564
FXUS64 KCRP 191737
AFDCRP

Area Forecast Discussion
National Weather Service Corpus Christi TX
1237 PM CDT Fri Jul 19 2024

...New AVIATION...

.SHORT TERM...
(Today through Saturday)
Issued at 259 AM CDT Fri Jul 19 2024

Water vapor imagery this morning reveals an upper trough extending
from the Midwest back into Texas. MSAS analysis depicts a stalled
cold front across the south-central part of the state. A cluster
of showers and storms can be seen, currently east of Austin,
moving south towards the coast. This activity is driven by a H5
shortwave rotating along the southern periphery of the trough.
Some of the latest CAMs bring this activity into our northern
counties early this morning while some suggest it breaks apart as
the shortwave moves far enough east. If it does collapse we will
need to be on the look out for additional development along any
outflows this morning.

Another batch of showers and storms are expected through the day as
the boundary sinks further south. Although we won`t have much upper
support, forecast soundings suggest convective temps will be met so
diurnal heating will help us out today. Similar to yesterday, we
will be fairly unstable but with little shear. Therefore, would
expect any storms that develop to be fairly short-lived this
afternoon. Any convection will wane with the loss of daytime heating
this evening. We remain under the influence of the upper trough as
we head into the weekend so we will see a similar story on Saturday
with most activity being diurnally driven.

High temperatures in the low 90s to near 100 degrees and heat
indices generally in the 105-109 range will promote a moderate risk
of heat-related impacts today and tomorrow. A few locations across
the southern Coastal Bend may briefly reach 110 this afternoon but
not for long enough to warrant a Heat Advisory.

To wrap this short term discussion up, I wanted to briefly touch on
our rip current risk. Went ahead and continued with a low risk as
winds will be light with swells generally around 5s. However,
Gerling-Hanson plots suggest a secondary wave system with swells
near 8s. If this were materialize, along with our proximity to our
next Full Moon (7/21), we could see our rip risk nudged up to
moderate.

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 259 AM CDT Fri Jul 19 2024

Key Messages:

- Minor to moderate heat-related impacts Sunday will gradually
improve to widespread minor through the middle of next week

- A marginal risk (5-14% chance) of flash flooding Sunday and
Monday, likely continue through the week

Increasing moisture on Sunday will lead to a medium chance of
showers and thunderstorms over the Victoria Crossroads and a low
chance elsewhere. Coverage is not as significant Sunday compared to
the rest of the long term due to lack of sufficient lift support.
However, a steep mid to upper level trough will stretch from the
Midwest into Texas early to the middle of next week, resulting in a
weak frontal boundary dissipating just north of South Texas, mid-
level shortwave disturbances aloft, and an inverted surface trough.
This lift support throughout the atmosphere, combined with 90-99th
percentile moisture (PWATs 2-2.5") and sufficient instability (1000-
1500 J/kg), will lead to medium to high chances (50-85%) of showers
and thunderstorms Monday through Thursday, with greatest chances and
rainfall expected Wednesday into Thursday.

NBM probabilities of precipitation greater than 2" from Tuesday
through Thursday night is around 40% uniformly across South Texas.
The mean of for the same time frame ranges from 1.5-2.0". Although
the 3-hr flash flood guidance across the area currently ranges from
3.5-4.5", daily rainfall will likely lower these values and increase
soil moisture, leading to greater runoff. Therefore, WPC has most of
South Texas in a marginal risk of flash flooding Sunday, and all of
South Texas on Monday. I expect the flash flood risk to continue if
not worsen as we head into the middle of next week with the CPC
indicating a slight risk of heavy rainfall heading into next weekend.

&&

.AVIATION...
(18Z TAFS)
Issued at 1229 PM CDT Fri Jul 19 2024

Still watching the showers and thunderstorms near VCT, some of
them may get into the TAF site, so will have TEMPO or VCTS for the
next few hours until we lose the heat from the day. Overnight
should remain VFR into Saturday morning. Otherwise, will continue
the VCTS at ALI and CRP as showers and thunderstorms are moving
south into the Brush Country and towards the Coastal Bend. May
have to add VCTS to the COT and LRD. ALI may drop to MVFR VSBY
around 12z/SAT, otherwise VFR for the rest of the night at the
rest of the TAF sites.

&&

.MARINE...
Issued at 259 AM CDT Fri Jul 19 2024

Weak to occasionally moderate south to southeasterly flow will
persist through the middle of next week. Winds may become variable
at times through early this weekend as a boundary nears the
region. Low to medium rain chances of 20 to 50 percent through
weekend will increase to medium to high chances of 50 to 70
percent heading into the middle of next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi    77  93  78  94 /  10  20   0  20
Victoria          74  92  75  93 /  20  30   0  50
Laredo            77  99  77  99 /  10  10   0  10
Alice             75  97  76  97 /  10  20   0  20
Rockport          78  88  81  93 /  20  20   0  30
Cotulla           76 100  77  99 /   0  10   0  10
Kingsville        76  95  76  95 /  10  20   0  20
Navy Corpus       79  88  81  91 /  20  20   0  20

&&

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

$$

SHORT TERM...TC
LONG TERM....EMF
AVIATION...JSL/86