Wednesday, May 23, 2012

Sunday Severe Threat Incorporated into LRC



Sunday's severe weather threat has been found to be incorporated into Lezak's Recurring Cycle, or LRC. Roughly 40-50 days ago, in mid April, we had the tornado outbreak across the central Plains. Severe weather reports are shown below.

As you can see, tornadic storms raced across much of Kansas, some of northern Oklahoma and parts of Iowa and Nebraska. Looking below at 500mb heights from April 14-15, we see a strong trough had shifted into the Plains, producing massive wind shear and a big chance for severe weather. In fact, that day involved the SPC issuing a high risk on Day 2 for only the 2nd time in history, as seen below.
500mb heights from April 14-15, 2012


Evolution of April 14-15 severe weather outbreak risks
The LRC looks to swing a trough into the East again, which has prompted the SPC to issue a risk area in the day 4-8 timeframe. Time will tell, but a storm with connections to the April 14-15 one will certainly be interesting to watch.

Plains Receives Sunday Severe Threat from SPC

The Storm Prediction Center has outlined a large section of the Plains into the upper Midwest for a long range severe weather risk on Sunday. It does appear a disturbance will generate enough heat and humidity to pose for some instability. The jet stream will likely be pumping under this system, so shearing may very well help storms fire in the midst of a potential cap in the atmosphere. This definitely does bear watching.

Andrew

Invest 94 Forms in Caribbean

Invest 94 has formed in the Caribbean seas today, with satellite imagery showing an area of showers and thunderstorms over Cuba to the southwest. There are a few clouds that look very bold. Those are the big time thunderstorms. The colors that are shown along with the satellite imagery shows dry air. As you can see, there is a lot of dry air to the north of the invest, and some to the south.

Believe it or not, this does appear to be the system that I was tracking on the FIM for over a week.

http://derecho.math.uwm.edu/models/al942012.png
Models vary greatly, but from what the FIM was showing a long while ago, the track through western Cuba and to the east of Florida does appear to have the backing of several models and the FIM runs I had been closely watching. There remains potential for this system to move into the Gulf or even hit Florida altogether, but I think I will go with the east of Florida solution for now.

http://derecho.math.uwm.edu/models/al942012_inten.png
Intensity forecasts are pretty weak, whereas the FIM had a full blown tropical storm for this system after it moved through Cuba. However, the heavy majority of models are indicating that it will die out rather quickly and not make much of an impact to land or sea.

Andrew