Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 291148

Area Forecast Discussion
National Weather Service Green Bay WI
648 AM CDT SUN MAY 29 2016

Updated aviation portion for 12Z TAF issuance

.SHORT TERM...Today...Tonight...and Monday
Issued at 323 AM CDT Sun May 29 2016

A sharp upper level trof and associated cold front will sweep
across the area this morning, and exit far ne WI during the
early afternoon. This system will bring showers and a few
tstms to the region. The best instability will build after the
front and upper level forcing have shifted east, so not
anticipating any organized severe weather today. The showers
should taper off over central and east central WI this afternoon,
but may linger over northern WI until late afternoon or early
evening. Used a blend of the better performing guidance sets for
high temps, which yielded readings in the upper 60s over north
central WI, and lower to middle 70s elsewhere.

A weak ridge of high pressure will build into the region late
tonight into Memorial Day, which should provide a brief respite
from the recent wet and humid conditions. May need to add some
patchy fog to our western counties late tonight into early Monday
as the ridge axis arrives, but will hold off and let the day
shift take a closer look at the potential. Lows tonight will be in
the 50s, and highs on Memorial Day should range from the middle
70s to lower 80s.

.LONG TERM...Monday Night Through Saturday
Issued at 323 AM CDT Sun May 29 2016

Mean flow to generally consist of a Western CONUS upper ridge, a
Western Atlantic upper ridge and an eastward moving shortwave
trough across the northern tier of states. The main forecast focus
will be the precipitation trends associated with this trough as it
impact NE WI during the Tue-Thu time frame. Mean flow to then turn
from the northwest and should bring cooler/drier air mass to the
region for the end of the week.

Clouds are expected to gradually be on the increase over the area
Monday night as a return flow sets up on the backside of the
retreating surface high and a warm front lifts northeast over the
Midwest. Models continue to show the potential for late night
isentropic lift-induced showers/thunderstorms trying to reach
toward Central WI toward daybreak. Previous forecast had this
well-covered, so little change necessary. Min temperatures to
range from the upper 40s to lower 50s north, mid to upper 50s

Precipitation chances continue to slowly rise on Tuesday as the
warm front approaches Southern WI and an area of low pressure
pushes east into the Upper MS Valley. Models also show a mid-level
shortwave lifting northeast in the SW flow aloft headed at WI by
Tuesday afternoon. If you add increasing gulf moisture (dew points
pushing 60 degrees), ingredients are there to fire off additional
showers and thunderstorms. Max temperatures will be limited due to
clouds/precipitation chances with readings around 70 degrees near
Lake MI, lower 70s north-central WI and mid to upper 70s

Unsettled weather conditions to persist Tuesday night through
Wednesday as the surface low shifts northeast toward Lake Superior
and drags a cold front toward western WI Wednesday afternoon.
There will also be a gradual increase in mid-level forcing as a
shortwave trough moves across the Northern Plains into the Upper
MS Valley. Likely pops appear necessary during this time frame and
we will have to watch for the potential of stronger storms on
Wednesday if enough instability can be realized. Shear values rise
through the day and WI gets under the right entrance region of the
upper jet for additional lift. Max temperatures for Wednesday
appear to be similar to Tuesday which is close to normal for the
first day of June.

Shower/thunderstorm chances should gradually taper off from west
to east Wednesday night once the cold front clears the area.
However, precipitation chances will linger over the region through
Thursday as the shortwave trough reaches the Western Great Lakes.
Do not see much in the way of QPF by Thursday as the cold front
will have taken the deeper moisture to the east by the time the
shortwave trough arrives. Northwest winds behind the cold front
are expected to usher cooler air into WI on Thursday with max
temps in the mid to upper 60s north-central WI, generally lower
70s elsewhere.

The mean flow by the end of the week to consist of a Western CONUS
upper ridge and an East-Central NOAM upper trough. The prevailing
northwest flow into WI will continue into next weekend, thus
temperatures should end up near normal with less humidity.
Preciptation chances appear pretty limited on Friday with an area
of high pressure situated over the Great Lakes. There is a
possibility for a weak mid-level shortwave trough/associated cold
front to drop southeast into WI by next Saturday. Timing of such
features this far out is usually futile, thus have followed the
consensus solution which only brings slight chance pops to parts
of northern and central WI.

.AVIATION...for 12Z TAF Issuance
Issued at 643 AM CDT Sun May 29 2016

An upper level trof and associated cold front will produce showers
and a few tstms today. The showers will be accompanied by mvfr
and local ifr conditions. Confidence is not high enough to include
tstms in the TAFs at this time. The showers will taper off this
afternoon, with clearing occurring in the late afternoon and early
evening. There may be some patchy fog in parts of central and
north central WI late tonight, as a weak ridge of high pressure
moves into the region.




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