Thur-Sun, May 16-19th Severe Weather Threat Update #1

(9:30PM - 5/15/19) A disturbance pushing through the region, along with a favorable northwest flow pattern, will set the stage for severe weather potential on Thursday. Additional periods of severe weather potential are then likely across portions of the state Fri-Sun...

Will continue with previous forecast for Thursday with this update, as guidance and thoughts regarding the scenario expected to unfold continues to stay fairly consistent. Severe weather potential for Fri-Sun will be discussed further on Friday's update.

​Previous forecast...
A complex of showers and t'storms will likely be ongoing across portions of Wisconsin and nearby areas Thursday morning. At this time it looks likely that this complex will push southeast, and across portions of Northern Illinois Thursday morning and potentially into the early afternoon. Given an increasingly favorable environment will be in place with time, an isolated strong to severe t'storm is possible with this activity.

The main focus will be Thursday afternoon into night, across much of Northern and possibly portions of Central Illinois. In the wake of morning and early afternoon activity, an increasingly favorable environment for severe t'storms will develop across Northern Illinois. The expected environment will feature high instability, good moisture and good shear. As another disturbance moves into the region during the afternoon, it looks fairly possible that there will be enough forcing to overcome a cap in place. At this time it looks as though new shower and t'storm development could potentially occur in Northern Illinois along an outflow boundary left over from the early day activity...As well as along a cold front pushing across Wisconsin, Iowa and Northern Illinois during the afternoon and evening. At this time will forecast isolated coverage during the afternoon and evening, becoming more widespread by early Thursday night. Given the aforementioned environment expected, some severe t'storms are likely. All modes of severe weather are possible, including a tornado threat. An upgrade in severe probabilities is possible in subsequent outlooks if conditions warrant.

It should be noted that a severe t'storm threat will likely extend beyond Thursday night, on into Sunday, for portions of the state. Additional information regarding the potential on each of those days will be discussed in later updates.

​Below is our updated TAM severe t'storm forecast for this event.

​JP

​Please consider becoming a Patreon as a way to say thanks and support us for what we do! ​www.patreon.com/user?u=16598980

​To receive text alerts via our in-telligent groups text ISC to 900900 ​​​​​​​​​​​​​​