Weather Synopsis

Currently:

The storm system that brought the severe weather yesterday has moved east, bringing in partly cloud skies throughout western SD. Isolated showers/tstorms developing in far southwestern-southcentral SD at the time of this writing. Surface low pressure centered in southern Saskatchewan, cold front spanning down Dakotas/MN border region into Neb. 500 hPa low also centered over southern Saskatchewan, shifting southward.

Today:

Unsettled weather should continue today, as the 500 hPa low shifts southward out of Canada into eastern ND. This should leave a cold pocket aloft, allowing for isolated convection to develop, primarily over the higher terrain, as highs approach the mid to upper 70s. 850 hPa temps for the region will be near 20C in the SW, to 15C in the NW, with NNW flow. Dewpoint temperatures should drop through the day, approaching much more comfortable levels (mid-40s) by mid-afternoon.

Next few days:

The active weather pattern that has been persistent over the high plains will finally take a break as the region will enter the backside of a mid-lat cyclone, and enter a high pressure region, resulting in northerly flow for the next 36-48 hours. This should keep temperatures seasonably cool and comfortable today and tomorrow. However, these cool conditions will be short lived as by Saturday night into Sunday southerly flow will commence, resulting in much warmer conditions into the latter half of the weekend. Expect highs to approach the low 90s by Monday with 850 temps back up near 24C. This southerly flow will also lead the region back into a daily chance of showers in the higher terrain preceding to a shortwave passage mid-week (possible severe).


TROPICAL UPDATE:

Not much to mention at the moment, and thus I will keep this short. Currently there are no substantial tropical disturbances in the Atlantic, with a small cluster of thunderstorms currently in the Gulf and a tropical wave, which shows some convection, in the mid-Atlantic. Both locations have substantial dry air inhibiting storm development, and none of the reliable tropical models are predicting development from either system. The gulf storms have lost much of their convection in the last hour or so, and will likely fizzle as the day goes on. The Atlantic wave looks its best right now, but with the dry air and higher wind shear to the west (up to 50 knots) should keep it from developing.

The Tropical East Pacific, on the other hand, is very active, with Tropical Storm Boris looking very strong (possible hurricane in the next 24-48 hours) and a strong looking low pressure region to Boris' west. The low pressure region will have to intensify quickly if it will have any chance of developing (24 hours, or so) as it will be moving into a region of cooler sea surface temperatures (SST). Boris still has a few days of possible development time until it will be in the lower SST, thus strengthening is likely over the next 48-72 hours. The models are also predicting a third system might develop off of the Mexican coast (European, CMC, and GFS) and move up the coast towards the Baha. This will need to be monitored.

7-14 Day Period:

The GFS and CMC are beginning to forecast tropical development off of the coast of Africa in 7-10 days. SST in this area are supportive of development, but climatologically it is rare that a system develops this close to the Africa continent (at any time of the year, let alone July!). A very strong Bermuda high should keep any system that does develop on a west-northwest heading towards the Caribbean, or just to its north. The European model is also indicating enhanced activity in the Caribbean in 10 days as well. With a conducive MJO and a neutral ENSO forecasted at this same time period, the possibilities of an Atlantic Tropical system in the 7-14 day period look 'good'. I would put it at 35%.