Alert archive / Mississippi / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 147
The Storm Prediction Center issued this severe thunderstorm watch at May 4, 2021, 12:18 PM CDT for 22 counties in Mississippi. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- May 4, 2021, 12:18 PM CDT (17:18 UTC)
- Expired
- May 4, 2021, 4:48 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 22 counties
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
The radar
The Memphis radar (KNQA), 90 km from the middle of the area, began a volume at 17:19 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
- 30%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 4, 1:06 PM CDT | Severe Thunderstorm Warning | MEG | Lafayette, Marshall, Panola, Tate | 24 min |
| May 4, 1:27 PM CDT | Severe Thunderstorm Warning | MEG | Benton, Lafayette, Marshall, Panola, Tate, Union | 33 min |
| May 4, 2:30 PM CDT | Severe Thunderstorm Warning | MEG | Alcorn, Benton, Tippah | 30 min |
| May 4, 2:37 PM CDT | Severe Thunderstorm Warning | MEG | Itawamba, Lee, Pontotoc, Prentiss, Tishomingo, Union | 26 min |
| May 4, 2:58 PM CDT | Severe Thunderstorm Warning | MEG | Calhoun, Chickasaw | 47 min |
| May 4, 3:00 PM CDT | Severe Thunderstorm Warning | MEG | Alcorn, Benton, Tippah | 19 min |
| May 4, 3:02 PM CDT | Severe Thunderstorm Warning | MEG | Itawamba, Lee, Prentiss, Tishomingo, Union | 16 min |
| May 4, 3:17 PM CDT | Severe Thunderstorm Warning | MEG | Itawamba, Lee | 28 min |
| May 4, 3:33 PM CDT | Severe Thunderstorm Warning | MEG | Chickasaw, Itawamba, Lee, Monroe | 57 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 (KLZK), launched 12:00Z, 5.3 hours before the alert went out and 41 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.
- Mixed-layer CAPE
- 10 J/kg
- Mixed-layer CIN
- -373 J/kg
- Mixed-layer LCL
- 1101 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 62 m²/s²
- 0-3 km storm-relative helicity
- 100 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
777 WWUS20 KWNS 041714 SEL7 SPC WW 041714 ARZ000-MSZ000-042100- URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 147 NWS Storm Prediction Center Norman OK 1215 PM CDT Tue May 4 2021 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Arkansas Northern Mississippi * Effective this Tuesday afternoon from 1215 PM until 400 PM CDT. * Primary threats include... Isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Clusters along the northern periphery of a broader QLCS should pose a risk for isolated large hail and damaging winds, along with a brief tornado across northern Mississippi through mid-afternoon. The severe thunderstorm watch area is approximately along and 45 statute miles north and south of a line from 50 miles southwest of Memphis TN to 30 miles east of Tupelo MS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 142...WW 144...WW 145...WW 146... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Grams
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 4, 8:33 AM CDT | Mesoscale Discussion | SPC | Adams, Amite, Claiborne, Clarke, Copiah, Covington and 31 more | 117 min |
| May 4, 9:03 AM CDT | Mesoscale Discussion | SPC | Clay, Lowndes, Monroe, Oktibbeha | 117 min |
| May 4, 9:18 AM CDT | Tornado Watch | SPC | Attala, Carroll, Choctaw, Clarke, Clay, Copiah and 26 more | 7 hr |
| May 4, 10:52 AM CDT | Tornado Watch | SPC | Adams, Amite, Bolivar, Claiborne, Franklin, Grenada and 9 more | 7 hr |
| May 4, 11:58 AM CDT | Mesoscale Discussion | SPC | Alcorn, Benton, Calhoun, Chickasaw, Coahoma, DeSoto and 13 more | 2 hr |
| May 4, 12:16 PM CDT | Mesoscale Discussion | SPC | Adams, Claiborne, Copiah, Franklin, Hinds, Issaquena and 4 more | 89 min |
| May 4, 2:17 PM CDT | Mesoscale Discussion | SPC | Attala, Choctaw, Claiborne, Clarke, Copiah, Covington and 26 more | 88 min |
| May 4, 3:03 PM CDT | Mesoscale Discussion | SPC | Chickasaw, Choctaw, Clay, Itawamba, Kemper, Lowndes and 5 more | 117 min |
| May 4, 3:31 PM CDT | Tornado Watch | SPC | Clarke, Covington, Forrest, George, Greene, Hancock and 22 more | 6 hr |
| May 4, 4:46 PM CDT | Mesoscale Discussion | SPC | Clarke, Forrest, George, Greene, Hancock, Harrison and 9 more | 89 min |
Nearby
Severe Thunderstorm Watches in Mississippi, 2021Every severe thunderstorm watch in 2021
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.