ROCKFORD (WREX) — When rain returns Thursday, we will likely hear the first rumbles of spring thunder. A low risk for severe weather may develop later on Thursday as the atmosphere heats up.
Leading up to the Thursday thunder, conditions go quiet for a while Wednesday night. Cloudy weather stays in place, while any rain from earlier in the day dries up. Foggy conditions are possible with the humid air in place. Temperatures remain milder and near 40 degrees overnight. Drizzly conditions are possible by early Thursday morning.
Light rainfall kicks in by late Thursday morning, then turns to heavier rainfall closer to noon. A few rumbles of thunder are possible as the somewhat heavier rainfall moves in. Temperatures warm up quickly. We soar back into the 50's by noon. A few spots may hit 60 degrees by the afternoon. The added heat sets us up for severe weather, however.
Later on in the afternoon, our risk for severe weather develops. However, there are a couple of factors that may limit our severe weather potential. If clouds and showers in the morning to early afternoon linger long enough, we could stay cooler, which limits the energy the atmosphere can build up.
Also, a cold front coming in during the late afternoon to evening will be our trigger for severe weather. If that lags behind the weather system and doesn't arrive until late evening, our chances for severe weather also go down. The front won't be able to tap into the high amount of energy in the atmosphere if the front is late in arriving.
That said, enough warm and humid air builds in with Thursday's weather system that we have a low risk for severe weather. A few strong to severe thunderstorms are possible. Damaging wind gusts and large hail look to be the main threats. An isolated tornado risk can't be ruled out either, mainly west of I-39.
Our window for severe weather looks to be from 4 pm to midnight, though diminishing returns are expected after sunset.
Regardless of whether our window for severe storms stays opens or closes quickly, be ready for rain showers and occasional downpours and rumbles of thunder. Move quickly indoors if you do hear thunder.
The weather dries up quickly Thursday night, while temperatures drop like a stone. While the weather looks dry Friday through Sunday, conditions stay in the 30's to 40's for highs.