Monday, November 09, 2015

Wednesday's Severe Weather Threat, Update 11/9

It still appears that we will have a line of storms come through on Wednesday, which could be severe. Here are my thoughts as of 1:00 PM on Monday, 11/9:
  • We are currently forecasting a MEDIUM risk of severe weather.
  • There will not be a lot of rain with this line of storms. Rainfall will range from a Trace-0.40" or so. Most location will get less than 0.25"
  • This is a storm system with high wind sheer, but not much instability.
  • Straight-line winds are the main threat.
  • There is a chance of tornadoes.
  • If a tornado occurs, it will develop quickly and move quickly. Treat every storm seriously.
  • Timing of the strongest storms in Region 8:
    • 3:00 PM-6:00 PM: Baxter, Stone, Fulton, Izard, Cleburne, White, Independence, Sharp, Howell, Oregon Counties.
    • 6:00 PM-9:00 PM- Ripley, Butler, Dunklin, Pemiscot, Randolph, Lawrence, Jackson, Woodruff, Clay, Craighead, Poinsett, Cross, St. Francis, Mississippi, and Crittenden counties. 
We have a strong a upper-low moving across the country. Ahead of that low, the air "spreads out" or "fans out". We call that difference and it is a prime setup for severe weather. It's kind of hard to explain, but maybe you can see the area highlighted below:
As mentioned before, there is not much "instability" with this storm system. This map below shows the "CAPE" or Convective Available Potential Energy. Notice the thin ribbon that moves through. It's not much, but enough to give these storms some lift:
I mentioned that there will not be much rain with this storm system. It's a fast mover and I'd be shocked to see many people get over 0.25" of rain. In fact, many areas will struggle to get over a trace. The storms that DO form will be small, move fast, and have some gusty winds. The chance of a tornado is also possible:
While the threat is not quite into the high or extreme range, we still need to keep an eye on these storms. Thankfully, they are not coming in after we go to bed.

Stay tuned for more updates!


Anonymous said...

Thank you for the update. I live in Pemiscot County.

T Presson said...

Thank you for the breakdown!

Caitlin m said...

What about greene county?

Anonymous said...

How bad is the wind going to be?