357
FXUS64 KOUN 221740
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
1240 PM CDT Tue Apr 22 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 1235 PM CDT Tue Apr 22 2025

- Storm chances this evening, especially in the western portions
  of our area.

- More widespread storms are possible tomorrow evening and
  overnight.

- Daily chances for storms and heavy rain continue after that.

&&

.NEAR TERM...
(Today and tonight)
Issued at 213 AM CDT Tue Apr 22 2025

Today is the start of a very subtle, late-May-like flow pattern.
About 30 knots of 500 mb westerlies will sit over our area by this
afternoon, with a weak surface low located right around Greensburg,
KS. The dryline will extend south-southwest off of it. Quality of
boundary layer moisture is expected to be poor during daylight hours
with dewpoints reaching perhaps into the upper 50s. Still, in the
absence of an overly strong capping EML, 1,000-1,500 J/kg of MLCAPE
will develop east of the dryline. Storms are likely to form in the
Panhandles late in the afternoon and move eastward toward our area
in the early overnight period. Would expect these storms to be on a
general weakening trend toward 04-05Z with the LLJ axis remaining
west of the 100th meridian, but cold pool dynamics have been known
to surprise before. The primary severe risk in our area will likely
be damaging wind gusts up to 65 mph given the relatively large
dewpoint depressions expected. Heatbursts from decaying convection
will also be possible.

Moisture advection will continue into the night tonight, so lows
will remain near 60 degrees in most spots. Cloud cover will increase
throughout the night as increased moisture transport allows stratus
to develop.

Meister

&&

.SHORT TERM...
(Wednesday through Thursday night)
Issued at 213 AM CDT Tue Apr 22 2025

The subtle flow pattern continues on Wednesday with considerable
uncertainty in outcomes. The main jet will remain well to the
north in the Northern Plains, so synoptic-scale forcing for
convection will be limited. With that said, most guidance is
depicting robust moisture return with dewpoints into the mid-60s
across much of our area. Some models have indicated that a remnant
MCV from the late Tuesday storms could wander into our area, and
that would be an obvious forcing mechanism for such storms. The
LLJ will be further east on Wednesday, so any storms that develop
in the afternoon/evening will have the chance to mature into
supercells. With time, a squall line is likely to develop to our
north in central KS, and that may propagate southward along the
LLJ into northern Oklahoma Wednesday night. Once again: all of
this seems quite nebulous and will be heavily dependent on the
behavior of storms this evening. Regardless, be prepared for
Wednesday and especially Wednesday night to be a possible subtle
severe weather day with more widespread rain chances.

Predictability in this pattern drops even lower as we get into
Thursday. Medium-range guidance such as the GFS and NAM both show
the moist sector surging northward into Kansas again following the
Wednesday night storms, with a sharpening dryline pushing to the
eastern edge of the Caprock. The primary limiting factor for severe
weather will likely be the weakness of mid-level flow, which may
promote outflow-dominance within storms as they develop and move
east off of the dryline. Of course, the moist sector might also end
up shunted southward by a Wednesday night MCS, completely altering
the forecast. Alternatively, we could see an outflow boundary serve
as a focusing mechanism for severe weather. The point is that there
are plenty of unknowns, and we`ll have to take things a day at a
time through the rest of this week.

Meister

&&

.LONG TERM...
(Friday through Monday)
Issued at 213 AM CDT Tue Apr 22 2025

Beginning on Friday, a large closed low will move onshore from the
Pacific and begin impacting our weather. The immediate impact will
be a tendency for surface winds to back from southerly to
southeasterly, letting the moist sector pour back onto the Llano
Estacado. A ridge will try to develop over Mexico and Texas during
the early weekend, but our area will remain more in the transition
zone/southwest flow aloft. As I`ve already said several times,
uncertainty is high. However, this kind of pattern looks especially
favorable for storm development on the High Plains with nocturnal
MCSs arriving into our area. We`ll monitor that forecast and start
to pinpoint possible targets of opportunity between Friday and
Sunday as the weekend draws closer.

The trough (or at least a lobe of it) will begin its ejection into
the Great Plains on Sunday and especially Monday. We`ll have to
watch those days for the potential for the more classic,
synoptically driven severe weather events the Southern Plains are
known for.

Bottom line: Many chances for storms in the coming week.

Meister

&&

.AVIATION...
(18Z TAFS)
Issued at 1235 PM CDT Tue Apr 22 2025

VFR conditions will prevail through 23Z with a breezy
south to southwest wind. Late this afternoon and evening,
scattered thunderstorms are expected to develop across
northwestern Oklahoma and the Texas Panhandle.  Some of
these storms may impact terminal sites (WWR,CSM, SPS, LAW).
The stronger storms may produced wind gusts over 50 knots
and some hail.  Late overnight into Wednesday morning, MVFR
ceilings are possible, especially across southern and central
Oklahoma.


&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  60  77  62  75 /  20  80  60  80
Hobart OK         58  78  60  78 /  40  80  60  80
Wichita Falls TX  61  79  62  80 /  50  80  50  80
Gage OK           54  77  56  78 /  40  80  70  80
Ponca City OK     57  76  59  75 /  30  70  60  80
Durant OK         62  81  64  77 /  10  70  40  70

&&

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

$$

NEAR TERM...04
SHORT TERM...04
LONG TERM....04
AVIATION...06