298
FXUS63 KGRB 081757
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1157 AM CST Fri Nov 8 2024

Updated aviation portion for 18Z TAF issuance

.KEY MESSAGES...

- High confidence for above average temperatures continuing into next
  week.

- The next chance for rain arrives from the southwest Saturday
  evening. Rainfall amounts to range from 0.10 to 0.25", with
  areas of locally higher amounts from central to far northeast
  Wisconsin.

- Another system arrives during the middle of next week. There are
  timing differences on when the precip should arrive, but most
  of the precipitation should be in the form of rain.

&&

.DISCUSSION...
Issued at 231 AM CST Fri Nov 8 2024

Short Term...Today...Tonight...and Saturday

Sunny and mild weather will continue today, despite the arrival
of a weak backdoor cold front during the late afternoon hours.
Highs today will be about five degrees above normal.

Some lake effect clouds could form over the lake and bay during
the evening hours and move inland into the lakeshore counties and
the Fox Valley, but the remainder of the region should be clear.
Temperatures will be around five degrees above average.

Middle and high clouds will increase from the west Saturday as a
system approaches from the Plains. There is a chance of showers
towards evening in central Wisconsin. The clouds and a southeast
winds from Lake Michigan will make for temperatures a few degrees
cooler than today.

Long Term...Saturday Night Through Thursday

Split flow regime is expected to continue into next week. The
first system to impact the area will bring rain into the area
Saturday evening, then continue through the day before ending
Sunday evening. Precipitation amounts off the models not impressive
with most amounts between 0.10 to 0.25 inches. Compared to last
night, the probabilities of a quarter of an inch are lower than
last night. With the closed upper system moving across the area on
Sunday, would suspect that would be some locally higher amounts
from central into northeast Wisconsin. High pressure builds into
the region Sunday night and Monday, then east of the area
Tuesday.

For Tuesday night and Wednesday, the next 500mb trough will
move across the region. The GFS model is the quickest to bring
rain into the area Tuesday night, while the ECMWF and Canadian do
not bring it into the area until Wednesday. Took a compromise
between the two solutions and will have a small chance of rain
late Tuesday night. High confidence in rain chances are on
Wednesday. Not expecting a heavy rainfall, as the probabilities
of a quarter inch with this system are only 30-50%, with the
lowest chances across far north-central WI and highest chances
across east-central WI.

Looking at numerical guidance, above normal temperatures are
expected during the period. Looking at the Green Bay guidance,
going to have a hard time finding a night with lows below
freezing over the next week, probably Saturday morning will be
the coldest. Average low temperatures are around 30. Highs should
be mainly in the upper 40s to middle 50s (normal high is now in
the upper 40s). Typically in November, we drop a degree every two
days.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1155 AM CST Fri Nov 8 2024

Mostly clear skies and good visibility will continue through the
remainder of today. Late this evening and into the overnight,
there is a likely chance of lake effect clouds from Lake Michigan
and the bay. These clouds could produce a 2500 foot ceilings at
MTW after 00z, and at SUE, OCQ, 3D2, and 2P2 after 04z. It is
possible that GRB could have a few hours of these clouds as well
tonight... however confidence was not high enough to warrant IFR
or MVFR at this time.

These lake effect clouds will exit the area Saturday morning,
and VFR conditions are expected until Saturday night when showers
will arrive.

&&

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

&&

$$

DISCUSSION.....RDM/Eckberg
AVIATION.......Kotenberg