173
FXUS64 KOUN 162037
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
337 PM CDT Thu May 16 2024

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Friday)
Issued at 336 PM CDT Thu May 16 2024

Still a "wet" forecast in the short term until this current system
exits Friday night, but less severe with much of this afternoon
through tonight`s severe convection staying south of our CWA.

An upper trough will continue to dig across the U.S. Southwest
toward the Southern Plains with its axis bisecting our CWA by Friday
afternoon.  This trough will continue to expel shortwave
disturbances downstream prior to its arrival although expecting most
of them (with strongest vorticity) triggering elevated severe storms
to stay south of our CWA.  Although much of the elevated forcing and
abundant surface moisture will be south of our CWA, we still have a
surface boundary/stalled cold front stretched across our area with
lower 60s dewpoints and weak mid-level capping on both sides of the
stationary front and our western CWA is diurnally heating up.  Much
of our CWA is still weakly unstable (SBCAPE: 1000-2000 J/kg) with
ample deep-layer shear south of I-40.  As a result and with current
convection already over northern Texas moving toward our western
north Texas counties, will keep storm POPs at 60-70% across our
southwestern CWA with a few strong but below severe. With the upper
trough starting to move in, will keep storm POPs (up to 50-60%)
through tonight although elevated instability is weak so convection
should remain below severe as well as surface based CAPE with the
stalled surface boundary should it start moving. Also added patchy
radiation fog across the eastern two-thirds of our CWA for few hours
mid-morning.  Will maintain a marginal/low-end risk across southeast
Oklahoma for Friday afternoon until this system exits out, with hail
& winds as the potential severe hazards.

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 336 PM CDT Thu May 16 2024

The polar jet finally digs our upper trough to the east exiting our
area as weak ridging from a now subtropical jet starts building over
the Southern Plains through the weekend resulting in a heating
trend. Further upstream a weak trough will be slowly digging across
the eastern Pacific toward the Southern California coast which will
be our next system to come through around Tuesday/Wednesday.  Prior
to this next systems arrival we will start heating up into the lower
90s by Sunday across the western half of our CWA to the upper 80s to
the east.  A surface low lee of the Colorado Rockies will start
bringing a return circulation of strong southerly flow Sunday with
strong low-level jets overhead both Sunday & Monday nights.  As a
result, gusty south winds will start Sunday afternoon and will
likely stay windy through Monday night.  Expecting to mix up to at
least 850 mb off the surface Sunday and Monday afternoons so could
see 30-35 mph gusts or possibly higher to near advisory criteria on
Monday afternoon. Although NBM default windspeeds look fine for
Sunday, did increase them for Monday afternoon by nudging 50% of the
NBM 90th percentile winds.  Monday may also be the hottest afternoon
with all of our CWA heating up to the 90s, to upper 90s across far
southwest Oklahoma and adjacent western north Texas.  Our increasing
southerly flow will also include gulf moisture transport forming a
dryline through western Texas.  With upper 60s dewpoints creeping
in, Monday will also feel quite muggy, although windy conditions may
provide some relief.  Although we stay mostly dry until this
Tuesday/Wednesday system comes through, will still maintain storm
POPs (20-30%) across northcentral Oklahoma for both Sunday & Monday
nights due to potential MCS activity expected mainly across the
Central Plains/Kansas.

Our next system comes through Tuesday into Wednesday which will push
a cold front through although models differ with the handling of the
dryline with the front overtaking the dryline with the GFS solution
while the ECMWF does not punch the dryline through until late in the
week.  Either way, moisture advection will be strongest east of I-35
and quite unstable and strongly sheared ahead of the cold front for
thunderstorm development. For now, will have storm POPs Tuesday
afternoon and overnight across central through southeast Oklahoma
and can`t completely rule out severe based on current model runs,
although probabilities are still too low this far out but it will be
a day to keep an eye on.  Lastly will have storm POPs in for
Thursday across central through southeast Oklahoma with a potential
shortwave coming through, although keeping them low (20-30%) due to
model differences with a wet GFS & NBM solution although the ECMWF
keep us dry.

&&

.AVIATION...
(18Z TAFS)
Issued at 1142 AM CDT Thu May 16 2024

VFR conditions will become MVFR and IFR later tonight into the
overnight hours. Winds overall will remain weak through the TAF
period. There is a low chance for showers and storms to redevelop
across the area this afternoon and evening, but confidence in
storms affecting any TAF site is low at this time.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  61  77  59  87 /  60  40  10   0
Hobart OK         59  78  58  89 /  70  30   0   0
Wichita Falls TX  62  78  60  89 /  70  40  10   0
Gage OK           54  82  57  91 /  30   0   0   0
Ponca City OK     60  78  58  86 /  40  20   0   0
Durant OK         62  79  62  87 /  50  50  20   0

&&

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

$$

SHORT TERM...68
LONG TERM....68
AVIATION...13