Alert archive / Mississippi / Tornado Watches in 2013

Tornado Watch 126

April 18, 2013Ashley County, Chicot County, Union County, Arkansas; 17 parishes in Louisiana; 34 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Apr 18, 2013, 1:43 PM CDT for Ashley County, Chicot County, Union County, Arkansas; 17 parishes in Louisiana; 34 counties in Mississippi. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Apr 18, 2013, 1:43 PM CDT (18:43 UTC)
Expired
Apr 18, 2013, 10:02 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 54 counties

Ashley County, AR, Chicot County, AR, Union County, AR, Caldwell Parish, LA, Catahoula Parish, LA, Concordia 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, Ouachita Parish, LA, Richland Parish, LA, Tensas Parish, LA, Union Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Attala County, MS, Bolivar County, MS, Carroll County, MS, Choctaw County, MS, Claiborne County, MS, Clay County, MS, Copiah County, MS, Franklin County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Lawrence County, MS, Leake County, MS, Leflore County, MS, Lincoln County, MS, Madison County, MS, Montgomery County, MS, Neshoba County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 115 km from the middle of the area, began a volume at 18:40 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
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 18, 2:16 PM CDTSevere Thunderstorm WarningSHVUnion29 min
Apr 18, 2:20 PM CDTSevere Thunderstorm WarningJANAshley, Chicot55 min
Apr 18, 2:25 PM CDTTornado WarningSHVBienville, Jackson, Natchitoches, Red River, Winn35 min
Apr 18, 2:45 PM CDTSevere Thunderstorm WarningJANAshley60 min
Apr 18, 2:56 PM CDTTornado WarningSHVCaldwell, Jackson, Ouachita, Winn34 min
Apr 18, 3:07 PM CDTTornado WarningJANAshley38 min
Apr 18, 3:40 PM CDTTornado WarningJANAshley, Chicot65 min
Apr 18, 3:45 PM CDTSevere Thunderstorm WarningJANAshley, Chicot60 min
Apr 18, 3:45 PM CDTTornado WarningSHVCaldwell, Ouachita45 min
Apr 18, 3:52 PM CDTTornado WarningJANAshley, Chicot38 min
Apr 18, 3:55 PM CDTTornado WarningJANFranklin, Richland65 min
Apr 18, 4:24 PM CDTTornado WarningJANWashington51 min
Apr 18, 4:31 PM CDTTornado WarningJANWashington29 min
Apr 18, 4:41 PM CDTTornado WarningJANChicot19 min
Apr 18, 4:45 PM CDTTornado WarningJANChicot60 min
Apr 18, 4:59 PM CDTTornado WarningJANEast Carroll, Franklin, Madison61 min
Apr 18, 5:00 PM CDTSevere Thunderstorm WarningJANBolivar, Humphreys, Issaquena, Leflore, Sharkey, Sunflower75 min
Apr 18, 5:23 PM CDTTornado WarningJANHumphreys, Issaquena, Leflore, Sharkey, Sunflower, Washington52 min
Apr 18, 5:26 PM CDTTornado WarningJANSunflower34 min
Apr 18, 5:43 PM CDTSevere Thunderstorm WarningJANIssaquena, Sharkey, Warren47 min
Apr 18, 5:48 PM CDTTornado WarningJANLeflore42 min
Apr 18, 6:03 PM CDTSevere Thunderstorm WarningJANYazoo72 min
Apr 18, 6:06 PM CDTTornado WarningJANHolmes, Leflore39 min
Apr 18, 6:08 PM CDTTornado WarningJANSharkey, Yazoo67 min
Apr 18, 6:20 PM CDTFlash Flood WarningJANSunflower, Washington3 hr
Apr 18, 7:09 PM CDTSevere Thunderstorm WarningJANAttala, Holmes66 min
Apr 18, 7:55 PM CDTFlash Flood WarningJANAttala, Holmes2 hr
Apr 18, 8:14 PM CDTSevere Thunderstorm WarningJANAttala, Choctaw, Oktibbeha61 min
Apr 18, 8:20 PM CDTFlash Flood WarningJANAttala, Leake10 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

Jackson, MS (KJAN), launched 12:00Z, 6.7 hours before the alert went out and 105 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, Jackson, MS at 12:00Z on 2013-04-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 73 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, Jackson, MS at 12:00Z on 2013-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 228 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
73 J/kg
Mixed-layer CIN
-438 J/kg
Mixed-layer LCL
606 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
228 m²/s²
0-3 km storm-relative helicity
351 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 17, 10:47 PM CDTTornado WatchSPCBenton, Carroll, Crawford, Madison, Washington7 hr
Apr 18, 2:01 AM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Franklin, Madison and 2 more89 min
Apr 18, 4:02 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Conway, Crawford, Franklin and 17 more58 min
Apr 18, 7:26 AM CDTMesoscale DiscussionSPCBaxter, Boone, Clay, Cleburne, Conway, Craighead and 20 more2 hr
Apr 18, 9:25 AM CDTTornado WatchSPCArkansas, Baxter, Bradley, Calhoun, Clark, Clay and 43 more8 hr
Apr 18, 12:48 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clay and 29 more87 min
Apr 18, 4:56 PM CDTMesoscale DiscussionSPCEast Carroll, Franklin, Madison, Tensas, West Carroll94 min
Apr 18, 5:52 PM CDTTornado WatchSPCCalhoun, Chickasaw, Itawamba, Lafayette, Lee, Monroe and 6 more5 hr
Apr 18, 6:52 PM CDTMesoscale DiscussionSPCAttala, Calhoun, Carroll, Chickasaw, Choctaw, Clay and 12 more83 min

Nearby

Tornado Watches in Mississippi, 2013Tornado Watches in Louisiana, 2013Tornado Watches in Arkansas, 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; radar from the NEXRAD Level II archive.