Alert archive / Mississippi / Tornado Watches in 2021
Tornado Watch 37
The Storm Prediction Center issued this tornado watch at Mar 17, 2021, 7:07 PM CDT for 9 counties in Alabama; 14 counties in Mississippi; 4 counties in Tennessee. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 17, 2021, 7:07 PM CDT (00:07 UTC)
- Expired
- Mar 17, 2021, 10:30 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 27 counties
Colbert County, AL, Cullman County, AL, Franklin County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Pontotoc County, MS, Prentiss County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Fayette County, TN, Hardeman County, TN, Hardin County, TN, McNairy County, TN
The radar
The Columbus AFB radar (KGWX), 110 km from the middle of the area, began a volume at 00:12 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- 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
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 17, 7:17 PM CDT | Severe Thunderstorm Warning | MEG | Chickasaw, Itawamba, Lee, Monroe, Pontotoc | 43 min |
| Mar 17, 7:35 PM CDT | Flash Flood Warning | MEG | Itawamba | 2 hr |
| Mar 17, 7:38 PM CDT | Tornado Warning | MEG | Itawamba, Lee, Monroe | 10 min |
| Mar 17, 7:44 PM CDT | Severe Thunderstorm Warning | MEG | Itawamba, Lee, Monroe, Prentiss, Tishomingo | 31 min |
| Mar 17, 8:45 PM CDT | Flash Flood Warning | MEG | Itawamba, Prentiss, Tishomingo | 69 min |
| Mar 17, 9:07 PM CDT | Flash Flood Warning | HUN | Colbert, Lauderdale | 3 hr |
| Mar 17, 9:19 PM CDT | Flash Flood Warning | HUN | Jackson, Madison, Marshall, Morgan | 3 hr |
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 00:00Z, 0.1 hours before the alert went out and 150 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
- 959 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 873 m above ground
- 0-6 km bulk shear
- 71 kt
- 0-1 km storm-relative helicity
- 133 m²/s²
- 0-3 km storm-relative helicity
- 134 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 4.3
The text
As transmitted.
269 WWUS20 KWNS 180005 SEL7 SPC WW 180005 ALZ000-MSZ000-TNZ000-180500- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 37 NWS Storm Prediction Center Norman OK 710 PM CDT Wed Mar 17 2021 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Far northern Alabama Northern Mississippi Western Tennessee * Effective this Wednesday night from 710 PM until Midnight CDT. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph likely Scattered large hail events to 1.5 inches in diameter possible SUMMARY...A severe thunderstorm/tornado risk may linger this evening across the region as low-level shear further strengthens, potentially supporting a mixed mode of strong/severe thunderstorms. The tornado watch area is approximately along and 55 statute miles north and south of a line from 30 miles north northwest of Oxford MS to 35 miles east of Huntsville AL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && OTHER WATCH INFORMATION...CONTINUE...WW 34...WW 35...WW 36... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Guyer
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 17, 9:16 PM CDT | Mesoscale Discussion | SPC | Cullman, DeKalb, Jackson, Limestone, Madison, Marshall and 1 more | 89 min |
| Mar 17, 10:15 PM CDT | Mesoscale Discussion | SPC | Baldwin, Barbour, Bullock, Calhoun, Chambers, Cherokee and 18 more | 90 min |
| Mar 17, 11:02 PM CDT | Tornado Watch | SPC | Coffee, Covington, Dale, Geneva, Henry, Houston | 9 hr |
| Mar 18, 1:52 AM CDT | Mesoscale Discussion | SPC | Barbour, Coffee, Covington, Dale, Geneva, Henry and 2 more | 83 min |
| Mar 18, 4:28 AM CDT | Mesoscale Discussion | SPC | Coffee, Dale, Geneva, Henry, Houston | 92 min |
| Mar 17, 7:26 PM CDT | Mesoscale Discussion | SPC | Hancock | 94 min |
Nearby
Tornado Watches in Mississippi, 2021Tornado Watches in Alabama, 2021Tornado Watches in Tennessee, 2021Every tornado 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.