634
FXUS63 KGRB 170857
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
357 AM CDT Wed Jul 17 2024

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Below normal temperatures are expected today and tonight, then
  temperatures return closer to normal for the end of the week.

- Mainly dry weather is expected through Saturday morning. The
  next chance of showers and storms is on Saturday afternoon, with
  a continuing chance of afternoon showers and storms into the
  middle of next week. The risk of severe weather is low over the
  weekend, and uncertain next week.

&&

.DISCUSSION...
Issued at 357 AM CDT Wed Jul 17 2024

Short Term...Today...Tonight...and Thursday

WV imagery showed a fairly potent short-wave trough moving through
NW WI early this morning, but a lack of moisture and instability
was limiting shower development, except over the bay and Door
County, where over-water instability was promoting scattered
thunderstorm development. North winds were pulling cooler
Canadian air into the region, and bringing an area of low clouds
into the MN Arrowhead and western Lake Superior. These low clouds
will likely impact at least NC WI this morning.

Precipitation Trends: The previously-mentioned short-wave will
sweep through the region early this morning, with additional
short-wave energy brushing far NE WI during the afternoon and
evening. Current thunderstorm activity over the bay/Door County
and isolated showers elsewhere will persist until the short-wave
moves out early this morning. Additional shower chances will
occur over far NC WI (Vilas and northern Forest/Oneida counties),
where NNW flow and lake-H8 delta-t`s up to 13 C will provide
lake-enhancement this morning through midday/early afternoon.
A few light showers may also form in eastern WI this afternoon.
Canadian high pressure brings dry conditions tonight into
Thursday.

Smoke trends...RAP/HRRR smoke models show less elevated smoke over
the region today/tonight than yesterday, and given that impacts
have been minimal to this point, will leave any mention out of
the forecast.

Temperatures & Humidity...Below normal temperatures and lower
humidity will prevail through Thursday, so air conditioners should
get a break for a couple days. Highs will be in the middle 60s to
middle 70s (along with NW-N winds gusting to around 20 mph) today,
and middle to upper 70s on Thursday. Lows tonight should be in the
40s to middle 50s. Dew points will be in the middle 40s to middle
50s; very comfortable for outdoor activities.

Long Term...Thursday Night Through Tuesday

Quiet weather at the start of the long term forecast, with a few
chances for showers and thunderstorms this weekend and early next
week.

High pressure keeps conditions dry, mostly sunny, and seasonable
on Friday. As the high slides east Friday night a weak surface
front is able to move down on Saturday. The front appears to stall
out, and then oscillate back north and south for a few days. This
boundary along with daytime instability will bring chances for
isolated to scattered showers and thunderstorms Saturday and
Sunday afternoons (mainly between Noon to 7PM). Anything that does
develop this weekend would likely be short-lived and non-severe.
Heavy rain concerns will also be quite minimal with a lack of deep
moisture. NBM probabilities show a roughly 20 to 40 percent
chance of any precip Saturday and Sunday, but less than 10 percent
chance to receive even a quarter inch at any given location.

This setup persists into early next week, but it is too early to
get a full grasp of severe potential.

Temperatures will generally be near normal through the forecast
period, with highs in the upper 70s and low 80s, and lows in the
50s to low 60s.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1034 PM CDT Tue Jul 16 2024

VFR conditions are expected in most places through at least
Wednesday night. Cool air flowing across Lake Superior could
produce lake effect clouds across north-central Wisconsin late
tonight through Wednesday morning, mainly north of a RRL to IMT
line. These clouds will likely have bases between 2500 and 3500
ft, with the lowest bases near the Michigan border.

VFR ceilings are expected Wednesday with diurnal cumulus clouds,
with the dissipating Wednesday evening, with clear skies
Wednesday night.

.OSH...VFR conditions are expected for the next few days. Clear
skies are expected overnight through Wednesday morning. Scattered
to broken stratocumulus clouds are expected Wednesday afternoon
with bases above 4000 feet, then dissipating Wednesday evening.

&&

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

&&

$$

DISCUSSION.....Kieckbusch/KLJ
AVIATION.......Kurimski