Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 152312

Area Forecast Discussion
National Weather Service Omaha/Valley NE
612 PM CDT Sat Jul 15 2017

.SHORT TERM...(Tonight through Tuesday)
Issued at 305 PM CDT Sat Jul 15 2017

Temperatures will provide the main forecast challenges into Monday
then will have to look at precipitation chances for our area.

Pattern is still very similar to 24 hours ago, with a large mid
and upper tropospheric ridge over the Rockies extending out into
the western Plains. Closed low at 500 mb over CO shows up quite
nicely in water vapor imagery. Some thunderstorms noted at mid
afternoon over parts of eastern CO, western KS and southwest NE.
700 mb temperatures in this area were a little cooler (from KDEN
to KLBF) compared to areas farther to the west, north and east.
At the surface, synoptic scale cold front was pushing south toward
our area. There was another weak boundary that extended from the
southwest corner of SD into north central NE. ESRL HRRR keeps most
of the activity out over western and parts of central NE into at
least early Sunday afternoon, so will keep the forecast dry for
now. Look for lows tonight in the upper 60s to around 70.

On Sunday, that weak front should start to lift north, but it
doesn`t look like convergence will be strong enough to generate
any precipitation. Look for highs in the lower and mid 90s. A low
pressure system and cold front should move into the western
Dakotas Sunday night, with southerly low level in our area
increasing a bit. The result will be lows in the upper 60s and
lower 70s. Surface pressure gradient and low level winds will be
increasing a bit more on Monday, and the closed low that is to our
west today should be moving slowly east but as more of an open
wave. The front could stay to our south, but the combination of a
few different factors may be enough to trigger some showers and
thunderstorms in our area, especially by Monday night. The GFS in
general seems to have been too aggressive with development of
precipitation in our area Monday/Tuesday, but will keep at least
some low POPs going. Airmass does not change a lot, so will keep
highs Monday (and Tuesday) in the lower and mid 90s.

.LONG TERM...(Tuesday night through Saturday)
Issued at 305 PM CDT Sat Jul 15 2017

At the start of this period, a 500 mb ridge should stretch from UT
and CO eastward into MO and AR. There will be a weak Rex block off
the coast of western Canada with the southern branch of polar
jetstream from the Pacific northwest across the northern Plains
and into Ontario Canada. We will probably be on the northern
edge of a hot airmass centered to our south across KS and OK. Some
intermittent low thunderstorm chances are expected, mainly Tuesday
night and then Thursday night into Friday.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 610 PM CDT Sat Jul 15 2017

VFR conditions are forecast through Sunday evening. Mainly
scattered mid and high clouds are expected overnight, then maybe
scattered cumulus between FL050 and FL070 Sunday afternoon.




LONG TERM...Miller
AVIATION...Dergan is the U.S. government's official web portal to all federal, state and local government web resources and services.