Alert archive / Texas / Special Weather Statements in 2021

Special Weather Statement, NWS Houston/Galveston, TX

July 11, 2021Houston County, Texas

NWS Houston/Galveston, TX issued this special weather statement at Jul 11, 2021, 7:21 PM CDT for Houston County, Texas. It was in force for 39 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 11, 2021, 7:21 PM CDT (00:21 UTC)
Expired
Jul 11, 2021, 8:00 PM CDT
In force
39 min
Issued by
NWS Houston/Galveston, TX

County Houston County, TX

The radar

The Shreveport radar (KSHV), 182 km from the middle of the area, began a volume at 00:24 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.

What was reported inside it

TimeReportWhereRemark
Jul 11, 7:37 PM CDTHAIL 0.881 W Grapeland, TXPEA TO NICKEL SIZED HAIL WAS REPORTED JUST WEST OF GRAPELAND.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 0.4 hours before the alert went out and 191 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, Shreveport, LA at 00:00Z on 2021-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 868 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, Shreveport, LA at 00:00Z on 2021-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 square meters per square second.193958Sfc1 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
868 J/kg
Mixed-layer CIN
-52 J/kg
Mixed-layer LCL
1186 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.5

Open this sounding in Storm Lab

The text

As transmitted.

379 
WWUS84 KHGX 120021
SPSHGX

Special Weather Statement
National Weather Service Houston/Galveston TX
721 PM CDT Sun Jul 11 2021
 
TXZ163-120100-
Houston TX-
721 PM CDT Sun Jul 11 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN HOUSTON COUNTY UNTIL
800 PM CDT...

At 719 PM CDT, Doppler radar was tracking a strong thunderstorm 8
miles west of Grapeland, or 14 miles northwest of Crockett, moving
east at 25 to 30 mph.

Pea size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Grapeland and Latexo. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
office in League City.

&&

LAT...LON 3158 9526 3134 9522 3143 9568 3151 9570
      3156 9557 3159 9527
TIME...MOT...LOC 0019Z 260DEG 28KT 3148 9562 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 7:39 PM CDTSpecial Weather StatementHGXHouston51 min
Jul 11, 7:58 PM CDTSpecial Weather StatementHGXHouston47 min
Jul 12, 8:29 AM CDTAreal Flood AdvisoryHGXBrazos, Madison3 hr
Jul 12, 9:03 AM CDTAreal Flood AdvisoryHGXWalker117 min
Jul 12, 9:08 AM CDTSpecial Weather StatementHGXSan Jacinto37 min
Jul 12, 9:36 AM CDTSpecial Weather StatementHGXSan Jacinto39 min
Jul 12, 10:12 AM CDTSpecial Weather StatementHGXLiberty, Polk, San Jacinto48 min
Jul 12, 11:29 AM CDTAreal Flood AdvisoryHGXBrazos, Madison3 hr
Jul 12, 11:33 AM CDTAreal Flood AdvisoryHGXHouston3 hr
Jul 12, 12:01 PM CDTSpecial Weather StatementHGXBrazos59 min
Jul 12, 12:43 PM CDTSevere Thunderstorm WarningHGXBrazos, Burleson18 min
Jul 12, 1:10 PM CDTAreal Flood AdvisoryHGXBrazos, Grimes110 min
Jul 12, 1:21 PM CDTTornado WarningHGXMontgomery, Walker12 min
Jul 12, 2:34 PM CDTSpecial Weather StatementHGXMontgomery, San Jacinto, Waller41 min
Jul 12, 3:06 PM CDTSpecial Weather StatementHGXHarris39 min
Jul 12, 3:43 PM CDTSpecial Weather StatementHGXFort Bend, Harris47 min
Jul 12, 4:31 PM CDTSpecial Weather StatementHGXChambers, Fort Bend59 min

Nearby

Special Weather Statements in Texas, 2021Every special weather 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.