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000
FXUS64 KOUN 251137
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
637 AM CDT Thu Apr 25 2024

...New UPDATE, AVIATION...

.UPDATE...
Issued at 636 AM CDT Thu Apr 25 2024

The warm front has lifted north quickly and is currently near the
Kansas border. With that, the isentropic lift above the frontal
surface and the associated showers have shifted north and
developed primarily north and northeast of the forecast area this
morning. We still will have some potential for shower development
this morning as low-level moisture continued to advect north, but
with the primary lift now to the north of the area, will lower
POPs for this morning and early afternoon.

&&

.SHORT TERM...
(Today and tonight)
Issued at 352 AM CDT Thu Apr 25 2024

Isentropic ascent/warm air advection is resulting in a few showers
and thunderstorms across north central Oklahoma this morning as
the warm front lifts to the north. This convection will likely
persist through the morning hours before experiencing a downward
trend late morning into the afternoon. Elsewhere, an isolated
shower or storm may occur due to the warm air advection; however,
coverage will be much more sparse (i.e., most locations should
remain dry today).

By this late afternoon, a shortwave trough will lift into the
Plains with increasing synoptic-scale ascent. At the surface, a
dryline will sharpen from Kansas, southward through the Texas
panhandle, as a low deepens across eastern Colorado into western
Kansas. While the synoptic-scale pattern is favorable for severe
convection, a capping inversion at around 800 mb will likely limit
the southern extent of daytime convection. Forecast soundings and
HREF members indicate the southern extent of convective
initiation might be as far south as the first two rows of counties
in the Texas panhandle. If isolated supercells do develop this
far south, they would move to the northeast and could affect
northwest Oklahoma this evening before dissipating with the loss
of daytime heating. Large hail, damaging wind gusts, and tornadoes
are possible with any supercells that can sustain themselves into
northwest Oklahoma. Note that the probability of this scenario
occurring has been on a downward trend given the strength of the
cap.

Overnight, the trough will lift across the area with the
dryline/Pacific front accelerating to the east. Thunderstorms will
develop from the large-scale forcing--likely near Lubbock--and
quickly move to the northeast and likely grow upscale into a
quasi-linear convective system (QLCS)/squall line. Areas along
and south of I-40 west of I-35 and along and southeast of I-44 to
the east I- 35 have the highest probability of being affected by
the line of thunderstorms. Damaging wind gusts will be the primary
hazard with any bowing segments and QLCS mesovortices. Given ~30
to 35 knots of 0 to 1 km shear, tornadoes are possible with any
QLCS mesovortices--especially on the left side of any bowing
segments.

Mahale

&&

.LONG TERM...
(Friday through Wednesday)
Issued at 352 AM CDT Thu Apr 25 2024

Friday: Thunderstorms will exit southeast Oklahoma during the
morning hours. As the trough lifts toward the Midwest, the
trailing dryline will stall near I-35. While synoptic-scale ascent
will be lacking with the departing trough, the environment ahead
of the dryline across south central and southeast Oklahoma will
have little or no cap present during the afternoon and early
evening. Therefore, while the probability is rather low, the
chance for redevelopment is not zero. If storms develop in this
environment, they would likely be supercells with the threat for
large hail, damaging wind gusts, and tornadoes.

To the west of the dryline, critical fire weather conditions will
likely develop across far northwest into west central Oklahoma.
Southwest winds at 20 to 25 mph with wind gusts in around 30 mph
will be combined with relative humidity values around 15%.

Saturday: Saturday still has the potential for a significant severe
weather event across the entire area as another trough lifts into
the Southern Plains with the dryline near or just east of the
Oklahoma/Texas state line.

While the synoptic-scale pattern is a classic significant severe
weather event for the Southern Plains, there remains forecast
uncertainty that could impact the magnitude of the risk. Several
deterministic models and ensemble members indicate the potential
for morning convection associated with a 700 mb wave and attendant
isentropic ascent/warm advection. If morning convection occurs,
there is uncertainty on the magnitude of convective-overturning
and recovery that will happen in its wake. At this time, most
guidance indicates enough of a recovery for some severe weather
with a moist, unstable, and highly-sheared environment east of the
dryline during the late afternoon and evening. There is even the
potential the morning convection may intensify and become the
start of the severe weather event itself (with more than one round
of severe weather).

These sub-synoptic/mesoscale details on the morning convection will
not be resolved until we are closer to the event. However, given the
synoptic-scale pattern, the ceiling for the worst case scenario
(e.g. How bad could it be?) is quite high on Saturday. Significant
severe weather with large hail (2" or larger), damaging wind gusts
(74 mph or higher), and tornadoes (EF2 or stronger) are all possible
if the atmosphere sufficiently recovers (or remains undisturbed) and
the storm mode is discrete supercells. In addition, with the
rainfall Thursday night/Friday morning and the possibility of
multiple rounds of thunderstorms on Saturday, flooding will also be
possible. Bottom Line: It is important to stay weather aware on
Saturday!

In addition, if the dryline is east of the Oklahoma/Texas state
line, near critical to perhaps critical fire weather conditions
are likely near the 100th meridian across northwest into west
central Oklahoma Saturday afternoon.

By late Saturday night, a strengthening low-level jet will likely
result in upscale growth into a complex of thunderstorms across
southeast Oklahoma. This would increase the flooding threat across
this area.

Sunday: The chance for strong to severe thunderstorms along with a
flooding risk may continue across southeast Oklahoma on Sunday.
Elsewhere, a slightly less humid and cooler air mass is forecast.

Monday through Wednesday: There will be a low chance of showers
and thunderstorms, primarily across the southeast on Monday and
Tuesday. More widespread chances of rain return on Wednesday with
a trough potentially impacting the area.

Mahale

&&

.AVIATION...
(12Z TAFS)
Issued at 636 AM CDT Thu Apr 25 2024

Despite the low-level moisture advection, the stratus has been
slow to develop with only patchy areas of the MVFR ceilings so far
this morning. Still expect increase in stratus and lowering of the
ceilings through the morning as moisture continues to move in.
Although some isolated showers are possible this morning and
afternoon (primarily north, but with probabilities too low to
include in the TAFs), showers and thunderstorms are expected to
develop in west Texas this evening and move northeast across much
of the southern and central portion of the forecast area
overnight. Some of these storms may be severe with hail and strong
winds.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  78  63  83  65 /  20  90  30   0
Hobart OK         78  60  85  60 /  20  70   0   0
Wichita Falls TX  79  64  85  65 /  20  80  10   0
Gage OK           81  55  86  55 /  20  20   0   0
Ponca City OK     75  63  83  64 /  60  90  30   0
Durant OK         80  66  80  68 /  10  90  80  20

&&

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

$$

SHORT TERM...10
LONG TERM....10
AVIATION...26