848
FXUS64 KSHV 220810
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
310 AM CDT Wed May 22 2024

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

.SHORT TERM...
(Today through Thursday Night)
Issued at 205 AM CDT Wed May 22 2024

Tricky short term forecast as there have been some changes with
the 00z progs that will result in the heavier rain threat shifting
further south towards the I-20 Corridor if these latest trends end
up verifying.

Currently dealing with widely scattered showers and thunderstorms
across portions of SE OK and SW AR along remnant outflow boundary
and a weak perturbation that moved out of the Ouachitas earlier
Tue Evng. Plentiful mid and high level cloud cover, not to mention
returning low cloud cover and a tight surface pressure gradient
is resulting in very warm predawn temperatures still near 80
degrees in a few locations. Meanwhile, the true cold front remains
across NW AR into Eastern and Central OK attm with this feature
forecast to move a little further south, perhaps in the
Upper/Middle Red River Valley by 00z this evening.

The setup today for renewed convection remains the same. Upper
flow remains from the WSW and ripples in this flow will interact
with extreme instability today to produce intense convection, some
of which will produce damaging thunderstorm wind gusts and large
hail, especially if an MCS can materialize off the stalled frontal
boundary and move into our region as some of the latest CAMS and
deterministic progs suggest. There will be plenty of CAPE and Deep
Layer shear to suggest that supercell thunderstorms will also be
possible and with lapse rates near 8 deg in the 700-500mb layer,
hail larger than 2 inches in diameter will also be possible. While
an isolated tornado cannot be ruled out initially with any
discrete supercell thunderstorm or embedded in any QLCS segments,
the tornado probability is a distant third risk compared to the
wind and hail risks through tonight.

As mentioned above assuming this MCS does develop, it`s movement
will be more likely to the southeast vs east (per previous
deterministic model runs) which suggest the heavier rain threat
may be further south through tonight or closer to the I-20
Corridor than the I-30 Corridor. Regardless, rainfall amounts of
1-3 inches will be possible which we should be able to take
without much in the way of any widespread flooding concerns.
Therefore a Flood Watch will not be necessary with this forecast
package.

Given the uncertainty with the first 24hrs of convective evolution
across our region, this opens up even more uncertainty pertaining
to the Thu/Thu Night forecast when it comes to additional
severe/heavy rain potential. A lot of this potential will be based
on where outflow boundaries will be present and the capability of
atmospheric recovery during the day Thursday. Much of the first
half of Thu looks fairly uneventful until we see afternoon,
diurnally driven instability once again. Upstream disturbances
will quickly move out of the TX Hill Country and into the Middle
Red River Valley for another chance for strong to severe
thunderstorms, this time mainly across our northwest half. Again,
large hail and damaging thunderstorm wind gusts along with heavy
downpours will accompany the late Thu/Thu Night event per SPC and
WPC`s Slight Convective Risk and Slight Excessive Rainfall
Outlooks.

13

&&

.LONG TERM...
(Friday through Tuesday)
Issued at 205 AM CDT Wed May 22 2024

Much of Friday looks quiet, except by late afternoon into the
evening and overnight hours when strong to severe thunderstorms
could redevelop along the old frontal boundary which may be
located across SE OK into SW AR and NE TX. Extreme instability
and steep mid-level lapse rates would again promote large hail and
damaging thunderstorm wind gusts and the same could be said for
late Sat Aftn/Sat Night across the same general areas.

Held onto small pops across our northern and northeastern zones
for Sunday/Sunday Night and areawide Monday/Monday Night that will
come with an apparent frontal passage. This frontal passage is
setup by a change in the overall upper level pattern with upper
ridging across the Intermountain West and a longwave trough
swinging through the Plains.

Ahead of the frontal boundary, some of the hottest temperatures
of the late Spring Season will be felt across our region Sat and
again on Sunday with afternoon high temperatures in the middle 90s
across much of the region. Combine this with high afternoon
humidity values and Heat Indices will come dangerously close to
Heat Advisory Criteria of 105 degrees, especially on Sunday.

13

&&

.AVIATION...
(06Z TAFS)
Issued at 1247 AM CDT Wed May 22 2024

Low clouds and MVFR ceilings will continue to spread across the
region affecting all TAF sites early in the period. A very slow
improvement is expected after sunrise, but VFR flight conditions
should return to most sites by 22/19z except across Southeast
Oklahoma, Southwest Arkansas and portions of Northeast Texas.
Scattered showers and thunderstorms will also begin to develop by
22/19z along and north of Interstate 30 before increasing in
coverage and intensity while gradually spreading east and
southeast. All TAF sites are expected to be affected by strong to
severe convection before the end of the period.

CN

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  91  74  91  74 /  50  70  20  20
MLU  90  72  90  72 /  40  60  20  20
DEQ  83  67  82  67 /  90  70  50  50
TXK  87  71  88  72 /  90  70  40  40
ELD  87  68  87  68 /  80  60  30  30
TYR  89  73  89  73 /  60  70  20  20
GGG  90  72  90  72 /  50  70  20  20
LFK  91  73  92  74 /  20  50  20  20

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&

$$

SHORT TERM...13
LONG TERM....13
AVIATION...09