Special Weather Statement, NWS Corpus Christi, TX

Area Forecast Discussion
National Weather Service Corpus Christi TX
1149 PM CDT Mon May 17 2021

.AVIATION...

Conditions are running the gambit across South Texas, with IFR to
VFR conditions. Low ceilings across the Coastal Plains are
leading to periods of IFR conditions, the Victoria Crossroads will
have ceilings bounce between MVFR and VFR, and the Brush Country
will continue with periods of IFR to VFR conditions. These
conditions are expected to continue through the period. Ongoing
convection across the Brush Country will continue to push east
across the CWA, hopefully weakening as it does so. Regardless,
thunder is mentioned in all TAFs, with earliest arrival times
across the west and latest end times across the east.
Precipitationwill be quite heavy in these storms, with frequent
lightning, gusty winds, and the potential for hail.

&&

.PREV DISCUSSION... /Issued 931 PM CDT Mon May 17 2021/

DISCUSSION...

Quick update to raise pops out west where convection looks to
persist into the overnight hours.

PREV DISCUSSION... /Issued 749 PM CDT Mon May 17 2021/

DISCUSSION...

Severe Thunderstorm Watch 184 has been issued for an area that
includes Webb and LaSalle counties until 04z. Isolated slow-moving
thunderstorms are possible, and some may produce large hail.

AVIATION...

MVFR and low VFR conditions will become all MVFR overnight with
convection possible this evening at KCOT. Otherwise expect
conditions to improve Tuesday morning. Southeast surface winds
will pick up again by Tuesday afternoon and become gusty.

PREV DISCUSSION... /Issued 438 PM CDT Mon May 17 2021/

SHORT TERM (Tonight through Tuesday Night)...

Very difficult forecast continues through the short term period.
Models are all over the place, and you can probably find one run
of one model for every different scenario you could imagine. So
the challenge is figuring out the most likely scenario given all
the inconsistencies. For tonight, the most likely scenario seems
to be convection our of Mexico staying north of...or just into our
northern counties. 850-300mb thickness lines are oriented pretty
well E-W, and with MCS movement generally along or just to the
right of that, would expect the majority of the convection to
stay north (and south) of our area given current radar picture and
anticipated development locations. Do have slight chance to chance
PoPs in northern counties to account for the uncertainty here. If
storms do make it, there would be a marginal threat for strong
winds and large hail given the favorable environment to the
northwest. Given the amount of rain we had over the weekend,
there is also a concern for localized flash flooding if these
storms move over the same areas that received the heavy rains.
Will not issue a flash flood watch at this time given the high
uncertainty in tonight's rains.

By tomorrow, the deep 500mb closed low will be pushing eastward
bringing with it some intense energy and beginning a very active
period that will extend into the long term forecast discussion
below. For Tuesday have increased PoPs a bit inland with chance
PoPs extending through the middle of the forecast area. The key
that makes tomorrow different from the rest of the week is that
PWATs should be around 1.5 inches across the area, which is only
around normal, so expect the rain rates of showers and storms
tomorrow to be lower than what we saw over the weekend and what we
will see later this week. PWATs will begin sneaking up Tuesday
night and could begin seeing hints at the heavy rains to come by
that point.

High temperatures will be near normal tomorrow, with warm/humid
nights.

There is still a potential for minor coastal flooding tomorrow
around mid-day with high tide, but given today's levels did not
make it to 2ft MSL, will hold off on issuing an advy for this.

LONG TERM (Wednesday through Monday)...
A very wet week is in store for South Texas as the synoptic setup
continues to favor a significant rainfall event Wednesday into
Thursday. An upper-level trough will shift east into Texas from the
Four Corners region during the day Wednesday and bring strong upper
level winds along with it. At the 500mb level, a closed low will
open into a wave, allowing energy to dive into South Texas during
this Wed/Thu time frame. This 500mb trough, along with high pressure
to the east will help draw an ample amount of moisture into the
region. Southeasterly winds in the lower levels (850 mb to surface)
will do the same, creating a deep profile of moist air as this
energy at the 500mb digs south into our area. PWAT values will be
near 2.0 inches as a deep moisture axis sets up over South Texas.
Have maintained 70-80% PoPs for Wednesday morning, increasing to 80-
90% Wednesday afternoon into Thursday. With all of this in place,
high rainfall rates as well as high rainfall totals are possible.
Rainfall totals through Thursday may reach 6-8 inches for the
Victoria Crossroads area with 3-6 inches of rain expected over most
of South Texas. Locally higher amounts are possible. A flash flood
watch will likely be issued tomorrow for the Wednesday into
Thursday period.

Latest model guidance for the weekend time frame continues to show a
narrow trough over the area that becomes trapped between ridging to
the west and to the east. PWAT values increase to 2.0 inches and
above through Sunday for much of the area in response to the influx
of moisture from this system. Will need to continue to monitor over
the coming days to see if the location of this trough/moisture axis
shifts, but the Coastal Plains should expect a chance of rainfall
for this weekend.

Minor coastal flooding is possible at times of high tide through
Thursday as tidal levels reach to near 2 feet MSL at Bob Hall Pier
and Aransas Pass.

MARINE...

Generally moderate onshore flow will continue tonight and
Tuesday. Conditions may briefly approach small craft advisory
levels, but overall should remain at exercise caution. Chances for
showers and thunderstorms will return Tuesday and persist through
the week as a series of upper level disturbances pass through the
area. A few storms could be strong to potentially severe.
Moderate to strong onshore flow will lead to periods of Small
Craft Exercise Caution and Small Craft Advisory conditions through
the week and into the weekend.

HYDROLOGY...

This past weekends rainfall has primed the area for the potential
for significant river flooding going into the latter half of this
week. With current rainfall forecasts over South Texas and north
over the upstream rivers, we could be looking at widespread river
flooding, with some rivers to moderate or major flood stage. This
will make for a potential very long duration event as it takes
days for water to work its way down some of our rivers...the
Nueces in particular.

&&

.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi    77  85  76  83  69  /  20  30  40  80  80
Victoria          75  85  75  82  68  /  20  50  60  90  80
Laredo            77  98  75  87  69  /  40  20  30  90  50
Alice             76  91  76  86  67  /  20  40  40  90  80
Rockport          77  84  77  83  70  /  20  30  50  80  80
Cotulla           75  95  75  86  69  /  40  30  40  90  50
Kingsville        77  88  77  85  68  /  20  30  30  90  80
Navy Corpus       77  83  77  83  71  /  10  30  40  80  80

&&

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

&&

LS/77...AVIATION

Hazardous Weather Outlook
National Weather Service Corpus Christi TX
643 PM CDT Mon May 17 2021

TXZ229>234-239>247-342>347-442-443-447-182345-
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-
643 PM CDT Mon May 17 2021

This hazardous weather outlook is for South Texas.

.DAY ONE...Tonight

Isolated thunderstorms are possible over the western brush country
this evening. One or two of these storms could produce large hail.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Scattered to numerous showers and thunderstorms will be possible
daily through the week. A few storms could become strong to severe,
along with a threat of locally heavy rainfall.

There is a MODERATE risk of rip currents Tuesday.

Minor coastal flooding is possible through the middle of the week,
with tidal levels reaching near 2 ft MSL..

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

GMZ230-235-250-255-270-275-182345-
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-
643 PM CDT Mon May 17 2021

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

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Scattered to numerous showers and thunderstorms will be possible
daily through the week. A few storms could become strong to possibly
severe.

Small Craft Advisory conditions may be possible on and off through
the week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
152 AM CDT TUE MAY 18 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0135 AM     TSTM WND GST     2 ENE SAN DIEGO         27.77N 98.21W
05/18/2021  E60 MPH          JIM WELLS          TX   TRAINED SPOTTER

            SPOTTER NOTICED GAS STATION COVER OVER THE
            PUMPS WAS MOVING.

&&

LS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
154 AM CDT TUE MAY 18 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0152 AM     TSTM WND DMG     1 NE BENAVIDES          27.61N 98.40W
05/18/2021                   DUVAL              TX   BROADCAST MEDIA

            REPORTS OF ROOFS TORN OFF OF HOMES.

&&

LS

Special Weather Statement
National Weather Service Corpus Christi TX
219 AM CDT Tue May 18 2021

TXZ242>244-342>344-442-443-180745-
Inland Nueces-Inland San Patricio-Kleberg Islands-Coastal
Nueces-Coastal San Patricio-Coastal Kleberg-Nueces Islands-Inland
Kleberg-
219 AM CDT Tue May 18 2021

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTHERN NUECES...SOUTH
CENTRAL SAN PATRICIO AND NORTHEASTERN KLEBERG COUNTIES...

At 219 AM CDT, radar indicated strong thunderstorms were located
along a line extending from near Odem to near South Texas Botanical
Gardens to 9 miles west of Malaquite Beach. Movement was east at 35
mph.

Wind gusts of 50 to 55 mph are possible with these storms.

These storms will be near...
  South Texas Botanical Gardens and Cabaniss Field around 225 AM
  CDT.
  Kings Crossing Subdivision, Spohn Hospital South, Corpus Christi
  Country Club, La Palmera Mall and Driscoll Childrens Hospital
  around 230 AM CDT.
  Waldron Field, Malaquite Beach, Bay Area Medical Center and Texas
  A&M University Corpus Christi around 235 AM CDT.
  Flour Bluff around 240 AM CDT.
  Portland, Packery Channel, Padre Balli Park and Corpus Christi
  North Beach around 245 AM CDT.

Other locations impacted by these storms include Petronila, Tuloso,
Chapman Ranch and Corpus Christi Naval Air Station.
This includes the following highways...
 Interstate 37 between mile markers 1 and 10.
 US Highway 181 between mile markers 642 and 648.
 US Highway 77 between mile markers 672 and 676.

LAT...LON 2794 9737 2761 9719 2736 9732 2740 9764
      2775 9776
TIME...MOT...LOC 0719Z 270DEG 28KT 2792 9760 2764 9747 2742 9745

LS

Special Weather Statement
National Weather Service Corpus Christi TX
231 AM CDT Tue May 18 2021

TXZ230>232-180800-
Live Oak-McMullen-Bee-
231 AM CDT Tue May 18 2021

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT EAST CENTRAL
MCMULLEN...CENTRAL LIVE OAK AND WEST CENTRAL BEE COUNTIES...

At 231 AM CDT, radar indicated strong thunderstorms were located
along a line extending from near Ray Point to 6 miles northeast of
Dinero to near Mathis. Movement was east at 30 mph.

Winds in excess of 40 mph and pea size hail are possible with these
storms.

These storms will be near...
  Karon around 250 AM CDT.
This includes the following highways...
 Interstate 37 between mile markers 49 and 72.
 US Highway 281 between mile markers 618 and 642.
 US Highway 59 between mile markers 700 and 734.

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 2861 9807 2850 9793 2836 9776 2813 9817
      2830 9847
TIME...MOT...LOC 0731Z 259DEG 24KT 2852 9815 2831 9791 2813 9780

LS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
243 AM CDT TUE MAY 18 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0200 AM     TSTM WND DMG     1 SE ALICE              27.75N 98.06W
05/18/2021                   JIM WELLS          TX   BROADCAST MEDIA

            REPORT OF WIND DAMAGED HOME, STORAGE UNIT
            BEHIND HOME IS GONE, AND DOWNED POWERLINES.

&&

LS

Special Weather Statement
National Weather Service Corpus Christi TX
301 AM CDT Tue May 18 2021

TXZ231>233-243>246-343>346-443-180830-
Live Oak-Inland Nueces-Inland San Patricio-Coastal Refugio-Coastal
Nueces-Bee-Coastal San Patricio-Inland Refugio-Nueces Islands-Coastal
Aransas-Aransas Islands-Goliad-
301 AM CDT Tue May 18 2021

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT WESTERN ARANSAS...
CENTRAL NUECES...SAN PATRICIO...SOUTHERN GOLIAD...WESTERN REFUGIO...
CENTRAL LIVE OAK AND BEE COUNTIES...

At 300 AM CDT, radar indicated strong thunderstorms were located
along a line extending from Tulsita to near Blanconia to near
Bayside. Movement was northeast at 35 mph.

Winds in excess of 30 mph and pea size hail are possible with these
storms.

Locations impacted include...
Corpus Christi, Portland, Beeville, Rockport, Sinton, Mathis, Port
Aransas, Taft, Refugio, George West, Three Rivers, Woodsboro, Corpus
Christi International Airport, Skidmore, Lamar, Ingleside, Aransas
Pass, Odem, Gregory and St. Paul.

This includes the following highways...
 Interstate 37 between mile markers 1 and 12, and between mile
markers 17 and 72.
 US Highway 281 between mile markers 618 and 634.
 US Highway 181 between mile markers 572 and 648.
 US Highway 183 between mile markers 646 and 668.
 US Highway 59 between mile markers 670 and 724.
 US Highway 77 between mile markers 612 and 658.

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 2852 9722 2793 9686 2791 9687 2772 9745
      2809 9784 2842 9833 2871 9790 2867 9778
      2878 9762
TIME...MOT...LOC 0800Z 230DEG 30KT 2864 9779 2834 9746 2804 9722

LS