NWS-Green Bay Forecast Discussion

 

						FXUS63 KGRB 111141
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
641 AM CDT Tue Aug 11 2020

Updated aviation portion for 12Z TAF issuance

.SHORT TERM...Today...Tonight...and Wednesday
Issued at 320 AM CDT Tue Aug 11 2020

A sunny and warm, but much less humid day is expected today, in
the wake of yesterday's cold frontal passage. Highs should be in
the upper 70s to middle 80s, with comfortable dew points in the
upper 40s to middle 50s. West winds will gust to 15 to 20 mph by
afternoon.

Clear skies and diminishing winds may lead to patchy fog
development late tonight, especially over the favored areas of
central and north central WI. Good sleeping weather is
anticipated, with lows in the 50s and lower 60s.

On Wednesday, have ignored the outlier GFS model, which produces
a significant area of rain over northern WI in the afternoon.
Will keep our dry forecast intact, with high pressure remaining
over the western Great Lakes. Temperatures may a degree or two
warmer than today, with highs in the lower to middle 80s inland.
Developing light southeast winds will keep readings a little
cooler along the lakeshore, where highs should be in the upper
70s and lower 80s.

.LONG TERM...Wednesday Night Through Monday
Issued at 320 AM CDT Tue Aug 11 2020

Zonal pattern at 500mb will continue into the weekend, which will
result in temperatures at or slightly above average. Later in
the weekend into early next week, 500 mb ridge expected to build
across the western United States with a downstream trough across
the Great Lakes. Temperatures early next week will fall to or
slightly below normal for mid August.

Dry conditions are expected Wednesday night as high pressure
lingers across the Great Lakes. Like the last few night, models
have differing solutions when precipitation chances arrive late in
the week. Low confidence in the small chances of rain on Thursday
across portions of central and north-central Wisconsin as the new
GFS/NAM/ECMWF keep the forecast area dry. For Thursday night,
convection is expected to break out across Minnesota and western
Wisconsin. The GFS/NAM/Canadian try to spill some of the
precipitation into our western counties towards 12z Friday
although the ECMWF remains dry. The same holds true for Friday
as the ECMWF remains dry while the other models have some
precipitation across our far western counties. Did lower rain
chances across the east Thursday and Thursday night, and won't
be surprised if they will be lowered on later shifts for the
Friday period.

For the upcoming weekend, chances of showers and storms are in the
forecast. Low confidence at the moment in when and where to place
the highest chances of rain over the weekend due to timing
differences in the models. Humidity will increase slightly each
day into the weekend before humidity levels drop off early next
week.
&&

.AVIATION...for 12Z TAF Issuance
Issued at 638 AM CDT Tue Aug 11 2020

VFR conditions can be expected through the TAF period, with the
possible exception of patchy MVFR/IFR fog in parts of central and
north central WI late tonight. West winds will increase later
this morning, with gusts to 15 to 18 kts during the afternoon. The
winds will subside by sunset.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....Kieckbusch
LONG TERM......Eckberg
AVIATION.......Kieckbusch