Area Forecast Discussion

KEY MESSAGES

- Showers and storms tonight along and north of Interstate 90. There is some concern that we might be holding onto the rain chances too long late tonight and on Saturday morning.

- Additional showers and storms are expected on Saturday afternoon and early Saturday evening. With favorable shear and instability, there may be a few strong storms along and south of Interstate 90 during the afternoon and evening. Damaging winds and hail are the primary concerns.

- Periodic showers and storms and unseasonably cool temperatures will be seen much of next week.

DISCUSSION

Issued at 1238 PM CDT Fri Jun 12 2026

Tonight

A shortwave trough will round the southern periphery of a broad northern longwave trough located over western Ontario and Manitoba tonight. As a 30-knot 850 mb jet moves into the region from the Central Plains, showers and storms will develop along and north of Interstate 90. This activity will then move off into northeast Wisconsin and Upper Michigan as this jet veers overnight. Somewhat concerned that we are holding on to the rain chances too long overnight and on Saturday morning in central and north- central Wisconsin. While there is strong 0-3 km and 0-6 km CAPES, the 0-1 mixed-layer CAPES are less than 100 J/kg. As a result, not anticipating any organized severe storms. Low temperatures will range from the mid-50s to lower 60s.

Saturday and Saturday night

A stronger shortwave trough will move through the region on Saturday and Saturday night. As this occurs, it will cause the 500 mb longwave trough to dig southward into the Mid Mississippi River Valley. As this occurs, a surface cold front will move southward through the Upper Mississippi River valley on Saturday and Saturday evening and through the Mid Mississippi River Valley late Saturday night. With the 0-1 km mixed-layer CAPES ranging from 500-1000 J/kg along and 0-3 km and 0-6 km shear greater than 40 knots along and south of the Interstate 90 corridor on Saturday afternoon and early evening, there could be some stronger storms. The main hazards would be damaging wind gusts and hail up to 1 inch in diameter. High temperatures will range from the lower 70s to lower 80s. Low temperatures will range from the mid-40s to mid-50s.

Sunday through Monday

With the polar jet being south of the region and surface high pressure over the region, it will be dry and unseasonably cool across the region for both Sunday and Monday. The largest temperature anomalies (around 10F) will be on Sunday when high temperatures will range from the mid-60s to lower 70s. Low temperatures on Sunday night will range from the mid-40s to lower 50s. On Monday, high temperatures will range from the upper 60s to mid-70s.

Monday night through Friday

With an active polar jet located across the region, there will be periodic showers and storms. Temperatures will remain unseasonably cool with high temperatures will be in the lower and mid-70s and low temperatures will range from the upper 40s to mid 50s.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1228 PM CDT Fri Jun 12 2026

VFR conditions are expected to prevail through the taf period. Westerly winds will mix down from aloft this afternoon and gusts up to around 25 knots at both RST/LSE taf sites. Next concern are rain chances. Weak cold front moves across the area late this evening into Saturday. First main area of convection will remain north of the taf sites tonight. However...there is the possibility of showers to impact the taf sites and will introduce vicinity of showers after 04z. As the weak cold front moves south over the area Saturday morning enough convergence will provide scattered showers or storms along and south of Interstate 90. For now...have introduce vicinity of showers after 15z Saturday based on coverage of convection and instability will be weaker in the morning hours.

ARX WATCHES / WARNINGS / ADVISORIES

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