So after several days of hyping the next severe weather outbreak from the performers…what’s really going to happen? Let’s find out together.
First off, we need more rain. The drought monitor continues to expand into Oklahoma. Texas needs a lot more rain too. The great news is that over the Tuesday-Thursday period, a lot of rain will fall in these deserving areas. The caveat is that it may come with brief flash flooding. So keep that in mind. Favored areas of flooding in OK will be across the SE 1/3rd of the state.
As I’ve stated many times in my live broadcasts, the timing and exact track of these upper lows makes all the difference in who see’s severe weather, the magnitude of the storms, and the type of storms. A lot has changed in the last 5 days in the jet stream pattern. So much so, the forecast isn’t even close. Here’s an example at the 500 mb flow. The first image was the forecast for Tuesday in the old data last week. The red box highlights the best lift zone for storms. The second image is today’s forecast for Tuesday. Notice how the upper low is now southwest near Mexico. Now the best lift zone doesn’t coincide with other needed severe storm ingredients. That changes everything. All of that talk of a severe weather outbreak over a large area now gets shrunk down to normal magnitude which I’ll discuss next.
So with the 500mb low ever further west, that creates a timing and track problem. For one, it doesn’t allow the right ingredients to get into place for an outbreak of storms. For two, the slower track keeps most of the instability into Texas while we stay on the wet and somewhat cooler side, until it slowly passes through the state by Thursday. The SPC severe weather outlook represents this uncertainty.
We’re just now getting into that 48 hour window for discussing tornadoes. As of now it doesn’t look like anything out of the ordinary. As new data comes in, I’ll follow up with you on our nightly live broadcasts. So for now, I see a poor moisture return to western Oklahoma with a weakly convergent dryline and the mid and upper level energy too far west. The thickest low level instability in C OK is off-axis from the dryline which is located in W OK. Models are indicating a CAP will be in place to prevent surface based storms from developing. The models will fight with the CAP over the coming cycles to produce potentially tornadic storms. As of right now, it looks like the CAP wins out to force elevated storms with hail in the mid to late afternoon across C OK. Then storms will try to fire along the dryline out west. Those late afternoon storms would move east and there is only a small window near 7pm where instability coincides with a weak CAP and decent shear to produce a tornado or two. Take a look at the model below, it indicates this activity in two waves. The helicity tracks can be interpreted for large hail up to 2″ in diameter or a potential tornado from supercell storms. The take home is that you don’t see a lot of these, therefore no outbreak, but yes a few severe storms.
I’ll update you as new data arrives and start fine-tuning the forecast with respect to timing, location, and severity. Be sure to download my free weather app, ATsWeatherToGo, from Apply or Google Play. It predicts tornadoes in advance giving you more lead time to prepare. A live-saving tool at your disposal, for free! -AT