567
FXUS63 KGRB 192330
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
630 PM CDT Wed Aug 19 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- Chance (40-70%) of showers and storms returns on Thursday across
  north- central and far northeast WI.

- Rain won`t arrive until Thursday night across east-central WI
  with rain chances lingering across the entire area on Friday.

- A drought busting rain is not expected.

- Another cool night across the north, but not as cool as this
  morning with lows in the 40s. Seasonable temps expected into the
  weekend, although some cool nights are possible over the north.

&&

.DISCUSSION...
Issued at 115 PM CDT Wed Aug 19 2026

Skies were partly cloudy this afternoon with temperatures in the
70s. The fair weather cumulus clouds across the north will
dissipate around sunset, with mostly clear skies should allow
temperatures to fall back into the 40s across the north to the
lower to middle 50s over east-central WI and Door County. It
should not be as cool as this morning where readings were in the
upper 30s in Vilas County. Did lower minimum temperatures which
was coordinated with surrounding offices.

On Thursday, a system will approach from the west. This system
will bring a chance of showers and thunderstorms for locations
well north and west of the Fox Valley from late morning and
through the afternoon on Thursday. Based on the latest model
trends, there are timing differences on how quick the rain will
make it into the northeast and east-central WI. A few models would
not bring rain until towards 12z Friday across east-central WI.
Took a blended approach with the rain chances which matched up
with surrounding offices. For Thursday and Thursday night, the
Storm Prediction Center Day 2 Outlook has pushed the Marginal
Risk further east into western WI, but at this time does not reach
our forecast area. Couldn`t rule out a few stronger storms, but
widespread severe weather is not expected.

On Friday, a weak cold front Will move across the area during the
weather. Surface convergence along the boundary combined with
daytime heating could trigger additional thunderstorm activity.
The NAM and GFS are not bullish on rain during this timeframe,
partly due to a warm layer aloft. Models were showing 800 to
1,500 J/KG of CAPE with shear values around 20 knots or less.
Could get a few stronger storms during the afternoon.

The weekend should be mainly dry. Low confidence in the low
chances of rain across north-central and northeast WI on Saturday.
Dry conditions are expected Sunday and Monday with the next chance
of rain on Tuesday. Unfortunately, rainfall totals over the next
week are not expected to help the drought conditions across the
area, and most likely make them worse in spots. Seasonable
temperatures are expected into early next, although some cool
nights are possible especially across the north.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 600 PM CDT Wed Aug 19 2026

VFR conditions prevail through Thursday evening. Skies clear out
and winds become light and variable overnight, resulting in
potential for patchy ground fog development through Thursday
morning. However, vsbys should not dip below MVFR. Otherwise,
winds at the surface shift to the southwest Thursday afternoon.
Rain arrives from the northwest toward the end of the TAF period,
though was too early to include mention in the TAF.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION.....Eckberg
AVIATION.......Goodin

NWS GRB Office Area Forecast Discussion