Severe and Snow

It looks like there really isn't too much to add from my last blog post. The snow threat has increased substantially with all of the thickness values now turning over to all snow. The soundings in South Dakota look very promising for snow as well, along with momentum transfer of up to 60 knots of winds! What does this mean? Blizzard conditions can be expected from Rapid City to Mitchell, SD and north. I wouldn't be surprised to see snowfall totals in the 6-10 inch range in much of central S/N Dakota.

The severe threat is still considerable, however the moisture return actually does not look like it will be has high as I expected. The tornado threat is still there, and we could see a few isolated tornadoes in the central northern Oklahoma to southeastern Nebraska region as the storms fire in the afternoon on Wednesday. Quickly, however, a strong squall line will develop resulting in a much greater wind threat. I wouldn't be surprised to see a vast area of 70 mph wind gusts as the line tracks through eastern Kansas/Oklahoma/Nebraska into Missouri/Iowa/Arkansas.

This is going to be a major fall storm. The strongest of the season so far. If you are in the Dakotas, make sure to keep indoors. If you are in the area with a severe threat, make sure to keep that weather radio on in the event severe weather threatens your area.

Severe Threat Wed-Thurs

A severe weather threat will materialize this coming Wednesday evening into Thursday as a strong storm system pulls out into the plains. Currently this system hasn't even interacted with the United States yet, but will pull on shore of the California coast tomorrow. The strong 500 mb trough will begin to dig into the plains early Wednesday, becoming slightly negatively tilted and bringing along a substantial amount of vorticity. The low will close off over Nebraska Wednesday afternoon and evening, deepening the low and enhancing the dynamics of the system.

Moisture return seems like it will easily be set up for a severe weather event with dewpoints already in the 50s in Wichita, KS. This will only increase as we go towards Wednesday, likely reaching into the 60s. Storm relative helicity values near 400 are predicted by the NAM Wednesday afternoon, resulting in high EHI values. The threat for supercells at initiation from northern Oklahoma into Iowa seems possible, with the greatest threat from central Oklahoma into eastern Kansas. The NAM and GFS initialize convection in the Wichita area. Could get interesting.

Quickly the strong dynamics of the system will take over, likely resulting in a substantial squall line / high wind event. However, as the storms initialize a tornado threat will be very much possible. The tornado threat could stretch from Iowa to Oklahoma before the line goes linear and moves to the east into Thursday. 850 mb winds in Kansas look to be 50 knots as the cold front and dry line approach. The triple point might move right through the Wichita area.

Out ahead of the storm on Tuesday will be a substantial synoptic wind event, with 55 mph wind gusts possible along the entire front range and much of New Mexico. Additionally, some wind gusts to 50 might occur in northern Arizona. Wind gusts to 45-50 mph could occur even in the Wichita area before storms develop on Wednesday.

A decent blast of cold air will move into the northern plains behind the storm, possibly leading to a snow event in the Dakotas. The central Dakotas look like to be the area of greatest threat currently, but knowing the last system and how it didn't quite get cold enough with much the same set up as this one...it will be close. However, the threat is there. Strong winds will also accompany any snow or rain on the backside, possibly leading to blizzard conditions if the precipitation is snow.

Also, watch out along the eastern coast as the models are now unanimously producing a substantial hybrid system that moves along the Atlantic seaboard bringing not only the threat of some heavy rainfall, but gusty conditions along the coast. The rip tide threat will be high.