819
FXUS63 KOAX 220438
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1138 PM CDT Sat Sep 21 2024

.KEY MESSAGES...

- Marginally severe storms generally along and south of I-80
  through 8pm. Hail and strong winds the primary hazards.

- Much cooler and breezy with widespread showers diminishing by
  Sunday afternoon and evening.

- More seasonable temperatures for the work/school week with
  mostly dry conditions.

&&

.DISCUSSION...
Issued at 324 PM CDT Sat Sep 21 2024

Tonight into Sunday:

Latest water vapor imagery and subjective upper air analysis shows a
strong low moving toward the Four Corners region with a low
amplitude shortwave ejecting out ahead of the main wave across
the Central Plains. Meanwhile, a cold front continues to slowly
drift south and currently has made it through the northwestern
half of the CWA and appears to be directly overhead at our
office as of this writing. The boundary is showing up well on
radar, likely pinging off particulates.

This boundary continues to move into an unseasonably warm and muggy
airmass with temperatures in the upper 80s to low 90s and dewpoints
in the upper 60s to around 70. We have seen an increase in
northwesterly gusts behind the surface boundary in the 35-40
mph range. There remains a brief window (through 8 pm) for
marginally severe storms to develop along the boundary as we
approach convective temperatures this afternoon and large scale
forcing from an approaching mid-level shortwave moves into the
region late this afternoon and early this evening. SPC continues
our Marginal risk of severe storms where hail and possibly some
wind would be our primary hazards. Latest SPC mesoanalysis
shows around 3000 J/kg of mixed-layer CAPE and around 35KTS of
deep layer shear are available ahead of this boundary.

Severe window should be relatively short-lived with much
drier/cooler and somewhat breezy conditions behind the front.
Meanwhile, large-scale forcing for ascent will continue over the
area as the above mentioned low over the Four Corners region begins
to eject into northwestern Kansas and southwestern Nebraska. This
forcing should be sufficient to produce widespread showers with
a few embedded rumbles of thunder possible. Lows tonight will
drop into the 50s with highs on Sunday remaining in the lower to
mid 60s under mostly cloudy skies with off and on showers.

Monday through next week:

Monday through Thursday look dry after the departure of the above
mentioned low. After the much cooler day Sunday, temperatures are
forecast to rebound to more seasonal levels for this time of
September, with highs in the 70s and lows in the 40s and 50s.
Some uncertainty remains late next week in regards to the
evolution of the a large upper low that is forecast to drop
through the Northern and Central Plains and potentially become
cut off as it moves into the Southern Plains. We have maintained
some very small (20%) pops late this week into early next week
but forecasters confidence is quite low due to the uncertainty.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1131 PM CDT Sat Sep 21 2024

VFR conditions are favored through the forecast period.
Scattered showers will gradually become more widespread across
southeast Nebraska through the night. A few scattered
thunderstorms will also be possible. With low confidence in the
coverage of thunderstorms, have opted to leave them out of the
TAFs at this time. Amendments will be made if needed. Both KOMA
and KLNK are expected to receive light showers until 14-17Z.
Overcast clouds at FL060 will accompany these showers, with VFR
conditions still favored. Confidence is low that these showers
will reach KOFK. Northerly to northeasterly winds will continue
above 12 kts with gusts up to 22 kts possible across all
terminals before calming after 09-10Z at KOFK and 21-22Z at KOMA
and KLNK.

&&

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

&&

$$

DISCUSSION...Kern
AVIATION...Wood