together, the system would likely entrain this dry air which would help to weaken it once again. Currently a surface circulation is not visible, and not present on QSCAT images either, so the prospects of rapid strengthening or development look unlikely. 850 mb vorticity is also very low in the vicinity of 95L.

QSCAT for 95L: No Circulation Noted

Considering all of the negative issues with 95L, I would give it a very low probability of development, which is about what the NHC is currently saying (Low Chance). Even if it did develop, the track of 94L tells me that 95L would interact with 94L resulting in an even greater chance of the system not developing. Below are the current models for 95L, with the Canadian (Bold Green Line) being the only 'reliable' tropical model currently forecasting 95L to develop.

Model Tracks (Bold Green: Canadian Model)

94L: The Threat

94L is currently located near 12N, 57W which is very close to the continent of South America. Normally when a system is located in this region it would be considered a non-threat because it would interact with South America, entraining drier air from the interior of the continent, killing the circulation. However, looking at the mid-level steering maps, the system looks like it will be steered to the north and west over the next few days. This would bring it away from South America giving it a much better chance of development.

Steering Currents

Additionally, the highest water temperatures and tropical cyclone heat potential waters in the deep Atlantic are located just off of the South American coast, which likely indicates why such explosive thunderstorm development has occurred in the last 12-24 hours. Low shear is present over the system, and low shear continues (and is forecasted to continue) throughout the Caribbean and into the Gulf of Mexico. The SHIPS model predicts shear to stay at 10 knots or lower for the next 120 hours, which this time seems reasonable, and develops the system into a 83 knot storm, again reasonable for the shear forecast. 850 vorticity is the highest, in the entire tropical Atlantic (besides Fay) in the region around 94L and strong upper-level divergence and lower-level convergence is already present with the system. However, one major factor has not yet come together for 94L, and that is a low level circulation.

The QSCAT images currently show a low level wind shift boundary, but no closed circulation with 94L. This wind shift boundary is a starting point, and if convection can continue to occur, a surface low could develop along this boundary with time. However, with 94L so far south, the Coriolis force is not quite as strong as if it were at 15N (or further north). Thus, as the system follows the steering currents to the northwest towards the islands, the Coriolis force will increase, helping to spin up a system in a few days. Of course, if convection were to subside before the system can move north, this would reduce the chances of a surface circulation, but the low level wind shift boundary should continue to enhance thunderstorm development.

QSCAT for 94L: Notice the boundary parallel to the South American coast.

Currently 30 knot surface winds have been detected by QSCAT, which would be strong enough to designate the system a tropical depression if a surface low was present. Thus, whenever this system gets a low level closed circulation, we will see a tropical depression designated. The system will then track northwest into the Caribbean towards Hispaniola, as forecasted by the European (Red Line) and Canadian (Green Line) in the image below. Some of the less reliable models forecast 94L to move more westward, but this is most likely only if 94L stays weak. A trough will weaken the ridge to the north of Hispaniola over the next 72-96 hours, which should allow 94L to drift north before the ridge re-builds. I think 94L should get near Hispaniola before the ridge builds back in and forces it back westward. The system will act much like Fay did over Florida when it stalled out and moved back towards the west.

94L Model Tracks (Red Line: European, Green Line: Canadian)

78 Hour GFS Forecast

I give 94L a high chance of development, which is a bit stronger than the NHC (Medium Chance). Everything is coming together for a system in the Caribbean, a strong surface boundary is already present, and many of the models are predicting a system to develop from this wave. I think we will likely see a named storm (Gustav) from this system in 2-4 days. It will be a threat to the islands of the Caribbean before moving further west. If the system does reach Hispaniola, it could get weakened by the mountainous island, but should keep its circulation intact to traverse towards Florida or the Gulf as a strong ridge of high pressure will build off of the southeast coast of the United States.

Beyond 94L and 95L:

The 'wave train' that often occurs this time of year is starting to come together. The Cape Verde season will be very active over the next two to three weeks, with two strong waves already present over Africa (shown in the satellite below). Many of the models, including the Canadian, European, and GFS are indicating these waves could develop into tropical systems, so it will be important to watch them carefully over the next few weeks.

Tropical Waves in Africa

Philip, SD Weather Update

Only because I have been posting about Philip for a while now, and have been amazed that we had not hit 100F this entire year, I thought I would put in a quick update:

We hit 101F! Yes, two days ago we finally reached the illusive number, and were the only town in the state to reach it on that day. However, the heat was short lived and last night, yes only 36 hours later, the low was 43F. Thats a 58F temperature change! Fall is approaching and the cold fronts are starting to get stronger once again.

But now I am going to be moving to Wichita, KS...so Philip, SD weather isn't going to be as much of an interest to me. Expect to see more about Wichita in the coming weeks.

Now back to the tropics....

Fay Re-forms?

Earlier this morning I looked at the radar and could have sworn Fay was a little further south than it is now. The original center location would have tracked Fay into the Gulf of Mexico, giving it time to slightly strengthen and live a bit longer before weakening to a depression. However, the new location makes it much less likely that Fay will get a chance to strengthen at all. The hurricane possibilities are now at 0%, as far as I am concerned. There is the possibility that it moves back out over the water for a very short time near Pensacola, but even then it will be only for a few hours, not allowing Fay to strengthen.





The 'L' on the radar indicates the center of Fay, with the lines representing the old track, jump and then new track of the center. This is great news for the southeast, which before this jump was in line for many, many days (possibly another week!) of heavy rainfall. This threat still exists, but with Fay not able to re-energize, the storm should slowly start to weaken to a depression by the end of tomorrow (if it doesn't go over water at all). I think a remnant circulation will still be present over Mississippi in 5 days, but not the strength the GFS is forecasting, which should hold back on the extreme flooding that could occur. I'm not saying the threat is gone, but it sure will be less than originally thought.

Addition: Wait...what? That circulation broke down now too? Its broad, its tough to see, and now it looks like its going southwest. Basically, we are just going to have to watch this over the long hall because Fay is so weak the circulation can't center itself. Maybe some warm sea surface water in the Gulf will cause it to organize better, but right now, its tough to say. Will Fay even get over water?!? If so, 5 landfalls, if not, the dissipation will be much faster than anticipated.

Beyond Fay

We are moving into the busiest period of tropical development, with the peak of the hurricane season coming on September 10th. So what can we expect over the next few weeks?

First ENSO:

Currently ENSO is slightly positive, which is often correlated to higher levels of wind shear in the tropical Atlantic. However, it is only slightly positive and coming out of a strong negative phase. A lag is often seen in effects reaching the Atlantic, and thus the higher shear is not impacting the Atlantic as you might expect. Also, the long range forecasts predict ENSO to stay near neutral, so no real inhibiting factors should be felt from ENSO on the tropical Atlantic. Its impact on tropical development in the Atlantic will be near zero.

MJO:

Not forecast to be in a conducive (positive) or inhibiting phase (negative). Near neutral conditions means little influence on tropical development.

SST and TCHP:

Sea Surface Temperatures are now supportive of tropical development throughout the tropical Atlantic. The warmest areas are in the western Caribbean, Gulf of Mexico, Bahamas and surrounding waters, and off the South American coastline into the central Atlantic. Tropical Cyclone Heat Potential is greatest in the same locations. Thus, any storm that gets into the northwestern Caribbean into the Gulf of Mexico look to be the most dangerous.

Shear forecasts:

Shear is forecasted to be conducive for development throughout most of the tropical Atlantic development region, especially the Caribbean and into the Gulf over the next week.

Models and Predictions:

The models are continuing to be aggressive with their tropical development. The European and Canadian models develop the current 94L wave just east of the islands in the Caribbean in the next 2-3 days. They bring this system towards Hispaniola north into the Bahamas and stall it in this area. Again, just like with Fay, a trough tries to pull it north (the one currently moving through the mid-western United States) but pulls out before it can completely grab the system. 94L then stalls and begins to move westward as a ridge builds in! Sounds very familiar. If this were to happen, the only hope would be for the teleconnection from Asia working out, which supports a trough digging off the eastern seaboard in about 9-10 days. This would hopefully grab 94L and pull it north.

However, if 94L does not develop quickly, it could continue to track west through the Caribbean and miss both troughs, moving towards Mexico or the Gulf. I think it might be slow to develop, and thus not move as far north, but this should definitely be watched.

Beyond 94L, a second area of interest (95L) is in the central Atlantic. A broad area of circulation is seen and low levels of convection are present. However, no models predict this system to develop and the system is not sitting over the warmest sea surface temperatures. Shear is near 10 knots and will stay near that value for the next few days, likely keeping it from developing before it pulls north and out to sea.

Further waves are forecasted to move off the African coast over the next two weeks, and some of the models forecast one or more to develop. Considering ENSO and and MJO are not going to be inhibiting or helping factors, shear is to be low, and TCHP is decent, I think an average period of tropical development should occur over the next two weeks. This would mean 1-2 tropical systems should develop in this time frame, which is reasonable.

Fay Still Alive and Kicking

Fay has made the turn west after making it into the Atlantic as a moderate Tropical Storm. Fay intensified only minimally to 60 mph before making landfall once again in northeast Florida. Currently it is in the middle of the peninsula moving towards the Gulf of Mexico, shown below:






A ridge of high pressure has built in from the north and east forcing Fay to move westward. This ridge should hold on for the next few days continuing this motion. Any southward component looks unlikely as an upper-level low (Orange 'L' below) is situated over northwest Arkansas funneling the upper-level winds northward over Arkansas and Mississippi. The ridge (Yellow line) is built in a southeast to northwest fashion from the Atlantic into the Ohio Valley. Thus, the steering currently should force Fay either to the west or slightly north for the next 3 days while Fay moves very slowly. Once Fay reaches Mississippi however, it will begin to be impacted by the upper-level low in Arkansas which has been cut off and is not moving very much. This will force Fay to the north and likely northeast as a trough of low pressure (Purple arrow in MN) dives in from the northwest breaking apart the ridge.




Fay never became a hurricane in its lifetime, and even with another two landfalls (thus two more times over the Gulf of Mexico) forecasted, it shouldn't strengthen enough to reach hurricane status in the future. However, Fay will be remembered throughout the state of Florida as EVERY location will be impacted by it before its departure. Flooding rainfall approaching 30 inches has been estimated by doppler radar, and Melbourne, Florida was above 18 inches of rain in their rain gauge. Lucky for Florida, the soil type, flat surface, and proximity to the ocean, allows the rainfall to be mostly soaked up or flow into the ocean before catastrophic flooding can occur. Also, without steep hills or valleys, flash flooding and fast flowing water is not as likely. Thus, damage and deaths have been on the low side even though the rainfall has been so high. For instance, if this storm had parked over Houston, it would be been devastating (remember: Allison).



The tropical season has not even reached its peak yet, and we are to 6 named storms! With 10 being the average, we are definitely above normal. The European and Canadian models are forecasting more systems to continue to move west from Africa and show a new system in the Caribbean or Bahamas within the week. I will go more into this in a future blog later today.

Update coming...

Tomorrow morning. Wed and Thur are the days my wife is off work, so we are travelling around. Check in tomorrow.

Fay Continues Across Florida

Fay is continuing its trek across Florida and is currently right in the middle of the state. The NHC has said the storm has dropped in pressure since it made landfall and an eye feature has appeared while over land! Fay is obviously strengthening while over land, which is very rare. Florida has such flat land and abundant moisture that it appears it is doing little to interfere with Fay.

Consistency with the GFS and European models is starting to make me worried that we really will have the Gulf of Mexico solution. Both models have been consistent now for two days bringing Fay off the eastern coast of Florida and then back across into the Gulf, making landfall in the panhandle to LA border region. I am leaning towards this solution, especially with the GFDL and HWRF trending towards the GFS and European. Should be very interesting.

Fay makes 2nd landfall

Fay made landfall around 5 am EST near Cape Romano. This was well south of the original forecasted landfall site of Tampa, but still a decent forecast for the NHC and myself considering any little change east/west was going to lead to a large change in the north/south landfalling location. In Fay's case, it found the weakness in the ridge a bit early and pulled north through Cuba and then directly over Key West. From the time Fay started to pull north south of Cuba it was obvious Fay was not making it to the Tampa area. The overall track was right, but just shifted to the west 50 miles too much.

But that correct track was only good through landfall on the western portion of Florida. While Fay was still south of Cuba the models were generally forecasting Fay to move north into the Ohio Valley and into Canada in 5-6 days. This would have brought some needed rain to the southeast, but not the drastic flooding threat of a very slow moving system. Oh how things have changed! Now all of the models are forecasting Fay to move up Florida...possibly make it off the coast into the Atlantic (which I think it will) and then turn back west making a third landfall either in Florida or Georgia. A few models are saying South Carolina, but I think that a landfall that far north is impossible at this point, considering the large ridge that will be building in pushing Fay west. The furthest north I see Fay going is the Florida/Georgia border, which seems to be the consensus location.

However, we know how well consensus locations have worked with Fay so far. I am not fully buying even landfall that far north. I am inclined to go with the more recent GFS solution which stalls Fay just off the coast of Florida, allowing her to re-strengthen to a strong Tropical Storm or weak Hurricane before backing back into Florida near Daytona Beach, or slightly north of there. Fay will then have a very good chance of pushing across Florida into the Gulf of Mexico to make a FOURTH landfall in the panhandle of Florida/AL/MS/LA, depending on how strong the ridge becomes. I think the most likely location is the panhandle, but this is still 6-7 days away! It is possible Fay makes one more landfall near the coast of Florida while it is stalled drifting around. Fay could make up to 5 landfalls on the US before this is over (not to mention Haiti, Cuba, and Cuba again).

Yes, Fay is going to be around for a while. The flooding threat from Fay is going to be immense. A slow moving system tracking over the same general locations for days is never a good thing. In a worse case scenario Fay stalls very close to the Florida coast, but just offshore. It strengthens, continuing to rain over northern Florida for 2-3 days, then pulls back into Florida as a weak Hurricane, raining for an additional day to day and a half. This would lead to 20+ inches of rainfall from Fay in the Daytona Breach area into Orlando. Major flooding would occur and lives would be threatened. I am hoping the storm moves out to sea enough to keep the rain away while strengthening, or does not come off the coast before it moves back west. In any case, northern Florida is going to get hammered.

The good news, Fay should bring some much needed rainfall to the southeast, including Georgia which is still in the middle of its worst drought ever.

In the rest of the tropics, another tropical wave (Invest 94L) is currently floundering in the central Atlantic. Convection wained this morning, but a broad circulation is present. If the system can get its act together in the next 2 days we might have our 7th named storm of the year...but if it doesn't, higher shear will start to impact the system likely killing it. Something to watch, definitely with the models trending towards a brush with Florida...again!

Evidence Mounts

I am not going to say the NHC is wrong with the northern path, but it sure is starting to look questionable.

First, lets take a quick look at the evidence:

SREFS 10m wind, 4 days out:

GEFS low pressure, 5 days out:

GFS 4 and 8 days:

CMC 5 days out:

The NHC has Fay into North Carolina in 5 days. All of the models above move Fay north much more slowly, most stall it in the Atlantic off of the Florida coast and bring it back west. The GFS has been consistent with the last two runs and again has Fay hitting Florida three times! Also, the European at 12Z is also still predicting a strengthening storm making landfall on the eastern coast of Florida in 4-5 days. It even almost brings it back into the Gulf like the GFS! This mounting evidence makes me want to think that Fay is more likely to cross Florida and get into the Atlantic, allowing for additional development until a second landfall occurs either in SC, GA, or FL. I am sceptical of the third landfall in the panhandle of Florida, but it is a possibility if the ridge builds in strongly before Fay can move north. The more slowly Fay moves, the greater the risk of a second landfall on the southeast coast after rapid strengthening over the Gulf Stream.

So, now with this evidence, I feel safe to say that Fay will move across Florida and into the Atlantic, allowing it to strengthen before a second landfall sometime in 3-5 days. Fay is not going to be a short lived system. The NHC has fay dissipated after 120 hrs, or in 5 days. I guess we will see who is right. However, the NHC comes out with a new forecast at 5 pm eastern, or in two hours. It is possible they may shift the track into the Atlantic as well.

I guess it also should be mentioned that the CMC/UKMET/NOGAPS bring Fay right up the spine of Florida before weakening. This would be because the ridge is even stronger than the GFS/European are forecasting, and would not allow Fay to strengthen. The models still predict a stall and move towards the Gulf of Mexico, but a much weaker system would result because of the extended period over land.

Fay makes landfall in Key West

The radar indicates that Tropical Storm Fay is currently making landfall, or will within the hour, at Key West, Florida. Here are the current conditions:


Humidity: 96 %
Wind Speed: N 33 G 51 MPH
Barometer: 29.64" (1003.8 mb)
Dewpoint: 76°F (24°C)
Heat Index: 78°F (26°C)
Visibility: 0.50 mi.


Considering the lowest pressure recorded by the hurricane hunters is 1003 mb, it is safe to say the center is very close to Key West at this time! Sustained winds at 33 mph with gusts to 51 indicate that the system is not quite as strong on the western side (notice: North wind) as to the east. Fay is starting to wrap up and should stay over water for a good 12-24 hours, which should give it enough time to reach hurricane status.

GFS/European Surprise for Fay

Fay moved over Cuba during the night and is now moving into the Florida straights toward Key West. The storm is starting to get its act together now with visible satellite images showing good outflow in the northwest quadrant which it didn't have before. Shear is still low, around 10 knots, and should stay low for the near future. The radar our of Miami shows a vast field of rainfall already over the Everglades and Miami. A tornado watch for this region should go out soon.

Whatever Fay does at this point, it is definitely going to be a major rain maker. Currently radar estimates are already up to 3.25 inches from some isolated thunderstorms north of the main rain shield in south-central Florida. Just off the coast a large shield of rainfall has already produced 3-4 inches. Needless to say, as this shield continues to move onshore the rainfall amounts in southern Florida will increase substantially. Localized flooding looks likely with local rainfall amounts of up to 10-15 inches possible.

Beyond the rainfall however is the threat of wind and surge, which is much more reliant on where the center of circulation makes landfall. Currently the models are starting to pinpoint the Ft. Myers area, with the GFS ensembles going towards Tampa. The further south landfall would be a best case scenario as the storm would have less time to strengthen before landfall. Currently at 60 mph and 1002 mb, the storm has a good chance of becoming a hurricane before landfall even in the Ft. Myers region. If the storm makes it all the way to Tampa there is a greater chance of a strong Cat 1 or low end Cat 2 hurricane, so lets hope for the Ft. Myers area. The rain will be welcomed in this area as Lake Okeechobee is still 3 feet below normal. Currently the radar is supporting a landfall even further south of Ft. Myers as the center of circulation looks to be moving towards the Everglades. However, radar can be deceiving, so we will have to watch this over the next few hours to see what Fay is doing.

But the big question now is what will Fay do AFTER landfall. Most of the models want to bring Fay north into the southeastern United States and then up through Ohio into Canada. However, a few, including the GFS, European, and CMC are saying otherwise. The 12Z run yesterday of the European was the first (that I saw) which indicated Fay moving off the eastern shore of Florida, stalling out, backtracking into Florida into the Gulf and making landfall in the Florida Panhandle again! Thats three hits on Florida! I threw out that scenario at the time considering it seemed so far fetched, but now here is the GFS:

GFS at 30 hrs: Landfall near Ft. Myers

GFS at 108 hrs: Landfall near Palm Bay/Daytona Beach

GFS at 168 hrs: Landfall in the Panhandle of Florida

Red: GFS Track, Green: Consensus Tracks

The GFS and European (from last night) solutions are a worst case scenario for Florida as Fay looks to strengthen before landfall near Ft. Myers, off the eastern coast, and then again in the Gulf! Basically, Florida would not break apart Fay very much since the peninsula is so flat and Fay would only get stronger and stronger from one landfall to the next. This is NOT a good situation! Hopefully the ridge building off of the eastern seaboard will not be as strong as the models are starting to indicate and the storm will just go up through the US into Canada do minimal damage. But with the models hinting more and more at a cross through Florida and then a back up into Florida or the southeast coast, the entire southeastern seaboard and eastern Gulf coast needs to keep a close eye on Fay.

NHC 5pm Discussion

Straight from the NHC discussion:

THE FORECAST TRACK SITUATION IS SIMILAR TO THAT OF HURRICANE CHARELYFROM AUGUST 2004...IN THAT A SMALL CHANGE IN THE TRACK OF THE STORMCOULD MAKE A BIG DIFFERENCE IN THE EVETUAL LANDFALL LOCATION. THENHC WIND SPEED PROBABILITIES PRODUCT SHOWS ABOUT AN EQUAL CHANCE OFHURRICANE-FORCE WINDS FOR THE ENTIRE WEST COAST OF THE FLORIDAPENINSULA.


In addition to that, the models have shifted....to the east and west, depending on the model. In other words, it is very difficult to tell what is going to happen just yet. I will stick with my prediction of the Tampa Bay area.

Fay's Future

Tropical Storm Fay has been a pesky little storm already. Forming near Puerto Rico a few days ago, the storm had difficulty forming a closed low level center even though it was underneath an upper-level anti-cyclone and appeared to be a tropical depression on satellite 24 hours before it was designated Tropical Storm Fay. Currently Fay is south of Cuba moving to the WNW. The storm is beginning to go through a substantial strengthening phase with winds of 50 mph. The infrared, visible, and water vapor satellite images all indicate cloud tops have grown, cooled, and are continuing to develop. So, what is the forecast for Fay and where will it make landfall?


The NHC is currently tracking Fay across Cuba, through the keys and into the Tampa Bay area. I have a few friends that disagree with this track, and rather think the storm will move up the coast and hit in the Big Bend/Panhandle of Florida. The difference between a Tampa landfall and a Panhandle landfall is huge, not only in track, but in intensity since Fay would have many more hours to strengthen if it moved through the entire Gulf of Mexico. Looking at the models, and what is currently occurring in the southeastern United States, it is difficult for me to go against the NHC. The current track is in the middle of the forecast envelope, with the only models bringing the storm further west being the NOGAPS, BAMS, and SHIPS models. Each of these models are considered inferior models to the European, GFS, GFDL, UKMET, CMC, and others. This makes it difficult to go with the more western tracks.

Model Tracks

On top of this, the GFS ensembles have started to come into better alignment with a Tampa landfall as well. A few are still going to the west into the central Gulf, but this seems very unlikely considering the upper air maps.

GFS Ensembles

The GFS is currently forecasting a strong ridge located over the south-central/western United States, with a weakening in the ridge forecasted near Florida. The GFS then tracks the storm up the western coast of Florida into Tampa.

GFS 500 mb Forecasted Heights

The current upper air sounding data supports the GFS solution. So, in the end, I find it difficult to go against GREAT model agreement, upper-level support for the solution of the GFS, and the current strengthening of Fay which would support an earlier turn. All in all, I agree with the NHC with a near Tampa landfall. Considering the storm will be moving directly up the coast, it will be difficult to pinpoint the exact landfall, but I doubt it will go into the panhandle. At the furthest north, we could see a Big Bend landfall if Cuba disrupts the circulation resulting in a redeveloped center of circulation further west for some reason.

Upper-Air Rawinsonde

As for the strength, the island of Cuba should do a number on Fay as the storm crosses. I expect Fay to continue to strengthen while it is over the highest TCHP waters in the entire Tropical Atlantic as long as it stays south of Cuba. This should bring Fay to near Hurricane strength, possibly near 70 mph. Cuba will then interfere with Fay, breaking up the circulation a bit, likely weakening Fay slightly or at least not allowing Fay to develop while over land. Fay will likely come off of Cuba with winds 65-70 mph and begin to move up the coast. If the circulation is broken up Fay will have a very difficult time developing much further before landfall as the storm begins to race to the north. I think a Cat 1, 85 mph looks probable if Fay makes it all the way to Tampa as predicted. If Fay makes landfall near Naples it will be weaker, if it stays over water and makes it to the Big Bend we could see a high end Cat 2. TCHP is much lower in the northeastern Gulf, so I don't see a major at landfall.