Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
000
FXUS63 KOAX 251651
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1151 AM CDT Mon Sep 25 2017

.UPDATE...
Issued at 1150 AM CDT Mon Sep 25 2017

Made a few adjustments to temperatures, winds and rain chances
through the afternoon. Lift is somewhat being enhanced in the
elevated frontal zone due to the right entrance region of a jet
streak at 300 mb which extends from western SD into western
Ontario Canada. Expect that precipitation will fill in across
southwest IA and far southeast NE as the front settles to the
southeast.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 329 AM CDT Mon Sep 25 2017

Slow-moving front and associated precipitation have arrived.
Subjective 00Z upper-air analysis indicates an upper-level low
centered near the UT-WY border, with upper-level ridging dominating
the eastern half of the CONUS (along with Maria centered well off
the coast of the Carolinas). A 110kt upper-level jet streak was
noted ahead of the trough from western NE into the central Dakotas.
An 850mb high was centered around Lake Erie, with an ill-defined
trough from around western ON toward CO/NM. A front was evident from
the weak low in western ON through eastern SD and northeast to
central NE, then toward western KS and eastern NM. A surface low was
centered in western ON, with a secondary low in northeast NM, and a
front between through MN to western IA to southeast NE through KS
toward the secondary low.

Main forecast concern is persistent rain and isolated thunderstorms
today and tonight, tapering off tonight into Wednesday. Western US
low will eject northeastward through the Dakotas through Tuesday,
leaving troughing in the southwestern US. Front will linger through
today and tonight, with a distinct band of mid-level frontogenesis
and instability above the frontogenetic layer lingering through
Tuesday morning as it slowly slides eastward through the area. In
short, persistent forcing for ascent should continue to drive waves
of rain through Tuesday, tapering from northwest to southeast
through the day. MUCAPE is weak, but there is enough to support at
least an isolated embedded thunderstorm today and perhaps tonight.
By Tuesday, instability is virtually nil, and thunder threat
likewise should be nil. Temperatures today will change little from
morning readings, but did give a slight bump in the afternoon.
Temperatures on Tuesday will remain cool, with highs in the 60s.

In wake of the slow-moving system, high pressure will linger for
several days as an upper-level ridge lingers between the ejecting
low/trough and the western US low, but temperatures will remain on
the cool side as 850mb temperatures linger in the upper single
digits to low teens.

.LONG TERM...(Wednesday night through Sunday)
Issued at 329 AM CDT Mon Sep 25 2017

Cooler temperatures will continue through next weekend, with an
upper-level trough digging into the Great Lakes by late week and
providing a reinforcing push of cooler air into the north central
US. As the surface ridge slowly slides eastward, return flow should
bring moisture back into the central Plains over the weekend, along
with chances for showers and thunderstorms as the western US trough
slowly emerges toward the Plains.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1150 AM CDT Mon Sep 25 2017

Expect mainly IFR conditions at all three sites, with some TEMPO
MVFR conditions. SHRA with some embedded TSRA will make for a
messy TAF forecast the next few cycles. Conditions should improve
at KOFK toward 18Z Tuesday, but probably closer to 00Z Wednesday
for KOMA and KLNK.

&&

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

$$

UPDATE...Miller
SHORT TERM...Mayes
LONG TERM...Mayes
AVIATION...Miller



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.