10/27 – Rob Knight’s “SEVERE THREAT Ahead” Wednesday Morning Forecast
Rapidly changing weather conditions will be the rule over the next 24 hours, with the threat of severe weather and heavy rainfall continuing to be a concern late afternoon/evening. Low level moist inflow will increase rapidly this morning with the front surging northward as a warm front. A cold front will follow later this evening.
A line of convection over central Texas this morning is expected to continue to work eastward during the morning hours and likely accelerate toward the area by early to mid-afternoon. While the very warm and moist airmass is expected to limit instability/buoyancy to some extent, forecast soundings still show the threat for SEVERITY. The main threat with the squall line will be straight line winds, but bowing segments could also produce brief tornadoes. Hail will be less of a threat (but not zero). Instability is expected to gradually weaken during the evening with the threat waning beyond sunset.
Locally very heavy rainfall is possible with the very high moisture content of the airmass. Rainfall rates in excess of 2.5 inches in an hour are possible, but with the progressive nature of the system, and the fact that October has been rather dry across most of the area, that should limit any widespread flooding concerns. The main timing for severe weather will be between 4 pm – 9 pm, with the front clearing the area to the east around midnight. Winds will gust through the day Thursday into the 30/40 mph range with a wind advisory more than likely to be issues tonight.
A rather quiet forecast period for the extended term as the upper level low pressure system continues to move off to the east coast Saturday. Lingering breezy winds will subside through the day Saturday and look to be back to calm by early Sunday. Clear skies will persist for Halloween weekend and early next week as a surface high pressure system builds over our region.