356
FXUS64 KOUN 172003
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
303 PM CDT Fri May 17 2024

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

.SHORT TERM...
(This evening through Saturday)
Issued at 301 PM CDT Fri May 17 2024

Our upper trough will be exiting to the east through today with
ridging building in behind it setting us up for a heating trend
starting Saturday.  The stalled surface boundary/cool front has
washed out with a broad dryline stretched lee of the Colorado/New
Mexico Rockies.  Will maintain storm POPS across southeast Oklahoma
this afternoon through early evening as embedded vorticity in the
trough of the wave could initiate isolated elevated storms. Although
weak in intensity, forecast sounding showing sufficient high-based
instability (above 800 mb) for convection although shear is very
weak for any organization or going severe.  Visible satellite
imagery was already showing some cyclonic circulation with the cloud
cover over southeast Oklahoma while the latest three HRRR runs
suggesting isolated convection.

With no surface boundaries coming through, our surface moisture
won`t be going anywhere so expect temperatures tonight to cool to
the dewpoint (lower 60s) enhanced by clear night skies and
light/calm winds. As a result, could see some radiational fog
develop by mid-morning mainly east of I-35. Although much of the fog
should be patchy, there could be some embedded areas going dense.
Any fog should that develops should burn off shortly after sunrise.
As previously mentioned, pressure heights will start rising Saturday
as an upper ridge start building in and under sunny skies afternoon
temperatures will heat about 10 degrees warmer than today with highs
in the lower 90s across our western CWA to the upper 80s to the
east.

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 301 PM CDT Fri May 17 2024

Gusty south winds return Sunday as well as the the dryline
sharpening up across the Panhandles through west Texas as surface
moisture increases across our area.  Will see much of our western
and northern CWA warm well into the mid 90s and although
conditional, could see some convection develop east of the dryline
by late afternoon but due to uncertainties with instability strength
just east of the dryline will keep them very low (14-18%) but
mentionable for now. Although the GFS is the weaker solution with
respect to surface based instability, the ECMWF is much more
aggressive in the moderate (3000 J/kg) range while deep-layer shear
will be sufficient for organized severe convection in a most likely
uncapped environment.  The mid-level cap strengthens closer to I-35
so will keep POPs and the marginal severe risk for Sunday afternoon
across all of western Oklahoma into a few of our adjacent western
north Texas counties with large hail & damaging wind gusts as the
potential severe hazards.  If convection off the Southern High
Plains does not initiate, then have a higher chance for storms with
an MCS developing across Kansas through northern Oklahoma late
Sunday as a shortwave digs through the westerlies. For this system,
will have up to 40% POPs for elevated storms overnight extending
down to I-40.  Can`t rule out a few strong to marginally severe
storms overnight as well.

A persisting tight surface pressure gradient will maintain windy
conditions Sunday night into Monday with a low-level jet developing
through the night.  Mixing into the jet late Monday morning could
result in 30-35 mph gusts during the afternoon, and perhaps higher
should the GFS solution be correct verses a weaker ECMWF solution
with the strength of the jet in the afternoon.  Our heating trend
will peak on Monday afternoon with all of our CWA rising well in the
90s, to upper 90s across our western CWA.  Both models in agreeance
with the dryline punching into western Oklahoma during the
afternoon.  It will feel quite muggy as well ahead of the dryline
with those upper 60s dewpoints, although windy conditions might
bring some relief from it.  Our upper ridge is scooted out on
Tuesday with a broad trough digging through from the west, pushing
our next cold front and the dryline through late into Wednesday.
This will bring a return of storm POPs late Tuesday mainly along and
east of I-35 along with a severe risk.  This cold front may lift
back through our area as a warm front on Thursday so will maintain
rain/storm POPs widespread for late next week.  Although
temperatures should be cooler more in the 80s after Tuesday,
afternoon temperatures still trend warmer than climatically average
through the end of next week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1211 PM CDT Fri May 17 2024

Winds will remain generally light, gradually becoming more
southerly. An isolated shower or storm may develop in south
central Oklahoma this afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  61  88  65  90 /   0   0   0   0
Hobart OK         61  92  65  93 /   0   0   0  20
Wichita Falls TX  62  92  66  93 /   0   0   0  10
Gage OK           59  93  63  95 /   0  10  10  20
Ponca City OK     59  88  63  89 /   0   0   0  10
Durant OK         62  89  65  90 /  20   0   0   0

&&

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

$$

SHORT TERM...68
LONG TERM....68
AVIATION...14