Area Forecast Discussion
Issued by NWS Oklahoma City, OK

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000
FXUS64 KOUN 131133
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
633 AM CDT Wed Mar 13 2024

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 311 AM CDT Wed Mar 13 2024

The warm front/leading edge of greater boundary-layer moisture has
advanced farther north and west this evening than short-range
guidance forecasted. Therefore, some locations along the northwest
fringe of the moist axis may see temperatures 10 or more degrees
warmer this morning than anticipated.

This airmass likely will not get much further north or west until
daybreak, when cyclogenesis will commence across the northern
Panhandles in response to the approach of an upper-level jet max
from the southwest. We are seeing some key differences in the
overall synoptic setup even compared to 24 hours ago, which will
impact both fire weather and severe potential. Most notably, the
upper trough/jet max has slowed down quite a bit on model
guidance as the main trough cuts off to our west. This means that
instead of a 994-996 mb low across central Kansas this afternoon,
we may see something more in the range of a 999 mb low across far
northwest Oklahoma. Even between the 0Z and 06Z HRRR, this trend
has been notable.

How will this impact fire weather? For one, there may be a zone
across far northwest Oklahoma (Harper and Woods Counties) wherein
southwest winds are weaker than initially anticipated due to the
low`s presence overhead. To the south of the low, synoptic
conditions still favor the development of a low-level thermal ridge
with gusty southwest winds to the west of the dryline, which will
mix eastward to near I-35 by afternoon. A potential corridor to
watch for maximum wind potential will be along an axis running from
Garfield to Baylor Counties, where the TTU WRF shows maximum wind
gust potential of about 35-40 mph. Meanwhile, both the TTU WRF and
HRRR are in agreement that minimum dewpoints will reach or drop
below 10 percent across the western two tiers of counties. Given the
very dry, very warm, and breezy conditions, a large area of critical
fire weather with embedded very critical potential just south of the
surface low seems like a fair approximation. A wind shift will
enter northwest Oklahoma late tonight, bringing much higher
relative humidity.

How will the slower trough/weaker surface response impact severe
weather? Well, for one, model trends on the HRRR/RRFS suggest that a
weaker surface low will lead to somewhat poorer moisture advection
to the east of the dryline, though the NAM and NSSL WRFs notably do
not show as strong of a trend. For now, would lean toward the NSSL
solution which brings low-60s dewpoints up to around I-40 by late
afternoon. Given the late approach of the upper-level trough, CI
looks to be unlikely prior to sunset across the entire dryline.
However, there is at least a weak model signal for convection to
develop after sunset across our far eastern zones, which would
coincide with the approach of upper-level forcing. If any storms
do manage to form, a band of around 2000 J/kg of MLCAPE will
exist, as well as hodographs that would suggest supercell
organization. Large hail would be the primary concern with these
storms.

Temperatures should continue to be warm overnight as the LLJ ramps
up and the dryline once again sloshes back to the north and west.

Meister

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 311 AM CDT Wed Mar 13 2024

A rather widespread round of showers and thunderstorms is expected
along and southeast of cold front Thursday afternoon and evening.
The exact location of this cold front remains one of several
uncertainties; however, the trend has been for this cold front to be
further northwest, and it may be just southeast of I-44 by
midafternoon. All severe threat will be concentrated in the area
south and east of the front - say, from Lincoln to Clay Counties and
southeast.

Convection initiation may occur early in the afternoon as extremely
rich (by March standards moisture) piles up in the warm sector and
an uncapped reservoir of 1,500-2,500 J/kg of instability. An impulse
within the STJ may be the initiating forcing, which could occur as
early as early afternoon in southeast Oklahoma. Although upper-level
winds will be seasonably strong, promoting ample cloud-layer shear
for supercell development, there is a strong signal for the LLJ to
be displaced well east of our area during the day. The result will
be negligible curvature to hodographs and rather minimal 0-6 km
shear, promoting splitting cells. Given the rather abundant forcing,
the infringement of a boundary that will be parallel to the deep
flow, and the propensity for updrafts to split, a reasonable
assumption will be a messy/highly forced convective mode with many
updrafts competing in limited space. Within this regime, and given
PWATS approaching 1.5 inches, wet microbursts and flooding may be
the primary concerns. However, given the strong instability and deep
shear, large-to-very-large hail are possible early in the convective
cycle, and a tornado risk cannot be entirely ruled out with up to
100 J/kg of 0-3 km CAPE expected.

After the convectively-reinforced cold front pushes through the
area, a much cooler day will commence on Friday with high
temperatures sitting around 60. Precipitation chances will continue,
particularly across western north Texas where the remnants of
isentropic lift from a High Plains snowstorm will contribute to
occasional showers during the day on Friday.

Beginning this weekend, our area will be sandwiched in between two
dominant upper-level features - the same trough whose cutting off is
slowing today`s jet streak approach, and a reinvigorated northern
stream jet streak that will come crashing from the northwest into
the northern Plains and Midwest. This close proximity to the two
features means that forecast predictability is low in the extended
range, but with little to no indication of ridge development between
the two features, it can be plausibly inferred that there be
continued "cooler" temperatures near 60 with periodic rain chances
across western north Texas and southern Oklahoma through the weekend.

Meister

&&

.AVIATION...
(12Z TAFS)
Issued at 628 AM CDT Wed Mar 13 2024

MVFR conditions expected to continue first half of the day at
KDUA, with cigs possibly rising into VFR this afternoon, but lower
again tonight. Farther north, at least tempo MVFR central Oklahoma
this morning as moisture increases ahead of veering and dryline
flow. Near and north of warm front, which will affect KSWO and
KPNC, IFR conditions possible first 3 to 6 hours of forecast
before warm sector surges north and flow begins to veer this
afternoon. Winds will be gusty (20 to 30 KT common) with dominant
direction southwesterly most sites this afternoon. Backing and
weakening winds after 00Z, with a west/northwest shift toward end
of forecast northwest Oklahoma as front moves in. TSRA chances too
low to mention this forecast cycle.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  83  59  78  45 /  10  20  20  10
Hobart OK         83  49  76  44 /   0   0   0   0
Wichita Falls TX  87  59  81  50 /   0  10  20  10
Gage OK           83  42  68  38 /   0   0   0   0
Ponca City OK     82  57  77  44 /  10  30  20  10
Durant OK         79  64  79  53 /  10  20  80  70

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Red Flag Warning from noon today to 7 PM CDT this evening for
     OKZ004-005-009>011-014>016-021-022-033>036.

TX...Red Flag Warning from noon today to 7 PM CDT this evening for
     TXZ083>085-087-088.

&&

$$

SHORT TERM...04
LONG TERM....04
AVIATION...11


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