Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 122336

Area Forecast Discussion
National Weather Service Omaha/Valley NE
636 PM CDT Thu Oct 12 2017

.SHORT TERM...(Tonight through Sunday)
Issued at 311 PM CDT Thu Oct 12 2017

A shortwave trough over the northern High Plains this afternoon
will continue northeast into Ontario tonight while the associated
surface cold front advances through all but far southeast NE and
southwest IA by 12z Friday. The front will slowly settle south
into KS and northwest MO on Friday with a wave rippling northeast
along the boundary during the day. This cyclone is apparently
associated with a low-amplitude perturbation translating through
the mid-MO Valley, embedded within a prevailing southwesterly
mid-level flow regime. Forecast soundings across central and
southern parts of the forecast area indicate a gradual "bottom-up"
saturation within the post-frontal air mass with slight-chance
PoPs warranted during the day. Cloudiness will temper daytime
heating with highs mainly in the 60s.

Friday night into Saturday night, 12z deterministic guidance
remains consistent in suggesting that a potent shortwave trough
will track from the Interior West into the Great Plains. This
disturbance will induce a deepening frontal wave which will
develop from central KS Saturday morning to southwest WI by
Saturday evening. Increased forcing for ascent and destabilization
ahead of the shortwave trough and surface cyclone will foster a
growing shield of showers and thunderstorms late Friday night into
Saturday across the southern half of the forecast area.

It remains unclear what impact the early-day storms will have on
how far north the surface warm sector can develop into southeast
NE and southwest IA on Saturday. Nonetheless, it does appear that
there will be some potential for a few severe storms and
localized flooding over the southern CWA Saturday afternoon into
evening. Highs on Saturday will range from around 60 near the SD
border to lower to mid 70s over far southeast NE and southwest IA.

Blustery northwest winds are expected to materialize Saturday
night on the backside of the surface cyclone with precipitation
chances diminishing from northwest to southeast.

Sunday will be cooler (i.e. highs in the mid to upper 50s) owing
to the passage of a deep-layer thermal trough through the mid-MO

.LONG TERM...(Sunday night through Thursday)
Issued at 311 PM CDT Thu Oct 12 2017

Latest medium-range guidance continues to advertise west-northwest
flow aloft across the north-central States early next week; to
the north of a subtropical ridge nosing through the Desert
Southwest. By the middle to latter part of the work week,
the spread in model solutions grows. In aggregate, these data
suggest a transition to zonal and then southwest mid-level flow
during that time frame. This translates to a seasonably warm and
dry forecast.


.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 631 PM CDT Thu Oct 12 2017

MVFR cigs are forecast to develop behind a cold front drifting
southeast into eastern Nebraska later tonight and Friday morning.
Winds will turn from southeast to northeast behind the front, with
arrival at KOFK around 05Z, then KLNK and KOMA by 09Z. Cigs
between FL015 and FL025 are expected between by 12Z at KLNK and
KOMA by 15Z. Some improvement to VFR is possible by late in the
TAF cycle. Also, there is a small chance for showers at KLNK and
KOMA between 09Z and 15Z, but coverage is expected to be isolated.




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