868
FXUS63 KOAX 181106
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
606 AM CDT Tue Aug 18 2026

.KEY MESSAGES...

- Strong to severe thunderstorms are expected tonight into
  early Tuesday afternoon. Large hail, damaging winds, heavy
  rain, and an isolated tornado are potential hazards.

- Cooler temperatures arrive behind a cold front on Tuesday
  and Wednesday. Lingering showers and thunderstorms are
  anticipated with a low chance of a strong to severe
  thunderstorms.

- A warming trend begins on Thursday with temperatures gradually
  increasing into the 80s. Periodic rain chances remain in the
  forecast.

&&

.DISCUSSION...
Issued at 1250 AM CDT Tue Aug 18 2026

Widespread strong to severe thunderstorms have developed across
western South Dakota and Nebraska. Closer to our area, a few
relatively isolated severe thunderstorms have formed in a weak
confluence zone over northeast Nebraska. All this activity is
expected to spread east through the remainder of the evening into at
least early Tuesday afternoon as multiple rounds of thunderstorms.
This broad area of strong to severe weather is associated with a
weak upper-level trough moving across the northern Plains and a weak
cold front draped over the region. These features are helping to
initiate widespread activity over a seasonably unstable airmass. In
addition, stronger westerly and northwesterly upper-level winds have
begun to overspread the area helping to increase effective wind
shear to between 40-50 kts. The combination of all these factors is
resulting in a combined threat of large hail, damaging winds, heavy
rain, and perhaps a tornado or two.

Heading into Tuesday, a combination of the cold front and outflow
behind late morning and early afternoon thunderstorms should limit
the amount of additional thunderstorms later Tuesday afternoon. That
said, areas of far southeast Nebraska nearest the cold front may see
additional afternoon thunderstorms by afternoon. At least some risk
of severe weather is expected with this activity. Further to the
north, a cooler and more stable airmass should limit additional
thunderstorm development. A few showers and thunderstorms may linger
despite this. The severe weather threat with this activity will be
comparatively lower. Otherwise, cooler temperatures begin to filter
into the region behind the front, bringing afternoon highs in the
70s for many.

Wednesday sees temperatures in the 70s once again. Our next weather
system begins to push into the northern Plains by Wednesday
afternoon. Initial thunderstorms development is expected to the west
of the region, but this is forecast to spread east into our area by
Wednesday evening into the overnight hours. Severe weather may again
be a potential hazard with this activity, but this threat is low
currently.

Heading into Thursday and beyond, a gradual warming trend begins.
Afternoon high temperatures return to the 80s. The broad pattern
across the northern Plains does not change substantially during this
time, This will result in continued periodic rain chances for the
region with steady temperatures.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 606 AM CDT Tue Aug 18 2026

Thunderstorms will continue to push through the area this
morning, with occasional MVFR to IFR conditions and periods of
gusty winds. Some additional development is possible this
afternoon/evening, but latest guidance suggests highest chances
will be southeast of the TAF sites. Still some questions on
ceilings following the main storms this morning, with some
guidance hinting at lingering MVFR ceilings, but for now kept
VFR. Winds will also be somewhat variable and turning through
the day, but should generally remain light outside of storms.
Eventually expect northerly to northeasterly by late
afternoon/evening.

&&

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

&&

$$

DISCUSSION...Chehak
AVIATION...CA