Alert archive / Texas / Tornado Watches in 2012

Tornado Watch 89

March 19, 20124 counties in Arkansas; McCurtain County, Oklahoma; 36 counties in Texas

The Storm Prediction Center issued this tornado watch at Mar 19, 2012, 7:28 PM CDT for 4 counties in Arkansas; McCurtain County, Oklahoma; 36 counties in Texas. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Mar 19, 2012, 7:28 PM CDT (00:28 UTC)
Expired
Mar 20, 2012, 4:00 AM CDT
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 41 counties

Howard County, AR, Little River County, AR, Miller County, AR, Sevier County, AR, McCurtain County, OK, Anderson County, TX, Bell County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Delta County, TX, Ellis County, TX, Falls County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Leon County, TX, Limestone County, TX, Marion County, TX, McLennan County, TX, Milam County, TX, Morris County, TX, Navarro County, TX, Rains County, TX, Red River County, TX, Robertson County, TX, Rockwall County, TX, Rusk County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 148 km from the middle of the area, began a volume at 00:30 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Mar 19, 8:15 PM CDTSevere Thunderstorm WarningFWDBosque, Coryell, McLennan45 min
Mar 19, 9:51 PM CDTFlash Flood WarningFWDBell, Coryell, McLennan3 hr
Mar 19, 10:02 PM CDTFlash Flood WarningFWDRockwall3 hr
Mar 19, 11:32 PM CDTSevere Thunderstorm WarningFWDBell, Coryell43 min
Mar 19, 11:42 PM CDTSevere Thunderstorm WarningFWDHenderson, Kaufman, Navarro, Van Zandt48 min
Mar 20, 12:10 AM CDTFlash Flood WarningFWDHill3 hr
Mar 20, 12:13 AM CDTSevere Thunderstorm WarningFWDHenderson, Hopkins, Hunt, Rains, Van Zandt62 min
Mar 20, 12:40 AM CDTFlash Flood WarningFWDBell, Falls, McLennan3 hr
Mar 20, 12:41 AM CDTSevere Thunderstorm WarningSHVCamp, Franklin, Red River, Smith, Titus, Upshur and 1 more49 min
Mar 20, 12:50 AM CDTFlash Flood WarningFWDDallas, Ellis3 hr
Mar 20, 1:08 AM CDTFlash Flood WarningFWDNavarro3 hr
Mar 20, 1:26 AM CDTSevere Thunderstorm WarningFWDMilam49 min
Mar 20, 2:04 AM CDTFlash Flood WarningFWDHenderson3 hr
Mar 20, 2:09 AM CDTSevere Thunderstorm WarningFWDFalls, Limestone, Milam, Robertson51 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

Shreveport, LA (KSHV), launched 00:00Z, 0.5 hours before the alert went out and 189 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 00:00Z on 2012-03-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 298 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 00:00Z on 2012-03-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 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
298 J/kg
Mixed-layer CIN
-113 J/kg
Mixed-layer LCL
1562 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
206 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

054 
WWUS20 KWNS 200025
SEL9  
SPC WW 200025
ARZ000-OKZ000-TXZ000-200700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 89
NWS STORM PREDICTION CENTER NORMAN OK
725 PM CDT MON MAR 19 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       SOUTHWEST ARKANSAS
       SOUTHEAST OKLAHOMA
       NORTHEAST TEXAS

EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 725 PM UNTIL
200 AM CDT.

TORNADOES...HAIL TO 2 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 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES NORTH NORTHEAST OF DE
QUEEN ARKANSAS TO 40 MILES SOUTH OF TEMPLE TEXAS.  FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU9).

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 85...WW 86...WW 87...WW
88...

DISCUSSION...A LINE OF INTENSE STORMS IS MOVING EASTWARD ACROSS
CENTRAL AND NORTH CENTRAL TX...WHILE A FEW ISOLATED CELLS FORM AHEAD
OF THE LINE ACROSS NORTHEAST TX.  THIS REGION IS NEAR THE AXIS OF A
STRONG LOW LEVEL JET...AND AREA WHERE LARGE SCALE LIFT SHOULD
INCREASE THROUGH THE EVENING.  THESE FACTORS SUGGEST AN INCREASING
RISK OF LOCALLY SEVERE STORMS INCLUDING ISOLATED TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24030.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 19, 8:48 PM CDTMesoscale DiscussionSPCBenton, Carroll, Crawford, Madison, Sebastian, Washington57 min
Mar 19, 10:17 PM CDTMesoscale DiscussionSPCBaxter, Boone, Marion, Newton, Pope, Searcy58 min
Mar 19, 10:35 PM CDTSevere Thunderstorm WatchSPCBaxter, Boone, Marion, Newton, Searcy3 hr
Mar 20, 1:48 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Cleburne, Cleveland and 22 more117 min
Mar 20, 2:55 PM CDTTornado WatchSPCArkansas, Baxter, Bradley, Calhoun, Cleburne, Cleveland and 25 more7 hr
Mar 20, 5:57 PM CDTMesoscale DiscussionSPCArkansas, Fulton, Independence, Izard, Jackson, Monroe and 4 more93 min
Mar 19, 8:22 PM CDTMesoscale DiscussionSPCBandera, Bell, Bexar, Blanco, Burnet, Comal and 30 more53 min
Mar 19, 9:46 PM CDTMesoscale DiscussionSPCBandera, Bell, Blanco, Burnet, Coryell, Ellis and 18 more119 min
Mar 19, 11:53 PM CDTMesoscale DiscussionSPCAtascosa, Bastrop, Bell, Bexar, Burleson, Caldwell and 28 more67 min
Mar 20, 12:48 AM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Austin, Bastrop, Bee, Bexar and 52 more9 hr
Mar 20, 2:43 AM CDTMesoscale DiscussionSPCAransas, Bee, Calhoun, Colorado, DeWitt, Duval and 13 more92 min
Mar 20, 5:26 AM CDTMesoscale DiscussionSPCBrazoria, Calhoun, Fort Bend, Harris, Liberty, Matagorda and 3 more2 hr
Mar 20, 9:03 AM CDTMesoscale DiscussionSPCChambers, Galveston, Hardin, Jasper, Jefferson, Liberty and 6 more87 min
Mar 20, 9:46 AM CDTTornado WatchSPCHardin, Jasper, Jefferson, Newton, Orange, Sabine and 3 more7 hr

Nearby

Tornado Watches in Texas, 2012Tornado Watches in Arkansas, 2012Tornado Watches in Oklahoma, 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.