Chance of strong to severe thunderstorms into the weekend
TALLAHASSEE, Fla. (WCTV) - Cold fronts and mid-level energy are forecast to move near and through the Southeast through the weekend, bringing a threat of severe weather for at least parts of the viewing area through the weekend.
The Storm Prediction Center has placed a level-1 (marginal) risk of severe weather for Miller, Seminole and a part of Decatur counties for Thursday and Friday. The SPC also placed a large portion of the Big Bend and South Georgia under a 15% risk of severe weather for Saturday.
A surface low over the Midwest and attached cold front is forecast to move eastward into Thursday, though the low doesn’t move much as the upper-level trough is forecast to move relatively slow. The slower and lower forcing will keep the cold front well to our north, but a threat of showers and thunderstorms will increase. There may be enough convective energy in the western viewing area to bring a threat of damaging winds and small hail.
For the timing, so far it appears that a line of showers and thunderstorms may enter the western counties around or afternoon Thursday. The in-house GRAF model is going for a weakening line as it moves east while the High-Resolution Rapid Refresh extended model keeps the line stronger.
The SPC’s outlook doesn’t change much from Thursday’s with a level-1 risk for the northwestern viewing area. The hazards to be alert to are damaging winds and hail. The front from Thursday’s storm system is likely to remain well north of South Georgia and likely be more stationary, but surging moisture along with mid-level energy wrapping around the low/trough is forecast to move through the area. The moisture, mid-level energy and some convective energy (mainly in the western viewing area) will allow for a better chance of showers and thunderstorms.
The GRAF model shows rain and storms developing as early as mid-morning and likely be scattered to numerous during the day.
A developing trough of low pressure in the mid-levels is expected to bring greater energy aloft. Accompanying that, a surface low and cold front is forecast to develop over the Midwest Friday and advance eastward Saturday. The American GFS and European models show a potent line of showers and thunderstorms is forecast to arrive near the Apalachicola and Chattahoochee rivers between late morning and early afternoon, and move easterly through the afternoon and evening.
Based on forecast upper-air profiles early Saturday afternoon, there is a chance of damaging winds, small hail, and an isolated tornado.
The cold front will either be just to the north of or bisecting the viewing area Sunday. This would keep rain chances in place, though models suggest lower coverage. The GFS does show some convective energy in the area Sunday afternoon, keeping a chance of thunderstorms in place. It’s too early to say whether or not a reasonable risk of severe weather will be in place.
Be sure to keep tabs on the weather forecast through the weekend, and have multiple ways of receiving watches and warnings. Download the WCTV Pinpoint Weather App to get advisories on a smartphone.
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