Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 240812
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
312 AM CDT Tue Apr 24 2018

.SHORT TERM...(Today through Thursday)
Issued at 311 AM CDT Tue Apr 24 2018

A well-defined vorticity maximum over the northern High Plains
early this morning is forecast to translate south-southeast into
the NE Sandhills tonight before reaching central KS by midday
Wednesday. In the low levels, an associated surface low was located
over central SD as of 07z with a trailing cold front which extended
southwest into east-central CO. Ahead of the front and mid-level
system, mosaic radar data indicated a band of showers from central
SD into central and southwest NE.

Given an antecedent dry air mass (i.e. PW values < 0.50") in place
across the mid MO Valley, and that the primary band of forcing for
ascent will remain to our west today, it appears that the best
chance for measurable precipitation will remain across our
northwest counties at least into late afternoon. Temperatures
will range from the upper 60s to mid 70s ahead of the front to
mid to upper 50s behind it where clouds and areas of precipitation
will limit daytime heating.

By this evening into overnight, consensus of model guidance
indicates the best precipitation chances across our western
counties, decreasing with eastward extent into western IA. Rain
will be the predominant precipitation type, though a little wet
snow could mix in over far northeast NE toward daybreak
Wednesday.

On Wednesday, the precipitation should end from north to south
across the area as the stronger forcing for ascent associated with
the mid-level trough shifts to the south of the NE-KS state line.
Highs should be in the upper 50s to lower 60s.

By Thursday, another short-wave trough embedded within a
prevailing northwesterly mid-level flow regime will translate
through the area in tandem with a surface cold front. We will
indicate slight chance to low-end chance PoPs along the front with
gusty northwest winds developing within the post-frontal air
mass.

.LONG TERM...(Thursday night through Monday)
Issued at 311 AM CDT Tue Apr 24 2018

By Friday into the weekend, 00z model guidance is suggestive that
a mid-level ridge will overspread the Great Plains from the west,
supporting generally warmer and dry conditions. However, by Sunday
into Monday we begin to see dispersive model solutions with regard
to the evolution of the upper-air pattern. It does appear that we
will see an increasing chance of showers and thunderstorms during
the early to middle part of the upcoming week. However, details
remain quite uncertain at this juncture.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1142 PM CDT Mon Apr 23 2018

VFR conditions through the period with thickening cloud bases
eventually lowering 3500-6000 feet. Showers develop at KOFK by
18z, at KLNK by 20z, and KOMA by 23z. There are a couple models
that develop MVFR ceilings at KOFK by about 20z, and will
continue to monitor with the next forecast issuance.


&&

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

$$

SHORT TERM...Mead
LONG TERM...Mead
AVIATION...DeWald


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