Special Weather Statement, NWS Corpus Christi, TX

Area Forecast Discussion
National Weather Service Corpus Christi TX
649 PM CDT Tue Jul 6 2021

.AVIATION...

Weak scattered showers this afternoon are expected to wane briefly
this evening, then redevelop overnight into Wed morning. The best
chance for convection will be across CRP and ALI TAF sites due to
a surface low moving across central portions of S TX tonight
through Wed. The convection is expected to wane by late Wed
afternoon/early evening. Conditions are expected to be a mix of
prevailing VFR/MVFR, with brief periods of IFR/LIFR in and around
SHRA/TSRAs through much of the TAF period. Weak to moderate winds
are forecast to be east to northeast across the western areas and
southeast across the eastern areas. Winds could become variable
and gusty with the stronger storms.

&&

.PREV DISCUSSION... /Issued 337 PM CDT Tue Jul 6 2021/

SHORT TERM (Tonight through Wednesday Night)...

The stage is now set for what looks to be a significant, multi-day
rainfall event over much of the Coastal Bend courtesy of a
stationary mid-level low and exceptionally rich PWATs of 2.3" to
2.6" spanning all of South Texas. Some spots in Aransas County
have already received just over 6 inches (radar estimated) in the
past 24 hours. Although a large MCS in the RGV has currently
disrupted much of rainfall over the region this afternoon, this
should change toward midnight as coastal convergence ramps up and
leads to numerous showers and storms along our coastal counties.

Model soundings remain textbook for flash flooding given deep,
warm rain processes with tall and skinny CAPE, and generally weak
steering flow. The 700-500 mb low is forecast to wobble over S TX
through Wednesday night with a deep S-SE fetch extending from the
western Gulf through the Coastal Plains and Victoria Crossroads.
The greatest focus for flooding remains over these areas thanks to
stronger speed convergence along the coast, and mean northerly
shear carrying this activity slowly northward.

Conservative 48-hour QPF output from the HREF mean blankets our
coastal counties in 6-12" of rain, with pockets of even higher
values. Given increasing confidence in the location and timing of
convection in this pattern, we extended the Flash Flood Watch
until Thursday evening as another burst of nocturnal rainfall is
likely Wednesday night mainly along/near the coast. Rainfall
farther inland (west of the FF Watch) should be more scattered and
diurnal in nature with flash flooding less likely. WPC has upgraded
the Day 2 ERO to Moderate for roughly the eastern half of our
CWA. Lastly, no changes to note to the already seasonably cool
high temps in this cloudy and wet pattern.

LONG TERM (Thursday through Tuesday)...

Unsettled weather continues through the long term as the overall
synoptic pattern remains largely unchanged with a Monsoonal High
pressure meandering between the Great Basin and 4 corners region,
eastern Conus troughing extending down from Canada, and a Bermuda
High over the Atlantic. This blocking pattern will keep a mid-
level low more or less in place near the S.TX/NE Mexico border
with some westward regression this weekend.

Model guidance for Thursday has PWAT's 2.25" - 2.50" which is well
above the normal value of ~1.90" for this time of year. The GFS is
suggesting a peak of 2.58" on Thursday. The GFS compared to recent
obs has been slightly underestimating the amount of moisture. The
latest model runs have trended a little higher while the GFS has
trended lower. That being said am leaning towards a PWAT 2.50" for
Thursday.

Heavy rainfall and the flash flooding threat will continue into the
early part of the extended with a skinny CAPE profile. CAPE values
generally ranging less than 1,400 J/kg. WPC has most of S. TX under
a Slight Risk ERO for Thursday. Considering  the amount of rain
already received and the deep moisture profile with the lingering
low, expecting that additional flood/Flash Flood products will be
needed. Most of the uncertainty in the forecast lies in the exact
location of the low. If it remains close to S. TX with our CWA on
the eastern side, this scenario would result in higher rainfall
amounts as there would be more support and would help to promote a
deeper moisture layer profile.

As we head into the weekend, and as the low moves away, expecting
shower and thunder activity to decrease and PWAT's will trend lower,
perhaps dropping below 2.0" early next week. However, have
maintained chances each day throughout the period.

As Tropical Storm Elsa nears the Florida coast, wave heights and
swell periods across South Texas may increase heading into the
weekend. Guidance already has forecasted tide levels near 1.5 ft
above MSL, and combined with higher seas and longer swell periods,
increased rip current risk and minor coastal flooding will be
possible.

Expecting temperatures to remain largely unchanged with afternoon
highs in the mid to upper 80s and overnight lows ranging in the 70s
across South Texas.

MARINE...

Numerous showers and some thunderstorms will continue on and off
tonight through Wednesday night as an upper low remains parked
over South Texas. Moderate onshore flow is expected tonight and
Wednesday, with Small Craft Exercise Caution levels at times,
before becoming weak to moderate Wednesday evening. Occasional
strong storms will be capable of locally higher winds and waves,
along with brief waterspouts. Onshore flow becomes moderate
Thursday through the weekend. Swells from Tropical Storm Elsa
will likely move into the region and increase wave heights
Thursday through Saturday. Small Craft Exercise Caution conditions
are likely throughout this time-frame. Numerous showers and
thunderstorms are expected Thursday and isolated to scattered
showers and thunderstorms will be possible daily from Friday
through the end of the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi    74  83  74  83  76  /  90  90  80  80  60
Victoria          73  82  72  83  74  /  80  80  80  70  60
Laredo            74  83  74  86  75  /  60  50  70  70  60
Alice             74  82  73  85  73  /  80  80  80  80  60
Rockport          76  83  76  86  78  /  90  90  80  80  60
Cotulla           73  85  73  88  75  /  50  50  60  70  40
Kingsville        74  83  74  83  74  /  80  90  80  80  60
Navy Corpus       76  83  76  85  78  /  90  90  80  80  60

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...Flash Flood Watch through Thursday evening For the following
     zones: Aransas Islands...Bee...Calhoun Islands...Coastal
     Aransas...Coastal Calhoun...Coastal Kleberg...Coastal
     Nueces...Coastal Refugio...Coastal San Patricio...Goliad...
     Inland Calhoun...Inland Kleberg...Inland Nueces...Inland
     Refugio...Inland San Patricio...Jim Wells...Kleberg
     Islands...Live Oak...Nueces Islands...Victoria.

GM...None.

&&

TE/81...AVIATION

Hazardous Weather Outlook...UPDATED
National Weather Service Corpus Christi TX
342 PM CDT Tue Jul 6 2021

TXZ229>234-239>247-342>347-442-443-447-072045-
La Salle-McMullen-Live Oak-Bee-Goliad-Victoria-Webb-Duval-
Jim Wells-Inland Kleberg-Inland Nueces-Inland San Patricio-
Coastal Aransas-Inland Refugio-Inland Calhoun-Coastal Kleberg-
Coastal Nueces-Coastal San Patricio-Aransas Islands-
Coastal Refugio-Coastal Calhoun-Kleberg Islands-Nueces Islands-
Calhoun Islands-
342 PM CDT Tue Jul 6 2021

This hazardous weather outlook is for South Texas.

.DAY ONE...This afternoon and Tonight

A Flash Flood Watch is in effect for the Coastal Bend and the
Victoria Crossroads until Thursday evening.

Scattered to numerous showers and some thunderstorms are expected
through tonight, with heavy rainfall and flash flooding at times,
mainly from the Coastal Bend to the Victoria Crossroads.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Numerous showers and thunderstorms are expected daily Wednesday
through Thursday. Heavy rainfall could lead to localized flooding
at times Wednesday through Thursday. Isolated to scattered
thunderstorms will be possible Friday into the weekend.

A higher risk of rip currents along with minor coastal flooding will
be possible Wednesday through Friday in response to Tropical Storm
Elsa.

GMZ230-235-250-255-270-275-072045-
Bays and Waterways from Baffin Bay to Port Aransas-
Bays and Waterways from Port Aransas to Port O'Connor-
Coastal waters from Baffin Bay to Port Aransas out 20 NM-
Coastal waters from Port Aransas to Matagorda Ship Channel out
20 NM-Waters from Baffin Bay to Port Aransas from 20 to 60 NM-
Waters from Port Aransas to Matagorda Ship Channel from 20 to
60 NM-
342 PM CDT Tue Jul 6 2021

This hazardous weather outlook is for the Middle Texas
Coastal Waters.

.DAY ONE...This afternoon and Tonight

Numerous showers and thunderstorms are expected over the Gulf
waters through tonight. Some of the storms could produce gusty
winds.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Numerous showers and thunderstorms are expected daily through
Thursday. Some storms could produce gusty winds. Scattered
thunderstorms will be possible Friday, becoming isolated for the
weekend.

Increased swells from Tropical Storm Elsa may lead to Small Craft
Advisory Conditions Thursday and Friday.

Special Weather Statement
National Weather Service Corpus Christi TX
812 PM CDT Tue Jul 6 2021

TXZ342-343-442-443-070145-
Kleberg Islands-Coastal Nueces-Coastal Kleberg-Nueces Islands-
812 PM CDT Tue Jul 6 2021

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN NUECES AND
NORTHEASTERN KLEBERG COUNTIES...

At 812 PM CDT, a strong thunderstorm was located near Padre Balli
Park, or 18 miles southeast of Corpus Christi, moving northwest at 15
mph.

Winds in excess of 40 mph are possible with this storm.

Locations impacted include...
Corpus Christi, Flour Bluff, Corpus Christi Country Club, Packery
Channel, South Texas Botanical Gardens, Kings Crossing Subdivision,
Padre Balli Park, Bay Area Medical Center, Spohn Hospital South,
Malaquite Beach, Texas A&M University Corpus Christi, Waldron Field,
La Palmera Mall, Chapman Ranch and Corpus Christi Naval Air Station.

If outdoors, consider seeking shelter inside a building.

LAT...LON 2763 9752 2780 9728 2754 9712 2747 9716
      2740 9726
TIME...MOT...LOC 0112Z 142DEG 14KT 2752 9723

TE

Special Weather Statement
National Weather Service Corpus Christi TX
933 PM CDT Tue Jul 6 2021

TXZ243-343-344-443-070315-
Inland Nueces-Coastal Nueces-Coastal San Patricio-Nueces Islands-
933 PM CDT Tue Jul 6 2021

...A SHOWER WILL AFFECT SOUTHEASTERN NUECES AND SOUTH CENTRAL SAN
PATRICIO COUNTIES...

At 932 PM CDT, a shower was located over Flour Bluff, or 7 miles
southeast of Corpus Christi, moving northwest at 10 mph.

Winds in excess of 40 mph are possible with this shower.

Locations impacted include...
Corpus Christi, Portland, Corpus Christi International Airport, Flour
Bluff, Corpus Christi Country Club, South Texas Botanical Gardens,
Corpus Christi North Beach, Cabaniss Field, Kings Crossing
Subdivision, Bay Area Medical Center, Del Mar College East Campus,
Cole Park, Spohn Hospital South, Driscoll Childrens Hospital, Del Mar
College West Campus, Texas A&M University Corpus Christi, Waldron
Field, Downtown Corpus Christi, La Palmera Mall and Corpus Christi
Naval Air Station.

This includes the following highways...
 Interstate 37 between mile markers 1 and 5.
 US Highway 181 between mile markers 642 and 648.

If outdoors, consider seeking shelter inside a building.

LAT...LON 2775 9757 2791 9733 2766 9717 2756 9732
      2756 9735
TIME...MOT...LOC 0232Z 152DEG 8KT 2767 9731

TE