Alert archive / Texas / Rip Current Statements in 2021

Rip Current Statement 21, NWS Houston/Galveston, TX

April 30, 2021Brazoria County, Galveston County, Matagorda County, Texas

NWS Houston/Galveston, TX issued this rip current statement at Apr 30, 2021, 3:38 AM CDT for Brazoria County, Galveston County, Matagorda County, Texas. It was in force for 15 hr.

The area

The counties it named.

The facts

Issued
Apr 30, 2021, 3:38 AM CDT (08:38 UTC)
Expired
Apr 30, 2021, 7:00 PM CDT
In force
15 hr
Issued by
NWS Houston/Galveston, TX

Counties Brazoria County, TX, Galveston County, TX, Matagorda County, TX

The radar

The Houston radar (KHGX), 54 km from the middle of the area, began a volume at 08:37 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 8.6 hours before the alert went out and 241 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 00:00Z on 2021-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1919 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Corpus Christi, TX at 00:00Z on 2021-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -55 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1919 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
-55 m²/s²
0-3 km storm-relative helicity
-51 m²/s²
Significant tornado parameter
-0.8
Supercell composite
-5.8

Open this sounding in Storm Lab

The text

As transmitted.

906 
WHUS44 KHGX 300838
CFWHGX

Coastal Hazard Message
National Weather Service Houston/Galveston TX
338 AM CDT Fri Apr 30 2021

TXZ436>439-301645-
/O.NEW.KHGX.CF.Y.0006.210430T1500Z-210501T0000Z/
/O.NEW.KHGX.RP.S.0021.210430T0838Z-210501T0000Z/
Matagorda Islands-Brazoria Islands-Galveston Island-
Bolivar Peninsula-
338 AM CDT Fri Apr 30 2021

...HIGH RIP CURRENT RISK IN EFFECT THROUGH THIS EVENING...
...COASTAL FLOOD ADVISORY IN EFFECT FROM 10 AM THIS MORNING TO
7 PM CDT THIS EVENING...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding 
  expected. For the High Rip Current Risk, dangerous rip 
  currents.

* WHERE...Matagorda Islands, Brazoria Islands, Galveston Island 
  and Bolivar Peninsula Counties.

* WHEN...For the Coastal Flood Advisory, from 10 AM this morning 
  to 7 PM CDT this evening. For the High Rip Current Risk, 
  through this evening.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Rip currents can sweep even 
  the best swimmers away from shore into deeper water.



PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Swim near a lifeguard. If caught in a rip current, relax and
float. Don't swim against the current. If able, swim in a
direction following the shoreline. If unable to escape, face the
shore and call or wave for help.

&&

$$
1 follow-up statement
619 
WHUS44 KHGX 302035
CFWHGX

Coastal Hazard Message
National Weather Service Houston/Galveston TX
335 PM CDT Fri Apr 30 2021

TXZ436>439-010000-
/O.CON.KHGX.CF.Y.0006.000000T0000Z-210501T0000Z/
/O.CON.KHGX.RP.S.0021.000000T0000Z-210501T0000Z/
Matagorda Islands-Brazoria Islands-Galveston Island-
Bolivar Peninsula-
335 PM CDT Fri Apr 30 2021

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 7 PM CDT THIS
EVENING...

...HIGH RIP CURRENT RISK REMAINS IN EFFECT UNTIL 7 PM CDT THIS
EVENING...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding. 
  For the High Rip Current Risk, dangerous rip currents.

* WHERE...Brazoria Islands, Matagorda Islands, Bolivar Peninsula 
  and Galveston Island Counties.

* WHEN...Until 7 PM CDT this evening.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Rip currents can sweep even 
  the best swimmers away from shore into deeper water.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Swim near a lifeguard. If caught in a rip current, relax and
float. Don't swim against the current. If able, swim in a
direction following the shoreline. If unable to escape, face the
shore and call or wave for help.

&&

$$

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 29, 9:33 PM CDTFlash Flood WatchHGXAustin, Brazoria, Brazos, Burleson, Chambers, Colorado and 17 more55 hr
Apr 30, 3:17 AM CDTAreal Flood AdvisoryHGXHouston, Madison, Trinity, Walker3 hr
Apr 30, 3:38 AM CDTCoastal Flood AdvisoryHGXBrazoria, Galveston, Matagorda15 hr
Apr 30, 3:49 AM CDTSmall Craft AdvisoryHGX17 hr
Apr 30, 4:05 AM CDTSpecial Weather StatementHGXMatagorda40 min
Apr 30, 5:06 AM CDTSpecial Weather StatementHGXLiberty, Polk, San Jacinto39 min
Apr 30, 5:08 AM CDTSpecial Weather StatementHGXColorado, Wharton52 min
Apr 30, 5:40 AM CDTAreal Flood AdvisoryHGXAustin, Grimes, Harris, Montgomery, Waller, Washington3 hr
Apr 30, 6:01 AM CDTFlash Flood WarningHGXGrimes, Harris, Montgomery, San Jacinto, Walker, Waller5 hr
Apr 30, 7:05 AM CDTAreal Flood AdvisoryHGXLiberty, Montgomery, Polk, San Jacinto3 hr
Apr 30, 8:19 AM CDTAreal Flood AdvisoryHGXChambers, Harris, Liberty, Montgomery116 min
Apr 30, 9:12 AM CDTAreal Flood AdvisoryHGXHarris, Liberty, Montgomery, Polk, San Jacinto2 hr
Apr 30, 9:53 AM CDTAreal Flood AdvisoryHGXAustin, Harris, Waller, Washington112 min
Apr 30, 11:04 AM CDTAreal Flood AdvisoryHGXAustin, Brazos, Burleson, Grimes, Harris, Houston and 9 more116 min

Nearby

Rip Current Statements in Texas, 2021Every rip current statement in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.