Alert archive / Mississippi / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 69

March 7, 20174 states

The Storm Prediction Center issued this severe thunderstorm watch at Mar 7, 2017, 3:37 AM CST for 4 states. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Mar 7, 2017, 3:37 AM CST (09:37 UTC)
Expired
Mar 7, 2017, 12:00 PM CST
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 96 counties

Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Crittenden County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Jefferson County, AR, Lafayette County, AR, Lee County, AR, Lincoln County, AR, Little River County, AR, Miller County, AR, Mississippi County, AR, Monroe County, AR, Nevada County, AR, Ouachita County, AR, Phillips County, AR, Pike County, AR, Sevier County, AR, St. Francis County, AR, Union County, AR, Bienville Parish, LA, Claiborne Parish, LA, East Carroll Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Richland Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Alcorn County, MS, Attala County, MS, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Leflore County, MS, Marshall County, MS, Monroe County, MS, Montgomery County, MS, Oktibbeha County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Washington County, MS, Webster County, MS, Yalobusha County, MS, Yazoo County, MS, Chester County, TN, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Haywood County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN

The radar

The Little Rock radar (KLZK), 132 km from the middle of the area, began a volume at 09:36 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
20%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 7, 3:42 AM CSTSevere Thunderstorm WarningMEGLake48 min
Mar 7, 4:12 AM CSTSevere Thunderstorm WarningMEGDyer, Lake, Obion, Weakley48 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

Little Rock, AR (KBYH), launched 00:00Z, 9.6 hours before the alert went out and 169 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, Little Rock, AR at 00:00Z on 2017-03-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 208 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, Little Rock, AR at 00:00Z on 2017-03-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 338 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
208 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
755 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
338 m²/s²
0-3 km storm-relative helicity
509 m²/s²
Significant tornado parameter
0.5
Supercell composite
7.4

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 7, 1:40 PM CSTMesoscale DiscussionSPCBibb, Blount, Chilton, Choctaw, Cullman, Fayette and 12 more65 min
Mar 6, 6:02 PM CSTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Franklin, Madison and 2 more58 min
Mar 6, 6:51 PM CSTTornado WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more8 hr
Mar 6, 8:10 PM CSTMesoscale DiscussionSPCBaxter, Boone, Carroll, Clay, Cleburne, Conway and 27 more3 hr
Mar 6, 9:16 PM CSTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Franklin, Madison and 3 more119 min
Mar 6, 9:21 PM CSTTornado WatchSPCBaxter, Boone, Clay, Cleburne, Conway, Craighead and 31 more8 hr
Mar 7, 2:58 AM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 47 more92 min
Mar 7, 8:03 AM CSTMesoscale DiscussionSPCAshley, Chicot, Desha, Drew, Union117 min
Mar 7, 11:02 AM CSTMesoscale DiscussionSPCAvoyelles, Caldwell, Catahoula, Concordia, East Carroll, Franklin and 12 more58 min

Nearby

Severe Thunderstorm Watches in Mississippi, 2017Severe Thunderstorm Watches in Arkansas, 2017Severe Thunderstorm Watches in Tennessee, 2017Every severe thunderstorm watch in 2017

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.