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Area forecast discussion 
National Weather Service Green Bay WI
659 PM CDT Monday may 25 2015

Updated aviation portion for 00z taf issuance

Short term...tonight and Tuesday
issued at 256 PM CDT Monday may 25 2015

Atmosphere worked over from last nights heavy rain. Most
locations saw between one and two inches of rain. Latest radar
images from kgrb indicated showers trying to develop across
northeast Wisconsin...but having a hard time doing so due to warm
layer aloft. More active convection noted across northeast Iowa
that may be a concern for tonight.

Many model solutions to choose from this afternoon for placement
of highest chances for rain...location of highest chances and if
any precipitation would occur after midnight. Next system expected
to move into the area on Tuesday...with timing differences with
this feature as well. Several of the models take the convection
across Iowa and work it into central and northeast Wisconsin very
late this afternoon or into the evening. Based on movement of
storms...this seemed reasonable and will keep the mention of gusty
winds and small hail. Think best of potential for this type of
storm will be across portions of central Wisconsin. Meanwhile...
a few other models develop showers and storms along the boundary
and that will sink slowly southeast across the area overnight
(nam model). Have trended toward the GFS/European model (ecmwf) which pretty much
dissipates the precipitation during the evening hours.

On Tuesday...next system approaching from the southwest. Some
of the latest models have precipitation into the southern half
of the forecast area by early afternoon. This would have a
significant impact on high temperatures. Did lower the highs
across the south due to earlier arrival of the rain. Not expecting
any severe storms on Tuesday.

Long term...Tuesday night through Monday
issued at 256 PM CDT Monday may 25 2015

The upper trough will move through the northern Great Lakes
Tuesday night bringing showers and thunderstorms that should end
by midday Wednesday. Then drier and warmer air will prevail for
Wednesday afternoon through Thursday as a weak upper ridge moves
in from the northern plains. A more significant upper trough will
approach the area Friday with an associated cold front that should
produce showers and thunderstorms as it moves through Friday
afternoon and evening. There are some differences in the models as
to whether the front exits the region by early Saturday or whether
a wave moves along it and slows it down. After that a nice cool
surface high arrives from central Canada that should produce cool
and comfortable weather Saturday afternoon into early next week.
&&

Aviation...for 00z taf issuance
issued at 650 PM CDT Monday may 25 2015

Scattered thunderstorms may impact the auw/cwa/atw/grb taf sites this evg before
dissipating...so have added tempo groups for the first 2 or 3
hours. After that...expect a lull in the precipitation until late Tuesday
morning. Given all of the rain that has fallen over the past 24
hours...need to consider the potential for fog/stratus development
overnight. Stronger boundary layer winds may prevent significant
fog from occurring at atw/grb/mtw...but kept IFR/LIFR conditions
in the rhi/auw/cwa taf sites late tonight/early Tuesday. Low pressure
lifting north through the region will bring another round of
showers and isolated thunderstorms late Tuesday morning and afternoon...with
MVFR conditions developing late in the day.

Added some low level wind shear to the atw/grb/mtw taf sites for tonight...as SW
winds increase to around 40 kts just above the surface.
&&

Grb watches/warnings/advisories...
none.
&&

$$

Short term.....Eckberg
long term......rdm
aviation.......kieckbusch

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