781
FXUS64 KOUN 250411
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
1111 PM CDT Tue Sep 24 2024

...New AVIATION...

.UPDATE...
Issued at 1012 PM CDT Tue Sep 24 2024

Updated the forecast to primarily (a) adjust POPs for the rest of
the night keeping the highest storm potential east and south, and
(b) add at least patchy fog to the grids for Wednesday morning,
especially in the central and east.

&&

.KEY MESSAGES...
Updated at 1012 PM CDT Tue Sep 24 2024

    - Storm chances continue in the east and south overnight.
      Isolated strong to severe storms possible late this evening.

- Areas of fog are expected again Wednesday morning in central
      and east central areas.

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

&&

.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...
(06Z TAFS)
Issued at 1111 PM CDT Tue Sep 24 2024

Thunderstorms continue late this evening across eastern Oklahoma
in areas just east of the Oklahoma City metro. By 06Z, any
showers/storms will generally be southeast of KOKC/KOUN and KSPS,
so KDUA should be the only TAF site with any thunderstorm
potential early Wednesday morning. Some areas of fog will likely
develop again Wednesday morning across central Oklahoma
potentially affecting KOKC, KOUN, and KSWO. Some MVFR ceilings
will also be possible at KDUA in the morning.

&&

.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  20   0   0
Gage OK           83  52  83  52 /  10  10   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...26