ALBERTO RAINS & WINDS (ONLY ISOLATED SEVERE THREAT)…………..THEN SEVERE WEATHER RISK THURSDAY EVENING-NIGHT………..
Flash Flood Watch for Much of Tri-State Until Wednesday Morning……..
Center of Alberto (now a depression with max sustained winds of 30 mph) is just southwest of Huntsville, Alabama & moving northward.
“Arms” or spiraling bands of heavy showers & t’storms are pivoting around the center. One band is now approaching the Ohio River & moving northwestward.
A couple more spiraling arms or lines of showers & t’storms will likely pivot through the Tri-State before the center of Alberto nearly right over the top of Evansville to Washington early tomorrow morning.
Although there will be rainfall wrapping entirely around the center in a ball, the heaviest bands in & near the center will be on the western side of it. The strongest winds will tend to be on the eastern side of it with some gusts from the east & southeast up to 45 mph. It will be breezy all night, however, with sustained winds 15-20 mph with gusts to 30 mph.
An isolated brief, weak tornado cannot completely be ruled out near the center in the morning.
Following the rapid passage of the center (the heavier rainfall with it will last 3-4 hours), only spotty showers/t’storms are expected in the afternoon with sunshine & clouds. These will occur as highly-broken “arms” that pivoting east & northeastward underneath the center. An isolated, brief, weak tornado cannot be ruled out from a random t’storm in the afternoon-evening. Winds will turn to the southwest & be gusty at 20-30 mph. Highs will heat up to 83-89 with heat indices 90-96.
Counting what we received yesterday to what we will receive by Thursday morning, rainfall totals of 1-3″ will occur Tri-State-wide. However, there will also be some narrow bands of 3-5″, largely along the Wabash River, associated with the torrential rainfall of the western side of Alberto’s center.
As Alberto remnants depart to Michigan & Ontario Thursday, we will see a pretty potent disturbance with a cold front race eastward.
With temperatures heating up to 88-93 (heat indices 94-99), it appears that a complex of severe t’storms may form over western & central Illinois Thursday late afternoon & evening. This may sweep eastward & affect the Tri-State Thursday evening-night with the threat of damaging straight-line winds gusts. Given the parameters in place, this would be a situation of a Severe T’Storm Watch with Enhanced Risk by the Storm Prediction Center.