Alert archive / Louisiana / Tornado Warnings in 2011

Tornado Warning 77, NWS Shreveport, LA

May 25, 2011Grant Parish, Natchitoches Parish, Winn Parish, Louisiana

NWS Shreveport, LA issued this tornado warning at May 25, 2011, 10:16 PM CDT for Grant Parish, Natchitoches Parish, Winn Parish, Louisiana. It was in force for 44 min. 4 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 25, 2011, 10:16 PM CDT (03:16 UTC)
Expired: May 25, 2011, 11:00 PM CDT
In force: 44 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon

Counties Grant Parish, LA, Natchitoches Parish, LA, Winn Parish, LA

What was reported inside it

Time	Report	Where	Remark
May 25, 10:20 PM CDT	HAIL 1	Natchitoches, LA
May 25, 10:22 PM CDT	TORNADO	1 Ne Natchez, LA	AN EF0 TORNADO TOUCHED DOWN ONE MILE NORTHEAST OF NATCHEZ AND MOVED NORTH-NORTHEAST IN PARALLEL TO FISH HATCHERY ROAD. THE TORNADO RIPPED THE TOPS OFF SEVERAL TREES...KNOCKED SEVERAL LARGE LIMBS DOWN...AND BROKE NUMEROUS SMALL LIMBS OFF TREES ALL ALONG THE PAT
May 25, 10:24 PM CDT	HAIL 1.25	5 N Natchitoches, LA
May 25, 10:40 PM CDT	HAIL 1	Clarence, LA

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.

Issued	Product	Office	Lasted
May 25, 9:43 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 3.3 hours before the alert went out and 139 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1872 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 1613 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 131 m²/s²
0-3 km storm-relative helicity: 182 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 10.7

Open this sounding in Storm Lab

The text

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

893 
WFUS54 KSHV 260316
TORSHV
LAC043-069-127-260400-
/O.NEW.KSHV.TO.W.0077.110526T0316Z-110526T0400Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
1016 PM CDT WED MAY 25 2011

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* TORNADO WARNING FOR...
  WESTERN GRANT PARISH IN NORTH CENTRAL LOUISIANA...
  SOUTHWESTERN WINN PARISH IN NORTH CENTRAL LOUISIANA...
  SOUTHEASTERN NATCHITOCHES PARISH IN NORTHWEST LOUISIANA...
  THIS INCLUDES THE CITY OF NATCHITOCHES...

* UNTIL 1100 PM CDT

* AT 1013 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR
  NATCHITOCHES...MOVING SOUTHEAST AT 35 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  MONTGOMERY AND COLFAX...

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 3140 9270 3144 9269 3145 9271 3149 9271
      3151 9272 3140 9287 3163 9322 3189 9317
      3174 9258 3139 9268
TIME...MOT...LOC 0316Z 299DEG 30KT 3168 9308

$$

09

1 follow-up statement

591 
WWUS54 KSHV 260350
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1050 PM CDT WED MAY 25 2011

LAC043-069-127-260400-
/O.CON.KSHV.TO.W.0077.000000T0000Z-110526T0400Z/
NATCHITOCHES LA-GRANT LA-WINN LA-
1050 PM CDT WED MAY 25 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1100 PM CDT FOR WINN...
GRANT AND NATCHITOCHES PARISHES...

AT 1043 PM CDT...USING DOPPLER RADAR...NATIONAL WEATHER SERVICE
METEOROLOGISTS CONTINUED TO DETECT A TORNADO.  THIS TORNADO WAS
LOCATED NEAR ALOHA...OR 16 MILES NORTHWEST OF BOYCE...MOVING
SOUTHEAST AT 35 MPH.

A SECOND AREA OF ROTATION HAD DEVELOPED 5 MILES SOUTH OF 
NATCHITOCHES...OR 5 MILES NORTHWEST OF NATCHEZ...MOVING SOUTHEAST AT 
35 MPH. 

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO LAKE
IATT AND COLFAX

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 3140 9270 3144 9269 3145 9271 3149 9271
      3151 9272 3140 9287 3163 9322 3189 9317
      3174 9258 3139 9268
TIME...MOT...LOC 0346Z 299DEG 30KT 3156 9282

$$

09

The office that day

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

Issued	Product	Office	Counties	Lasted
May 25, 7:14 PM CDT	Severe Thunderstorm Warning	SHV	Natchitoches, Sabine	61 min
May 25, 7:28 PM CDT	Severe Thunderstorm Warning	SHV	Claiborne, Lincoln, Ouachita, Union	62 min
May 25, 7:42 PM CDT	Tornado Warning	SHV	Lincoln, Union	48 min
May 25, 8:03 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, Caldwell, Claiborne, Jackson, Lincoln, Ouachita and 2 more	57 min
May 25, 8:31 PM CDT	Tornado Warning	SHV	Ouachita, Union	30 min
May 25, 8:54 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, Caldwell, De Soto, Grant, Jackson, LaSalle and 4 more	66 min
May 25, 9:13 PM CDT	Tornado Warning	SHV	De Soto, Natchitoches, Red River, Sabine	32 min
May 25, 9:45 PM CDT	Tornado Warning	SHV	Natchitoches, Sabine	30 min
May 25, 9:57 PM CDT	Severe Thunderstorm Warning	SHV	Caldwell, LaSalle, Winn	39 min
May 25, 11:06 PM CDT	Severe Thunderstorm Warning	SHV	Grant, LaSalle, Natchitoches	39 min

Nearby

Tornado Warnings in Louisiana, 2011 Every tornado warning in 2011 Tornadoes 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.