Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 150515

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1115 PM CST Wed Feb 14 2018

.SHORT TERM...(Tonight through Saturday)
Issued at 320 PM CST Wed Feb 14 2018

A mainly dry forecast is expected into Saturday, with a cold day
Friday surrounded by milder days Thursday and Saturday.

Southerly winds and filtered sunshine helped warm temperatures well
into the 40s this afternoon, with some 50s noted in southeast
Nebraska and southwest Iowa. This has contributed to plenty of
snowmelt today, feeding moisture into boundary layer which could
mean fog potential tonight. Pressure gradient will be relaxing
overnight allowing light south or southwest winds to decrease.
However high clouds should continue streaming overhead in mainly
zonal flow regime. Thus there are competing influences regarding
fog formation tonight. Certainly patchy fog is expected over most
areas and was mentioned in our forecast, but widespread dense fog
is not expected.

A weak mid level shortwave moving into southern Minnesota this
evening will begin to nudge a cold front south overnight, then a
second wave will push front trough our area during the day Thursday.
Weak flow initially should still allow temperatures to rebound into
the 40s over the southern half of our area, but earlier arrival to
colder air in the north will keep temperatures there in the 30s.
Also, strong cold advection suggests wind speeds will increase into
the 15 to 30 mph behind the front later Thursday afternoon and
evening. The only real threat for precipitation through Saturday
will come behind this cold front Thursday afternoon as overrunning
flow over colder surface air could trigger areas of light snow in
far northeast Nebraska.

Lows of 5 to 15 will be common later Thursday night as surface high
pressure settles into the Mid Missouri River Valley bringing
clearing skies and decreasing winds.

That high slides southeast during the day Friday, bringing weak
return flow back to much of eastern Nebraska and southwest Iowa by
Friday afternoon. This won`t help much in regards to warming Friday
as mixing will remain tempered given light flow, keeping highs in
the 20s for the most part.

Strengthening southerly winds Friday night may lead to an evening
low with warming temperatures overnight. However another shortwave
will push another cold front into the region Saturday afternoon,
bringing at least a brief period of cooling then. Still expect
temperatures to rebound into the 40s in our south before cooling
arrives late in the day, with 30s in the north.

.LONG TERM...(Saturday night through Wednesday)
Issued at 320 PM CST Wed Feb 14 2018

A much cooler period is expected into the middle of next week as
Canadian air settles into the Plains and remains in place and upper
air pattern favors troughing in the middle of the CONUS.

Sunday should be the last potentially mild day as south winds ahead
of a strong shortwave pump warmer air into our region. Behind the
shortwave, a strong cold front will usher in that Canadian air
Sunday night and Monday, with lower height regime under mid level
trough spreading into the Plains through mid week. Thus after
temperatures in the 40s or even 50s Sunday, we switch to below
normal Monday through Wednesday when highs in the 20s will be common.

Best chance for precipitation will come with initial cold front
Sunday night and Monday. A wintry mix or even all rain is likely in
our southeast Sunday night until colder air overspreads that area on
Monday. Otherwise a good chance for light snow across the CWA is
forecast as mid level flow overrides colder surface air behind
front. A similar situation continues through the week when impulses
riding through mid level flow produce episodic chances for light
snow. However still not seeing any major snow outbreaks through


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1115 PM CST Wed Feb 14 2018

Expect considerable mid or high level clouds into Thursday
morning along with some fog. Visibilities as of 11 pm local time
were mainly in the 5 to 10 mile range with a few locations down to
near 2.5 miles. Expect that toward morning we could see some IFR
visibilities to 3 miles or less at KOMA and KLNK. North winds will
increase Thursday, which should cause the fog to diminish. Winds
increase more from the north/northwest in the afternoon as colder
air pushes in. There should also be some MVFR ceilings, mainly in
the late afternoon and evening.




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