381
FXUS63 KOAX 121022
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
522 AM CDT Mon May 12 2025

.KEY MESSAGES...

- A Red Flag Warning is in effect from noon to 9 PM for part of
  northeast Nebraska.

- Temperatures will remain well above normal through Wednesday,
  followed by return to near normal readings Thursday through
  the weekend. Gusty winds will continue through much of the
  week.

- Rain and thunderstorm chances return Wednesday evening (40-70%
  chance), with the potential for a few strong to severe storms.

- Additional rain and thunderstorm chances this weekend.

&&

.DISCUSSION...
Issued at 307 AM CDT Mon May 12 2025

Today and Tuesday:

A vigorous, mid-level trough and associated closed low are in
the process of moving onto the West Coast early this morning,
with those features progressing into the Interior West by
Tuesday. In the low levels, a lee trough currently located over
the High Plains will remain quasi-stationary today before slowly
shifting east across the Dakotas on Tuesday, in tandem with a
surface low. That large-scale pattern configuration will support
the continuation of gusty south winds, especially in northeast
Nebraska.

A deep-layer cyclone currently situated over the lower MS Valley has
slowed the poleward return Gulf moisture, despite the persistent
southerly winds. As such, conditions today are expected to be
similar to those on Sunday, with critically low relative humidity of
15-17% aligning with the gusty winds to create extreme fire danger
over our northwest counties. A Red Flag Warning is in effect from
noon-9 PM to account for those conditions. By Tuesday, the southern
U.S. low is forecast to shift east, allowing for an increasingly
moist air mass to advect into the region. Enough moisture may
return to limit fire danger to the very high category in those
locations.

Highs on both days are forecast to be in the mid 80s to low 90s with
Tuesday being the warmer of the two.


Wednesday and Thursday:

A potent vorticity maximum within the base of the western U.S.
trough is forecast to move into the central and southern Rockies by
Wednesday evening before accelerating northeast into the central
Plains by Thursday morning. That disturbance will continue north-
northeast into the upper MS Valley on Thursday, supporting the
intensification of a deep-layer cyclone situated over the Dakotas
and MN. Meanwhile, the associated surface front is projected to move
through the area on Wednesday night with some model signal for a
secondary surface low/frontal wave developing along the boundary.

Strong south winds with gusts of 30-40 mph are forecast ahead of the
front on Wednesday, with dewpoints rising through the 50s into the
low/mid 60s by evening. When coupled with unseasonably warm
temperatures in the upper 80s to low 90s, the warm-sector air
mass is forecast to become moderately unstable, but likely
capped through the afternoon (at least in our area).

By Wednesday evening, thunderstorms are expected to spread into our
area from central NE, and continue into the overnight hours (peak
PoPs of 40-70%). Forecast soundings indicate steadily strengthening
low-level and deep-layer shear; supportive of a few strong to
severe storms capable of all hazards.

Showers and isolated thunderstorms may continue into Thursday,
mainly across northeast NE and west-central IA, in closer proximity
to the deep-layer low mentioned above. Winds are expected to be
quite strong from the west with gusts of 40-45 mph appearing likely.
A number of the 00z EPS members indicate wind gusts > 50 mph, so it
could end up being even windier than what`s currently forecast. The
strong winds could offset marginally low relative humidity to
support a wildfire threat in some areas. Highs on Thursday will be
cooler than previous days with readings in the 70s to low 80s.


Friday through the weekend:

The low pressure system to our north on Friday is forecast to move
into the Great Lakes by the weekend with upstream height rises
occurring across the Great Plains. The models suggest that a
surface front could linger somewhere in the central Plains,
which could serve as a focus for showers and thunderstorm
development from Saturday night into Sunday (peak PoPs of
35-45%). Latest machine-learning guidance suggests some severe-
weather potential with that activity. However, it should be
noted that there is still a fair amount of model variability in
exactly where the boundary will be located. So, the PoPs and
severe weather potential are far from certain at this juncture.

Near-normal daytime highs in the 70s are forecast during this
timeframe.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 522 AM CDT Mon May 12 2025

VFR conditions will prevail through the forecast period with
a few clouds at FL250. Light southeast winds strengthen to 16
kt with gusts to 24 kt by 14z at KOFK. At KOMA and KLNK, speeds
increase to 12 kt with gusts to 20 kt by 17z. Wind speeds then
diminish to 10-12 kt by 00-01z at the terminal locations.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Red Flag Warning from noon today to 9 PM CDT this evening for
     NEZ011-016-030.
IA...None.

&&

$$

DISCUSSION...Mead
AVIATION...Mead