147
FXUS64 KCRP 140355
AFDCRP

Area Forecast Discussion
National Weather Service Corpus Christi TX
1055 PM CDT Mon May 13 2024

...New AVIATION...

.UPDATE...
Issued at 959 PM CDT Mon May 13 2024

Main issues for the overnight are temperature adjustments as the
drier, cooler air begins to move into the south Texas overnight.
While the overall lows are close the original forecast, there are
some adjustments that need to be made with post-convection. The
other issue is fog, which will be more of an aviation issue, there
will be patchy fog in the inland counties due to the rain,
clearing skies, and light winds overnight. Weatherwise, the rain
is almost out of the marine zones, and the back edge of the
cirrus shield from the thunderstorms earlier is just about to the
Coastal Bend. While the overall forecast is out, there may be
another tweak or two as I prepare the aviation forecasts for the
night.

&&

.SHORT TERM...
(Tonight through Tuesday night)
Issued at 241 PM CDT Mon May 13 2024

Key Messages:

 Slight to Enhanced Risk of Severe Thunderstorms through this
  early evening.

A line of showers and thunderstorms is currently tracking across
portions of the Victoria Crossroads into the northern Coastal
Bend. A few of these storms have become strong to severe with
damaging winds and large hail reported. Conditions are conducive
for further severe weather development through the afternoon with
dewpoints in the 70s, steep lapse rates, MUCAPE values at or
around 4000-5000 J/kg and a weakening cap. The Severe Weather
Watch has been extended to now include the northern coastal
counties and adjacent bays/nearshore waters through 00Z. This
activity is forecast to continue on a southeastward progression
through the reminder of the afternoon with the highest convective
chances transitioning into the waters by early evening. A few
discrete cells have redeveloped out west near the Rio Grande
Plains along the location of a frontal boundary. Additional severe
weather concerns reside with these western storms as they enter a
more unstable environment. Very large hail is possible.

Conditions are forecast to improve tonight with drier air
filtering in behind the boundary. PWATs are progged to drop below
an inch by Tuesday while the shortwave trough exists the region
and surface high pressure briefly settles. Winds will shift to
the north and northeast tonight, and out of the east on Tuesday as
the high drifts eastward. Moisture will begin to increase again
Tuesday night with the low-level flow becoming more southeasterly.

&&

.LONG TERM...
(Wednesday through next Sunday)
Issued at 241 PM CDT Mon May 13 2024

Key Messages:

 Low to medium chance of showers and thunderstorms Thursday

 Heat stress conditions possible Thursday, Sunday, and Monday in
  the Southern Coastal Plains and Brush Country

A shortwave will move across the Southwestern US Wednesday night
into Thursday. This will combine with well above normal PWAT values
(2.00-2.50 inches), which is flirting with the climatological max
for this time of year. The caveat for storm development will be the
uncertainty with the CIN values. Models are depicting moderate to
strong instability (2500-3500 J/kg), but aren`t in agreement with
how much of a cap will be over the area. Given the immense amount of
instability, it`s not out of the question to see some strong to
severe storms develop. SPC came to a similar conclusion on the
uncertainty with the CIN values which prevented them from issuing an
outlook. Models depict a surface trough developing during the day
Thursday in West/Central Texas. A chance for showers and
thunderstorms does exist nonetheless due to the presence of these
factors. This will likely need to be monitored as the situation
evolves.

Thursday, depending on the uncertainties with convection, could see
heat stress conditions across the Southern Coastal Plains and Brush
Country. With the abundance of moisture in the area it will be
pretty humid allowing for heat indices to increase to around 110. A
similar story will follow for Sunday and Monday. The need for a Heat
Advisory may come into play during these days and will also be
closely monitored as we transition through the week.

&&

.AVIATION...
(06Z TAFS)
Issued at 1036 PM CDT Mon May 13 2024

Skies have cleared out post convection, but with it the rain
earlier in the evening has left the moisture available for fog to
form at VCT and ALI, and CRP by early morning. Winds are or will
become light and variable overnight as weak high pressure and
subsidence following the storms keeps the skies cleared. However,
if you use the crossover temperature method, and look at the
aviation guidance, fog is expected at TAF sites mentioned earlier,
with some guidance getting to <1 SM. IFR VSBYs are possible (<3
SM) by 12z/Tue 50% chance at VCT and 20% at ALI and CRP, and less
then <1 SM at 30% and 10% respectively. So have kept the tempo
groups to around 1 sm or better. The other thing is possibly low
CIGs due to the fog, with the guidance suggesting 200-300 feet.
didn`t go that low as the confidence 10-25% for CRP and ALI and
50% at VCT for less than 500 feet. So have the CIGS at 900 feet to
trend the forecast down overnight. After 13z/Tues expect that the
clouds and fog will burn off and clear out, and remain clear
through 06z/Wed.

&&

.MARINE...
Issued at 241 PM CDT Mon May 13 2024

Showers and thunderstorms will impact the coastal waters this
evening in response to a passing disturbance. A few storms could
become strong to severe at times, with large hail and damaging
winds being the primary hazards. An associated weak frontal
boundary will move offshore this evening, shifting the winds out
of the northeast through Tuesday morning. A weak to moderate east-
southeasterly flow resumes Tuesday afternoon into the overnight
period. Drier conditions are in store on Tuesday. Isolated to
scattered showers and thunderstorms will be possible early
Thursday morning through Thursday evening. Weak to moderate
onshore flow is expected to continue through much of the week and
the remainder of the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi    68  91  72  90 /  30   0   0   0
Victoria          63  91  67  91 /  30   0   0   0
Laredo            68 100  73  98 /  10   0   0  10
Alice             66  95  70  93 /  20   0   0   0
Rockport          71  87  75  87 /  40   0   0   0
Cotulla           64  97  70  98 /  10   0   0   0
Kingsville        67  94  71  91 /  30   0   0   0
Navy Corpus       72  88  77  87 /  40   0   0   0

&&

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

$$

SHORT TERM...ANM
LONG TERM....NP
AVIATION...JSL/86