Green Bay, Wisconsin

Forecast discussion for routine afternoon forecast issuance

• Spotty light rain and sprinkles (30-60% chances) for Halloween. Rainfall amounts less than 0.10 inch.
• Unsettled conditions much of next week, with widespread showers (70-95%) and gusty winds Monday afternoon through Wednesday, peaking Monday night into Election Day.
• Shower chances (10-20%) lingers Thursday into Friday.
• The probability of 48-hour rainfall totals over 1" from Monday afternoon through Wednesday afternoon range from 60-90% north and west of the Fox Valley to 40-60% over Fox Valley east to Lake Michigan.
• Above normal temperatures continue through next week.

An area of light showers and sprinkles continues across central Wisconsin, associated with mid-level warm air advection. This activity will lift north through the evening across north-central Wisconsin and become more widespread as better moisture arrives from the south. Abundant dry air in place and weak forcing will limit the amount of rain that falls across the region, with less than one tenth of an inch expected. High pressure then builds back in on Sunday, bringing a return to dry conditions across the region to finish the weekend.

A slow moving, moisture-laden system arrives Monday afternoon/ evening and sticks around into at least Thursday. Rain is likely Monday night into Tuesday (80-95%) with the initial surge of moisture and forcing. Then chance/likely PoPs will continue into Wednesday, then taper off on Thursday as the system finally exits to our east. Another system lifting north at the end of next week could continue to rain chances into Friday; however, this is less certain as the models differ in how far west this system makes it.

Chances for exceeding 1 inch of rain Monday Night through Tuesday has increased a bit to 60-90% north and west of the Fox Valley with 40-60% over Fox Valley east to Lake Michigan. The probability for 2 inches or more is also a respectable 30-60% across central and north-central Wisconsin during this same period. This set up appears to look like a soaking rain at times. Some elevated instability and impressive dynamics with the initial WAA surge Monday night into Tuesday to include some thunder, especially across central and north-central Wisconsin.

Temperatures will be above normal through the middle of next week with temperatures cooling off behind the large system at the end of the week.

for 18Z TAF IssuanceIssued at 1127 AM CDT Sat Oct 31 2026

High pressure centered over the eastern Great Lakes will shift east as a storm system moves northeast across the central Plains. Deeper moisture ahead of this system will continue to gradually shift northeast and across Wisconsin this afternoon as evidenced by lowering ceilings and light rain showers moving across parts of central and northeast WI. Most shower activity should stay to the north and west of the east-central WI TAF sites (GRB/ATW/MTW). No impacts to visibility are expected.

MVFR CIGs will arrive to AUW/CWA/RHI this afternoon. IFR CIGs are expected at RHI starting this evening with a period of these lower conditions possible at AUW/CWA later tonight. VSBYs may also fall to MVFR in mist this evening as well; however, confidence is lower for these conditions. Spotty light rain showers and sprinkles will be possible through the day but little to no impacts are expected. Kept the PROB30 north and west of the Fox Valley and removed the chance for the east-central WI TAF sites this afternoon. These low conditions should clear the central WI TAF sites Sunday morning but linger at RHI through midday Sunday.

A slow moving low pressure system will move across the Great Lakes Monday night into Wednesday morning, bringing gusty south to southeast winds and large waves on the bay and Lake Michigan. A Small Craft Advisory will likely be needed. A few gale force gusts are possible Tuesday on Lake Michigan.

Winds will shift to the north on Thursday, possibly gusting to near 25 kts as the system departs to the east.

None.