Alert archive / Mississippi / Tornado Watches in 2020

Tornado Watch 121

April 19, 20209 parishes in Louisiana; 39 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Apr 19, 2020, 11:45 AM CDT for 9 parishes in Louisiana; 39 counties in Mississippi. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Apr 19, 2020, 11:45 AM CDT (16:45 UTC)
Expired
Apr 19, 2020, 9:00 PM CDT
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 48 counties

Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Richland Parish, LA, Tensas Parish, LA, West Carroll Parish, LA, Adams County, MS, Amite County, MS, Attala County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Warren County, MS, Wilkinson County, MS, Winston County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 61 km from the middle of the area, began a volume at 16:44 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
90%
One or more EF2 to EF5 tornadoes
70%
Ten or more severe wind reports
80%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
80%
One or more hailstones of 2 inches or more
80%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 19, 12:53 PM CDTSevere Thunderstorm WarningJANCopiah, Hinds, Rankin43 min
Apr 19, 1:52 PM CDTSevere Thunderstorm WarningJANFranklin, Richland68 min
Apr 19, 2:00 PM CDTSevere Thunderstorm WarningJANNewton, Scott, Smith60 min
Apr 19, 2:08 PM CDTSevere Thunderstorm WarningJANEast Carroll, Madison67 min
Apr 19, 2:30 PM CDTSevere Thunderstorm WarningJANMadison, Tensas45 min
Apr 19, 2:41 PM CDTSevere Thunderstorm WarningJANJasper, Simpson, Smith49 min
Apr 19, 2:46 PM CDTSevere Thunderstorm WarningJANHinds, Madison59 min
Apr 19, 3:01 PM CDTFlash Flood WarningJANLowndes, Noxubee, Winston3 hr
Apr 19, 3:09 PM CDTFlash Flood WarningJANWarren4 hr
Apr 19, 3:11 PM CDTSevere Thunderstorm WarningJANClaiborne, Copiah, Hinds43 min
Apr 19, 3:26 PM CDTSevere Thunderstorm WarningJANMadison, Rankin, Scott49 min
Apr 19, 3:36 PM CDTSevere Thunderstorm WarningJANClarke39 min
Apr 19, 4:00 PM CDTSevere Thunderstorm WarningJANJasper, Rankin, Simpson, Smith60 min
Apr 19, 4:00 PM CDTTornado WarningJANClarke30 min
Apr 19, 4:39 PM CDTSevere Thunderstorm WarningJANClarke, Jasper, Lauderdale, Newton66 min
Apr 19, 5:11 PM CDTSevere Thunderstorm WarningLIXWilkinson49 min
Apr 19, 5:27 PM CDTSevere Thunderstorm WarningJANCatahoula, Concordia, Franklin, Tensas63 min
Apr 19, 5:35 PM CDTSevere Thunderstorm WarningLIXAmite70 min
Apr 19, 5:41 PM CDTSevere Thunderstorm WarningLIXAmite49 min
Apr 19, 5:44 PM CDTSevere Thunderstorm WarningJANFranklin46 min
Apr 19, 6:01 PM CDTTornado WarningLIXAmite, Pike59 min
Apr 19, 6:19 PM CDTSevere Thunderstorm WarningJANFranklin, Lincoln41 min
Apr 19, 6:39 PM CDTTornado WarningLIXPike, Walthall38 min
Apr 19, 6:55 PM CDTTornado WarningJANLamar, Marion65 min
Apr 19, 7:24 PM CDTSevere Thunderstorm WarningLIXWilkinson11 min
Apr 19, 7:40 PM CDTSevere Thunderstorm WarningJANMarion35 min
Apr 19, 7:44 PM CDTTornado Warning Tornado observedConsiderable damage threatJANForrest, Lamar31 min
Apr 19, 7:45 PM CDTSevere Thunderstorm WarningJANForrest, Lamar30 min
Apr 19, 8:04 PM CDTFlash Flood WarningJANForrest, Lamar, Marion3 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

Jackson, MS (KJAN), launched 12:00Z, 4.8 hours before the alert went out and 51 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, Jackson, MS at 12:00Z on 2020-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 776 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, Jackson, MS at 12:00Z on 2020-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 323 square meters per square second.19395878Sfc1 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
776 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
610 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
323 m²/s²
0-3 km storm-relative helicity
329 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.7

Open this sounding in Storm Lab

The text

As transmitted.

847 
WWUS20 KWNS 191641
SEL1  
SPC WW 191641
LAZ000-MSZ000-200000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 121
NWS Storm Prediction Center Norman OK
1145 AM CDT Sun Apr 19 2020

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northeast Louisiana
  Central and Southern Mississippi

* Effective this Sunday morning and evening from 1145 AM until
  700 PM CDT.

* Primary threats include...
  Several tornadoes and a couple intense tornadoes likely
  Widespread large hail and scattered very large hail events to
    2.5 inches in diameter likely
  Widespread damaging wind gusts to 70 mph likely

SUMMARY...Clusters of thunderstorms over Louisiana will track
eastward across the watch area this afternoon.  The strongest storms
will pose a risk large hail, damaging winds, and tornadoes.  An
isolated strong tornado is possible.

The tornado watch area is approximately along and 70 statute miles
north and south of a line from 35 miles south of Monroe LA to 15
miles east northeast of Meridian MS. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU1).

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 120...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 25035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 18, 8:27 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more2 hr
Apr 18, 8:56 PM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Cameron, East Baton Rouge and 26 more2 hr
Apr 19, 8:41 AM CDTTornado WatchSPCAllen, Beauregard, Bienville, Bossier, Caddo, Calcasieu and 18 more6 hr
Apr 19, 10:45 AM CDTMesoscale DiscussionSPCCaldwell, De Soto, Grant, Jackson, LaSalle, Natchitoches and 5 more2 hr
Apr 19, 11:06 AM CDTMesoscale DiscussionSPCAvoyelles, Catahoula, Concordia, Franklin, Madison, Richland and 1 more54 min
Apr 19, 12:39 PM CDTMesoscale DiscussionSPCBeauregard, Calcasieu, Vernon66 min
Apr 19, 12:47 PM CDTMesoscale DiscussionSPCAvoyelles, Bienville, Caldwell, Catahoula, Concordia, De Soto and 14 more58 min
Apr 19, 2:03 PM CDTMesoscale DiscussionSPCAcadia, Allen, Assumption, Avoyelles, Beauregard, Calcasieu and 23 more57 min
Apr 19, 2:39 PM CDTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 39 more9 hr
Apr 19, 3:07 PM CDTMesoscale DiscussionSPCMadison, Tensas113 min
Apr 19, 5:40 PM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Catahoula and 18 more2 hr
Apr 19, 6:37 PM CDTMesoscale DiscussionSPCWashington53 min
Apr 19, 2:34 AM CDTMesoscale DiscussionSPCAttala, Bolivar, Calhoun, Carroll, Chickasaw, Choctaw and 29 more116 min
Apr 19, 3:56 PM CDTTornado WatchSPCGeorge, Greene, Perry, Stone, Wayne6 hr

Nearby

Tornado Watches in Mississippi, 2020Tornado Watches in Louisiana, 2020Every tornado 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.