Alert archive / Texas / Tornado Warnings in 2011

Tornado Warning 70, NWS Shreveport, LA

May 20, 2011Red River County, Texas; McCurtain County, Oklahoma

NWS Shreveport, LA issued this tornado warning at May 20, 2011, 5:27 PM CDT for Red River County, Texas; McCurtain County, Oklahoma. It was in force for 48 min. 3 reports 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
May 20, 2011, 5:27 PM CDT (22:27 UTC)
Expired
May 20, 2011, 6:15 PM CDT
In force
48 min
Issued by
NWS Shreveport, LA
Area
Storm-based polygon

Counties McCurtain County, OK, Red River County, TX

The radar

The Western Arkansas radar (KSRX), 171 km from the middle of the area, began a volume at 22:30 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
May 20, 5:36 PM CDTTORNADO10 S Valliant, TXA EF0 TORNADO BRIEFLY TOUCHED DOWN NORTHEAST OF MANCHESTER TEXAS ALONG FM 195 KNOCKING DOWN A FEW SMALL TREES AND SNAPPING LARGE BRANCHES. THE WEAK TORNADO WAS ON THE GROUND FOR 1.5 MILES AND WAS APPROXIMATELY 50 YARDS WIDE.
May 20, 5:50 PM CDTHAIL 1.752 Se Valliant, OK
May 20, 5:51 PM CDTFUNNEL CLOUD5 Sw Garvin, OKSHERIFF OFFICE REPORTING A FUNNEL CLOUD IN SOUTHWESTERN MCCURTAIN COUNTY

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

The watch it was issued in

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

IssuedProductOfficeLasted
May 20, 11:03 AM CDTTornado WatchSPC7 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 10.5 hours before the alert went out and 199 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 12:00Z on 2011-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2656 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 12:00Z on 2011-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 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
2656 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
648 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
231 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

158 
WFUS54 KSHV 202227
TORSHV
OKC089-TXC387-202315-
/O.NEW.KSHV.TO.W.0070.110520T2227Z-110520T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
527 PM CDT FRI MAY 20 2011

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* TORNADO WARNING FOR...
  NORTH CENTRAL RED RIVER COUNTY IN NORTHEAST TEXAS...
  SOUTHWESTERN MCCURTAIN COUNTY IN SOUTHEAST OKLAHOMA...

* UNTIL 615 PM CDT

* AT 526 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR
  MANCHESTER...OR 13 MILES NORTHWEST OF CLARKSVILLE...MOVING
  NORTHEAST AT 25 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  NEGLEY...SILVER CITY...REDLAND...ALBION AND FARMERS HILL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WARNING MEANS THAT STRONG ROTATION HAS BEEN DETECTED IN THE
STORM. A TORNADO MAY ALREADY BE ON THE GROUND...OR IS EXPECTED TO
DEVELOP SHORTLY. IF YOU ARE IN THE PATH OF THIS DANGEROUS STORM...
MOVE INDOORS AND TO THE LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM
WINDOWS. IF DRIVING...DO NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

&&

LAT...LON 3402 9507 3386 9487 3369 9517 3377 9528
TIME...MOT...LOC 2226Z 222DEG 13KT 3377 9518

$$

13
2 follow-up statements
745 
WWUS54 KSHV 202241
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
541 PM CDT FRI MAY 20 2011

OKC089-TXC387-202315-
/O.CON.KSHV.TO.W.0070.000000T0000Z-110520T2315Z/
MCCURTAIN OK-RED RIVER TX-
541 PM CDT FRI MAY 20 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR RED RIVER
AND MCCURTAIN COUNTIES...

AT 541 PM CDT...USING DOPPLER RADAR...NATIONAL WEATHER SERVICE
METEOROLOGISTS CONTINUED TO DETECT A TORNADO.  THIS TORNADO WAS
LOCATED NEAR SILVER CITY...OR 16 MILES NORTH OF CLARKSVILLE...MOVING
NORTHEAST AT 35 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FARMERS
HILL

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

13

LAT...LON 3378 9511 3383 9518 3402 9507 3386 9487
TIME...MOT...LOC 2241Z 224DEG 31KT 3387 9506

$$
602 
WWUS54 KSHV 202248
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
548 PM CDT FRI MAY 20 2011

OKC089-TXC387-202315-
/O.CON.KSHV.TO.W.0070.000000T0000Z-110520T2315Z/
MCCURTAIN OK-RED RIVER TX-
548 PM CDT FRI MAY 20 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR RED RIVER
AND MCCURTAIN COUNTIES...

AT 547 PM CDT...DOPPLER RADAR CONTINUED TO INDICATE A TORNADO ON
THE RED RIVER COUNTY...MCCURTAIN COUNTY LINE OVER THE RED RIVER JUST
SOUTHWEST OF THE FARMERS HILL COMMUNITY. THIS STORM IS MOVING NORTHEAST
AT 35 MPH. 

THE TORNADO WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS OF THE
INDICATED COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3382 9507 3389 9513 3399 9503 3386 9487
TIME...MOT...LOC 2247Z 244DEG 43KT 3389 9502

$$

13

The office that day

Everything else NWS Shreveport, LA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 4:58 PM CDTSevere Thunderstorm WarningSHVSmith, Upshur36 min
May 20, 5:02 PM CDTSevere Thunderstorm WarningSHVGregg, Harrison, Rusk43 min
May 20, 5:53 PM CDTSevere Thunderstorm WarningSHVGregg, Harrison, Marion, Rusk52 min
May 20, 6:38 PM CDTTornado WarningSHVHarrison, Marion21 min
May 20, 6:55 PM CDTSevere Thunderstorm WarningSHVBowie, Red River47 min
May 20, 5:59 PM CDTTornado WarningSHVMcCurtain21 min

Nearby

Tornado Warnings in Texas, 2011Tornado Warnings in Oklahoma, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.