664
FXUS63 KOAX 020818
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
318 AM CDT Tue Sep 2 2025

.KEY MESSAGES...

- Flooding is expected to continue today along stretches of Wahoo
  Creek and the Big Blue River.

- Areas of dense fog will linger until around 10 AM before dissipating.

- Unseasonably cool weather will continue into early next week,
  with a few chances for showers/storms.


&&

.DISCUSSION...
Issued at 318 AM CDT Tue Sep 2 2025

Early this morning through Wednesday:

Surface high pressure centered over the area early this morning is
creating conditions favorable for fog development, with several
locations already reporting visibilities of a 1/4 mile or less. As
such, a Dense Fog Advisory has been issued until 10 AM for portions
of eastern NE. An eventual expansion into southwest IA is possible
prior to sunrise if conditions warrant. The fog and clouds will
diminish this morning, with warmer afternoon temperatures in
the mid to upper 70s forecast.

A strong shortwave trough will dive south into the upper MS Valley
and upper Great Lakes tonight into Wednesday, with an associated
surface cold front moving through our area on Wednesday morning. A
couple strong storms are possible along the front in eastern SD and
southwest MN late this afternoon into tonight, with the CAMs
suggesting that activity may dissipate before reaching our area. As
such, this forecast update will indicate sub-15% PoPs through
much of tonight.

Better shower and thunderstorm chances (30-50% PoPs) will exist on
Wednesday, in tandem with the deeper frontal surge. A few strong
storms will again be possible during the peak of the diurnal heating
cycle on Wednesday afternoon, but by that time, the front is
expected to have slipped just to the south of our area. Precipitation
amounts should be light and generally less than 0.25", so no
additional flooding is expected. In addition to the rain chances,
the models indicate increasing near-ground, wildfire smoke
concentrations filtering into the area behind the front, which
could affect sensitive groups.

Highs on Wednesday will range from the mid to upper 60s in northeast
NE and west-central IA, to mid 70s along the KS and MO borders.


Thursday and Friday:

Another potent shortwave trough is forecast to move through the
northern Plains and upper Midwest on Thursday night into Friday,
with the attendant surface front traversing our area on
Thursday night. A strengthening warm advection regime ahead of
the front will support highs mainly in the 70s on Thursday, with
widely scattered showers and thunderstorms possible (15-25%
PoPs) with the passage of the front Thursday night. Surface
high pressure will build into the area on Friday, with highs in
the 60s.


Saturday through Monday:

Longwave troughing present east of the Rockies Friday morning is
forecast to deamplify over the weekend, with model guidance
indicating the movement of a lower-latitude disturbance through the
central and southern Plains on Sunday into Monday. There are model
differences in the amplitude of that feature, with some
solutions indicating increased rain chances across at least the
southern part of our area during that timeframe. This forecast
update will indicate sub-15% PoPs on Sunday, which increase to
15-30% on Monday morning.

High temperatures will remain below normal for this time of
year, with readings in the 60s to low 70s.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1143 PM CDT Mon Sep 1 2025

Fog has started to develop and will continue to overspread much
of the area overnight. Biggest questions will be exact timing
and southern extent of the lowest visibility, but we`ve seen
development earlier than guidance has depicted and clouds have
cleared out a little faster than expected. Therefore, expect fog
at all sites with OMA and OFK more likely to see LIFR
conditions. Fog is expected to dissipate by 14-15Z with some
scattered clouds around 2000-4000 ft lingering through the day.
Winds should largely remain under 5 kts, settling in at
southwesterly through the day on Tuesday.

&&

.HYDROLOGY...
Issued at 318 AM CDT Tue Sep 2 2025

Minor to moderate flooding continues early this morning along
stretches of Wahoo Creek, generally from Weston to Memphis in
Saunders County. Additional, minor flooding is being observed
along the Big Blue River from upstream of Crete to near De Witt,
affecting mainly eastern Saline County.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Dense Fog Advisory until 10 AM CDT this morning for NEZ011-012-
     015>018-030>034-042>045-050>053.
IA...None.

&&

$$

DISCUSSION...Mead
AVIATION...CA
HYDROLOGY...Mead