720
FXUS64 KOUN 212330
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
630 PM CDT Sat Sep 21 2024

...New AVIATION...

.KEY MESSAGES...
Updated at 621 PM CDT Sat Sep 21 2024

    - 60-80% shower/storm chances tonight through Monday morning.
      Marginal risk for severe storms Sunday afternoon & evening.

    - Marginal to slight risk for localized flooding tonight into
      Sunday, highest across southwest Oklahoma and western north
      Texas.

    - Below average temperatures Sunday into much of next week.

&&

.SHORT TERM...
(This evening through Sunday)
Issued at 211 PM CDT Sat Sep 21 2024

Water vapor imagery depicts the center of an upper level low
progressing eastward across eastern Arizona early this afternoon.
Ahead of this feature, large scale ascent is supporting widespread
showers and storms across eastern New Mexico and the Oklahoma/Texas
panhandles, with a few storms making it into northwest Oklahoma.
More substantial shower and thunderstorm activity is expected to
move into western Oklahoma tonight as a cold front makes its way
south and eastward. A few of these storms could be strong this
afternoon, but the majority of severe weather is expected to remain
to our west this afternoon and evening.

As the front continues its way southward and the upper low moves
closer to the area, showers and thunderstorms will continue to
progress across more of the area during the day on Sunday. Frontal
timing has sped up over the previous forecast which will have
implications on the temperature forecast and where severe potential
will be highest tomorrow afternoon. It appears that instability will
be highest near and SE of the I-44 corridor which is where we may
see redevelopment or intensification of ongoing convection tomorrow
afternoon. The main hazards with these storms will be damaging wind
gusts and marginally severe hail. Similar hazards are possible
further west tomorrow morning with convection expected to be ongoing
along and north of the front.

Given forecast PWATs of 1.5-2.0" heavy rainfall will also be
possible much of the day tomorrow. Given steering flow is fairly
parallel to the front we may see training of thunderstorms in some
locations which could lead to a localized flooding threat. However,
given the lack of recent rainfall our 1 and 3 hour flash flood
thresholds are rather high (2.5 to 4 inches) which will mitigate the
risk overall. As of now the highest overall heavy rain threat
appears to be across southwest Oklahoma and western north Texas
where thunderstorm activity is expected to be most numerous and
persistent.

Finally, the cold front is expected to bring much cooler
temperatures in its wake, with portions of northwest Oklahoma likely
stuck in the upper 50s to low 60s for much of the day tomorrow,
with a tight temperature gradient expected across southwest into
central Oklahoma. Forecasting exactly where this gradient will be
located is difficult, but it is quite possible that some
locations in central and southwest Oklahoma see steady or even
falling temperatures during the afternoon as the front passes
through.

Ware

&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 211 PM CDT Sat Sep 21 2024

Rain chances diminish Monday morning across southeast Oklahoma as
the front pushes further south of the area. Cooler temperatures are
expected to stick around for much of the coming week, with highs 5-
10 degrees below average for this time of year as a trough remains
over the central US. As shortwave energy digs across the central
plains and attempts to form another cutoff low, parts of the area
could see additional chances for showers and storms. However,
models still show significant disagreement on the track of this
next system and uncertainty is higher than normal at this range.
This system may then linger in the vicinity late next week,
maintaining cooler temperatures and potentially more rain chances
for parts of the area.

Ware

&&

.AVIATION...
(00Z TAFS)
Issued at 621 PM CDT Sat Sep 21 2024

MVFR conditions near TSRA and also tomorrow behind main cold
front, spreading north to south.

Area of RA and TSRA will mainly affect KWWR and KCSM first several
hours of the forecast, as lift continues north of the effective
frontal boundary (from outflow). Increased southward/eastward
progression of the front in terminals based on radar/obs trends,
but outflow induced wind shift will slow down this evening and
will leave overnight wind shift at KSPS and no shift at KDUA.
Main cold front will push through tomorrow with redevelopment of
TSRA near the front from KSPS/KLAW up through central Oklahoma.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  70  80  56  71 /  20  70  80  10
Hobart OK         68  75  52  75 /  50  80  60  10
Wichita Falls TX  74  88  58  77 /  10  50  60  10
Gage OK           57  63  46  73 /  90  50  10   0
Ponca City OK     68  77  55  70 /  50  70  60  10
Durant OK         73  92  63  79 /   0  10  30  40

&&

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

$$

SHORT TERM...08
LONG TERM....08
AVIATION...11