Forecast Discussion for GRB NWS Office
FXUS63 KGRB 041920

Area Forecast Discussion
National Weather Service Green Bay WI
220 PM CDT Tue Aug 4 2020

Forecast discussion for routine afternoon forecast issuance

.SHORT TERM...Tonight and Wednesday
Issued at 220 PM CDT Tue Aug 4 2020

Diurnally driven afternoon cumulus clouds should dissipate shortly
after sunset across northeast Wisconsin as high pressure slides
south of the area. Mostly clear skies and very light winds will
allow temperatures to plummet into the upper 30s to lower 40s
across north-central Wisconsin, with lows around 50 across east-
central Wisconsin and middle 50s near Lake Michigan. There could
be some patchy frost at the typical cold spots tonight across
north-central Wisconsin, however it should be isolated enough and
for a short enough period of time to forgo headlines. The clear
skies and light winds could also lead to some fog across far
north- central Wisconsin overnight.

Temperatures will rebound a bit on Wednesday as the high drifts
south and the area experiences some warm air advection as winds
back to the southwest throughout the day. This will allow high
temperatures to rise into the lower to middle 70s. Diurnally
drivel cumulus clouds are expected to once again develop across
the region as another shortwave tracks through the western Great
Lakes region.

.LONG TERM...Wednesday Night Through Tuesday
Issued at 220 PM CDT Tue Aug 4 2020

The main concern for the long term forecast will be the potential
for stronger storms this weekend into early next week.

Wednesday night through Friday...Surface high pressure will be on
its way out of the region Wednesday night, but will still help
keep the area dry through daybreak. Return flow will then increase
through the next couple days, bringing rising temperatures and
additional moisture back to the region0 High temperatures are
expected to be back in the upper 70s and lower 80s by Friday. The
weak WAA and a passing shortwave could also bring in a few
showers during the morning and afternoon on Thursday, but little
to no thunder is expected. Friday, the shortwave will have exited,
but diurnal heating and ongoing WAA will bring in another chance
for showers in the afternoon. Rain showers are not expected to be
widespread Thursday or Friday.

Rest of the forecast...Guidance continues to suggest the
possibility for a few MCSs to cross the region this weekend into
early next week. There are still many differences between models,
so locking in any timing or other details is unlikely at this
time. We will continue to monitor the potential for storms as we
get closer. Despite the uncertainty in storms however, the rising
temperature trend is expected to continue through the weekend,
with highs in the middle to upper 80s by early next week.

.AVIATION...for 18Z TAF Issuance
Issued at 1153 AM CDT Tue Aug 4 2020

VFR conditions will continue across each of the TAF sites through
Thursday. The main exception will be patchy ground fog that forms
overnight as winds become calm. Diurnal CU across the region this
afternoon should dissipate this evening with the loss of daytime
heating. Diurnal CU should then redevelop during the afternoon
on Wednesday. Cloud bases are expected to be around 4kft, however
some bases could hit MVFR at times. Northerly winds of 10 to 15
knots this afternoon will become light and variable tonight. Winds
will then back to the southwest through the day on Wednesday at 5
to 10 knots.



SHORT TERM.....Kurimski
LONG TERM......Uhlmann

NWS GRB Office Area Forecast Discussion