629
FXUS64 KOUN 181104
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
604 AM CDT Wed Sep 18 2024

...New AVIATION...

.KEY MESSAGES...
Updated at 533 AM CDT Wed Sep 18 2024

- Isolated to scattered thunderstorms in northern and western
  Oklahoma this evening, with scattered thunderstorms possible
  from northern to central Oklahoma tomorrow evening.

- Hot/humid conditions on Thursday and Friday.

- Heat relief looking probable by the weekend.

&&

.SHORT TERM...
(Today and tonight)
Issued at 221 AM CDT Wed Sep 18 2024

The near-term forecast is concerned with convection potential
across northwest Oklahoma through daybreak. Radar/satellite show
showers and storms moving eastward across the northern panhandles
into an environment with a strengthening low-level jet. Short-
range models show elevated instability increasing and peaking in
northwest Oklahoma around 4:00 am. Thus, although severe weather
is not anticipated, scattered storms are possible in northwest
Oklahoma early this morning.

Later today, a surface trough is expected to develop over the
southern High Plains as the dryline mixes eastward. Southerly winds
will contribute to warmer and more humid conditions than we`ve seen
over much of the past week. By afternoon, temperatures along and
just east of the dryline are expected to increase to near the
convective temperature. Forecast instability looks rather meager
compared to what model guidance showed yesterday, and heights
actually look to increase as a trough ejects northward across the
Rocky Mountain Front and the subtropical ridge restrengthens. All of
that points toward lower confidence in storm coverage compared to 24
hours ago. With that said, the potential will still exist for
isolated to scattered thunderstorms from western to northern
Oklahoma. The strongest of those updrafts will be capable of
downburst winds up to 60 mph. This threat should diminish fairly
rapidly toward and just after sunset.

Meister

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 221 AM CDT Wed Sep 18 2024

Thursday looks quite similar to today in many respects, though with
the addition of a frontal boundary that will approach (or reach)
northwest Oklahoma before stalling and washing out in the afternoon.
Height tendencies will be neutral with the subtropical ridge
migrating westward toward the Big Bend. The 0Z HREF (and other high-
res guidance) painted a surprisingly bullish picture of overall
storm coverage late in the afternoon near the pseudo-triple point in
northern Oklahoma, with some CAMs then propagating that activity
southward toward I-40 in the evening. Though global guidance does
not depict this scenario, the high-res guidance was robust enough to
warrant introducing chance (30 percent) PoPS late in the day
tomorrow. Deep-layer shear looks sufficient for updraft
organization, though high dewpoint depressions will likely promote
outflow dominance before long. The strongest storms will be capable
of winds up to 60 mph, and once again storm coverage should wane
pretty rapidly after sunset.

The approach and stall of the frontal boundary on Thursday will also
lead to prefrontal torching across the area. Highs will reach near
100 along and northwest of I-44 with temperatures in the upper 90s
south and east of it. This will be the first of two miserable days
of summer heat - the ridge moves overhead on Friday and temperatures
bump up another degree or two. Heat indices may eclipse 105 in parts
of our area tomorrow, so we will have to watch for the potential
need for a heat advisory.

Relief is expected to arrive this weekend as a trough lifts into the
central Plains and encourages a cold front to approach the area.
Right now the best rain chances look to be across the northern half
of Oklahoma on Saturday night, though there is some indication for
storm potential with the boundary sweeping through on Sunday.
Uncertainty increases after this, but a common model solution
shows a reinforcing cold front on Sunday night, which would bring
drier air into our region for the early part of next week.

Meister

&&

.AVIATION...
(12Z TAFS)
Issued at 533 AM CDT Wed Sep 18 2024

Showers and isolated thunderstorms will continue to make their way
across northern Oklahoma this morning. Have included a small
window to impact PNC. Otherwise, expect VFR conditions through the
forecast period. Winds will pick up some later this morning with
some gusts above 20kts across western Oklahoma. Additional
convective development will occur late this afternoon and evening
and this may impact WWR.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  73  97  74  97 /   0  30  10   0
Hobart OK         74 100  74 100 /  20  30   0   0
Wichita Falls TX  74 100  74 101 /   0  10   0   0
Gage OK           70 100  68  99 /  20  10   0  10
Ponca City OK     72 100  70  99 /  20  20  10  10
Durant OK         70  97  73  99 /   0   0   0   0

&&

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

$$

SHORT TERM...04
LONG TERM....04
AVIATION...30