Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 221739
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1239 PM CDT Mon Apr 22 2019

.SHORT TERM...(Today through Wednesday)
Issued at 401 AM CDT Mon Apr 22 2019

Scattered showers and cooler temperatures today, then a warming
trend through mid week, are the main highlights of the forecast.

Mid level shortwave that ejected from main low in the Southwest
CONUS was moving across eastern Nebraska this morning, and will
move into central Iowa by mid day. Attendant surface low was
analyzed south of Columbus Nebraska as of 3 AM, with a wavy
frontal boundary extending from northwest Iowa into south central
Nebraska. Also of note was a couple of mesoscale convective
vortices shown in radar data, one in southeast South Dakota and
one in east central Nebraska. Both of these features contributed
to enhancing convection in central and eastern Nebraska Sunday
evening as they drifted northeast across the region. Northern MCV
was still enhancing thunderstorm activity in eastern South Dakota
and southwest Minnesota as of 3 AM, while convection in eastern
Nebraska has been on a downward trend this morning but scattered
showers were still being generated.

As shortwave and surface low move east this morning, scattered
showers are still possible over much of eastern Nebraska and
southwest Iowa. Strong northwest low level winds will follow these
features, and we were already seeing winds gusting 25 to 30kt in
parts of central Nebraska behind surface low and cold front. Also,
extensive cloud cover was noted through all of South Dakota, and
will be sinking southeast in wake of surface low. Thus with lack
of sunshine and cold advection, should not see much rebound in
temperatures today, with highs generally from the mid 50s north to
mid 60s south.

High pressure settling into the region behind exiting system will
bring clearing skies later tonight and Tuesday. Lows could fall into
the middle 30s in northeast Nebraska where some frost may result. A
quick rebound of temperatures back into the 60s is expected Tuesday
afternoon under full sunshine and light winds.

Southwest low level flow on back side of retreating high pressure
Wednesday combined with plenty of sun should push highs into the 70s.

.LONG TERM...(Wednesday night through Sunday)
Issued at 401 AM CDT Mon Apr 22 2019

A mainly dry forecast remains for Thursday before shower and
thunderstorm chances return Friday into early Saturday. Upper low
in the Southwest CONUS is forecast to track across the Southern
Plains into the Southeast from Wednesday night into Thursday
night, leaving Nebraska and Iowa in light west to northwest mid
level flow on southern edge of westerlies extending from the
Pacific Northwest into the Great Lakes. A shortwave racing through
those westerlies may trigger a scattered shower in northeast
Nebraska late Wednesday night, but most of our area will remain
dry with temperatures holding in the 70s Thursday as heights make
a brief attempt at building into the Plains. That effort will be
thwarted quickly as a stronger shortwave approaches on Friday.
Increasing clouds and perhaps elevated showers are expected during
the day Friday as mid level theta-e advection gets underway. A
better chance for convection is forecast Friday night with
isentropic upglide maximized in eastern Nebraska as a 50kt low
level jet develops. Surface frontal system is scheduled into the
area toward sunrise Saturday enhancing convective potential before
exiting to the east by Saturday afternoon. Somewhat cooler but
dry conditions will follow for Sunday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1229 PM CDT Mon Apr 22 2019

Latest obs showing MVFR cigs prevailing across ERN NE on the
backside of exiting system in addition to stout NWLY winds. Given
model guidance, as well as satl trends the last several hours,
expect improvement from MVFR to VFR will take place in the early
evening at KOFK, mid evening at KLNK, and toward midnight at KOMA.
surface winds though should be subsiding by early evening at all
terminals.

&&

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

$$

SHORT TERM...Dergan
LONG TERM...Dergan
AVIATION...DEE


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