365
FXUS64 KOUN 181044
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
544 AM CDT Tue Aug 18 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 220 AM CDT Tue Aug 18 2026

- Dangerous heating returns across our entire area with triple
  digit high temperatures between 105-110 degrees

- Fire weather conditions increase to an Elevated Risk across
  western Oklahoma & western north Texas for Today & Wednesday.

- Weak summer cold front on Wednesday may restrict the dangerous
  heating to southern Oklahoma & western north Texas on Thursday.

- Dangerous heating becoming more widespread on Friday and hotter
  into the weekend.

&&

.NEAR TERM...
(Through Tuesday)
Issued at 220 AM CDT Tue Aug 18 2026

The main headlines for today will be the return of both extreme
heating and fire weather.

Our stalled "summer" cold front near the Red River is expected to
wash out or lift as a warm front with a return of southerly low-
level flow and increasing pressure heights as upper ridging builds
to our north & east.  A surface low lee of the Colorado Rockies is
expected to deepen increasing our surface winds out of the southwest
by this afternoon.  This will start advecting slightly drier "west
Texas-based" air already in place across western north Texas and
southwest Oklahoma further northward into central & northern
Oklahoma.  Although this may keep the heat index spread more narrow
and closer to the air temperatures, much of our excessive heating of
105 to 110 degrees will be more "air temperature" than "heat index"
driven. We may see a few to scattered CU develop this afternoon
especially in central through southeast Oklahoma but not expecting
that to abate solar heating.  The hot but driest air across our
western forecast area will result in very low afternoon RHs between
15-20% increasing fire danger there especially with dry vegetation
due to the persisting extreme drought conditions there.  Not
expecting southwest winds to be very strong but breezy for fire
spread (10-20 mph) or gusty due to the lack of a low-level jet to
mix into. However, high fuel loading and very dry air with an
ignition source will at least Elevate the risk for fire weather
during the afternoon hours till sundown across western Oklahoma and
adjacent western north Texas.

As far as the dangerous heating, will maintain an Extreme Heat
Warning across the eastern half of our forecast area where air
temperatures may exceed 105 degrees to a Heat Advisory across the
remaining western half of our area which including our Texas
counties. Both warning and advisory will be in effect from 11 AM
this morning until 8 PM near sundown.

&&

.SHORT TERM...
(Tuesday night through Thursday night)
Issued at 220 AM CDT Tue Aug 18 2026

Tonight will be our warmest night in the forecast period with many
locations only falling to 80 degrees which could come close to tying
or breaking daily warmest minimum temperature records.  There will
be a robust low-level jet develop overnight but expected to weaken
by the afternoon keeping afternoon wind gusts down.  Overnight south
winds veer southwest by Wednesday afternoon just ahead of our next
"summer" cold front coming down from the Central Plains.  Models
have speeded up timing of the front with the NAM & GFS pushing it
into northern Oklahoma during the latter half of Wednesday morning
with a slower ECMWF solution during the early half of the afternoon.
Because of the model uncertainty would expect the surface boundary
to be somewhere between the Kansas/Oklahoma state line to I-40 by
late afternoon heating.  A bit challenging with Wednesdays MaxT but
did trend slightly cooler than NBM across northern Oklahoma using
the CONSAll guidance.  Not sure how far north it will go but will
likely still see at least a Heat Advisory across the southern two-
thirds of our forecast area to perhaps even an Extreme Heat Warning
across southeast Oklahoma.  The upper support pushing Wednesdays
surface front will be shortwave digging through the upper ridging
across Kansas with a second (main) wave of energy trailing it.
Although some CAMs suggest rain developing along the front should it
come through late Wednesday morning I would expect it to be more
virga/high based with the lower-levels very dry and stable and
capped in the afternoon.  For now the best chances for rain/storm
POPs would be toward Wednesday evening across far northern Oklahoma
and more high-based with the 2nd trailing wave. For now expecting
the severe risk to be just north in Kansas across the Central Plains
where the strongest moisture & instability is in place.

By Thursday expecting the surface boundary somewhere between I-40 to
the Red River with decreasing pressure heights from the main upper
trough coming through.  Although still unseasonably hot this might
break our heatwave at least north of I-40 with upper 90s highs but
not much relief further south especially in southern Oklahoma and
western north Texas where triple digit highs will persist staying in
or near heat advisory criteria.

&&

.LONG TERM...
(Friday through Monday)
Issued at 220 AM CDT Tue Aug 18 2026

Upper ridging across much of the western U.S. continues to build
eastward over the Southern High Plains with our heatwave returning
across our entire forecast area with widespread triple digit highs
across our area by Saturday.  Sunday & Monday looking even hotter
between 105-110 degrees all air temperature vs heat index values.
Could see another "summer" cold front at least partially push
through early next week.

&&

.AVIATION...
(12Z TAFS)
Issued at 544 AM CDT Tue Aug 18 2026

VFR conditions are expected with few to scattered mid and high
level clouds. Non-convective low-level wind shear will likely
develop across north central Oklahoma with southwesterly winds
above the surface.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 105  80 109  76 /   0   0   0   0
Hobart OK        108  79 108  75 /   0   0   0   0
Wichita Falls TX 108  81 108  79 /   0   0   0   0
Gage OK          105  75  96  68 /   0   0  10  20
Ponca City OK    103  78  99  71 /   0   0   0  30
Durant OK        107  81 108  80 /   0   0   0   0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory from 11 AM this morning to 8 PM CDT this evening
     for OKZ004>006-009>011-014>017-021>023-033>038-044.

     Extreme Heat Warning from 11 AM this morning to 8 PM CDT this
     evening for OKZ007-008-012-013-018>020-024>032-039>043-
     045>048-050>052.

TX...Heat Advisory from 11 AM this morning to 8 PM CDT this evening
     for TXZ083>090.

&&

$$

NEAR TERM...68
SHORT TERM...68
LONG TERM....68
AVIATION...26