FXUS63 KGRB 210755 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 255 AM CDT Sun Jun 21 2026 Forecast discussion for routine morning forecast issuance .KEY MESSAGES... - Cloudy but dry today. Larger weather system passes across northern Illinois and southern Wisconsin. - Next chance for widespread rainfall will be the middle of next week. - Near to below normal temperatures and comfortable humidity will prevail through next week. && .DISCUSSION... Issued at 255 AM CDT Sun Jun 21 2026 Today and Monday... Some patchy fog will be in the area this morning but should burn off quickly this morning before high clouds from a more southerly system move in. The rest of the day continues to trend dry for most of the region. The only exception will be along the Upper Peninsula border, where isolated showers could develop briefly in the afternoon. If you are traveling southwards today however, expect scattered showers in Wisconsin and possibly severe weather if you're headed towards Illinois. Monday will be a fairly quiet day across the region as we get between systems, so expect a sunny and cool day for the region. Midweek... An approaching trough will bring rain back to the region late Tuesday into Wednesday. Although the potential for rain is relatively high (70-90%), with a fairly cool airmass, limited instability, and limited moisture, the potential for severe weather remains low. Similarly, the overall heavy rain potential will also be limited, with medium range probabilistic guidance maintaining around 30-50% chance of exceeding half an inch of rainfall. After this initial round of rain, additional showers will be in the region Thursday afternoon (40-60% chance). Although predictability towards next weekend does remain lower, early signs do point to a return of warmer temperatures and increased moisture. High temperatures by next Sunday will get highs into the middle 80s. && .AVIATION...for 06Z TAF Issuance Issued at 1004 PM CDT Sat Jun 20 2026 With mostly clear skies and light winds during the overnight period, favorable conditions will exist for ground fog to develop, particularly in the higher elevations of central and north- central WI and areas which received measurable rainfall today. No changes to forecast visibilities in the tempo groups at RHI, AUW, and CWA to IFR in the 08-12Z time period. Ground fog will burn off early Sun morning, likely by 13Z. Then fair weather cumulus will pop in the 15-17Z time frame. Convective allowing models indicate scattered shower activity will be possible across north-central WI in the afternoon. Coverage should not be as widespread as today, but an isolated shower could impact RHI. Light winds (under 10 kts) are expected through the TAF period. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Uhlmann AVIATION.......MPC