Area Forecast Discussion

KEY MESSAGES

- Light rain showers likely (40-80% chance) this morning through this afternoon. Lightning is unlikely, but an isolated bolt is possible near the WI/IL border. - An unsettled weather pattern will impact the area Monday through Wednesday, bringing widespread rainfall and potentially thunderstorms. Above normal temperatures are also likely through this time frame. Keep an eye on the forecast for changes.

- Unsettled weather may continue into the end of the week before dry conditions take hold next weekend.

SHORT TERM

Issued 1226 AM CDT Sat Oct 31 2026

Today through Sunday night:

Waves of 850-700 mb warm frontogenesis continue to push northeastward through southern Wisconsin, bringing on and off showers across the region through much of the day. Showers will progress northeastward out of southern Wisconsin this afternoon into this evening. With plenty of dry air across central to northern Wisconsin from high pressure over the eastern Great Lakes, expecting showers to become more widely scattered as they move northeastward through the afternoon. With light southeasterly winds and plenty of cloud cover, expect highs in the upper 50s to low 60s (highest temperatures near the WI/IL border).

Precipitation tapers off this evening into tonight as frontogenesis weakens and parent low pressure propagates northward into the northern Plains. Expect lows in the upper 40s and light and variable to calm winds overnight. Some low-lying areas may see patchy fog development.

A developing shortwave propagating through the Middle Mississippi Valley may produce enough lift for a few showers across far southern Wisconsin on Sunday (~15% chances), but not expected to be widespread. Outside showers, expect steady south-southeasterly winds and highs in the mid 60s. The northern Plains low looks to phase with a shortwave traversing the central Rockies, deepening the low in the High Plains and leading to increasing southerly winds across southern Wisconsin into Sunday night.

MH

LONG TERM

Issued 1226 AM CDT Sat Oct 31 2026

Monday through Saturday:

As low pressure continues to deepen in the central High Plains Monday, southeasterly winds will increase across southern Wisconsin. Low pressure then ejects northeastward into the northern Plains, bringing widespread showers to western Wisconsin by Monday afternoon as WAA develops in all levels. With this strong WAA, expect highs in the mid-60s. Instability may build into the region briefly, bringing lightning potential. Severe storms do not appear likely at this time, but clear skies in the afternoon may be enough to enhance instability to the point that stronger winds may become possible within storms that do develop.

The low continues to propagate northeastward along the western edges of high pressure centered over the Northeast U.S. Monday night into Tuesday, keeping southern Wisconsin within the warm sector with continued gusty south winds. Temperatures may even reach 70 degrees on Tuesday simply through strong WAA. However, plenty of cloud cover and rain continues across the area. Areas that see multiple rounds of storms may see local ponding of water and rises on area streams.

Wednesday, low pressure propagates into southern Ontario, bringing a break in precipitation as its associated occluded front finally exits to the east. Wrap-around showers move back in by Wednesday night as low pressure continues to progress northeastward. Winds diminish and become westerly. High pressure building through the Canadian Prairies will likely bring an end to precipitation, but with high pressure remaining mainly to the north of Wisconsin, modeling indicates potential for shortwaves bringing additional precipitation chances Thursday through Friday. High pressure finally propagates into the Great Lakes Saturday, bringing an end to precipitation chances and highs back in the 50s.

MH

AVIATION

Issued 1226 AM CDT Sat Oct 31 2026

VFR conditions expected to dominate through the TAF period. MVFR ceilings are possible in southwestern to central Wisconsin this morning into this afternoon, rising back to VFR by the evening hours. Very light showers early this morning becoming more widespread late this morning into the late morning to afternoon hours before ending this evening. Minor reductions in visibility expected underneath showers.

East-southeasterly winds through sunrise will gradually shift to become south-southeast and increase to around 10 kt this afternoon. Winds gradually diminish this evening into tonight to become near calm into Sunday morning. Patchy fog may become possible into Sunday morning in low-lying areas.

MH

MARINE

Issued 1226 AM CDT Sat Oct 31 2026

High pressure around 30.5 inches will continue to slide southeastward through the eastern Great Lakes, becoming stationary over the Northeast U.S. by tonight. Low pressure around 29.9 inches over the central High Plains today will strengthen to 29.5 inches by Sunday evening, bringing gradually increasing southeasterly winds through today, and again Sunday night into Tuesday as low pressure ejects into the northern Plains. Conditions hazardous to Small Craft are expected in nearshore regions north of Milwaukee this afternoon into this evening as southerly winds increase. Gusty south winds and Gales are likely Tuesday as low pressure makes its closest approach through Minnesota and continues to deepen. Isolated thunderstorms are also possible Tuesday into Tuesday night. Southerly winds gradually diminish through Wednesday, with a cold front Wednesday night bringing westerly light winds to the Lake. West winds gradually shifting to northwesterly are then expected through Thursday.

MH

MKX WATCHES / WARNINGS / ADVISORIES

WI...None. LM...Small Craft Advisory...LMZ643-LMZ644...1 PM Saturday to 10 PM Saturday.