Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 051115

Area Forecast Discussion
National Weather Service Omaha/Valley NE
515 AM CST Mon Dec 5 2016

.SHORT TERM...(today through Wednesday)
Issued at 244 AM CST Mon Dec 5 2016

Latest water vapor imagery in combination with RAP 500mb analysis
shows fast and nearly zonal flow over the region with a potent shortwave
trough digging across north central Montana. At the surface, a
broad area of low pressure over the northern High Plains continues
to move east ahead of the upper shortwave. All eyes are on
associated cold front behind this system which will be our biggest weather
story of the week.

For today, strong southwesterly 850mb flow ahead of the previously
mentioned system should allow highs to warm into the upper 40s to
lower 50s despite increasing cloud cover. The front will drop through
the Dakotas today, reaching our northwestern counties by mid/late
afternoon. A few scattered sprinkles/flurries across our
northeastern CWA can`t be ruled out as the front dives into the
region with gusty northwest winds behind the front. The above
mentioned shortwave trough will deepen and close as it moves
across the Northern Plains allowing continued cold air advection
to ooze south into the Central Plains.

A quick moving shortwave currently off the Pacific Northwest coast
will drop southeast toward the forecast area late Tuesday into
Wednesday. Model guidance continues to vary in regards to whether
the strongest associated forcing for ascent occurs primarily over
Kansas like the GFS and NAM or near the KS/NE border like the
ECMWF. Our model blends continue to go with a middle of the
road solution but confidence in any snowfall north of I-80 is
fairly low. Storm total snowfall grids give the KS/NE border
the highest accumulations of around an inch. The anticipated strong
Arctic surge will follow this trough into the end of the week
as a 1040mb surface high builds in from the Northern Plains.

.LONG TERM...(Wednesday night through Sunday)
Issued at 244 AM CST Mon Dec 5 2016

First Arctic airmass of the season lingers over the area through
Thursday with the high pressure ridge overhead by Friday morning,
This should be our coldest morning of the season with lows dropping
into the single digits for all areas. Strong return flow will set
up by early Friday bringing strong warm air advection into the
region. The models diverge again with the GFS developing pcpn
across the area near a strong warm front while the ECMWF keeps
this frontal boundary north of us. Forecast blends put some small
pops in our northern counties which seems reasonable at this
point. Temperatures over the weekend will be closer to normal with
highs in the low 30s and lows in the low 20s.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 513 AM CST Mon Dec 5 2016

VFR conditions through the period. There will be some low level
wind shear early in the TAF period with winds at 2000 feet around
40 knots from 210-220 degrees. This should diminish by 15-16z.
Otherwise, south-southwest winds, that eventually become northwest
by 22-02z.




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