Forecast Discussion for GRB NWS Office
299
FXUS63 KGRB 090645
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
145 AM CDT Thu Jul 9 2026
Forecast discussion for routine morning forecast issuance
.KEY MESSAGES...
- Scattered showers and a few thunderstorms will come to
an end late this afternoon. Severe storms are not expected.
- Will need to watch precipitation trends this weekend. A few
storms are possible Saturday and Sunday.
- Trends continue to be monitored for the excessive heat potential
early next week with highs in the 90s at some locations.
&&
.DISCUSSION...
Issued at 145 AM CDT Thu Jul 9 2026
Scattered showers continued early this morning near Rhinelander
and Merrill eastward into northern Door County ahead of a weak
cold front that is expected to sag southward today. As the front
sags southward, rain chances return to central and east-central WI
this morning which will continue into the afternoon. Bufkit
soundings indicated 500 to 800 J/KG of CAPE and shear values
around 20 knots, thus not expecting severe weather today. The
showers and storms will end from north to south this afternoon.
Tranquil conditions are expected on Friday. A new wrinkle to the
forecast for the weekend. High pressure is expected to set up
across the state. Return flow/850mb warm advection sets up Friday
night, which should result in scattered thunderstorms developing
across Minnesota and western WI. Some of the activity may spill
into far north-central WI towards 12z Saturday. The combination of
daytime heating and possibly an outflow boundary from the
overnight convection is expected to bring a chance of showers and
storms across the north Saturday afternoon. Confidence is low on a
dry forecast for Sunday as the Canadian/ECMWF are bringing a weak
impulse across the area at 500mb. The ECMWF is more bullish than
the Canadian model on the QPF output for Sunday. Will continue to
monitor to see if rain will need to be added for this period.
500mb ridge builds early next week, resulting increasing heat and
humidity later this weekend through the middle of next week.
850mb temperatures are pretty toasty off the ECMWF/Canadian/GFS
that would support highs in the lower to middle 90s at our typical
hot spots. Current forecast is a little bit lower that what the
max values would be each day. None the less, it will be hot.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1050 PM CDT Wed Jul 8 2026
Isolated to scattered showers and a couple storms will continue
overnight into Thursday morning as a cold front sags south across
the area. Main hazards will be heavy rain and lightning. Ceilings
and visibilities will drop through the night as low clouds and fog
spread in/develop, with IFR/LIFR conditions for much of the area.
Some VLIFR conditions are possible, especially across northern
WI. The fog will lift Thursday morning, with clearing skies
expected in the afternoon. Patchy/areas of fog is again expected
Thursday evening/night. Winds will remain under 10 kts.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Eckberg
AVIATION.......Bersch
NWS GRB Office Area Forecast Discussion