Tornadoes & Flooding Tonight

The SPC has upgraded southwest Mississippi to a Moderate Risk of severe weather, including an enhanced risk for strong tornadoes (EF-2 or higher). Click the maps below to make them larger.

The map below plots the wind barbs, temperature and dewpoint (moisture). The shaded areas of green represent dewpoints in 60 or above. You can "feel" the "humidity" when the dewpoint gets to 60, and it only get more humid from there.

It is a little uncertain how far north the 60s dewpoints will make it, but it is possible they could get far enough to make strong tornadoes a possibility north of I-20.

Instability is still not the best further northeast. The latest run of the NAM model shows the best combo of instability and wind shear meeting up across southwest Mississippi around 3am Wednesday.

Damaging winds over 70 mph will be possible in the strongest storms, along with hail up to golfballs, maybe larger.

What is a little troublesome to me is the potential to very high rainfall totals. The WRF (Weather Research and Forecasting) model brings widespread 2"-5" rain totals, with local amounts as much as 7". Here is the 24 hour rainfall forecast from the WRF, ending at 6am Wednesday. The legend is along the left side of the graphic. You can click the graphic to enlarge it.

If you live in an area that floods, you will really want to be watching for storms to move over your area repeatedly. If that starts happening, the flood risk will be very high. Some of these same areas picked up 2-3" of rain over the weekend.

Everyone needs to be weather aware from 6PM Tuesday-8AM Wednesday. If you have a weather radio and it needs to be programmed, you can click here for help with that. Also be sure to follow me on Twitter as I'll be sending out updates the rest of the day and especially tonight. I know some of you depend on Facebook for weather information. I want to stress you should not wait for us to post weather information to Facebook. We will try to keep it updated, but if we have a lot of warnings, that won't be possible. Twitter is a far better way to get the information than Facebook. Also, you can check the radar here or from your phone by going here.

I will likely post a brief update on the blog this evening.

Eric - elaw@wlbt.com