290
FXUS63 KOAX 032224
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
524 PM CDT Sun Aug 3 2025

.KEY MESSAGES...

- Showers and storms expected in portions of eastern Nebraska
  again tonight into early Monday (30-50% chance). Some could
  produce heavy rain and localized flooding, especially if they
  move over locations that received heavy rain early Sunday
  morning.

- Near daily shower and storm chances (10-30% chance) will
  continue through the week, with the highest chances being each
  evening and overnight. Severe weather will be possible at
  times.

- Temperatures will gradually increase through the week, with
  temperatures in the 90s and heat indices near 100 for many by
  Thursday.

&&

.DISCUSSION...
Issued at 352 PM CDT Sun Aug 3 2025

Early afternoon analysis showed a shortwave trough sliding
through with another MCV pushing through southeast NE and
leading to some pesky, lingering light showers. In addition to
the rain, the associated cloud cover was helping to keep us
cool, with temperatures as of 3 PM in the upper 60s to mid
70s. Additional storms are expected tonight, though there`s
still some questions on how exactly things will pan out. There
are some storms currently going up along a front in central into
western NE and those are progged to approach the area, but
weaken or completely dissipate before pushing into northeast NE
with weak shear and diminishing instability over this way.

However, by the early morning hours Monday, better forcing
arrives as a shortwave trough currently spinning over central SD
pushes in and low level moisture transports strengthens a bit
and points into the area. As a result, a handful of CAMs show a
cluster of thunderstorms developing along the CAPE gradient
stretching north to south somewhere in northeast into east-
central NE. Unfortunately, there remains a decent amount of
spread in overall storm coverage and strength. While
hail/damaging winds are not expected, we`ll have decent
precipitable water and warm cloud depths in place for some
pockets of heavier rain and localized flooding. This is
especially true in areas that received the heaviest rain last
night (eastern Knox into northern Pierce counties), and while
latest guidance suggests the highest potential for heavy rain
will be just east of there, it`s definitely close enough to keep
a very close eye on.

For Monday, upper level ridging will amplify over the Desert
Southwest with us being on the northeastern periphery. This will
kick off a gradual warmup through the week with 80s returning
to some locations on Monday, fairly widespread 90s with heat
indices cracking 100 for many by Thursday and Friday and
lingering into the weekend.

Despite the ridging building in, we`ll see daily at least small
shower and storm chances (10-30%), especially during the evening and
overnight hours as various bits of shortwave energy slide through
and the low level jet and moisture transport ramp up. There will be
plenty of smaller scale details to work out each day, as the
previous night`s convection will likely impact what happens between
modified instability and remnant outflow boundaries, but it looks
like we`ll have at least occasional severe weather chances with
building instability and even decent shear at times. That said,
there is the question of what wins out between a building larger
scale ridge and weaker shortwaves pushing through. So overall severe
weather forecast confidence on a given day is on the lower side. For
what it`s worth, various severe weather machine learning algorithms
give us daily 5-15% chances. Higher chances look to arrive sometime
Friday night or Saturday as guidance shows the ridge shifting east
with a trough digging into the northwestern CONUS while a cold front
pushes through the forecast area. Still some spread on timing,
somewhat owing to amplification of the ridge, with EPS ensemble
members generally favoring a more amplified ridge and slower
passage of the trough/front and GEFS favoring the opposite.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 518 PM CDT Sun Aug 3 2025

VFR conditions are favored this evening. However, a scattered
to broken cloud deck at 2000-3000 ft may bring brief drops to
MVFR conditions, especially at KOFK. Southerly to southeasterly
winds will continue at 8-12 kts, gradually calming into the
evening. A cluster of showers and thunderstorms is expected to
develop early Monday morning (08-12Z) in northeast Nebraska
before pushing to the south, likely impacting KOFK. Brief
periods of MVFR conditions will be possible in any heavier
showers. Confidence is low (20% chance) that showers will hold
together long enough to impact KOMA or KLNK.

&&

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

&&

$$

DISCUSSION...CA
AVIATION...Wood