MON 9:30AM - Taking a small step back on this forecast. Models the last 24 hours have performed poorly. Confidence is LOW today. Rain and some storms will move in today. We can see it taking shape to the SW at 9:25AM...
9:25AM radar
I debated removal of the 1-2" heavy rain zone leaving a broad zone of 0.5-1.0" rainfall amounts over the SE 2/3rds of WI. Locally higher amounts into the 1-2" range. But looking at radar situation to the SW, I'm going to keep it around. Axis looks ok. Extended it further SW to Prairie du Chien (hopefully make up for miss last night).
9:30AM picture from outer space.
As for T-STORM threat, 06 HresNAM was interesting but it's an outlier. Looking at the current situation; with outflow boundary WELL into central IL...I highly doubt the NAM will come to pass. Thick clouds will sit over WI today. Clearing attempting to sneak in from the south. Severe is likely to remain well south. I removed the TARGET from eastern WI but will keep mention of TSTRMS. I adjusted the map to jive closer to the SPC's latest and will go from there.
Will send out updates today if needed. -JP
SUN 10:50PM - CONFIDENCE LOW-NORMAL - Monday will be a wet day for the eastern 2/3rds of Wisconsin with periods of rain. SUN overnight activity will slide in the eastern half of the state during the morning(this forecast excludes SUN overnight activity.
Still underneath a large upper trough sending subtle waves of energy through WI; the gift that keeps on giving. Storm events have been on the weak side lately so will continue down that line of thinking. Two things I'm watching for on Monday; heavy rain & strong t-storm potential.
Heavy rain; the GFS & EC keep signaling northeast WI (or EC WI perhaps) with the bullseye. Seems a bit too far north w/ respect to short range models; which are also a buck shot. NAM is unique; not handling current situation well. HRRR was alright. 1-2" is definitely possible with this system; spots that could eclipse 2". PLACEMENT CONFIDENCE LOW. And overall threat appears to be low too. There are definitely some dry spots that will soak the rain right up. So will keep this low key for the moment (reassess in the AM).
With plenty of rain, clouds, and morning debris will only see pockets of weak instability develop. Shear vectors are poor; unidirectional. Short range models kind of agree on bringing a band of t-storms out of southwest WI into SE or EC WI during the morning hours with a bit of instability out ahead. This might be the best chance for a strong wind gust or small hail? Afternoon doesn't look much better for severe parameters given debris. I decided to hold off a STRONG zone. Keeping it GENERAL w/TARGET for now.
Heavy rain probably the biggest threat. Don't expect a repeat of SAT PM.
NAM sounding; pointing out a few things. Mainly the issue is poor wind shear. 15z time frame.
.JP