Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 181750
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1150 AM CST Sat Nov 18 2017

.SHORT TERM...(Today through Monday)
Issued at 255 AM CST Sat Nov 18 2017

Precipitation ending this morning, cloud cover today and
temperatures the next few days will provide the main forecast
challenges.

Two main jet segments were noted at 00Z on the 300 mb chart. One
extended from ND into northern MN (120-125 knots) and another was
punching east from CO. At 500 mb, strongest height falls were over
Ontario Canada, but values of 50 meters or more extended down as
far as NM and north TX. Modest thermal gradient was in place at
700 mb, and upper level dynamics were acting on this to produce
mid level frontogenesis. At the surface, low pressure was over
eastern KS, while a cold front trailed from near Chicago to near
Kansas City and then to north of Amarillo.

A couple of frontogenetically forced bands of precipitation have
affect then area, and as of around 215 am the most prominent band
stretched from around Grand Island to Wahoo, Omaha and Harlan
Iowa. Heaviest precipitation should be along and south of
Interstate 80 through mid morning, decreasing from north to south
with time. Snow accumulations do not seem likely, although there
will probably be a rain/snow mix at times. Some low level clouds
may linger well behind the precipitation shield, as noted by
recent RAP model output. Expect sunny to partly cloudy skies by
the afternoon for most of the forecast area.

North/northwest winds will be somewhat gusty today, but will
decrease this evening. Tonight, winds turn more to the west as
surface ridge axis builds east across the region. Lows should drop
into the lower and mid 20s, despite weak warm air advection late
tonight. Look for dry conditions Sunday and Monday with highs in
mostly in the lower and mid 50s Sunday, then mid to upper 50s on
Monday.

.LONG TERM...(Monday night through Friday)
Issued at 255 AM CST Sat Nov 18 2017

A mainly dry pattern is forecast through the week, with models in
good agreement that a 500 mb ridge will build over the Rockies.
There are some weak signals for light precipitation from both
the 00Z runs of the GFS and ECMWF by Friday night into Saturday.
That will be associated with a trough moving across the region
from the northwest.

Tuesday and Wednesday will be noticeably cooler than Monday.
Thursday and Friday expect highs mainly in the 50s, with some
lower 60s possible Friday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1150 AM CST Sat Nov 18 2017

VFR conditions will prevail through most of the period with
northwest winds diminishing by 00Z. High pressure will build into
the area overnight with winds becoming light. A period of MVFR
cigs is possible through 22Z as area of low level moisture over
southeast South Dakota drops southeast this afternoon.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&

$$

SHORT TERM...Miller
LONG TERM...Miller
AVIATION...Fobert


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