269
FXUS64 KCRP 170511
AFDCRP

Area Forecast Discussion
National Weather Service Corpus Christi TX
1211 AM CDT Fri May 17 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Friday night)
Issued at 239 PM CDT Thu May 16 2024

Key Messages:

- Slight Risk (level 2 out of 5) of Severe Storms across the
Victoria Crossroads through tonight.

- A Marginal to Slight Risk of Severe Storms on Friday with
the Slight Risk being across the eastern portions of South Texas.

- A Marginal Risk of Excessive Rainfall across the Victoria
Crossroads tonight.

Models are having trouble with timing of embedded short waves aloft
ahead of an approaching long wave trough. There is also uncertainty
with the timing of a cold front or outflow boundary from ongoing
convection currently moving into the Hill Country and whether it
will stall north of S TX or across S TX by Friday. These features
will dictate where, when and how strong storms become. What is known
is that the environment is very unstable and there is ample moisture
in place across the region, but there is also a strong capping
inversion.

Mainly showers have occurred across S TX today due to the cap
inhibiting deeper convection, along with the fact that there
currently is little to no low level forcing. That will change once
the cold front/outflow boundary sinks southward toward S TX. This
will also coincide with an embedded short wave tracking northeast
across the region.

It is expected that there will be two rounds of storms with the
first round late this afternoon into evening hours, mainly across
the Victoria Crossroads due to the cap weakening across that area
allowing for deeper convection. A few hours of generally quiet
weather is expected behind those storms through overnight. The
second round, based on short range models, is progged to develop
across Mexico southwest of the area around 09-12Z and move northeast
as another embedded short lifts to the northeast. In addition, the
main trough will also be nearing the area leading to increasing
upper level diffluence as a 105-110kt upper jet sinks southward
across the area. The boundary is forecast to stall across S TX (if
it can get this far south) between 09-18Z Friday. This boundary will
provide strong low level moisture convergence where ever it stalls.

Most models prog that convection will shift from southwest to
northeast with the embedded short wave, but the models differ on
when it will move into the Rio Grande Plains with models ranging
anywhere from 09Z to 15Z and exiting the region to the northeast
between 18-23Z Friday afternoon. Rain chances range from low to
medium (20-50%) across the Victoria area tonight and low to medium
(20-40%) across S TX on Friday.

The overall time frame is this afternoon through Friday afternoon.
Given the instability and abundant moisture combined with the upper
and lower support, some storms could become strong to severe with
damaging wind being the main threat and hail being the secondary
threat. The threat of tornadoes is very low (<5%), but can not be
ruled out. The Storms Prediction Center has placed the Victoria
Crossroads in a Slight Risk of severe weather through tonight and
the eastern half of S TX on Friday with a Marginal Risk across the
west.

The Weather Prediction Center has placed the Victoria Crossroads in
a Marginal risk of excessive rainfall through tonight. Rainfall
totals are expected to be one inch or less, but some locations,
mainly across the Victoria Crossroads, could have up to 2-3 inches
leading to localized flooding of low lying and urban areas.

&&

.LONG TERM...
(Saturday through next Wednesday)
Issued at 239 PM CDT Thu May 16 2024

Key Messages:

 Temperatures trend warmer through Tuesday

 A Moderate to Major risk of heat related impacts from dangerous
heat next week across much of South Texas

As an upper level disturbance moves east of Texas, this will allow
for ridging to build over the state, ushering in drier conditions
aloft. The lack of moisture combined with subsidence will preclude
any rain/storm chances throughout the long term period as we remain
under strong mid-level ridging and a dry vertical profile. The
synoptic pattern is going to remain quasi zonal and quiet as most
disturbances stay in the higher latitudes.

PWAT`s of around 1.25" (GEFS mean) are progged to remain below the
normal value (~1.50" for mid May) through the first half of next
week but will steadily rise to near or slightly above normal in
response to weak to moderate onshore flow helping to promote an
increase in low level moisture. As moisture and surface temperatures
both increase so does the heat index and the risk for heat related
illness.  Tuesday looks to be the peak with a Heat Index around 110-
115 degrees across much of the region except northeast where a more
modest 105 degrees is expected. The rest of the work week, look for
heat indices around 105-110 across the CWA. Regardless, these
conditions will result in a Moderate to Major risk for heat related
illnesses. This level of heat can affect anyone without effective
cooling and/or adequate hydration. Please be prepared for the heat
and take proper precautions to stay cool and hydrated.

&&

.AVIATION...
(06Z TAFS)
Issued at 1047 PM CDT Thu May 16 2024

A boundary surging south across the area has resulted in northerly
winds gusting to around 25 knots. Thoughts are that these strong
winds will diminish shortly before the beginning of the 06Z TAF
cycle, but it is possible a few locations could see these
lingering for a few hours. Otherwise, light winds are generally
expected through the TAF period. Ceilings will bounce between MVFR
and VFR overnight before eventually settling on MVFR by morning.
Sites over the Coastal Plains and Victoria Crossroads may
experience brief IFR conditions so have included a TEMPO for this.
There is a low to moderate chance for showers and thunderstorms to
develop late tonight and into midday Friday. A few of these could
be strong to severe, with large hail and damaging winds as the
primary threats. Ceilings and visibility could be reduced in and
around any thunderstorms. Haze is expected to persist across South
Texas, but ceilings and visibility should become VFR by Friday
evening.

&&

.MARINE...
Issued at 239 PM CDT Thu May 16 2024

Moderate onshore flow will decrease to under 15 knots tonight, then
becoming light by Friday. There is a low chance for showers and
thunderstorms across the bays and nearshore waters tonight, mainly
north of Port Aransas. If a storm does develop, there is a low
chance they could become strong to severe. There is a low to medium
chance of showers and thunderstorms continuing into Friday.
Rain chances decrease Friday night, followed by drier conditions
Saturday. Weak onshore flow may be variable at times veering
northeast briefly Saturday before returning to onshore flow. Flow
increases to weak to moderate early Monday and prevails through
the work week. Chances for rain or thunderstorms during the period
is extremely low, less than 10%.

&&

.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi    76  91  75  95 /  10  30  10   0
Victoria          72  86  69  94 /  70  30  10   0
Laredo            74  95  74 102 /  10  30   0   0
Alice             74  90  71  97 /  10  40  10   0
Rockport          76  87  75  91 /  30  40  10   0
Cotulla           73  93  72 100 /  10  20  20   0
Kingsville        75  91  74  96 /  10  40  10   0
Navy Corpus       79  89  78  91 /  20  30  10   0

&&

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

$$

SHORT TERM...TE
LONG TERM....BF
AVIATION...LS/77