textproduct: La Crosse

KEY MESSAGES

- Periodic showers and perhaps some storms are possible this evening-overnight (30-50%) through Saturday afternoon, but the greatest chances lie northwest of our area.

- Temperatures begin warming this weekend into next week with above normal temperatures favored through at least Wednesday.

DISCUSSION

Issued at 1200 AM CDT Fri May 22 2026

Today - Saturday: Periodic Shower and Storm Chances

Primarily dry weather is expected across the Upper Mississippi River Valley today ahead of a 500hPa shortwave trough that is expected to eject into the northern Great Plains this morning. This wave deepens and pivots northward across South Dakota into central Minnesota throughout the day. A deepening surface low will be associated with this upper level feature, shifting northward across central Minnesota where a maximum of QG forcing and moisture transport is expected.

This is all to say that the best moisture and dynamics for precipitation development exists northwest of our area this evening into tonight. Those closer to the Twin Cities are the most favorable locations to see showers (30-50%) whereas the rest of the area has relatively low probabilities for precipitation (10-30%). With the relative lack of available moisture across our area, rainfall amounts are expected to generally be a few hundreths, with a 10-30% chance of up to 0.1 inch for those closer to the Twin Cities per the 21.18z REFS.

As the cold front associated with the surface low marches eastward through the region on Saturday, additional showers are possible (20- 50%) from the late morning through the afternoon. East of the Mississippi River, some weak instability is depicted in 22.00z RAP/HRRR soundings, around 500 J/kg of MUCAPE, which would support some rumbles of thunder during the afternoon hours.

Sunday - Thursday: Warming Temperatures

Deterministic and ensemble guidance continues to depict rising heights through at least the middle of next week as a high amplitude 500hPa ridge develops across the central United States. Confidence is high in this feature developing and associated surface conditions given the agreement amongst the various model suites.

Under the rising heights aloft, warming temperatures are expected across much of the CONUS this weekend into at least mid next week. High temperatures are depicted to rise into the upper 70s to mid 80s during this period, generally 10 degrees above normal. Variability in the 25th-75th percentiles for temperature is also quite low for being several days out yet, generally only 2-3 degrees in the 21.18z ensemble suite (GEFS, EPS, GEPS, and their AI counterparts), further building on the aforementioned confidence in the temperature forecast.

Beyond Wednesday, the forecast becomes far more uncertain as the 21.18z ensemble suite begins to diverge on their solutions regarding the evolution of the upper level pattern.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 549 AM CDT Fri May 22 2026

Some light rain showers will continue over portions of southeast Minnesota and northeast Iowa, just east of the I-35 corridor, through the mid morning. Mostly dry conditions for the rest of the day until this evening when a band of light rain moves into southeast Minnesota and northeast Iowa. Lower confidence on this band making it to the Mississippi River so have not included rain in the KLSE TAF. Southeast winds sustained at 15 to 20 mph with gusts of 25 to 30 mph expected throughout the day, then diminishing this evening. CIGS remain in the 5kft to 10kft range during the TAF period.

CLIMATE

Issued at 127 PM CDT Thu May 21 2026

With average high temperatures in the mid-and upper 70s and average low temperatures around 50 for the Memorial Day weekend, this looks to be warmest Memorial Day weekend since 2023.

There is concern that we could see the area rapidly dry out as the heat returns to the area next week. For the month of May, Rochester has only received 0.55 inches (currently the 2nd driest May and the driest since 1934) and La Crosse has only received 1.02 inches (currently the 7th driest May - driest since 1988).

ARX WATCHES/WARNINGS/ADVISORIES

WI...None. MN...None. IA...None.