Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 172120

Area Forecast Discussion
National Weather Service Omaha/Valley NE
320 PM CST Wed Jan 17 2018

.SHORT TERM...(Tonight through Saturday)
Issued at 253 PM CST Wed Jan 17 2018

A significant warning trend will continue through the short term
with benign weather and zonal flow developing aloft. Quit dry
weather the next three days, with highs in the mid 30s to upper
40s on Thursday, then into the upper 40s to mid 50s for Friday. A
weak cool front does edge into the area Friday night, but moisture
is quite limited, although the Nam hints at some spotty precip,
but other models remain dry. Saturday will be slightly cooler than
Friday, but still pretty decent with highs in the lower to mid 40s.

.LONG TERM...(Saturday night through Wednesday)
Issued at 253 PM CST Wed Jan 17 2018

...Potential Winter Storm to Affect the Area Sunday into Monday...

Main focus remains a potential winter storm that should affect
the region Sunday into Monday. Models are still focusing on the
low that is currently west of the British Columbia Coast that
eventually sends a strong trough into the Pacific Northwest, which
then eventually closes off across the central Rockies and onto the
Plains late in the weekend. Seeing good model continuity overall
between the GFS and ECWMF initially, but those difference become
magnified through Monday as the low ejects through the mid
Missouri Valley region.

Ahead of the low, low level moisture will be drawn northward,
with rain or snow showers Sunday, but then changing to snow
behind the system, which lingers through early Monday. The
eventual track of the storm system will have a big impact on snow
amounts, and not surprisingly, we are still seeing a very wide
spread among GEFS members. Operational GFS would support a swath
of 6-10" of snow from central through northeast NE into northwest
IA and MN. ECMWF would also support a band of 6-10", but displaced
eastward by 100 miles in some instances. The 21 GEFS members are
quite variable narrowing down the snow band. So while confidence
may be increasing of a heavy snow band somewhere within our
forecast area Sunday night into Monday, it`s still 4 1/2 days
away and a lot of uncertainty remains. It also remains well outside
our snow forecasting window of 84 hours.

It does not look like another arctic surge will accompany this
storm. However, can`t say the same for the wind, blowing snow
looks increasing likely as northwest winds increase to 20 to 30
mph as the colder air moves in. The bulk of the measurable
precipitation should be over by 6 am Monday, but there may still
be a few lingering flurries and areas of blowing snow Monday,
while we dig out from whatever occurs Sunday night.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1121 AM CST Wed Jan 17 2018

VFR conditions through the period. Southwest winds around 12
knots through 00z, but lower beyond then.




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