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Area forecast discussion 
National Weather Service Omaha/valley NE
607 am CST Monday Dec 29 2014

Short term...(today through wednesday)
issued at 357 am CST Monday Dec 29 2014

Light snow today then bitterly cold temperatures remain the primary
forecast concerns.

Middle level shortwave was noted on water vapor imagery and rap
analysis spinning into the Nebraska Panhandle this morning. Wave
appears weaker than model forecasts from yesterday...however still
seeing band of light snow in weak frontogenetic zone across northern
Nebraska. Easterly track of shortwave puts northeast Nebraska in
zone of best precipitation potential through the morning...with area
slowly sinking south through the day with gradually weakening shear
axis. Moisture is somewhat limited this morning...and expect a slow
top-down saturation to occur with southward extent. But when
saturation is sufficient enough for snow...much of that moisture
will reside in dendritic temperature layer of soundings. Thus
even with weak lift expect efficient accumulation with fluffy snow
and high snow-water ratios...in the neighborhood of 17 to 1 or
higher. This puts snow amounts in the 1 to 2 inch range over our
western County Warning Area with lower amounts to the east and southeast where
moisture and lift decrease markedly.

Snow should end this evening in the south with only a gradual
decrease in clouds in the north. Very cold temperatures will follow
given very cold airmass characterized by 1052mb high pressure
sliding into the plains. Daytime temperatures in the teens and 20s
are expected to fall during the afternoon...then fall below zero for
much of the County Warning Area. Thicker clouds south may hold temperatures above
zero...and snowcover in the north will aid in plunging temperatures closer
to 10 below. Brisk north winds are also expected overnight...not
dropping below 10 miles per hour. This combination puts wind chills colder than
20 below for several hours in our northwest half. So a Wind Chill
Advisory will be posted midnight to noon there.

Little recovery expected Tuesday afternoon as cold advection
continues...with most areas in the single digits for highs. Clearing
skies Tuesday night and a period of light winds will allow temperatures to
again plunge well below zero. Our north may halt cooling after
midnight as west or southwest winds increase. However this again
puts wind chills close to or below 20 below. Will likely need
another advisory then. Southwest winds and sunshine Wednesday will
lead to a nice recovery of temperatures into the teens.

Long term...(wednesday night through sunday)
issued at 357 am CST Monday Dec 29 2014

A minor rebound in temperatures will continue into the weekend as
middle level heights rise ahead of upper low swinging through the
southwest. Models are in relatively decent agreement in timing this
low into the Southern Plains on Saturday...which is slower and
farther south than solutions from 24 hours ago. This suggests
lowering precipitation chances...especially on Friday. Will maintain
a small chance for rain or snow in the south then. Temperatures
Thursday through Saturday should approach freezing in the south with
20s north. Then colder air to follow Sunday drops temperatures back into
the teens and 20s.

&&

Aviation...(12z tafs for kofk...klnk and koma.)
Issued at 603 am CST Monday Dec 29 2014

Variable conditions across eastern Nebraska at 12z with light
snow moving into the area. MVFR conditions expected to prevail
at all 3 sites through 00z then becoming VFR with ceilings lifting
to at or above fl090 through 06z as Arctic high builds into the area.

&&

Oax watches/warnings/advisories...
NE...Wind Chill Advisory from midnight tonight to noon CST Tuesday
for nez011-012-015>018-030>034-042>044-050-051-065-078.

Iowa...Wind Chill Advisory from midnight tonight to noon CST Tuesday
for iaz043.

&&

$$

Short term...dergan
long term...dergan
aviation...fobert

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