843
FXUS63 KOAX 171106
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
606 AM CDT Mon Aug 17 2026

.KEY MESSAGES...

- Strong to severe thunderstorms are expected Monday
  evening/night with hail, damaging winds, heavy rain, and a few
  isolated tornadoes possible.

- Strong to severe thunderstorms are expected Tuesday afternoon
  and evening. Damaging winds, large hail, a few isolated
  tornadoes, and flash flooding will be possible with any storms
  that develop.

- Cooler temperatures return to the forecast Wednesday, with a
  gradual warming trend expected heading into the weekend. Periodic
  chances for showers/storms are expected Wednesday through
  Friday.

&&

.DISCUSSION...
Issued at 1130 PM CDT Sun Aug 16 2026

The forecast period begins with a mid-level ridge over the Rockies
and northwest flow over the Great Plains. Clouds have cleared out
over most of eastern Nebraska/western Iowa this evening. With calm
to fairly light winds and cooling temperatures, fog development will
be possible, particularly for areas along the Missouri River and the
Iowa/Missouri border. A few models have been trying to bring some
fog as far west as Lancaster and Gage counties for a few hours
Monday morning. A few areas may have visibility reductions to 1 mile
or less for a few hours around sunrise.

A few isolated thunderstorms are expected to develop across southern
South Dakota overnight, dropping into eastern Nebraska by sunrise
Monday morning. A few areas may wake up to some showers or weak
storms moving through. High temperatures will reach the upper 70s to
upper 80s across the region. A shortwave trough will move into the
region Monday afternoon, bringing some chances for showers and
storms. Moving into a decent environment, this first potential wave
of storms will have the potential of becoming strong to severe. The
main hazards with any storms that are able to strengthen would be
large hail, strong winds, and heavy rainfall which may result in
localized flash flooding, particularly for areas that have already
had decent rainfall over the past few days. An isolated tornado risk
cannot be entirely ruled out. A second wave of thunderstorm activity
will be possible after midnight Monday night/Tuesday morning. With
the earlier convection and a more stable environment, the
possibility for severe weather will go down some with this later
wave of storms.

Surface low pressure develops over the Central High Plains on
Tuesday and a slow moving cold front arrives in northern Nebraska
and Iowa. Expect some slightly cooler temperatures near the NE/SD
border, ranging from the mid-70s to low 80s for highs. Areas further
south will top out in the low to mid-80s. Moisture will be moving
into the region and destabilization is expected over southeastern
Nebraska/southwestern Iowa during the afternoon. Strong to severe
thunderstorms are expected Tuesday afternoon and evening across the
entire Omaha CWA, with large hail, damaging winds, and a few
isolated tornadoes all possible. Precipitable water values of 1.5-
2.0" are expected as well. Heavy rainfall with any storms may result
in some localized flash flooding. Several areas across the region
have already received quite a bit of rainfall over the past few days
and may therefore be more prone to flooding with any additional
heavy rainfall.

An amplifying ridge over the western CONUS will send a series of
weak shortwaves through the Great Plains Wednesday through Friday.
This will bring periodic chances (30-60% Wednesday; 20-30% Thursday
and Friday) for showers and storms to the region. Wednesday high
temperatures will be fairly nice for August standards, reaching the
mid-70s to low 80s. Typical highs for eastern Nebraska/western Iowa
are in the mid-80s. Expect a gradual warming through Friday with
highs returning to the low to mid-80s.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 606 AM CDT Mon Aug 17 2026

A few showers and storms will continue southeast early in the
period, but guidance suggests they should taper off prior to
reaching OMA. Latest guidance has also trended toward lower
storm chances this afternoon/evening, so no longer including
mention at OFK, though still can`t completely rule out something
popping up around 00-04Z. Higher storm chances now look to
arrive overnight, likely after 08Z at OFK and around or after
12Z at OMA and LNK, with potential for 40-50+ kt gusts and hail
in the strongest storms. Otherwise, could see some patchy fog
early in the period, with VFR conditions favored thereafter
outside of storms. Southerly to southwesterly winds should
remain under 10 kts with some 5000-7000 ft clouds through much
of the day.

&&

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

&&

$$

DISCUSSION...ANW
AVIATION...CA