839
FXUS64 KOUN 300713
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
213 AM CDT Wed Sep 30 2026

...New NEAR TERM, SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 211 AM CDT Wed Sep 30 2026

- Periods of heavy rain are expected from this afternoon through
  at least Thursday morning. Flash flooding is possible in
  southern Oklahoma and western north Texas.

- Chance of severe storms this afternoon and evening.

- Cooler temperatures heading into the weekend.

&&

.NEAR TERM...
(Wednesday and Wednesday night)
Issued at 211 AM CDT Wed Sep 30 2026

A day/night of impactful weather is expected across the CWA.
Thunderstorms, heavy rainfall, and a chance for severe weather
(primarily a conditional tornado risk) will occur across much of the
area.

Regional radar observations depict a large stratiform band with
embedded thunderstorms across eastern New Mexico and the Texas
panhandle. Model guidance suggests that this wave is not the one
that will reach into our area - storm redevelopment will occur in
the eastern panhandle/western Oklahoma closer to daybreak. Either
way, the impact is the same: we anticipate a cluster of showers and
thunderstorms to move northeastward across western and northern
Oklahoma during the morning hours. Portions of that area have
received heavy rainfall over the last week and thus there will be a
low-to-medium risk for flooding of streams, low-water crossings, and
poor-draining roads.

The primary wave of storms with the greatest chance for flooding and
severe weather will begin this afternoon and last through the
nighttime period. Storms will initially develop in western north
Texas and western Oklahoma within the warm sector and over time grow
upscale into an MCS. With the approach of the trough, 500 mb flow
will become increasingly meridional, signaling a decrease in
forward progression of that MCS. This will bring areas in the path
of the line under heavy precipitation for 1-3 hours. Under those
circumstances, flash flooding is likely in parts of western north
Texas and southern Oklahoma this evening and tonight. The
northward extent of the MCS remains in question with contradictory
solutions in model guidance. This is of particular importance to
flood-prone areas such as Lawton, OKC, and Stillwater, who have
wide ranges of potential outcomes from "deluge" to
"disappointingly low rain totals".

The severe risk is also worth watching, though uncertainties abound.
Two potential regimes for severe weather exist. The first is along
the dryline late in the afternoon in western Oklahoma. The degree of
destabilization and lingering subsidence from this morning`s showers
and storms will act to make the potential for supercells quite
conditional. On the other hand, the dry slot`s approach will steepen
mid-level lapse rates, and sufficient wind shear will exist in the
area for supercells to develop. If (and this is a big if) supercells
were to develop, the primary severe weather risk would be tornadoes.
The second severe regime runs from western north Texas to southern
Oklahoma with the MCS. Lapse rates will be very poor and deep-layer
flow will be meridional, so from a parameter perspective these
storms will not be working from a favorable environment.

Meister

&&

.SHORT TERM...
(Thursday through Friday night)
Issued at 211 AM CDT Wed Sep 30 2026

Rain continues in the forecast across much of the area during the
day on Thursday. While flash flooding does not look to be as likely
or as widespread, the antecedent conditions will favor further cases
of excessive rainfall.

The basis for Thursday`s rain event will be the approach of the
upper-level low. While the low will be weakening on its approach,
sufficient vorticity/cooling aloft will occur for instability to
return, particularly across northern Oklahoma closer to the cooler
500 mb temperatures. This will be the basis for scattered
thunderstorms to redevelop in the afternoon. Storms will be slow-
moving with heavy rainfall rates. Sufficient shear exists for the
organization of updrafts, but there`s enough uncertainty that it
will probably be best to wait until after tonight`s MCS to try to
assess any potential severe weather risk.

As the upper low lifts northeastward out of the area, a cold front
will crash southward into the area late Thursday evening and
Thursday night. This will bring much cooler air into the CWA. If the
front had occurred last week, we`d probably have a crisp and sunny
Friday, but with all of the lingering moisture on the ground,
widespread stratus development seems like a given. That will keep
temperatures to a much more fall-like 70-80 range across the CWA.
Lingering rain chances will continue across southern Oklahoma into
Friday afternoon/evening as the tropical airmass remains there the
longest.

Meister

&&

.LONG TERM...
(Saturday through Tuesday)
Issued at 211 AM CDT Wed Sep 30 2026

Several near-to-slightly-cooler-than-normal days await us for the
upcoming weekend. Though the ridge will build back in over the
Southern Rockies, enough weakness in the ridge will exist for us to
feel the full extent of a prolonged period of northwest flow over
the Central Plains. That will keep northerly surface winds perhaps
as long as Monday evening in our area. Lingering rain chances are
expected mostly southeast of I-44 on Saturday, but the rest of the
weekend and into Monday looks much drier.

The one constant in 2026 has been that any cooldown can`t last long,
and sure enough, guidance and our gridded forecast are starting to
warm back up beginning next Tuesday. Fortunately, it looks like
we`ll be doing "October warm" instead of "July warm", with
temperatures rebounding into the 80s at most sites. For those in
search of more good news, model trends beyond the official long-term
period do suggest that we`ll be seeing more frontal intrusions in
the first half of October.

Meister

&&

.AVIATION...
(06Z TAFS)
Issued at 1110 PM CDT Tue Sep 29 2026

The scattered showers over northwest Oklahoma and the Oklahoma and
Texas panhandles will continue moving northeast overnight,
primarily affecting KWWR. The tropical plume of moisture will
shift slowly east tomorrow eventually bringing high chances for
showers and storms across the other TAF sites. There will be some
areas of MVFR ceilings both with showers/storms and some stratus
on Wednesday, as well as MVFR visibilities with the
precipitation.

Western and northern Oklahoma sites will also be dealing with some
non-convective low-level wind shear with a low-level jet of around
40 knots.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  84  68  81  63 /  80  80  70  50
Hobart OK         84  68  85  63 / 100  50  30  20
Wichita Falls TX  88  69  85  65 /  90 100  40  30
Gage OK           83  62  79  55 /  90  20  40  50
Ponca City OK     83  66  77  60 /  80  70  70  60
Durant OK         92  70  83  67 /  40 100 100  80

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch from this afternoon through Thursday afternoon for
     OKZ031-032-040>043-045>048-050>052.

TX...Flood Watch from this afternoon through Thursday afternoon for
     TXZ086-088>090.

&&

$$

NEAR TERM...04
SHORT TERM...04
LONG TERM....04
AVIATION...26