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Area forecast discussion
National Weather Service Omaha/valley NE
1127 PM CST Mon Nov 11 2019

..updated aviation forecast discussion...

Discussion...
issued at 230 PM CST Mon Nov 11 2019

At 2 PM, it was cold cold cold, with temperatures in the teens and
low 20s across the region. Winds were breezy out of the north (peak
gusts 20 to 30 mph), pushing afternoon wind chills into the -5 to
10 degree range. A few light flurries were reported over the
region this afternoon, but they were far to light and brief for
any accumulations. Light snow accumulations from last night and
this morning were evident on visible satellite imagery over the
majority of Nebraska and Iowa. Snow reports generally ranged from
half an inch to two inches, with a peak report of 2.8 inches in
Norfolk. Though, it should be noted that all snow measurements
this morning were a challenge because of the light and fluffy
nature of the snow and how much it blew around. Thanks to all
those who submitted reports!

The main forecast story remains the Arctic air mass over the
region. This will be especially noteworthy tonight as the Arctic
high (surface high) settles over the Central Plains, bringing
clear skies and lighter winds. Combine this with light snow cover
on the grounds and we have a primo setup for radiational cooling
between midnight and 6 am. Due to these expected conditions, went
ahead and adjusted tonights low temperatures downward, to several
degrees below model guidance. The going forecast now favors
temperatures in the -5 to 5 degree range over most of the region
by sunrise Tuesday. Overnight lows could threaten record lows,
although forecaster confidence in records falling is only around
35% (record lows for November 12th: Omaha 1 in 1911, Lincoln 2 in
1911, & Norfolk -3 in 1911). Evidently November 12th, 1911 was a
real Downer.

Temperatures will remain chilly Tuesday (~20 degrees below
seasonal averages), despite the return of breezy southerly winds
as the Arctic high shifts to our south and east. This should
result in another period of sub zero wind chills tomorrow morning,
with recovery only into the teens Tuesday afternoon. Peak wind
gusts of 30 to 35 mph are possible between 11 am and 4 PM
(isolated gusts to 45 possible in northeast nebraska). At this
time a Wind Advisory isn't in the cards, the evening shift can
reevaluate.

On Wednesday, the next shortwave trough and associated cold front
will make there way through the plains. Guidance continues to
indicate some potential for a light rain/snow mix with this
system as it visits our neck of the Woods. Confidence is high that
any precipitation will be less than a quarter inch. The best
precipitation chances are anticipated between 6 am and 6 PM.

Beyond Wednesday, temperatures should trend closer to average
values for this time of year as weak upper level ridging
develops. Looks like high temperatures in the 50s may make a
comeback for some by Friday and Saturday. Another upper level
trough may produce some light precipitation late Saturday into
Sunday. Otherwise, dry and non hazardous weather is expected
Thursday through Sunday.

&&

Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 1126 PM CST Mon Nov 11 2019

Clear skies and light winds generally from the northwest to
southwest will continue through mid Tuesday morning. Southerly
winds 15 to 25kt are expected after 15z and will likely continue
through the end of the taf period. Mainly clear skies are
forecast through the period.

&&

Oax watches/warnings/advisories...
NE...none.
Iowa...none.
&&

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