Area Forecast Discussion
Issued by NWS Green Bay, WI
Issued by NWS Green Bay, WI
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
109 FXUS63 KGRB 201804 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 1204 PM CST Thu Nov 20 2025 Updated aviation portion for 18Z TAF issuance .KEY MESSAGES... - Overcast skies with patchy light rain or drizzle expected today. Areas of fog in north central and central WI this morning. - Additional precipitation chances from Monday night through Thursday. - Near normal to above normal temperatures expected through early next week, then turning cooler Wednesday into Thursday. && .DISCUSSION... Issued at 325 AM CST Thu Nov 20 2025 A cold front was moving through Minnesota early this morning, and south flow ahead of this front was advecting low-level moisture into GRB CWA. Widespread low clouds covered the region and patchy light drizzle was occurring, especially over north central and central WI, where very low ceilings and fog were also observed. Radar showed a small area of light rain moving through northwest WI, in association with a weak coupled upper level jet and short-wave trough. This rain may clip Vilas County over the next few hours. Temperatures had warmed into the middle to upper 30s over most of the forecast area, thus limiting potential for freezing/frozen precipitation. The weak frontal system will move through the forecast area today, bringing a small chance of light rain/drizzle regionwide. The best chance for measurable precipitation will be across far northern WI, where deeper moisture will be present. With widespread low clouds lingering through the day, have opted to lower high temperatures a few degrees. Dry weather is anticipated from tonight through Monday. High pressure arrives later tonight and lingers through Friday night. A weak cold front moves through Saturday into Saturday night, but with the associated low pressure system and short-wave energy tracking well north of the region, dry weather should prevail. High pressure returns Sunday into Monday. Rest of the forecast: The remnants of a Southwest U.S. upper low will lift northeast toward the Great Lakes, bringing a chance of light rain Monday night into Tuesday. A strong upper low over the Northern Plains will then shift northeast toward Lake Superior, bringing a mix of rain/snow Tuesday night into Wednesday, and a chance of snow Wednesday night into Thursday. Temperatures: Normal to above normal temperatures are expected through early next week, with a trend toward below normal readings mid to late week. && .AVIATION...for 18Z TAF Issuance Issued at 1203 PM CST Thu Nov 20 2025 Stratus covered the entire forecast area late this morning with LIFR cigs in central and north-central WI and IFR/MVFR cigs in east-central and far NE WI. Fog, drizzle, and some light rain were also observed late this morning, with the light rain mainly in far NE WI. The low clouds, fog, and drizzle will continue through late this afternoon, with gradual improvement (to at least MVFR) occurring at most sites by this evening. The MVFR cigs will remain at the central and north-central WI TAF sites through late tonight followed by some clearing towards Friday morning, in the wake of a weak cold front. Good flying conditions return Friday morning, with the exception in north-central WI where MVFR cigs may linger through Friday. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Kieckbusch AVIATION.......Kruk