Alert archive / Louisiana / Tornado Watches in 2009

Tornado Watch 762

October 9, 200917 counties in Arkansas; 24 parishes in Louisiana; 11 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Oct 9, 2009, 8:36 AM CDT for 17 counties in Arkansas; 24 parishes in Louisiana; 11 counties in Mississippi. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Oct 9, 2009, 8:36 AM CDT (13:36 UTC)
Expired
Oct 9, 2009, 1:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 52 counties

Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Jefferson County, AR, Lincoln County, AR, Monroe County, AR, Ouachita County, AR, Phillips County, AR, Union County, AR, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Bolivar County, MS, Coahoma County, MS, Humphreys County, MS, Issaquena County, MS, Leflore County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Warren County, MS, Washington County, MS

The radar

The Shreveport radar (KSHV), 179 km from the middle of the area, began a volume at 13:37 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
30%
One or more EF2 to EF5 tornadoes
40%
Ten or more severe wind reports
50%
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
5%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 9, 8:42 AM CDTSevere Thunderstorm WarningSHVUnion63 min
Oct 9, 8:48 AM CDTSevere Thunderstorm WarningSHVBienville, De Soto, Jackson, Natchitoches, Red River, Sabine and 1 more57 min
Oct 9, 8:50 AM CDTSevere Thunderstorm WarningLZKBradley, Calhoun, Cleveland, Dallas, Grant, Ouachita55 min
Oct 9, 9:07 AM CDTFlash Flood WarningLZKGrant, Jackson, Jefferson, Lonoke, Monroe, Prairie and 4 more3 hr
Oct 9, 9:28 AM CDTSevere Thunderstorm WarningSHVUnion62 min
Oct 9, 9:40 AM CDTSevere Thunderstorm WarningJANAshley80 min
Oct 9, 9:42 AM CDTSevere Thunderstorm WarningLZKBradley, Calhoun, Cleveland, Drew, Grant, Jefferson and 1 more63 min
Oct 9, 9:49 AM CDTSevere Thunderstorm WarningLZKArkansas, Jefferson, Lincoln, Monroe, Prairie41 min
Oct 9, 10:09 AM CDTSevere Thunderstorm WarningSHVJackson, Ouachita, Union51 min
Oct 9, 10:22 AM CDTSevere Thunderstorm WarningJANFranklin, Richland68 min
Oct 9, 10:26 AM CDTSevere Thunderstorm WarningLZKArkansas, Desha, Drew, Jefferson, Lincoln, Monroe64 min
Oct 9, 10:48 AM CDTSevere Thunderstorm WarningMEGPhillips42 min
Oct 9, 10:49 AM CDTSevere Thunderstorm WarningJANAshley, Chicot71 min
Oct 9, 10:54 AM CDTSevere Thunderstorm WarningJANAshley, Chicot81 min
Oct 9, 11:17 AM CDTTornado WarningJANBolivar58 min
Oct 9, 11:27 AM CDTSevere Thunderstorm WarningMEGCoahoma, Lafayette, Marshall, Panola, Quitman, Tallahatchie and 2 more63 min
Oct 9, 11:29 AM CDTTornado WarningJANChicot46 min
Oct 9, 11:31 AM CDTSevere Thunderstorm WarningLZKArkansas, Desha29 min
Oct 9, 11:35 AM CDTSevere Thunderstorm WarningJANEast Carroll55 min
Oct 9, 12:00 PM CDTSevere Thunderstorm WarningJANBolivar, Sunflower60 min
Oct 9, 12:03 PM CDTTornado WarningJANLeflore, Sunflower57 min
Oct 9, 12:06 PM CDTTornado WarningJANBolivar, Sunflower37 min
Oct 9, 12:24 PM CDTSevere Thunderstorm WarningJANCarroll, Grenada, Holmes, Humphreys, Leflore, Sunflower and 1 more66 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 12:00Z, 1.6 hours before the alert went out and 170 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 12:00Z on 2009-10-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1981 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, Shreveport, LA at 12:00Z on 2009-10-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 377 square meters per square second.19395878Sfc1 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
1981 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
625 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
377 m²/s²
0-3 km storm-relative helicity
416 m²/s²
Significant tornado parameter
5.2
Supercell composite
19.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 8, 7:35 PM CDTMesoscale DiscussionSPCBaxter, Boone, Clay, Cleburne, Conway, Craighead and 15 more55 min
Oct 8, 8:00 PM CDTTornado WatchSPCBaxter, Boone, Clay, Cleburne, Conway, Craighead and 23 more7 hr
Oct 8, 11:06 PM CDTMesoscale DiscussionSPCBaxter, Clay, Cleburne, Conway, Craighead, Faulkner and 17 more84 min
Oct 8, 11:40 PM CDTMesoscale DiscussionSPCCrawford, Sebastian95 min
Oct 9, 2:38 AM CDTMesoscale DiscussionSPCClark, Cleburne, Craighead, Crittenden, Cross, Faulkner and 24 more52 min
Oct 9, 6:59 AM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 14 more3 hr
Oct 9, 8:24 AM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 7 more66 min
Oct 9, 10:45 AM CDTMesoscale DiscussionSPCChicot, Desha90 min
Oct 9, 11:26 AM CDTTornado WatchSPCAlcorn, Attala, Benton, Calhoun, Carroll, Chickasaw and 27 more5 hr
Oct 9, 1:41 PM CDTMesoscale DiscussionSPCAttala, Chickasaw, Choctaw, Clay, Itawamba, Kemper and 9 more94 min
Oct 8, 8:20 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 25 more115 min
Oct 8, 11:53 PM CDTMesoscale DiscussionSPCBrown, Coke, Coleman, Concho, Crockett, Glasscock and 14 more97 min

Nearby

Tornado Watches in Louisiana, 2009Tornado Watches in Arkansas, 2009Tornado Watches in Mississippi, 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.