


Area Forecast Discussion
Issued by NWS Green Bay, WI
Issued by NWS Green Bay, WI
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528 FXUS63 KGRB 121149 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 649 AM CDT Sun Oct 12 2025 Updated aviation portion for 12Z TAF issuance .KEY MESSAGES... - Above average temperatures continue early this week, slighter cooler mid-week. - Light rain returns for most tonight into Monday morning, with a few chances for additional rain next week. && .DISCUSSION... Issued at 352 AM CDT Sun Oct 12 2025 Fog/Low Stratus/Cloud Trends: Southeast, upslope, moist flow will continue to produce a large north to south orientated area of low stratus over much of the area. This area should remain pretty stationary this morning, morphing a little on the sides, then should start to erode through the later morning and afternoon hours. Some disagreement on just how fast the lower clouds will depart. On either side of the stratus deck, mostly clear skies and light winds could lead to some patchy ground fog early this morning. Any fog would burn off shortly after sunrise. Otherwise, look for high clouds to spread across the region for most of the day. Rain Chances: Dry conditions are expected for most of today as mid-upper level ridging exits to the east. Chance for rain showers arrive west to east after dark into early Monday morning as a weakening frontal boundary moves across the region. Highest probabilities reside across central and north-central WI, where we will continue the likely (55-70%) PoPs, with 20-50% PoPs elsewhere. As with the last front, the precip looks to be on the light side due to limited moisture and dynamics, with only a 20-30% chance of more than 0.15" of rain over central and north- central WI, with lower chances to the south. Thunder threat is pretty much nil with no instability to work with (only up to ~150 MUCAPE). The showers will exit west to east Monday morning. As an omega block sets up over the CONUS mid-week, mainly dry conditions are expected, but a weak shortwave could clip the south on Tuesday, bringing small (15-25%) chance for showers. Ridging builds over the western Great Lakes in the mid-late week period, but a couple ridge riders could touch off some shower activity. But the better rain threat looks to arrive over the weekend as a deep trough approaches from the west. Temperatures: Highs today look to be a little above normal for most locations, with most spots climbing into the low to mid 60s. If/where the lower clouds stick around into the afternoon, temps will struggle to climb out of the upper 50s or low 60s. A much milder night compared to the past several nights in on tap as persistent WAA occurs ahead of the approaching front. Lows should hold in the upper 40s and 50s. On Monday, the showers/clouds will limit temps from rising much in the morning, but as the clouds/showers exit and the CAA is slow to arrive, the W/NW downsloping winds and sunshine will allow temps to quickly climb into the mid 60s to around 70 for most locations (a little cooler near Vilas Co.). The stronger CAA arrives on Tuesday into Wednesday, dropping highs back near seasonal normals, with highs in the upper 50s to low 60s. A gradual warming trend toward slightly above normal temps is expected late in the week. && .AVIATION...for 12Z TAF Issuance Issued at 648 AM CDT Sun Oct 12 2025 A large north-south orientated area of MVFR stratus, along with other low clouds to its west, will continue to move across the area this morning. The low clouds will eventually erode, but models differ on just how fast this will occur. Followed the GLAMP guidance for the most part, but trends will need to be monitored. Otherwise, look for high clouds spread across the region through the day. Dry conditions are expected for the daylight hours, then light showers will spread west to east into the region ahead of a weak cold front, especially across central and north-central WI. Some lower clouds will be along and behind this front. Southeast winds will increase through the morning, gusting to around 20 kts this afternoon. LLWS is expected this evening into early Monday as surface winds decrease and south winds at 2000 ft increase to 35-45 kts. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Bersch AVIATION.......Bersch