-- Discussion containing changed information from previous version are highlighted. --
298
FXUS64 KOUN 061745
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
1245 PM CDT Sun Sep 6 2026

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

.KEY MESSAGES...
-- Changed Discussion --
Updated at 1237 PM CDT Sun Sep 6 2026

- Ongoing heatwave continues through at least midweek with triple
  digit heat indices and lows well above normal.

- Very low chances for rain/storms this afternoon across
  northwestern and eastern parts of the forecast area this afternoon
  to southeast Oklahoma on Monday.

- Possible pattern shift by late week with less dangerous heating
  and increasing rain chances late Wednesday into Thursday.
-- End Changed Discussion --


&&

.NEAR TERM...
-- Changed Discussion --
(Rest of today and tonight)
Issued at 1237 PM CDT Sun Sep 6 2026

Big changes may be coming in our weather pattern later this week but
unfortunately not in the near or short term periods as dangerous
heating and most likely dry conditions will persist across most of
our forecast area.  Surface moisture has increased across southeast
into east-central Oklahoma where the muggiest lower 70s dewpoint are
in place.  Very little moisture change across the rest of our area
with a pseudo-dryline gradient generally along I-35 as per Oklahoma
Mesonet observation with our relatively driest air (lower 60s
dewpoints) across northwest Oklahoma.  This will keep heat indices
down across parts of western Oklahoma and adjacent western north
Texas and out of this afternoons advisory.  Not 100% direct sun for
today as afternoon heating should produce widespread scattered CU
across our area with perhaps additional thin high Cirrus.  With
southeasterly low-level flow under strong upper ridging still
expecting triple digit high temperatures today between 100-104
degrees.  The aforementioned drier air across parts of our west
should keep heat indices negligible there but the rest of our area
will see heat indices above 105 degrees although a couple of our
counties in southeast Oklahoma could approach warning criteria of
110 degrees.  For now will have a Heat Advisory in effect starting
in the afternoon hours and did add Jackson County to the advisory.
With tonight`s lows about 10-15 degrees warmer than normal and
advisory conditions for Monday, will keep our Heat Advisory going
overnight.

As far as POPs, will add a swatch of 15-20% chance for an isolated
thunderstorm this afternoon across eastern portions of our forecast
area. Isolated thunderstorms may be possible across eastern Oklahoma
just ahead of a backdoor cold front pushing into southwest Missouri.
Capping is rather weak as the boundary layer heats up and mixes as
forcing ahead of the front may be sufficient to initiate some
convection.  Surface-based instability will be rather weak in east-
central Oklahoma but cannot rule out a short-lived isolated storm
pulsing up. DCAPE values would be sufficient producing brief gusty
winds from storm collapsing should any develop.  Will also add a
second area of mentionable 14% storm POPs for this afternoon across
northwest Oklahoma due to the ongoing convective activity in the
Central through Southern High Plains.
-- End Changed Discussion --

&&

.SHORT TERM...
-- Changed Discussion --
(Monday through Tuesday night)
Issued at 1237 PM CDT Sun Sep 6 2026

Our synoptic weather pattern will persist early this week with a
blocking pattern in the main jet stream.  Deep troughing across the
western one-third of the country and the Eastern Seaboard with
ridging in-between strongest across the Southern Plains with a
closed high.  As a result our heatwave will persist through the
short-term period with the overnight Heat Advisory continuing
through Monday afternoon.  Heat Advisory conditions will also be met
on Tuesday as well.  Expecting surface moisture transport to
increase or persist generally east of I-35 and especially into
southeast Oklahoma with little change across the rest of our
forecast area.  Will need to keep an eye on southeast Oklahoma as a
couple of our counties could meet warning criteria due to the
strongest moisture advection there.  We will continue to see triple
digit high temperatures in the short term between 100-104 degrees
but did go with the NBM 50th percentile vs default for Monday`s
MaxT.  Did add 15-20% storm POPs in east-central through southeast
Oklahoma for Monday afternoon with weak but final ascent again
across eastern Oklahoma as the aforementioned backdoor front gets
washed out.
-- End Changed Discussion --

&&

.LONG TERM...
(Wednesday through Saturday)
Issued at 125 AM CDT Sun Sep 6 2026

The ridge begins to flatten Wednesday as several waves begin to
make their way through the northern flow. Most models (80-90%)
depict Wednesday as hot and dry like previous days, though a few
ensemble members (~10%) suggest that we could see thunderstorms
approach northern Oklahoma from Kansas.

Thursday through the end of the week redevelops the ridge over the
western conus, putting us in the path of several waves in the
upper flow. This will bring back low chances for rain (10-30%) and
a chance for some relief from the heat. High temperature
uncertainty jumps on Thursday across northern Oklahoma--where the
middle 50% (interquartile range) of potential outcomes spans a
10-degree range--before spreading farther south toward the
weekend. Even with the potential cooling, the likelihood of daily
highs reaching or exceeding 100 degrees remains moderate to high
(50-80% probability, highest in north Texas) through Saturday. Key
factors determining whether relief arrives and any rain chances
will be the position / strength of the ridge and timing of
approaching upper level waves.

Day

&&

.AVIATION...
(18Z TAFS)
Issued at 1224 PM CDT Sun Sep 6 2026

VFR conditions and mainly dry conditions are expected to prevail
through the period outside of widely scattered showers and storms
possible this afternoon, mainly across central and eastern OK.
Light south/southeast winds will continue through the day on
Monday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  76 100  77 100 /   0  10   0   0
Hobart OK         76 101  77 102 /   0   0   0   0
Wichita Falls TX  75 102  77 103 /   0   0   0   0
Gage OK           73 100  74 101 /   0   0   0   0
Ponca City OK     75 100  76 101 /   0  10   0   0
Durant OK         76 103  76 103 /   0  10   0   0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory until 7 PM CDT Monday for OKZ006>008-011>013-
     017>020-023>032-035>048-050>052.

TX...Heat Advisory until 7 PM CDT Monday for TXZ085-086-088>090.

&&

$$

NEAR TERM...68
SHORT TERM...68
LONG TERM....14
AVIATION...08