508
FXUS64 KOUN 230319
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
1019 PM CDT Wed May 22 2024

...New AVIATION...

.SHORT TERM...
(This evening through Thursday)
Issued at 104 PM CDT Wed May 22 2024

Northerly winds will begin to weaken this evening as the upper
trough ejects into the Great Lakes. Skies may be clear in the early
part of the period prior to an expected switch to southerly surface
winds as southwesterly flow builds back in aloft. The moist airmass
will begin to filter back in prior to daybreak, especially in
southern Oklahoma and western north Texas where 6-hour dewpoint
rises may be as much as 5-10 degrees. Given this regime, the
development of advection fog along and south of I-40 is possible
late tonight and lingering into tomorrow morning.

The surface low will deepen to 994 mb across the High Plains
tomorrow afternoon, allowing for an impressive surface response. By
all indications, even the overmixed models like the HRRR/FV3/ARW all
show a pool of 70-73 dewpoints within our area by 22Z with the
dryline hanging around the 100th meridian. Storm coverage is very
much in question; the primary forcing mechanism will be a trough
moving into the central/northern Plains, and secondary forcing from
the STJ will pass through central Texas. On numerous occasions this
year we have seen STJ "lead waves" throw a wrench in the forecast on
Day 1. However, given the extremely rich boundary-layer moisture, a
sufficient environment is in place along the dryline that only weak
forcing will be necessary to trigger convection. If storms do
develop, the environment is favorable for supercells with an initial
risk for large-to-very-large hail. In the evening, the tornado risk
with supercells will increase as the LLJ increases and hodographs
take on a more streamwise shape. Overall, the risk for severe
weather at any one place tomorrow is on the low-to-medium side due
to questions about storm coverage, but interests in the path of any
of those storms tomorrow evening will want to pay very close
attention.

As an aside: a flood watch remains in effect for southeast Oklahoma
until late tomorrow evening. It doesn`t look like we`re going to end
up verifying widespread flooding conditions, but given the potential
for early-day CI in southeast Oklahoma with the STJ and maybe
another round later on, will continue the watch for at least one
more cycle.

Meister

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 104 PM CDT Wed May 22 2024

As the upper-level wave translates eastward across the northern
Plains Thursday night into Friday morning, another cold front will
crash southward. Right now, no members of the HREF suggest a signal
for convection with this front at least through 12Z on Friday
morning. Based on the 12km NAM, the front may begin to slow down in
our southeast Oklahoma counties Friday afternoon and evening, so we
may see some anafrontal convection develop with a low-end
severe/flood risk in the region. Highs during the day look
stratified across our area, with northern Oklahoma staying in the
low 80s and western north Texas/southern Oklahoma approaching 90.

Potentially the highest-ceiling day for severe weather in the
current stretch will be on Saturday. More substantial (50+ knots at
500 mb) flow will be impinging on the dryline near the 100th
meridian during peak heating, with plenty of instability and deep-
layer shear forecasted. Supercells capable of all severe hazards
will be possible in the afternoon and evening as it currently
stands, although uncertainty remains high thanks to the multiple
rounds of storms between now and then.

The dryline looks like it will make an eastward push during the day
on Sunday, keeping the storm risk lower and allowing highs to soar
into the 90s across a large portion of our area. By Monday, a
transition to western ridging looks likely across the US, which will
increase the potential for northwest flow, cold fronts, and
potentially MCSs across the northern half of our area.

Meister

&&

.AVIATION...
(06Z TAFS)
Issued at 1017 PM CDT Wed May 22 2024

Stratus will continue to develop overnight with MVFR/IFR ceilings.
Winds will gradually shift towards the S and SE this TAF period.
Moisture increasing could lead to BR at some sites overnight into
Thursday morning. Showers/storms will be possible overnight into
early Thursday, mainly at KDUA. Some storms will then be possible
again Thursday afternoon/evening starting in western parts of the
area but chances are too low for mention at some sites.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  62  82  66  83 /  10  50  10   0
Hobart OK         60  89  64  85 /   0  30   0   0
Wichita Falls TX  66  88  69  89 /  40  40   0   0
Gage OK           55  91  57  81 /   0  20   0   0
Ponca City OK     58  81  65  81 /   0  40  30   0
Durant OK         66  84  68  91 /  50  50  30   0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch through late Thursday night for OKZ032-041>043-
     046>048-050>052.

TX...None.
&&

$$

SHORT TERM...04
LONG TERM....04
AVIATION...25