841
FXUS63 KOAX 042018
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
318 PM CDT Sat Oct 4 2025

.KEY MESSAGES...

- Windy and dry conditions are leading to isolated fire starts
  this afternoon.

- Chances for showers and thunderstorms return to the area
  Sunday afternoon and continue into Tuesday morning. A strong
  storm or two is possible late Sunday afternoon and evening.
  Additional rain chances exist on Wednesday and Thursday.

- Much cooler by Monday, with highs in the upper 50s to mid 60s.
  Temperatures gradually warm back into the 70s by late in the
  workweek.

&&

.DISCUSSION...
Issued at 318 PM CDT Sat Oct 4 2025

Rest of this afternoon through tonight:

A vigorous upper low over the Great Basin/central Rockies as of
early afternoon is forecast to weaken as it accelerates
northeast into the northern Plains overnight. That upper-air
system has induced a 30-40 kt low-level jet (LLJ) across the
region today, with steep lapse rates associated with an
unseasonably warm air mass enhancing the transfer of the strong
winds to ground level. The strong winds are combining with the
hot temperatures and decreasing moisture content to create
favorable wildfire conditions, and a number of fire starts have
been detected by satellite so far this afternoon.

The LLJ is forecast to strengthen to 50-55 kt this evening, and
there`s some concern that partial downward mixing of those winds
could yield wind gusts of 45-50 mph across portions of northeast
NE, near the SD border. We`ll be monitoring that situation for a
possible wind advisory. Otherwise, the various CAMs indicate the
potential for isolated to widely scattered, elevated convection
along the LLJ overnight into Monday morning, with cloud bases
at around 12kft. Model soundings show a considerable amount of
dry air in the sub-cloud layer, so there`s some question as to
how much precipitation will actually reach the ground. As such,
the 10-20% PoPs will be maintained.


Sunday through Monday night:

The strong LLJ mentioned above is forecast to linger into
Sunday morning ahead of a surface cold front moving into
northeast NE, with some model indication that southerly wind
gusts of 40-45 mph could develop across portions of southeast
and east-central NE into southwest IA. The winds are expected to
gradually weaken through the afternoon as the front continues
southeast through the area. By that time, the combination of
unseasonably warm temperatures (highs in the mid 80s) and modest
boundary-layer moisture content will yield a marginally
unstable, and largely uncapped air mass along and ahead of the
cold front.

In the absence of any appreciable forcing for ascent, latest
CAM data suggest that thunderstorms will initiate along or ahead
of the cold front by late afternoon, before gradually increasing
in areal coverage Sunday night, generally south of I-80. The
marginal instability is expected to preclude an organized
severe weather episode. However, strengthening vertical shear
could support a few strong storms capable of gusty winds and
perhaps some hail. Locally heavy rainfall will also be a
concern, especially Sunday night into Monday in the vicinity of
the front slowly progressing through southeast NE and southwest
IA. Precipitation chances linger into Monday night for locations
along and south of I-80.

The greatest storm-total rainfall is expected south of I-80,
with the NBM indicating a 50-60% chance of an inch or more in
those locations. Local amounts of 2-3" are certainly possible,
but the threat for flooding currently appears low.

Widespread clouds and the influx of a cooler, Canadian air mass
will contribute to significantly cooler temperatures on Monday,
with highs in the upper 50s to mid 60s forecast.

Tuesday through Friday:

The 12z global ensembles indicate the potential for a weak mid-
level disturbance to glance the region in the Wednesday-
Thursday timeframe, with the forecast maintaining the 15-25%
PoPs. By Friday, there is a fairly consistent model signal that
mid-level heights will begin to build over the central U.S.

We`ll see gradually warming temperatures this period, with
highs in the 60s on Tuesday warming into the 70s by Thursday and
Friday.


&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1153 AM CDT Sat Oct 4 2025

VFR conditions will prevail through the forecast period, with a
small chance (15%) of a shower or thunderstorm at the terminal
locations late tonight into Sunday morning. Winds will be quite
strong from the south, with gusts of 25-35 kt continuing into
tonight. LLWS is also likely, mainly from 05/03z-05/15z.

&&

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

&&

$$

DISCUSSION...Mead
AVIATION...Mead

NWS OAX Office Area Forecast Discussion