Severs Weather Expected Wednesday

Message from Rick Smith
Warning Coordination Meteorologist
Norman Forecast Office
National Wester Service

As you may have seen by now, we are forecasting the possibility of severe thunderstorms across much of our area on Wednesday. Some of the ingredients coming together may support supercell thunderstorms and maybe even tornadoes.

Thunderstorms will become more likely across far western Oklahoma overnight tonight, and we have upgraded our hazardous weather outlook to include a slight risk for that area, primarily after midnight.

Thunderstorms could be ongoing and spreading across a larger section of Oklahoma and north Texas Wednesday morning. These storms may be capable of producing marginally severe hail and wind gusts.

The morning storms will likely complicate the forecast for later in the day, perhaps causing clouds to linger and instability to possibly not be a great as it could be. Low level moisture in the form of high dewpoints in the 65 to 70 degree range will be in place. One big question right now involves timing, and there are some indications that while we will have all the ingredients for a significant severe weather event, they may not be lined together at the right time of day. This is one of the main things we will be watching as we get new computer model data.

Our current thinking is that the dry line will approach the I-35 corridor by mid to late afternoon, with the highest chances of organized severe storms - including supercells - ahead and east of the dry line. I would think parts of the area would be under a tornado watch by early to mid afternoon. Low level wind shear, which helps storms to rotate, will be much stronger than on Sunday. If we can recover from morning rain and storms and the atmosphere can become unstable enough, the combination of wind shear and instability could lead to significant storms, including some tornadoes. Right now, it looks like the highest threat would be from I-35 eastward, but that will depend on exactly how things line up.

THINGS TO WATCH FOR:
- dry line location and speed of movement through the day tomorrow. Storms will be most likely east of the dry line.
- morning clouds and rain. If we see less rain and clouds, and more sunshine during the morning and early afternoon, the threat of supercells will be higher east of the dry line.