Alert archive / Texas / Tornado Warnings in 2011

Tornado Warning 4, NWS Midland/Odessa, TX

April 21, 2011Terrell County, Texas

NWS Midland/Odessa, TX issued this tornado warning at Apr 21, 2011, 6:45 PM CDT for Terrell County, Texas. It was in force for 60 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 21, 2011, 6:45 PM CDT (23:45 UTC)
Expired
Apr 21, 2011, 7:45 PM CDT
In force
60 min
Issued by
NWS Midland/Odessa, TX
Area
Storm-based polygon

County Terrell County, TX

The radar

The Laughlin AFB radar (KDFX), 198 km from the middle of the area, began a volume at 23:46 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 21, 3:03 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Del Rio, TX (KDRT), launched 12:00Z, 11.8 hours before the alert went out and 146 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, Del Rio, TX at 12:00Z on 2011-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2808 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, Del Rio, TX at 12:00Z on 2011-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 176 square meters per square second.1939Sfc1 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
2808 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
643 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
176 m²/s²
0-3 km storm-relative helicity
223 m²/s²
Significant tornado parameter
0.7
Supercell composite
4.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

728 
WFUS54 KMAF 212345
TORMAF
TXC443-220045-
/O.NEW.KMAF.TO.W.0004.110421T2345Z-110422T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
645 PM CDT THU APR 21 2011

THE NATIONAL WEATHER SERVICE IN MIDLAND HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL TERRELL COUNTY IN SOUTHWEST TEXAS...

* UNTIL 745 PM CDT

* AT 639 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 7 MILES EAST OF
  SANDERSON...MOVING SOUTHEAST AT 25 MPH.

* THE TORNADO WILL AFFECT THE FOLLOWING LOCATIONS... 
  RURAL LOCATIONS NORTH OF U.S. HIGHWAY 90 BETWEEN SANDERSON
  AND DRYDEN...
  DRYDEN...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO MAY FORM AT ANY TIME...DRYDEN IS IN THE PATH OF THIS 
STORM. RESIDENTS IN DRYDEN SHOULD TAKE COVER NOW! ABANDON MOBILE 
HOMES AND VEHICLES FOR MORE SUBSTANTIAL SHELTER. AVOID WINDOWS.

IN ADDITION TO THE TORNADO... THIS STORM IS CAPABLE OF PRODUCING
LARGE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS. SEEK SAFE SHELTER
NOW.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. IF YOU WAIT TO SEE OR HEAR
IT COMING... IT MAY BE TOO LATE TO GET TO A SAFE PLACE. TAKE COVER
NOW.

&&

LAT...LON 3028 10176 2980 10199 3011 10243 3036 10230
TIME...MOT...LOC 2344Z 295DEG 21KT 3015 10225

$$
2 follow-up statements
992 
WWUS54 KMAF 220001
SVSMAF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
701 PM CDT THU APR 21 2011

TXC443-220045-
/O.CON.KMAF.TO.W.0004.000000T0000Z-110422T0045Z/
TERRELL TX-
701 PM CDT THU APR 21 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR CENTRAL
TERRELL COUNTY...

...RESIDENTS IN THE COMMUNITY OF DRYDEN SHOULD SEEK IMMEDIATE 
SHELTER...

AT 656 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THE 
MOST DANGEROUS PART OF THIS STORM WAS LOCATED 6 MILES NORTHWEST 
OF DRYDEN...MOVING SOUTHEAST AT 25 MPH.

THE COMMUNITY OF DRYDEN IS IN THE PATH OF THIS STORM. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO MAY FORM AT ANY TIME...ABANDON MOBILE HOMES AND VEHICLES 
FOR MORE SUBSTANTIAL SHELTER. AVOID WINDOWS.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. IF YOU WAIT TO SEE OR HEAR 
IT COMING... IT MAY BE TOO LATE TO GET TO A SAFE PLACE. RESIDENTS IN 
CENTRAL TERRELL COUNTY...INCLUDING THE COMMUNITY OF DRYDEN SHOULD 
TAKE COVER NOW!

&&

LAT...LON 3028 10176 2980 10199 3011 10243 3036 10230
TIME...MOT...LOC 2359Z 302DEG 20KT 3010 10218

$$
517 
WWUS54 KMAF 220020
SVSMAF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
720 PM CDT THU APR 21 2011

TXC443-220045-
/O.CON.KMAF.TO.W.0004.000000T0000Z-110422T0045Z/
TERRELL TX-
720 PM CDT THU APR 21 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR SOUTHERN
TERRELL COUNTY...

...RESIDENTS IN THE COMMUNITY OF DRYDEN SHOULD SEEK IMMEDIATE 
SHELTER...

AT 710 PM CDT...THE TERRELL COUNTY ASOS REPORTED A WIND GUST OF 58 
MPH. 

AT 713 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THE 
MOST DANGEROUS PART OF THIS STORM WAS LOCATED NEAR DRYDEN...MOVING 
SOUTHEAST AT 20 MPH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO MAY FORM AT ANY TIME...ABANDON MOBILE HOMES AND VEHICLES 
FOR MORE SUBSTANTIAL SHELTER. AVOID WINDOWS.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. IF YOU WAIT TO SEE OR HEAR 
IT COMING... IT MAY BE TOO LATE TO GET TO A SAFE PLACE. RESIDENTS IN 
CENTRAL TERRELL COUNTY...INCLUDING THE COMMUNITY OF DRYDEN SHOULD 
TAKE COVER NOW!

IN ADDITION TO THE TORNADO...BASEBALL SIZE HAIL AND DAMAGING 
STRAIGHT LINE WINDS ARE LIKELY WITH THIS STORM.

&&

LAT...LON 3028 10176 2980 10199 3007 10237 3032 10221
TIME...MOT...LOC 0016Z 306DEG 18KT 3004 10210

$$

The office that day

Everything else NWS Midland/Odessa, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 20, 8:21 PM CDTSevere Thunderstorm WarningMAFPecos34 min
Apr 20, 9:08 PM CDTSevere Thunderstorm WarningMAFPecos37 min
Apr 21, 4:41 AM CDTRed Flag WarningMAF40 hr
Apr 21, 5:12 AM CDTHigh Wind WatchMAF10 hr
Apr 21, 3:29 PM CDTSevere Thunderstorm WarningMAFPecos61 min
Apr 21, 4:18 PM CDTTornado WarningMAFPecos, Terrell57 min
Apr 21, 5:14 PM CDTTornado WarningMAFPecos61 min
Apr 21, 5:47 PM CDTTornado WarningMAFPecos, Terrell58 min
Apr 21, 6:01 PM CDTSevere Thunderstorm WarningMAFScurry14 min

Nearby

Tornado Warnings in Texas, 2011Every tornado warning in 2011Tornadoes in 2011

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.