Severe weather threats are coming into focus today as a slight risk for severe thunderstorms remains in place for tomorrow, Feb. 19.
A low-pressure system is set to develop over the Midwest on Thursday, bringing a chance for thunderstorms for the Eastern St. Louis area through Southern Illinois. There is a good chance (30-60%) of thunderstorms along a cold front on Thursday from 10 a.m. to 8 p.m., mainly along/east of the Mississippi River.
St. Louis will be on the leading edge of the storm system, thus storms will be entering the region between 10 a.m. and noon. It will be entering the southern Illinois region between 1 and 3 p.m. If there is any severe weather in the Southern Illinois area, the main threats are expected to be damaging winds and isolated tornadoes.
“The more robust severe weather threat exists south of the warm front and ahead of the Pacific front,” the St. Louis NWS said. “Here we see SSE surface winds beneath increasingly strong west-southwest low and mid-level winds. So any surface-based storms will likely take the form of rotating supercell thunderstorms with a damaging wind and tornado potential.”
The St. Louis NWS notes that some limits to this severe weather threat will be low clouds may block heating and prevent strong storm development, morning storms that could disrupt the atmosphere and limit later severe storms, and the timing/speed of the Pacific front is uncertain, and once it passes, the severe threat ends…