Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 242009
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
309 PM CDT SUN JUL 24 2016

.SHORT TERM...(tonight through Wednesday)
Issued at 309 PM CDT Sun Jul 24 2016

Heat has finally broken, with temperatures closer to normal for
several days to come.  Subjective 12Z upper air analysis indicates a
flattening upper-level pattern across the CONUS, with embedded
shortwave troughs over ME, the norhtern Great Lakes, and the
Rockies.  An 850-mb trough extended from western ON through
WI/IA/KS, with moisture pooled along and ahead of the trough. Behind
it, drier air was advecting into the Plains.  Surface high at 19Z
was centered in southern to western SD.

Main forecast concern is potential for showers/storms on Tuesday
through Wednesday.  In the meantime, as showers in southeastern SD
and southeast NE/northeast KS move eastward, dry air should dominate
in their wake at least through Monday.  Showers/storms in northeast
KS tonight into Monday morning could skim southeasternmost NE, but
have leaned dry for now as drier air continues to filter into the
area, with most models keeping all precip south of the border.
Surface high pressure should slide through the area tonight into
Monday, with moisture returning around its base into western/central
NE on Monday night.  Have kept precip out of all but the extreme
northwestern CWA, under the moisture axis, before 12Z Tuesday.

Solutions diverge on Tuesday regarding the potential evolution of
convection in the Dakotas from Monday night into Tuesday morning, as
well as on convective development on Tuesday afternoon and its
evolution on Tuesday night.  The more aggressive GFS brings
widespread convection and possibly heavy rain to northeast NE on
Tuesday evening/night, but ECMWF keeps convection further west and
saves widespread convection for Wednesday.  NAM brings convection on
Tuesday evening/night, as well, but in a smaller and faster-moving
batch that just skims eastern NE.  Given uncertainties in evolution,
did remove mention of heavy rain in the grids, as I am just not that
comfortable getting specific about location and timing of any threat
at this point. POPs range from chance to likely from Tuesday evening
through Wednesday, but even so, confidence is on the low side.  Did
nudge temperatures downward a bit both Tuesday and Wednesdawy with
potential for clouds and remnant/ongoing convection.

.LONG TERM...(Wednesday night through Sunday)
Issued at 309 PM CDT Sun Jul 24 2016

A largely unsettled pattern will continue through the weekend.  It
isn`t likely to be a washout, but with northwesterly upper-level
flow, periodic shortwaves and associated showers/storms are possible
through the period.  Did try to tweak blend POPs at least down to
slight chances in periods with less consensus on precipitation in
the area, but confidence is low throughout the period.  Temperatures
should remain near to below normal.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1207 PM CDT Sun Jul 24 2016

Current water vapor imagery indicates a couple of mid-level
impulses which have contributed to increasing mid and high-level
cloudiness across the region today. One feature was tracking
east-northeast along the Nebraska-Kansas border southwest of KLNK,
and the other was lifting northeast through north-central Nebraska
and south-central South Dakota. Both disturbances are producing
showery precipitation, which will likely remain to the south of
KLNK and to the north of KOFK. Some FL070-080 ceilings have been
observed over south-central into southeast Nebraska, though
prevailing FL100-130 ceilings will be most probable at KLNK this
afternoon before clouds begin to diminish later this evening. At
KOMA and KOFK, brief periods of ceilings generally above FL140
will exist this afternoon.


&&

.OAX Watches/Warnings/Advisories...
NE...None.
IA...None.
&&

$$

SHORT TERM...Mayes
LONG TERM...Mayes
AVIATION...Mead


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