368
FXUS64 KOUN 241941
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
241 PM CDT Tue Sep 24 2024

...New AVIATION...

.KEY MESSAGES...
Updated at 239 PM CDT Tue Sep 24 2024

    - One or a few thunderstorms are expected to develop just
      north and west of the OKC metro this evening and move
      southeast, posing a risk for large hail and damaging winds
      through about 10 pm.

    - The weather turns pleasant afterwards for multiple days,
      with light north winds and largely clear skies tomorrow and
      Thursday.

    - High clouds and maybe some showers in our eastern zones as
      Helene passes to our east.

&&

.SHORT TERM...
(This evening through Wednesday)
Issued at 228 PM CDT Tue Sep 24 2024

The primary near-to-short-term forecast concern will be the
potential for one or a couple of strong to severe storms this
evening. Surface observations show a low pressure zone in northwest
Oklahoma a little after noon, and short-term guidance depicts that
low gradually migrating southeastward throughout the rest of the
day. Just to the east of that low, surface convergence mixed with
mild warm/moist advection should be sufficient to trigger convection
initiation just northwest of the OKC metro. Low-level thermodynamics
will be on the marginal side for surface-based convection,
especially with sunset occurring much earlier this time of year.
However, steep mid-level lapse rates will still contribute to at
least 1,000 J/kg of MLCAPE in central Oklahoma. 30-40 knot
northwesterlies aloft will lead to about 50 knots of deep-layer
shear, more than sufficient for semi-elevated supercell structures.
These storms will have a risk for severe hail and perhaps a damaging
wind risk as they begin to collapse in the evening.

Further storm development is expected overnight in southern Oklahoma
and potentially western north Texas as a cold front begins to
impinge on a reservoir of elevated instability. These storms should
be undercut by the boundary. However, the potential for strong wind
gusts, quarter-sized hail, and cloud-to-ground lightning will be
possible. Lows behind the front tonight will drop into the 50s in
most locations, with 60s hanging out near the Red River.

Cold/dry advection is expected through the day on Wednesday. Winds
will be on the lighter side - about 10 mph from the north. Skies
will also be clear. Highs will sit in the low 80s. That was about 4
sentences worth of info that can be wrapped up in one phrase -
beautiful weather tomorrow!

Meister

&&

.LONG TERM...
(Wednesday night through next Monday)
Issued at 228 PM CDT Tue Sep 24 2024

If you like the beautiful weather tomorrow, then good news: we`re
getting two for the price of one! Thursday will also see light north-
northeasterly winds, clear skies, and highs in the upper 70s to low
80s. The only real change on Friday will be an increase in the
pressure gradient as Helene lifts northward into the southeast U.S.
High cloud cover should also increase as the cirrus outflow is
channeled westward, and there will be at least a low chance for
showers east of I-35 Friday afternoon and evening. Otherwise, highs
will again be the upper-70s to mid-80s.

Once the tropical cyclone ejects northward through the East Coast,
the pressure gradient will weaken and we will return to light
northerly flow at the surface for the weekend.

Although the subtropical ridge is likely to remain locked in place
across the Desert Southwest through the week and into the weekend, a
trough will eject into the northern Plains early next week. There
are some indications that this might be preceded by a broad lee
trough across the entire High Plains. This pattern could potentially
support impactful fire or severe weather, but right now the
antecedent pattern does not look favorable for either. As that
trough translates across the northern Plains, another strong cold
front is possible by Tuesday or so.

Meister

&&

.AVIATION...
(18Z TAFS)
Issued at 239 PM CDT Tue Sep 24 2024

Scattered thunderstorms this evening will pose a chance for gusty
winds, hail, and lowered visibilities in central Oklahoma,
particularly KOKC and KOUN. A cold front is expected to move
southward through the area tonight, bringing northerly winds
behind it. Clearing/VFR skies and slackening north winds are
expected tomorrow.

Meister

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  82  57  79  56 /  30  60   0   0
Hobart OK         88  57  84  54 /  40  20   0   0
Wichita Falls TX  90  62  84  56 /  10  40   0   0
Gage OK           83  52  83  52 /  10   0   0   0
Ponca City OK     77  54  81  52 /  20  20   0   0
Durant OK         88  62  83  56 /   0  70  10   0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&

$$

SHORT TERM...04
LONG TERM....04
AVIATION...04