523
FXUS64 KCRP 302352 AAA
AFDCRP

Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
652 PM CDT Wed Sep 30 2026

...New AVIATION...

.KEY MESSAGES...
Issued at 644 PM CDT Wed Sep 30 2026

- There is a Moderate Risk for excessive rainfall for the western
half of S TX and a Slight Risk for the eastern half on Thursday.
There is a Slight Risk for the western areas on Friday.

- Heavy rainfall and flash flooding threat increases Thursday and
Friday and a Flash Flood Watch is in effect beginning Thursday
morning through Friday evening for portions of South Texas.

- Marginal Risk of Severe Thunderstorms Thursday across most of
  South Texas with damaging winds being the main threat.

- Minor coastal flooding possible early next week.

&&

.DISCUSSION...
Issued at 157 PM CDT Wed Sep 30 2026

Thursday and Friday are still shaping up to be wet with heavy
rainfall and the potential for flash flooding. High rain chances
remain in the forecast through the weekend with a cold front
possibly stalling along the Texas coast by Friday night into
Saturday. There remains a lot of uncertainty with regard to the cold
front`s timing, strength, and where it will ultimately stall across
S TX.

A long wave mid/upper level trough with a cut-off low centered over
the Desert SW, will continue to slowly move east-southeast through
the period. Deeper moisture is already advecting across S TX from
the gulf in the low and mid levels with PWATs already around 2.2
inches. The low will also tap into mid/upper level Pacific moisture
from the remnants of Polo with PWATs progged to increase to 2.4-2.5
inches with some models indicating 2.7 inches moving across S TX on
Thursday. This is well above normal for this time of year.

This deep moisture combined with a developing surface trough over S
TX, and embedded upper level short waves tracking northeast ahead of
the main low, will lead to a high chance of showers and
thunderstorms across the region Thursday. The highest chances up to
90% are forecast for the Brush Country and Rio Grande Plains to 40%
along the coastline. There is a Marginal Risk of severe
thunderstorms on Thursday. Some storms may become strong to severe
with wind damage expected to be the main threat.

The high chance of widespread convection will continue through
Friday as the upper low draws nearer to S TX and brings a cold front
to the area. The cold front is forecast to move into the Rio Grande
Plains and Brush Country on Friday and possibly stall somewhere
along the coast line Friday night into Saturday morning. There
remains uncertainty as to the timing, strength and just how far
southeast the cold front tracks. Where ever the front stalls will be
the main focus for the heaviest rainfall and highest risk for flash
flooding. For now, it looks like it will stall Friday night along
the coast, then push off the coast by Sunday. A second re-enforcing
cold front is possible by Monday with winds strengthening from the
northeast and maintaining the cooler temperatures across S TX. The
upper low is forecast to finally exit to the east with drier
conditions expected next week.

Temperatures are tricky for Thursday. With the increasing
clouds/rain, the max temps are expected to be slightly cooler than
today. However, if less cloud cover develops, this will allow higher
temps across the area which would combine with the high humidity and
lead to heat indices up to 110-112 across the eastern CWA.  Will
monitor trends for Heat Advisory conditions Thursday. Cooler
temperatures are expected Friday and into next week.

Minor coastal flooding is a possibility at times during high tide
through early next week, especially Monday due to strengthening
northeast winds across the gulf waters behind the second cold front.

&&

.AVIATION...
(00Z TAFS)
Issued at 644 PM CDT Wed Sep 30 2026

Difficult forecast for this period in terms of convection timing.
Confidence in convection is high, but in the exact timing is not.
The most likely scenario right now appears to be a round of
convection moving into the western terminals late in the night and
possibly making it all the way east, but chances of that line
making it to CRP and VCT are lower. Another round of storms is
then expected during the late afternoon that would start west and
again progress eastward through the terminals into the night.
Bottom line is there`s no certain time that we will be convection
free, but current forecasts are the best estimate at this time.

Within convection, expect periods of MVFR conditions but largely
VFR outside of those period. Gusty sea breeze winds this evening
will subside overnight and increase again tomorrow, though are not
expected to be quite as strong. May need to add some more detail
into tempo and prob groups for gusty winds with storms especially
tomorrow afternoon/evening.

&&

.MARINE...
Issued at 157 PM CDT Wed Sep 30 2026

A moderate to fresh (BF 4-5) south to southeast flow is expected
tonight into Thursday morning. Small Craft Should Exercise Caution
tonight. Winds weaken to a gentle to moderate (BF 3-4) onshore
breeze Friday and shift to the east to northeast Friday night or
Saturday as a cold front approaches the coastal waters. Low to
medium chance for showers and thunderstorms expected tonight through
Thursday, then increasing to a high chance Thursday night through
the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi    80  94  77  89 /  30  60  80  90
Victoria          77  97  74  90 /  40  80  90  90
Laredo            79  96  74  85 /  30  80  80  90
Alice             77  97  74  89 /  30  80  90  90
Rockport          80  93  77  90 /  40  60  80  90
Cotulla           78  93  73  83 /  30  90  90  80
Kingsville        79  96  76  90 /  30  70  80  90
Navy Corpus       83  91  81  88 /  40  40  80  90

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...Flood Watch from Thursday morning through Friday evening for
     TXZ229>232-239>244.

     Heat Advisory until 7 PM CDT this evening for TXZ241>244-342>344.

GM...None.
&&

$$


DISCUSSION...TE/81
AVIATION...PH/83