Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 230351

Area Forecast Discussion
National Weather Service Green Bay WI
1051 PM CDT Tue May 22 2018

Updated aviation portion for 06Z TAF issuance

.SHORT TERM...Tonight and Wednesday
Issued at 243 PM CDT Tue May 22 2018

Main forecast concerns include temperatures, fog potential late
tonight into early Wednesday, and low humidities across northern
WI on Wednesday.

Lingering low stratocumulus will continue to erode late this
afternoon, and diurnal cumulus will dissipate by sunset, leaving
mostly clear skies overnight. With the surface ridge axis and
associated light winds over the region, its reasonable to assume
at least patchy fog development overnight into early Wednesday.
The fog may be locally dense in parts of central WI and near the
lakeshore. Low temperatures will be in the upper 40s to middle

High pressure shifts into the central Great Lakes on Wednesday
and allows winds to become south-southwest by late morning.
Weak WAA, deep mixing and abundant sunshine should allow
temperatures to warm into the upper 70s to middle 80s, except
upper 60s to middle 70s lakeside, where winds will turn south-
southeast in the afternoon.

.LONG TERM...Wednesday Night Through Tuesday
Issued at 243 PM CDT Tue May 22 2018

After a long winter, and a fairly short spring, summer weather
will arrive in northeast Wisconsin for an extended period of time
starting on Thursday and lasting through the Memorial Day weekend.
This will mean daily highs in the 80s away from the Great Lakes,
with temperatures approaching 90 at times. The summer-like weather
will also bring the typical chances for showers and thunderstorms
as several shortwaves and weak low pressure systems track through
the western Great Lakes region.

While most of these thunderstorms are expected to be garden
variety, some could be strong or even approach severe levels
during the Memorial Day weekend, basically from Friday through
Memorial Day itself. MUCAPEs during this period will rise to 1500
to 2500 J/kg with bulk shear ranging from 15 to 30 knots. Model
soundings indicate the severe weather threat will mainly be large
hail given the CAPE profile will be fattest in the hail growth
zone with some gusty winds possible from the stronger storms.
Overall soundings show a fairly weak wind field in place which
indicates storms will be more of the pulse or multicell cluster
variety instead of a more organized severe weather threat.
Therefore pinpointing the best day or area for possible severe
weather would be difficult at best as each day could pose a threat
for an isolated severe storm.

.AVIATION...for 06Z TAF Issuance
Issued at 1051 PM CDT Tue May 22 2018

VFR conditions expected tonight and Wednesday except
for the possibility of low clouds straddling the lake Michigan
shore (possibly as far inland as MTW and SUE) late tonight, and
patchy ground fog between 09z and 12z Wednesday across central

Issued at 243 PM CDT Tue May 22 2018

Dry conditions will continue across northern WI through Wednesday,
with relative humidities dropping into the 20s again during the
afternoon. An increase in shower and thunderstorm chances are
forecast for the end of the week which could provide much needed
relief and ease the fire weather threat.



SHORT TERM.....Kieckbusch
LONG TERM......Kurimski
FIRE WEATHER...Kieckbusch is the U.S. government's official web portal to all federal, state and local government web resources and services.