Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 261937

Area Forecast Discussion
National Weather Service Green Bay WI
237 PM CDT WED OCT 26 2016

Forecast discussion for routine afternoon forecast issuance

.SHORT TERM...Tonight and Thursday
Issued at 236 PM CDT Wed Oct 26 2016

Surface low pressure over eastern Iowa at 18Z is forecast to reach
western Lake Erie by 12Z Thursday and Lake Ontario by 00Z Friday.
A mid level trough that was over Wisconsin at midday will
continue eastward to New York by 00Z Friday. Rain and gusty east
winds northeast of the low spread across the remainder of the
forecast area today, and there were even a few snowflakes in the

Precipitation should slowly diminish/depart as the low and upper
trough pass to the east. Some enhancement from lake effect may
cause the rain to linger in Door County on Thursday but rain will
come to an end at most locations overnight. Some mixed rain and
snow remains possible late this afternoon and during the evening
across parts of north central Wisconsin.

Surface high pressure and a low amplitude mid level ridge should
bring drier air to the area by Thursday afternoon, but plenty of
clouds will likely remain.

Lows should be mainly in the 30s tonight with highs in the 40s on

.LONG TERM...Thursday Night Through Wednesday
Issued at 236 PM CDT Wed Oct 26 2016

Latest GFS and ECMWF continue to indicate flattening of SW upper
ridge later this week into next week as stream of energy from
Pacific moves onshore and across the northern CONUS.

Active pattern that results from flattening flow will bring
periodic chances of precip into the region. Models showing timing
differences, especially beyond the weekend, in this regime. So,
while confidence is high in change to active pattern, it is low
with respect to timing of systems.

Lake effect precipitation possible Saturday behind low that moves
across the northern Great Lakes.

Temps during period will likely average above normal as mild air
will be pulled north ahead of each system. Behind systems, air
will be more of Pacific origin rather than Canadian.

.AVIATION...for 18Z TAF Issuance
Issued at 1254 PM CDT Wed Oct 26 2016

Surface low pressure that was in eastern Iowa at midday is
expected to move to western Lake Erie by 12Z Thursday as a mid
level trough makes its way across Wisconsin. IFR and low end MVFR
conditions are expected to prevail in stratus and rain into at
least this evening. Gusty east winds will continue throughout the
afternoon. The rain should taper off from west to east later
tonight, and winds will diminish, as the low pressure system
departs to the east, but do not think ceilings will get higher
than MVFR through 18Z Thursday.



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