Alert archive / Louisiana / Tornado Watches in 2013
Tornado Watch 37
The Storm Prediction Center issued this tornado watch at Feb 21, 2013, 1:37 PM CST for 16 parishes in Louisiana; 6 counties in Texas. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 21, 2013, 1:37 PM CST (19:37 UTC)
- Expired
- Feb 21, 2013, 7:00 PM CST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 22 counties
Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Vernon Parish, LA, Winn Parish, LA, Hardin County, TX, Jasper County, TX, Newton County, TX, Orange County, TX, Sabine County, TX, Tyler County, TX
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 30%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 21, 1:46 PM CST | Severe Thunderstorm Warning | LCH | Jasper, Tyler | 59 min |
| Feb 21, 1:59 PM CST | Severe Thunderstorm Warning | LCH | Vernon | 46 min |
| Feb 21, 2:22 PM CST | Tornado Warning | SHV | Sabine | 23 min |
| Feb 21, 2:53 PM CST | Tornado Warning | LCH | Vernon | 22 min |
| Feb 21, 3:06 PM CST | Tornado Warning | SHV | Natchitoches | 24 min |
| Feb 21, 3:28 PM CST | Severe Thunderstorm Warning | LCH | Rapides, Vernon | 62 min |
| Feb 21, 4:20 PM CST | Severe Thunderstorm Warning | SHV | LaSalle | 25 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Lake Charles Mun, LA (KLCH), launched 12:00Z, 7.6 hours before the alert went out and 82 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.
- Mixed-layer CAPE
- 13 J/kg
- Mixed-layer CIN
- -343 J/kg
- Mixed-layer LCL
- 461 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 509 m²/s²
- 0-3 km storm-relative helicity
- 644 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 7.8
The text
As transmitted, in the capitals the NWS used until 2016.
092
WWUS20 KWNS 211939
SEL7
SPC WW 211939
LAZ000-TXZ000-220100-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 37
NWS STORM PREDICTION CENTER NORMAN OK
140 PM CST THU FEB 21 2013
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
CENTRAL AND SOUTHWEST LOUISIANA
PORTIONS OF SOUTHEAST TEXAS
EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 140 PM UNTIL
700 PM CST.
TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 5 MILES EAST SOUTHEAST OF LAKE
CHARLES LOUISIANA TO 25 MILES NORTHEAST OF NATCHITOCHES
LOUISIANA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.
DISCUSSION...THUNDERSTORMS CONTINUE TO INTENSIFY ALONG AND IN
ADVANCE OF A COLD FRONT AND NORTHWARD-MOVING WARM FRONT. MOISTENING
BOUNDARY LAYER AND SUFFICIENT DEEP-LAYER SHEAR EXISTS FOR SUPERCELLS
AS WELL AS BOWING SEGMENTS. TORNADO POTENTIAL WILL BE RELATIVELY
HIGHEST FOR STORMS IN THE VICINITY OF THE WARM FRONT AND POSSIBLY
WITH MESOVORTICES ASSOCIATED WITH STRONGER BOWING SEGMENTS.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 25035.
...HARTSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 21, 1:22 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Avoyelles, Concordia, East Baton Rouge, East Feliciana and 14 more | 113 min |
| Feb 21, 3:15 PM CST | Mesoscale Discussion | SPC | Allen, Avoyelles, Beauregard, Catahoula, Evangeline, Grant and 4 more | 90 min |
| Feb 21, 3:48 PM CST | Mesoscale Discussion | SPC | Concordia, Franklin, Saint Helena, Tensas, Washington | 57 min |
| Feb 20, 10:52 PM CST | Mesoscale Discussion | SPC | Archer, Baylor, Brown, Callahan, Childress, Clay and 30 more | 113 min |
| Feb 20, 11:49 PM CST | Mesoscale Discussion | SPC | Gray, Hemphill, Lipscomb, Ochiltree, Roberts, Wheeler | 6 hr |
| Feb 21, 3:19 AM CST | Mesoscale Discussion | SPC | Concho, Gillespie, Kimble, Llano, McCulloch, Mason and 3 more | 86 min |
| Feb 21, 5:08 AM CST | Mesoscale Discussion | SPC | Bosque, Brown, Callahan, Clay, Comanche, Cooke and 16 more | 97 min |
| Feb 21, 7:22 AM CST | Mesoscale Discussion | SPC | Bell, Brazos, Burleson, Falls, Freestone, Grimes and 13 more | 83 min |
| Feb 21, 10:53 AM CST | Mesoscale Discussion | SPC | Angelina, Chambers, Hardin, Harris, Jasper, Jefferson and 6 more | 97 min |
Nearby
Tornado Watches in Louisiana, 2013Tornado Watches in Texas, 2013Every tornado watch in 2013
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.