Alert archive / Mississippi / Severe Thunderstorm Watches in 2018

Severe Thunderstorm Watch 110

May 20, 20186 states

The Storm Prediction Center issued this severe thunderstorm watch at May 20, 2018, 12:32 PM CDT for 6 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 20, 2018, 12:32 PM CDT (17:32 UTC)
Expired: May 20, 2018, 6:58 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 95 counties

Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Lawrence County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, Poinsett County, AR, Randolph County, AR, St. Francis County, AR, Alexander County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Johnson County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, White County, IL, Williamson County, IL, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Butler County, MO, Cape Girardeau County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Stoddard County, MO, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN

The radar

The Paducah radar (KPAH), 80 km from the middle of the area, began a volume at 17:33 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: 5%
One or more EF2 to EF5 tornadoes: 2%
Ten or more severe wind reports: 60%
One or more gusts of 65 knots or more: 20%
Ten or more severe hail reports: 40%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 20, 12:44 PM CDT	Severe Thunderstorm Warning	MEG	Lawrence, Randolph	46 min
May 20, 1:02 PM CDT	Severe Thunderstorm Warning	MEG	Clay	43 min
May 20, 1:13 PM CDT	Tornado Warning	MEG	Lawrence	32 min
May 20, 1:23 PM CDT	Severe Thunderstorm Warning	MEG	Lawrence, Randolph	52 min
May 20, 1:40 PM CDT	Severe Thunderstorm Warning	MEG	Clay	65 min
May 20, 1:41 PM CDT	Severe Thunderstorm Warning	MEG	Fayette, Hardeman	34 min
May 20, 1:42 PM CDT	Severe Thunderstorm Warning	MEG	Lawrence	48 min
May 20, 1:46 PM CDT	Tornado Warning	MEG	Lawrence, Randolph	12 min
May 20, 1:51 PM CDT	Severe Thunderstorm Warning	MEG	Clay, Greene, Lawrence, Randolph	54 min
May 20, 2:05 PM CDT	Severe Thunderstorm Warning	MEG	Lawrence	40 min
May 20, 2:12 PM CDT	Severe Thunderstorm Warning	MEG	Mississippi	48 min
May 20, 2:13 PM CDT	Tornado Warning	MEG	Lawrence	21 min
May 20, 2:14 PM CDT	Severe Thunderstorm Warning	PAH	Alexander, Pulaski	18 min
May 20, 2:18 PM CDT	Severe Thunderstorm Warning	PAH	Alexander, Pulaski	42 min
May 20, 2:30 PM CDT	Severe Thunderstorm Warning	MEG	Craighead, Greene, Lawrence	45 min
May 20, 2:37 PM CDT	Severe Thunderstorm Warning	MEG	Greene, Lawrence	53 min
May 20, 2:40 PM CDT	Severe Thunderstorm Warning	MEG	Clay	27 min
May 20, 2:42 PM CDT	Severe Thunderstorm Warning	PAH	Pulaski	30 min
May 20, 2:45 PM CDT	Severe Thunderstorm Warning	MEG	Clay, Greene	60 min
May 20, 2:45 PM CDT	Severe Thunderstorm Warning	PAH	New Madrid	45 min
May 20, 2:57 PM CDT	Severe Thunderstorm Warning	MEG	Benton, Lafayette, Marshall, Union	33 min
May 20, 2:59 PM CDT	Severe Thunderstorm Warning	MEG	Mississippi	46 min
May 20, 3:03 PM CDT	Flash Flood Warning	MEG	Mississippi	117 min
May 20, 3:09 PM CDT	Severe Thunderstorm Warning	MEG	Craighead, Greene	51 min
May 20, 3:10 PM CDT	Severe Thunderstorm Warning	PAH	Saline	35 min
May 20, 3:13 PM CDT	Severe Thunderstorm Warning	MEG	Panola, Tate, Tunica	32 min
May 20, 3:28 PM CDT	Severe Thunderstorm Warning	PAH	Fulton	47 min
May 20, 3:30 PM CDT	Severe Thunderstorm Warning	MEG	Pemiscot	45 min
May 20, 3:43 PM CDT	Severe Thunderstorm Warning	PAH	Fulton	32 min
May 20, 3:47 PM CDT	Severe Thunderstorm Warning	MEG	Craighead, Greene, Mississippi	22 min
May 20, 3:56 PM CDT	Severe Thunderstorm Warning	MEG	Shelby, Tipton	36 min
May 20, 3:58 PM CDT	Severe Thunderstorm Warning	MEG	Crittenden	47 min
May 20, 4:04 PM CDT	Severe Thunderstorm Warning	MEG	Coahoma	26 min
May 20, 4:18 PM CDT	Severe Thunderstorm Warning	MEG	Lee	27 min
May 20, 4:27 PM CDT	Severe Thunderstorm Warning	MEG	Dyer, Lake, Lauderdale, Obion	48 min
May 20, 4:35 PM CDT	Flash Flood Warning	PAH	Calloway	115 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 12:00Z, 5.5 hours before the alert went out and 193 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1368 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 1256 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: -28 m²/s²
0-3 km storm-relative helicity: -10 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.

Issued	Product	Office	Counties	Lasted
May 20, 1:11 AM CDT	Mesoscale Discussion	SPC	Polk, Scott, Sebastian	2 hr
May 20, 11:43 AM CDT	Mesoscale Discussion	SPC	Clay, Craighead, Crittenden, Cross, Greene, Independence and 11 more	3 hr
May 20, 3:32 PM CDT	Mesoscale Discussion	SPC	Clay, Craighead, Crittenden, Cross, Greene, Lee and 4 more	118 min
May 20, 3:32 PM CDT	Severe Thunderstorm Watch	SPC	Benton	4 hr
May 20, 6:25 PM CDT	Mesoscale Discussion	SPC	Benton, Carroll	95 min
May 20, 6:26 PM CDT	Mesoscale Discussion	SPC	Arkansas, Craighead, Crittenden, Cross, Greene, Jackson and 8 more	64 min
May 20, 5:40 PM CDT	Mesoscale Discussion	SPC	Boone, Boyd, Bracken, Campbell, Carter, Fleming and 11 more	3 hr
May 19, 7:41 PM CDT	Mesoscale Discussion	SPC	Bates, Benton, Cass, Henry, Johnson, Pettis	94 min
May 20, 12:42 AM CDT	Mesoscale Discussion	SPC	Barton, Bates, Benton, Camden, Cass, Cedar and 28 more	3 hr
May 20, 2:24 PM CDT	Mesoscale Discussion	SPC	Barry, Barton, Bates, Benton, Camden, Cedar and 16 more	3 hr

Nearby

Severe Thunderstorm Watches in Mississippi, 2018 Severe Thunderstorm Watches in Tennessee, 2018 Severe Thunderstorm Watches in Kentucky, 2018 Every severe thunderstorm watch in 2018

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.