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Area forecast discussion 
National Weather Service Green Bay WI
1052 PM CDT Sat may 23 2015

Updated aviation portion for 06z taf issuance

Short term...tonight and Sunday
issued at 228 PM CDT Sat may 23 2015

Weak upper level disturbance moving across the western Great Lakes
tonight could bring a few sprinkles...especially north and west of
the Fox Valley.

Attention then turns to system approaching from the soutwest on
Sunday. Most of the models have slowed the arrival by a few hours.
Believe most of the precipitation will hold off until the afternoon
hours. Did compromise with offices to the south and had Middle Range
probability of precipitation already by 18z. Looking at thunder parameters...not very
promising for even a clap of thunder. Did remove thunder across
the north and only had slight chances across the south during the

High temperatures on Sunday will be tricky due to slower arrival
of precipitation...thicker cloud cover and east winds.

Long term...Sunday night through Saturday
issued at 228 PM CDT Sat may 23 2015

The surface-based low pressure system in The Rockies will move to the
northern Midwest by Memorial Day morning. The low will deliver a
good chance for showers and thunderstorms to northeast WI for the
latter part of the Holiday weekend. Temperatures will be a little
warmer than normal through Monday with southerly winds drawing
warm moist air into the region. After Monday...a broad upper
level trough will spread across the entire northern U.S. And draw
the surface low NE into Canada. The broad upper level trough will
promote unsettled weather and a chance for showers...and a rumble
or two of thunder at times...for the rest of the week.

Aviation...for 06z taf issuance
issued at 1050 PM CDT Sat may 23 2015

VFR conditions should prevail through Sunday morning...with
mainly middle-level clouds and only isolated sprinkles anticipated.
An increasing surge of warm and moist air should lead to shower
development during the middle afternoon on Sunday...with a steady
rain spreading north across the forecast area during the late
afternoon and evening. Instability appears to be too weak to
mention thunderstorms in the tafs at this time. MVFR ceilings will develop in
the steadier showers over parts of central and east central
Wisconsin later in the afternoon...with IFR conditions likely
during the evening. Have added some low level wind shear at most of the taf
sites later in the evening.

Grb watches/warnings/advisories...


Short term.....Eckberg

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