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000
FXUS63 KGRB 041121
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
521 AM CST Thu Mar 4 2021

Updated aviation portion for 12Z TAF issuance

.SHORT TERM...Today...Tonight...and Friday
Issued at 233 AM CST Thu Mar 4 2021

Quiet weather continues through the short-term portion of the
forecast.

Northeast Wisconsin will remain on the southern edge of a strong
surface ridge, centered over western Hudson Bay, through much of
this time period. Aloft, the area will be on the inflection point
between a deep trough axis over the East Coast and a ridge building
across the western CONUS. This will keep northwest flow in place
through Friday, with little change in the overall pattern. Dry air
will linger across the area, keeping precipitation free conditions
under partly cloudy skies. The one caveat is that some lake effect
clouds will likely impact far northeast Wisconsin through early
afternoon before winds shift more to the northwest. The northwest
flow into the area will keep temperatures mainly in the mid to upper
30s to around 40 through this time period. Overnight lows will be in
the teens for much of the area; however, Northwoods locations could
see lows drop into the single digits above zero.

.LONG TERM...Friday Night Through Wednesday
Issued at 233 AM CST Thu Mar 4 2021

Quiet and mild weather will continue through much of the extended
portion of the forecast. The main concern will be the potential for
an unsettled period toward the middle of next week, bringing the
potential for a more widespread rainfall to the area.

Friday night through Sunday: A surface ridge and dry air will remain
in place through much of this time period. This will bring continued
partly cloudy skies along with precipitation-free conditions;
although, there will be some increase in cloud cover late Sunday
afternoon. Aloft, the upper-air pattern will transition from
northwest flow, on the inflection point, to a ridging pattern by
Sunday. This means that temperatures will steadily warm through the
weekend. Temperatures will warm from the low and mid 40s on Saturday
to the upper 40s and low 50s on Sunday.

Sunday night into Monday: A quick moving surface trough/cold front
is expected to pass through the area from west to east Sunday
evening through early Monday morning. This surface trough will be
bumping up against the aforementioned ridging aloft, which should
help to keep conditions dry across the area. The main impact will be
an increase in cloud cover and a wind shift from the south to the
west. Overnight temperatures may be kept a bit warmer, in the low to
mid 30s, due to increased winds and cloud cover ahead of the front.
High temperatures are expected to warm into the upper 40s to mid 50s.

Rest of the extended: Models are in good agreement that high
pressure will linger through early Tuesday morning before shifting
off to the east by Tuesday afternoon. At the same time, a fairly
strong spring low pressure system is expected to develop across the
Plains. This is where models vary on solutions, which is not
uncommon toward the end of the predictability horizon. The one thing
the models agree on, is that northeast Wisconsin is expected to
remain in the warm sector, keeping the precipitation in the form of
rain and temperatures in the 50s. There are some timing differences
with the GFS rushing the system through by late Tuesday night, while
the EC is slower, bring the system through the area late Wednesday
morning/early afternoon. Either way, the system will need to be
monitored closely as area rivers continue to have ice cover
(although this is slowly melting) and the ground is still frozen
across much of the area. The warmer temperatures over the next
several days will help improve these issues; however, they will
remain a factor in any flooding potential. Any flooding concern will
hinge on exactly how much rain falls with this system. Early
estimates would have between a half an inch and an inch, but
confidence in exactly where the heaviest rain will occur remains low.
&&

.AVIATION...for 12Z TAF Issuance
Issued at 521 AM CST Thu Mar 4 2021

Good flying conditions can be expected at each of the TAF sites
through this TAF issuance as high pressure lingers across the
area. Some 2500 ft bkn ceilings may briefly brush through the
GRB/ATW/MTW TAF sites early in the TAF period; however, these
clouds should mix out through the rest of the day. Clear skies are
expected to linger through tonight.

&&

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

$$

SHORT TERM.....Cooley
LONG TERM......Cooley
AVIATION.......Cooley