Alert archive / Texas / Tornado Watches in 2012
Tornado Watch 694
The Storm Prediction Center issued this tornado watch at Dec 25, 2012, 9:17 AM CST for 16 parishes in Louisiana; 22 counties in Texas. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 25, 2012, 9:17 AM CST (15:17 UTC)
- Expired
- Dec 25, 2012, 5:00 PM CST
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 65 kt
All 38 counties
Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Austin County, TX, Brazoria County, TX, Chambers County, TX, Fort Bend County, TX, Galveston County, TX, Grimes County, TX, Hardin County, TX, Harris County, TX, Houston County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Montgomery County, TX, Newton County, TX, Orange County, TX, Polk County, TX, San Jacinto County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Waller County, TX, Wharton County, TX
The radar
The Lake Charles radar (KLCH), 113 km from the middle of the area, began a volume at 15:18 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 60%
- One or more EF2 to EF5 tornadoes
- 60%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 40%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
31 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 25, 9:17 AM CST | Severe Thunderstorm Warning | HGX | Houston, Madison | 43 min |
| Dec 25, 9:45 AM CST | Severe Thunderstorm Warning | HGX | Polk, Trinity | 30 min |
| Dec 25, 9:57 AM CST | Tornado Warning | HGX | Houston, Trinity | 22 min |
| Dec 25, 10:15 AM CST | Severe Thunderstorm Warning | HGX | Harris, Liberty, Montgomery, Polk, San Jacinto | 30 min |
| Dec 25, 10:18 AM CST | Severe Thunderstorm Warning | HGX | Polk, San Jacinto, Trinity | 42 min |
| Dec 25, 10:30 AM CST | Severe Thunderstorm Warning | LCH | Tyler | 60 min |
| Dec 25, 10:39 AM CST | Tornado Warning | HGX | Harris, Liberty, Montgomery | 36 min |
| Dec 25, 10:42 AM CST | Severe Thunderstorm Warning | HGX | Liberty, Montgomery, Polk, San Jacinto | 17 min |
| Dec 25, 10:57 AM CST | Severe Thunderstorm Warning | LCH | Hardin, Tyler | 33 min |
| Dec 25, 11:00 AM CST | Severe Thunderstorm Warning | LCH | Jasper | 30 min |
| Dec 25, 11:01 AM CST | Severe Thunderstorm Warning | HGX | Chambers, Harris, Liberty | 44 min |
| Dec 25, 11:12 AM CST | Tornado Warning | HGX | Chambers, Harris, Liberty | 48 min |
| Dec 25, 11:18 AM CST | Severe Thunderstorm Warning | HGX | Brazoria, Galveston, Harris | 42 min |
| Dec 25, 11:23 AM CST | Severe Thunderstorm Warning | HGX | Chambers, Harris, Liberty | 55 min |
| Dec 25, 11:23 AM CST | Severe Thunderstorm Warning | LCH | Hardin, Jasper, Jefferson, Newton, Orange, Tyler | 67 min |
| Dec 25, 11:37 AM CST | Severe Thunderstorm Warning | LCH | Beauregard, Calcasieu, Rapides, Vernon | 68 min |
| Dec 25, 11:48 AM CST | Severe Thunderstorm Warning | LCH | Jefferson, Orange | 42 min |
| Dec 25, 11:54 AM CST | Tornado Warning | LCH | Vernon | 36 min |
| Dec 25, 11:54 AM CST | Severe Thunderstorm Warning | HGX | Brazoria, Galveston | 24 min |
| Dec 25, 12:20 PM CST | Severe Thunderstorm Warning | LCH | Beauregard, Calcasieu, Cameron | 55 min |
| Dec 25, 12:23 PM CST | Tornado Warning | LCH | Rapides, Vernon | 37 min |
| Dec 25, 12:27 PM CST | Severe Thunderstorm Warning | LCH | Cameron | 63 min |
| Dec 25, 12:37 PM CST | Severe Thunderstorm Warning | LCH | Allen, Avoyelles, Beauregard, Evangeline, Rapides, Saint Landry and 1 more | 53 min |
| Dec 25, 12:40 PM CST | Tornado Warning | LCH | Rapides, Vernon | 35 min |
| Dec 25, 12:51 PM CST | Severe Thunderstorm Warning | LCH | Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 3 more | 54 min |
| Dec 25, 12:53 PM CST | Tornado Warning | LCH | Avoyelles, Rapides | 22 min |
| Dec 25, 1:29 PM CST | Severe Thunderstorm Warning | LCH | Allen, Avoyelles, Evangeline, Rapides, Saint Landry | 61 min |
| Dec 25, 1:51 PM CST | Severe Thunderstorm Warning | LCH | Acadia, Calcasieu, Jefferson Davis, Lafayette, Saint Landry, Vermilion | 54 min |
| Dec 25, 2:08 PM CST | Tornado Warning | LCH | Avoyelles | 7 min |
| Dec 25, 2:29 PM CST | Severe Thunderstorm Warning | LCH | Avoyelles, Saint Landry | 31 min |
| Dec 25, 2:42 PM CST | Severe Thunderstorm Warning | LCH | Acadia, Iberia, Lafayette, Saint Landry, Saint Martin, Vermilion | 63 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, 3.3 hours before the alert went out and 115 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
- 1505 J/kg
- Mixed-layer CIN
- -9 J/kg
- Mixed-layer LCL
- 500 m above ground
- 0-6 km bulk shear
- 54 kt
- 0-1 km storm-relative helicity
- 265 m²/s²
- 0-3 km storm-relative helicity
- 353 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 10.9
The text
As transmitted, in the capitals the NWS used until 2016.
028
WWUS20 KWNS 251518
SEL4
SPC WW 251518
LAZ000-TXZ000-CWZ000-252200-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 694
NWS STORM PREDICTION CENTER NORMAN OK
920 AM CST TUE DEC 25 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTH-CENTRAL AND SOUTHWESTERN LOUISIANA
SOUTHEAST TEXAS
COASTAL WATERS
EFFECTIVE THIS TUESDAY MORNING AND AFTERNOON FROM 920 AM UNTIL
400 PM CST.
TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 75 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 45 MILES SOUTHWEST OF
HUNTSVILLE TEXAS TO 15 MILES NORTHEAST OF LAFAYETTE LOUISIANA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU4).
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.
OTHER WATCH INFORMATION...CONTINUE...WW 692...WW 693...
DISCUSSION...SFC-BASED SUPERCELL/TORNADO THREAT FCST TO INCREASE AND
SHIFT EWD ACROSS WW AREA THROUGH AFTN. WARM SECTOR EXPECTED TO
SHIFTS FARTHER INLAND AND BECOMES OVERLAIN BY STRENGTHENING
MID-UPPER FLOW AND ASCENT...PER SPC MESOSCALE DISCUSSION 2207.
POTENTIAL EXISTS FOR LARGE HAIL AND A FEW STG/DAMAGING TORNADOES
WITH ANY SUSTAINED/DISCRETE SUPERCELLS. BOW-ECHO/QLCS CIRCULATIONS
ALSO MAY BECOME TORNADIC...IN ADDITION TO SVR GUST POTENTIAL.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 65 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 25040.
...EDWARDSSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 25, 1:01 AM CST | Mesoscale Discussion | SPC | Allen, Beauregard, Sabine, Vernon | 59 min |
| Dec 25, 1:37 AM CST | Severe Thunderstorm Watch | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, De Soto and 9 more | 7 hr |
| Dec 25, 5:56 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, De Soto and 10 more | 94 min |
| Dec 25, 7:00 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Ascension, Assumption, Beauregard, Calcasieu and 24 more | 60 min |
| Dec 25, 7:28 AM CST | Tornado Watch | SPC | Acadia, Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia and 19 more | 6 hr |
| Dec 25, 8:46 AM CST | Mesoscale Discussion | SPC | Allen, Avoyelles, Beauregard, Bienville, Calcasieu, Caldwell and 21 more | 59 min |
| Dec 25, 9:02 AM CST | Severe Thunderstorm Watch | SPC | Bienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 20 more | 7 hr |
| Dec 25, 12:19 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 35 more | 71 min |
| Dec 25, 12:23 PM CST | Mesoscale Discussion | SPC | Bienville, Caldwell, Catahoula, Concordia, East Carroll, Franklin and 13 more | 67 min |
| Dec 25, 12:58 PM CST | Tornado Watch | SPC | Ascension, Assumption, Catahoula, Concordia, East Baton Rouge, East Feliciana and 20 more | 9 hr |
| Dec 25, 3:22 PM CST | Mesoscale Discussion | SPC | Caldwell, East Carroll, Morehouse, Richland, West Carroll | 53 min |
| Dec 25, 3:44 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 19 more | 91 min |
| Dec 25, 9:31 AM CST | Mesoscale Discussion | SPC | Archer, Baylor, Clay, Cooke, Denton, Hood and 10 more | 5 hr |
| Dec 25, 11:02 AM CST | Mesoscale Discussion | SPC | Wichita, Wilbarger | 4 hr |
| Dec 25, 1:00 PM CST | Mesoscale Discussion | SPC | Bowie, Camp, Cass, Collin, Dallas, Delta and 16 more | 5 hr |
| Dec 25, 2:50 PM CST | Mesoscale Discussion | SPC | Clay, Wichita, Wilbarger | 4 hr |
Nearby
Tornado Watches in Texas, 2012Tornado Watches in Louisiana, 2012Every tornado watch in 2012
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.