Severe Thunderstorm Warning 9, NWS Corpus Christi, TX

Area Forecast Discussion
National Weather Service Corpus Christi TX
753 PM CDT Fri Mar 15 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Saturday night)
Issued at 351 PM CDT Fri Mar 15 2024

MSAS analyses reveal that the quasi-stationary frontal boundary
to the north has been moving slowly southward and is currently just
north of the CWA. PWAT values over the CWA in advance of this
boundary are expected to remain around 2 standard deviations
greater than normal. LAPS analyses reveal a decrease in the CIN
values and increase in CAPE values this afternoon, with current
values below 20 J/kg (except Webb County) and 3000-4000 J/kg,
respectively. NAM deterministic run predicts BRN values suggesive
of supercells tonight. Thus, strong to severe convection is
possible tonight. A Severe Thunderstorm Watch is currently in
effect for the northern counties and Webb County until 01z
Saturday. Concur with deterministic output that the front will
meander approximately over the CWA tonight/Saturday. The
combination of the front, disturbances ejecting from the quasi-
stationary H5 low center SW of the Four Corners Region, copious
moisture, and instability will contribute to additional scattered
to numerous showers and isolated to scattered thunderstorms late
tonight/Saturday. Concur with the Slight risk for severe
Saturday. Deterministic global/mesoscale NWP model runs predict a
high amplitude disturbance to move across the northern
Plains/Midwest/upper Mississippi Valley, and the corresponding
surge of MSLP will finally force the front SWD across the CWA
Saturday night, resulting in additional convection, especially
over the southern CWA. With respect to flash flood potential,
although larger CAPE/vertical shear will decrease rainfall
efficiency, rainfall rates of 2 to 4 inches per hour are possible
per the WPC, which is near the FFG. Further, the quasi-stationary
boundary will likely contribute to persistent redevelopment of
convection. Thus, concur with WPC Marginal and Slight risk of
Excessive rainfall for much of the CWA tonight/Saturday.

&&

.LONG TERM...
(Sunday through next Thursday)
Issued at 351 PM CDT Fri Mar 15 2024

Key Messages:

- Marginal Risk for Severe Thunderstorms Sunday
- Marginal Risk for Excessive Rainfall Sunday

Synopsis: An upper-level low will meander around the Desert
Southwest early next week before ejecting eastward across the
Central/Southern Plains mid-week. Several mid-level disturbances
wrapping around the low are expected to move across our CWA
throughout much of the workweek, resulting in a Marginal Risk for
Severe thunderstorms and Excessive rainfall Sunday, isolated to
scattered rain and storm chances taper off from west to east Sunday,
then isolated chances through the middle of the week, and then
isolated to scattered Wed/Thu as a boundary moves through the region
from west to east.

Hazards: Severe thunderstorms and excessive rainfall remain possible
(very low around 5% chance within 25 mi of a point) into Sunday
across the northeastern portions of South Texas but is expected to
taper off by afternoon. Marine hazards are expected as a boundary in
response to a frontal boundary moves offshore. See Marine discussion
below.

Temperatures: A slight downtrend next week followed by an uptick in
high and low temperatures towards the end of next work-week. Look
for highs Mon-Tues in the upper 60s to low 70s to jump into the mid
to upper 80s during the second half of the week. Overnight lows
mainly in the 60s but dip into the 50s Mon-Tues nights.

&&

.AVIATION...
(00Z TAFS)
Issued at 641 PM CDT Fri Mar 15 2024

IFR cigs have made their way into the Coastal Bend and is
currently impacting CRP and will continue to advect eastward into
the Coastal Plains. MVFR cigs for VCT/ALI and VFR for COT/LRD.
IFR/LIFR cigs will likely cover most of South Texas late tonight
through tomorrow morning as showers and storms from Mexico advect
eastward. A Severe Thunderstorm Watch is in effect through 3 AM
for Jim Wells County westward. Very large hail and damaging winds
are the greatest threats for any direct terminal impacts.
Confidence is very low on coverage tonight but have included
TEMPOs for when timing is greatest for each site. Additional
showers and storms will be possible tomorrow but a lull in the
afternoon is expected.

&&

.MARINE...
Issued at 351 PM CDT Fri Mar 15 2024

Areas of fog will develop this evening and persist through
Saturday morning as moist weak to moderate onshore flow moves
across the cooler sea surface. The proximity of a frontal boundary
and copious moisture will contribute to isolated to scattered
showers and thunderstorms tonight through Saturday. Locally heavy
rainfall may also occur. Weak onshore flow veers to the
northeast Sunday and increases to moderate early Monday in
response to a frontal boundary moving offshore. Small Craft
Advisory conditions are expected to develop early Monday with
gusts to Gale in the morning and afternoon. Northeast flow will
then become moderate late Monday, will veer onshore and become
weak Wednesday. Scattered to numerous showers and thunderstorms
Sunday reduce in coverage to isolated Monday through mid-week and
then increase to scattered Wednesday or Thursday as another
frontal boundary moves offshore.

&&

.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi    69  82  67  79 /  40  30  50  50
Victoria          67  80  65  75 /  30  50  60  70
Laredo            69  82  67  79 /  70  60  70  40
Alice             68  84  66  79 /  40  40  60  50
Rockport          67  78  66  76 /  30  30  50  60
Cotulla           67  82  66  76 /  50  60  70  50
Kingsville        69  82  66  78 /  40  30  50  50
Navy Corpus       68  77  67  76 /  30  20  50  50

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

SHORT TERM...WC
LONG TERM....BF
AVIATION...EMF/94