000
FXUS63 KOAX 261945
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
245 PM CDT Sat Apr 26 2025

.KEY MESSAGES...

- Lingering showers and thunderstorms this afternoon into early
  evening in northeast Nebraska.

- Isolated occurrences of large hail and/or damaging winds are
  possible Sunday night. However, thunderstorm coverage is
  uncertain.

- Severe weather is likely along and east of a front Monday
  afternoon and evening. The frontal location at that time
  remains uncertain, with the most probable location being along
  or just east of the Missouri River.

&&

.DISCUSSION...
Issued at 244 PM CDT Sat Apr 26 2025

...Rest of this afternoon and tonight...

Scattered showers and isolated thunderstorms ongoing across
portions of northeast NE are expected to linger into early
evening before shifting east of the area. Most of the
precipitation will remain light with generally less than a tenth
of an inch expected. Tonight, persistent southeast winds will
advect an increasingly moist low-level air mass into the region,
leading to widespread low clouds and potentially some fog
development toward daybreak Sunday across our western counties.
Latest CAM output has backed off on shower and thunderstorm
potential tonight, so the PoPs have been lowered. The best QPF
signal is late tonight into Sunday morning across portions of
southeast NE and southwest IA, where forecast soundings suggest
the potential for drizzle or light rain showers.


...Sunday and Sunday night...

Clouds are expected to linger through much of the day, which
will limit daytime heating. As such, this forecast update will
indicate slightly cooler highs in the mid 60s to low 70s. The
models have also trended drier across our area as the primary
forcing for ascent will remain over the northern and central
High Plains, in closer proximity to a surface low and lead
shortwave trough overspreading western portions of SD and NE. A
tightening pressure gradient east of the surface low and
associated lee trough will lead to increased wind speeds with
south-southeast winds gusting to 25-35 mph Sunday afternoon into
Sunday night.

Interestingly, most of the 12z CAMs are at odds with the
parameterized models with respect to thunderstorm potential over
the mid MO Valley Sunday night. The CAMS largely maintain a dry
forecast, whereas many of the parameterized models show a QPF
signal. Given the inconsistencies, PoPs have been lowered to
20-40%. The presence of a moist and moderately unstable air mass
would support strong to severe storms capable of isolated
occurrences of hail and locally strong winds, given storm
development and sustenance.


...Monday and Monday night...

A vigorous shortwave trough and attendant, mid-level jetstreak
over the central High Plains Monday morning are forecast to
rapidly translate northeast into the upper MS Valley and upper
Great Lakes region by Monday evening. In the low levels, the
primary surface low is expected to develop from SD into MN,
while a trailing Pacific front advances into eastern NE and
western IA. Model differences exist in how far east that
boundary progresses by mid to late afternoon when thunderstorm
initiation is expected. That frontal location will ultimately
dictate how much of our area will be subject to a risk of severe
weather. East of the front, the models continue to indicate
that a moderately unstable, warm sector air mass will coincide
with 50-60 kt of deep-layer shear; supportive of supercells
capable of very large hail and locally damaging wind gusts. The
overall tornado threat could be limited --at least initially--
by veered low-level winds, which reduce low-level hodograph
curvature/SRH.

Any storms that develop in our area will quickly move the
east/northeast by Monday evening.

Highs on Monday are expected to top out in 80s at most
locations.

...Tuesday through Friday...

Loosely phased, polar and subtropical-branch shortwave troughs
are forecast to move through the central U.S. on Wednesday into
Thursday. That will result in increasing shower and thunderstorm
chances (peak PoPs of 30-50%) during that timeframe. Cooler
afternoon temperatures in the 60s on Tuesday are expected to
warm into the 70s Wednesday-Friday.


&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1205 PM CDT Sat Apr 26 2025

An area of light showers and isolated thunderstorms ongoing
across portions of north-central and northeast NE will continue
northeast this afternoon with periodic -SHRA expected at KOFK
into late afternoon. Elsewhere, an MVFR (FL020-025) cloud deck
has developed across southeast NE (including KLNK) with model
soundings suggesting that the MVFR conditions could last into
early evening. Those clouds are expected to remain to the
immediate south of KOMA, so prevailing VFR conditions will be
maintained there. MVFR to potentially IFR ceilings are expected
to become widespread late tonight into Sunday morning, which has
been reflected in the terminal forecasts. Finally, gusty east-
southeast winds have developed as of mid-day, with those winds
continuing this afternoon before decreasing slightly tonight.

&&

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

&&

$$

DISCUSSION...Mead
AVIATION...Mead