Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Green Bay WI
412 am CST sun Dec 28 2014

Forecast discussion for routine morning forecast issuance

Short Monday
issued at 410 am CST sun Dec 28 2014

Clouds and their effect on temperatures are the main challenge
for this part of the forecast period. Jet energy passing north of
Wisconsin coupled with a weak surface trough will produce some
broken clouds today. Lake effect snow showers or flurries possible
in the snow belts with little or no accumulation. Cold advection
and the clouds will make for near normal temperatures for the
first time in a long while.

Some clearing is expected tonight which will allow temperatures to
drop quickly. The extent of clearing will determine whether lows
fall below zero in areas with snow Cover. Lake effect snow showers
or flurries possible in the snow belts with no accumulation.

An upper trough will produce some middle clouds as it moves through
Monday along with an associated surface front that will bring in
even colder air.

Long term...Monday night through Saturday
issued at 410 am CST sun Dec 28 2014

The big story will be the Arctic firm that will be firmly in
place into the New Year as western ridge builds...and closed
500mb low meanders across eastern Canada. Lake effect snow
showers are possible at times across the far north Monday night
and Tuesday. Winds are a little more northwesterly than last
night...thus the snowbelt region could pick up an inch or two
during this period. Drier air working into northern Wisconsin
should shut off the snow shower activity Tuesday night. The big
story Monday night into New Years Day will be the Arctic air. The
combination of the cold and winds...wind chills Monday night into
Tuesday morning will be down to around 20 below across north-
central Wisconsin. Wind chills Tuesday night and Wednesday morning
will be down to 20 below to 30 below north and west of the Fox
Valley...and approaching 20 below across the Fox Valley and Lakeshore
region. Did add a blurb about the wind chills in the hazardous
weather outlook.

Upper/surface troughs swing across the region on Thursday. Added
light snow or flurries to much of the forecast area with this
feature. Attention then turns to bigger storm Friday into Saturday.
If 00z GFS is correct...winter storm warnings would be needed for
portions of northeast Wisconsin. European model (ecmwf) has come in more bullish
with precipitation amounts...thus expect later shifts to increase
chances for snow. Did raise them slightly per coordination
efforts with surrounding offices. Arctic air will follow this
storm for late next weekend into the following week.

Aviation...for 06z taf issuance
issued at 1016 PM CST Sat Dec 27 2014

The remaining area of MVFR ceilings will depart eastern Wisconsin by
midnight. After a period of sky clear tonight...a band of middle level
clouds will drift over the region late tonight into Sunday. Patchy
MVFR ceilings with isolated snow showers may brush over far northern
Wisconsin overnight into Sunday morning as well...otherwise VFR
conditions to prevail Sunday. &&

Grb watches/warnings/advisories...


Short term.....Rdm
long term......eckberg

National Weather Service Glossary of Abbreviations