197
FXUS63 KOAX 021101
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
601 AM CDT Sat Aug 2 2025

.KEY MESSAGES...

- Smoke impacts continue through this afternoon. The Nebraska
  Department of Environment and Energy has extended their Air
  Quality Alert until 5 pm this evening.

- Shower and storm chances return later this morning (15-30%
  chance) with low chances lingering into the afternoon in
  southeast Nebraska.

- More showers and storms redevelop late Saturday night into
  early Sunday (30-50%), and again Sunday night into Monday
  (20-30% chance)

- Temperatures remain in the low 70s and 80s through at least
  Sunday before warming up into the low 90s by Wednesday-
  Thursday. Nighttime chances (15-30%) for showers and storms
  are expected as well through at least Thursday.

&&

.DISCUSSION...
Issued at 448 AM CDT Sat Aug 2 2025

High pressure is slowly shifting off to the east, with showers
and storm activity along the southerly moisture plume over
central Nebraska this morning. This moisture plume will continue
to shift eastward, bringing low chances for showers across our
western counties later this morning. Meanwhile, radar shows a
MCV near Broken Bow which is forecast to travel across southeast
Nebraska through the day today, which could potentially trigger
additional showers and storms this afternoon across southeast
Nebraska. The 06Z HRRR seems to be suggest this, so we have
introduced low PoPs to southeast Nebraska through the day
today.

The upper-level pattern shows a fairly zonal jet regime with
weak ridging at 500-mb driving the broad surface high centered
over the Upper-Mississippi River Valley. As previously
mentioned, this surface High will continue to slowly drift east
over the next couple days bringing back the moisture-laden
nocturnal low-level jet, advecting in moisture from the Gulf.
With this in place, a shortwave will initiate storms over
western Nebraska this afternoon, making their way eastward
overnight, and arriving over eastern Nebraska and western Iowa
Sunday morning. Timing would suggest decaying elevated
instability should limit severe potential, as well as weak
environmental shear. CAMs model this showing disorganized
shower/storm activity as they arrive Sunday morning. PWAT values
around 1.4-1.5 could lend toward locally heavy rainfall, though,
with storm motion likely fairly slow. For this reason, WPC has
our area under a marginal risk for Excessive Rainfall and Flash
Flooding.

With cloud cover likely hanging around through the day on
Sunday, temperatures will likely stay similarly cool to the last
few days with highs staying down in the mid 70s despite the
increase in southerly flow across the region. Sunday night a
similar set-up remains in place with another weak shortwave
bringing more chances for showers and storms overnight into
Monday morning.

Over the weekend, we see a new ridge develop over the Four-
Corners Region in the upper-levle flow. This ridge quickly
amplifies Sunday into Monday, starting to push into the Central
Plains early next week. This will lead to a warming trend
bringing back seasonable temperatures and humidity towards
midweek, with highs approaching 90 by Wednesday and heat indices
approaching 100 by Thursday. With progressive northwesterly flow
aloft holding strong, we will continue to see chances for
nocturnal storms with subtle shortwaves riding down the
northeast portion of the Ridge. For this reason, anticipate we
hold on to at least low-end PoPs each night through the end of
the week for at least some portion of our area.

Going into next weekend, the models have two distinct scenarios,
one which would bring relief from the heat and potentially a
fairly significant storm system. The other would extend the
heat and humidity into the weekend. It will all depend on how
the ridge interacts with an incoming upper-level trough which
either is strong enough to break down the Ridge in place, or
gets held up over the Rockies, forcing the ridge eastward into
the Central Plains. For this reason, confidence is low in the
forecast next weekend and beyond.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 601 AM CDT Sat Aug 2 2025

Low-level smoke is again reducing visibility across the area
this morning. Expect vis to improve between 21-00Z this evening
as winds aloft help to clear the smoke off to the east. With
this expect VFR conditions to prevail overnight tonight through
the end of the TAF period. Winds through the period will remain
out of the southeast, increasing later this morning with gusts
to 20kt, primarily at KOFK, then weakening again this evening.

&&

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

&&

$$

DISCUSSION...McCoy
AVIATION...McCoy