Alert archive / Texas / Tornado Watches in 2009

Tornado Watch 78

March 27, 20094 counties in Arkansas; 7 counties in Oklahoma; 34 counties in Texas

The Storm Prediction Center issued this tornado watch at Mar 27, 2009, 12:58 PM CDT for 4 counties in Arkansas; 7 counties in Oklahoma; 34 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Mar 27, 2009, 12:58 PM CDT (17:58 UTC)
Expired
Mar 27, 2009, 8:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 45 counties

Howard County, AR, Little River County, AR, Miller County, AR, Sevier County, AR, Atoka County, OK, Bryan County, OK, Choctaw County, OK, LeFlore County, OK, Marshall County, OK, McCurtain County, OK, Pushmataha County, OK, Anderson County, TX, Angelina County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Collin County, TX, Delta County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 171 km from the middle of the area, began a volume at 18:02 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
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 27, 1:00 PM CDTSevere Thunderstorm WarningFWDHenderson, Hunt, Kaufman, Navarro, Rains, Van Zandt46 min
Mar 27, 6:02 PM CDTSevere Thunderstorm WarningTSALatimer, LeFlore, Pushmataha58 min
Mar 27, 6:35 PM CDTSevere Thunderstorm WarningTSALeFlore, Pushmataha55 min
Mar 27, 6:43 PM CDTTornado WarningSHVMcCurtain26 min
Mar 27, 6:54 PM CDTTornado WarningTSALeFlore, Pushmataha66 min
Mar 27, 7:46 PM CDTTornado WarningTSALeFlore44 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

Fort Worth, TX (KFWD), launched 12:00Z, 6.0 hours before the alert went out and 165 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, Fort Worth, TX at 12:00Z on 2009-03-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 542 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 12:00Z on 2009-03-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 165 square meters per square second.1939587897117Sfc1 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
542 J/kg
Mixed-layer CIN
-157 J/kg
Mixed-layer LCL
460 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
165 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 26, 9:28 PM CDTMesoscale DiscussionSPCHoward, Montgomery, Polk, Scott, Sevier62 min
Mar 27, 12:33 PM CDTMesoscale DiscussionSPCHempstead, Howard, Lafayette, Little River, Miller, Sevier57 min
Mar 27, 3:34 PM CDTMesoscale DiscussionSPCHoward, Little River, Miller, Sevier56 min
Mar 27, 5:53 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Clark, Cleveland and 16 more97 min
Mar 27, 6:35 PM CDTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 27 more7 hr
Mar 26, 7:32 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Coal, Jefferson, Johnston and 3 more4 hr
Mar 26, 11:34 PM CDTMesoscale DiscussionSPCCimarron, Texas4 hr
Mar 27, 2:55 AM CDTMesoscale DiscussionSPCBeaver, Cimarron, Texas4 hr
Mar 27, 6:50 AM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Canadian, Creek, Dewey, Garfield and 14 more85 min
Mar 27, 8:04 AM CDTMesoscale DiscussionSPCAlfalfa, Beaver, Beckham, Custer, Dewey, Ellis and 7 more4 hr
Mar 27, 12:30 PM CDTMesoscale DiscussionSPCAlfalfa, Beaver, Beckham, Blaine, Caddo, Canadian and 19 more6 hr
Mar 26, 9:13 PM CDTMesoscale DiscussionSPCAngelina, Cherokee, Hardin, Jasper, Jefferson, Nacogdoches and 6 more92 min
Mar 27, 10:24 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Brazoria and 43 more96 min
Mar 27, 11:48 AM CDTSevere Thunderstorm WatchSPCAustin, Brazos, Burleson, Chambers, Grimes, Hardin and 16 more5 hr
Mar 27, 3:43 PM CDTMesoscale DiscussionSPCChambers, Hardin, Harris, Jasper, Jefferson, Liberty and 6 more62 min
Mar 27, 4:49 PM CDTTornado WatchSPCBrazoria, Chambers, Galveston, Hardin, Harris, Jasper and 6 more3 hr

Nearby

Tornado Watches in Texas, 2009Tornado Watches in Oklahoma, 2009Tornado Watches in Arkansas, 2009Every tornado watch in 2009

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.