La Crosse, Wisconsin

• Scattered rain showers continue through afternoon before mostly diminishing by this evening. There are additional shower chances overnight into Sunday morning.
• Widespread rain chances (over 90%) are forecast for Monday and Tuesday with a high chance (+70%) for most locations to reach or exceed 1 inch of rainfall through Wednesday morning.
• Temperatures remain above normal for highs and lows this weekend through the next work week.

Today through Sunday: Scattered, Light Rain Showers - Drier Sunday

The forecast for the rest of today is neither frightful nor scary, given that current observations early this afternoon continues to show isolated to scattered light rain showers across portions of the forecast area. The rain shower activity has been waning over the past few hours and that trend should extend into the afternoon through this evening. No impacts are expected due to the light rainfall. As for this evening during Halloween activities, the weather should remain delightful with temperatures mainly in the 50s, light wind, and mostly dry conditions. Some rain showers may try to redevelop overnight across Minnesota into west central Wisconsin, but if any of that activity does reach the CWA, it should be after midnight. Overcast skies are expected to clear out a bit on Sunday to allow for stronger daytime heating resulting in afternoon highs in the 60s. Dry conditions are currently forecast for Sunday.

Monday through Wednesday: Widespread Rainfall

An upper level trough will move onshore from the Pacific on Sunday and will continue its trek east early this next work week. A strong surge of H700 theta-e advection will quickly move northward out ahead of the trough and is expected to reach the Upper Midwest on Monday morning. The lift provided by the trough and the plentiful moisture will result in widespread rain showers with embedded thunderstorms on Monday into Tuesday. Forecast soundings indicate that there may be just enough instability at times throughout the day to develop isolated thunderstorms with a threat for lightning. Otherwise, light to moderate rainfall is expected during these two days with the resultant rainfall totals having a high chance (+70%) of reaching or exceeding 1 inch area wide. The reasonable high end rainfall totals are upwards of 2.5-3 inches (10% chance or less of occurring) from Monday through Wednesday morning. Even though it will be cloudy and rainy during these days, temperatures will more likely than not remain above average.

Late Next Week: Trending Drier with Above Normal Temperatures

Beyond Tuesday, model guidance diverges with the evolution of the trough that provided the rainfall chances earlier in the week. Some guidance results in a cutoff low to the south of the forecast area whereas others are more progressive and quickly move the low off to the northeast. The longer the low pressure system remains in the vicinity, the longer any cooler air will stick around on the backside of the system. Right now, NBM blended high temperatures for Wednesday through the end of the week remain above normal, but are a bit cooler in the 50s. Any rain chances beyond Wednesday morning will be highly dependent upon the progression of the upper level low.

MVFR cigs will persist throughout much of the TAF period and into the overnight hours as low-level moisture remains in place. Some IFR reductions may persist at KRST through early evening, however guidance generally agrees on improving conditions to VFR later into the evening and overnight. Some periods of VFR will be possible as well throughout the afternoon in the wake of any showers. Ongoing showers will diminish in coverage over the coming hours, however still cannot rule out (20-40% chance) an isolated shower or two reaching either TAF site this afternoon. Winds will remain from the south to southeast at around 5 kts throughout much of the TAF period.

WI

None.

MN

None.

IA

None.