Alert archive / Louisiana / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 246
The Storm Prediction Center issued this severe thunderstorm watch at Jun 8, 2021, 12:42 PM CDT for 15 counties in Arkansas; 17 parishes in Louisiana; 10 counties in Mississippi. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 8, 2021, 12:42 PM CDT (17:42 UTC)
- Expired
- Jun 8, 2021, 7:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 55 kt
All 42 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, Jefferson County, AR, Lincoln County, AR, Ouachita County, AR, Phillips County, AR, Union County, AR, Bienville Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland 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, Washington County, MS
The radar
The Shreveport radar (KSHV), 177 km from the middle of the area, began a volume at 17:42 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
- 70%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 10%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
20 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 8, 12:44 PM CDT | Flash Flood Warning | LZK | Arkansas, Jefferson | 3 hr |
| Jun 8, 1:10 PM CDT | Flash Flood Warning | LZK | Calhoun, Clark, Dallas, Ouachita | 99 min |
| Jun 8, 1:19 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Cleveland, Jefferson, Lincoln | 41 min |
| Jun 8, 1:29 PM CDT | Severe Thunderstorm Warning | SHV | Bienville, Jackson, Natchitoches, Winn | 46 min |
| Jun 8, 1:37 PM CDT | Flash Flood Warning | LZK | Cleveland, Lincoln | 3 hr |
| Jun 8, 1:45 PM CDT | Flash Flood Warning | MEG | Phillips | 4 hr |
| Jun 8, 1:53 PM CDT | Flash Flood Warning | MEG | Calhoun, Coahoma, Lafayette, Panola, Quitman, Tallahatchie and 1 more | 4 hr |
| Jun 8, 2:00 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Desha, Drew, Jefferson, Lincoln | 45 min |
| Jun 8, 2:05 PM CDT | Severe Thunderstorm Warning | SHV | Caldwell, Jackson, Lincoln, Ouachita, Union, Winn | 55 min |
| Jun 8, 2:33 PM CDT | Severe Thunderstorm Warning | JAN | Franklin, Morehouse, Richland, West Carroll | 72 min |
| Jun 8, 2:38 PM CDT | Flash Flood Warning | JAN | Bolivar, Sunflower | 3 hr |
| Jun 8, 3:12 PM CDT | Severe Thunderstorm Warning | JAN | Bolivar | 63 min |
| Jun 8, 3:16 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Desha | 29 min |
| Jun 8, 3:37 PM CDT | Severe Thunderstorm Warning | JAN | East Carroll, Madison, Tensas, West Carroll | 53 min |
| Jun 8, 3:49 PM CDT | Flash Flood Warning | LZK | Arkansas, Drew, Jefferson, Lincoln | 3 hr |
| Jun 8, 4:08 PM CDT | Severe Thunderstorm Warning | JAN | Madison | 52 min |
| Jun 8, 4:39 PM CDT | Flash Flood Warning | JAN | Chicot | 2 hr |
| Jun 8, 4:47 PM CDT | Flash Flood Warning | LZK | Cleveland, Dallas, Grant, Jefferson | 3 hr |
| Jun 8, 4:51 PM CDT | Flash Flood Warning | LZK | Desha, Drew | 3 hr |
| Jun 8, 5:26 PM CDT | Severe Thunderstorm Warning | LZK | Dallas, Ouachita | 26 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, 5.7 hours before the alert went out and 168 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
- 1621 J/kg
- Mixed-layer CIN
- -10 J/kg
- Mixed-layer LCL
- 580 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 106 m²/s²
- 0-3 km storm-relative helicity
- 218 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.1
The text
As transmitted.
031 WWUS20 KWNS 081739 SEL6 SPC WW 081739 ARZ000-LAZ000-MSZ000-090000- URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 246 NWS Storm Prediction Center Norman OK 1240 PM CDT Tue Jun 8 2021 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Arkansas Northern Louisiana Northern Mississippi * Effective this Tuesday afternoon and evening from 1240 PM until 700 PM CDT. * Primary threats include... Scattered damaging wind gusts to 65 mph likely A tornado or two possible SUMMARY...A moist and increasingly unstable air mass exists across the region along/south of rain-reinforced boundary that extends from south-central Arkansas into northern Mississippi. Isolated damaging winds will be possible through the afternoon/early evening, along with a brief tornado risk. The severe thunderstorm watch area is approximately along and 75 statute miles north and south of a line from 45 miles north northwest of Natchitoches LA to 50 miles northeast of Greenville MS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). 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. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 22020. ...Guyer
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 7, 7:16 PM CDT | Mesoscale Discussion | SPC | Arkansas, Crittenden, Cross, Lee, Lonoke, Monroe and 4 more | 59 min |
| Jun 8, 11:17 AM CDT | Mesoscale Discussion | SPC | Ashley, Chicot, Columbia, Union | 118 min |
| Jun 8, 10:11 AM CDT | Mesoscale Discussion | SPC | Bossier, Caddo | 64 min |
| Jun 8, 2:47 PM CDT | Mesoscale Discussion | SPC | Caldwell, East Carroll, Franklin, Madison, Richland, West Carroll | 118 min |
Nearby
Severe Thunderstorm Watches in Louisiana, 2021Severe Thunderstorm Watches in Arkansas, 2021Severe 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.