Alert archive / Tennessee / Severe Thunderstorm Watches in 2020

Severe Thunderstorm Watch 37

March 3, 20207 counties in Arkansas; 7 counties in Mississippi; 21 counties in Tennessee

The Storm Prediction Center issued this severe thunderstorm watch at Mar 3, 2020, 12:59 AM CST for 7 counties in Arkansas; 7 counties in Mississippi; 21 counties in Tennessee. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Mar 3, 2020, 12:59 AM CST (06:59 UTC)
Expired
Mar 3, 2020, 5:00 AM CST
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 35 counties

Craighead County, AR, Crittenden County, AR, Cross County, AR, Lee County, AR, Mississippi County, AR, Poinsett County, AR, St. Francis County, AR, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Marshall County, MS, Tate County, MS, Tippah County, MS, Tunica 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 Memphis radar (KNQA), 21 km from the middle of the area, began a volume at 06:58 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
5%
Ten or more severe wind reports
20%
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
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 3, 1:38 AM CSTSevere Thunderstorm WarningMEGBenton, Decatur, Henderson30 min
Mar 3, 1:50 AM CSTSevere Thunderstorm WarningMEGCrittenden, Mississippi19 min
Mar 3, 2:53 AM CSTSevere Thunderstorm WarningMEGCarroll, Crockett, Henderson, Madison29 min
Mar 3, 3:11 AM CSTSevere Thunderstorm WarningMEGBenton, DeSoto, Marshall49 min
Mar 3, 3:55 AM CSTSevere Thunderstorm WarningMEGAlcorn, Benton, Tippah50 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 00:00Z, 7.0 hours before the alert went out and 78 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 2020-03-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 634 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 2020-03-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 261 square meters per square second.1939587897117136156175Sfc1 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
634 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
1095 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
261 m²/s²
0-3 km storm-relative helicity
361 m²/s²
Significant tornado parameter
1.1
Supercell composite
5.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 2, 11:10 PM CSTMesoscale DiscussionSPCCrittenden, Cross, Lee, Mississippi, Poinsett, St. Francis2 hr
Mar 3, 2:34 AM CSTMesoscale DiscussionSPCCrittenden, Lee, Monroe, Phillips, St. Francis116 min
Mar 3, 2:52 AM CSTMesoscale DiscussionSPCAttala, Calhoun, Carroll, Chickasaw, Choctaw, Clay and 29 more2 hr
Mar 2, 11:22 PM CSTTornado WatchSPCCannon, Cheatham, Clay, Cumberland, Davidson, DeKalb and 20 more7 hr
Mar 3, 1:02 AM CSTMesoscale DiscussionSPCClay, Davidson, DeKalb, Fentress, Jackson, Macon and 7 more118 min

Nearby

Severe Thunderstorm Watches in Tennessee, 2020Severe Thunderstorm Watches in Arkansas, 2020Severe Thunderstorm Watches in Mississippi, 2020Every severe thunderstorm watch in 2020

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.