Friday severe storm threat: timing, impacts

AUSTIN (KXAN) — As a powerful upper level storm system approaches Central Texas, heat and humidity are building on gusty southerly winds. A risk of severe weather is increasing in our area Friday evening and night, with damaging winds and tornadoes the biggest concerns.

Most of the KXAN viewing area is under a slight risk (level 2 out of 5) for scattered severe storms Friday evening, with a higher enhanced risk (3 out of 5) for numerous severe storms in Williamson, Milam and Lee County.

With heat and humidity in place Friday afternoon, the atmosphere will have the moisture and energy necessary to form severe thunderstorms. There will also be a lot of spin in the atmosphere due to the gusty winds at the surface, and turning winds higher in the sky from the low pressure system passing overhead.

A cold front entering the area late Friday afternoon or early in the evening is expected to act as the triggering mechanism to form scattered severe storms.

Rain appears least likely in the Hill Country, then the line of storms is expected to fill in somewhere near the Austin area, moving eastward later in the evening. There is still some uncertainty in whether or not the Austin area sees storms, or if the storms develop just east of town.

As the storms first develop along the cold front, the tornado threat will be highest. A few strong tornadoes are even possible, either in our viewing area or possibly just to our northeast. As the storms form into a line east of I-35, the damaging wind threat will surpass the tornado threat.

Some Hill Country communities may remain dry late Friday. Under 0.5″ is expected in the Austin area, with some amounts near 1″ possible east along Highway 77.

Stay with KXAN as we gather new data in the coming days and download the free KXAN Weather App in your smartphone app store to be warned first when storms develop.