Alert archive / Mississippi / Tornado Watches in 2018

Tornado Watch 47

April 14, 201828 parishes in Louisiana; 36 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Apr 14, 2018, 6:57 AM CDT for 28 parishes in Louisiana; 36 counties in Mississippi. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 14, 2018, 6:57 AM CDT (11:57 UTC)
Expired
Apr 14, 2018, 2:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 64 counties

Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Attala County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Hancock County, MS, Hinds County, MS, Jasper 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, Lowndes County, MS, Madison County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pearl River County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Wilkinson County, MS, Winston County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 83 km from the middle of the area, began a volume at 11:58 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
60%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
70%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 14, 6:58 AM CDTSevere Thunderstorm WarningLIXEast Baton Rouge, East Feliciana, Iberville, Pointe Coupee, Saint Helena, West Baton Rouge and 1 more62 min
Apr 14, 7:05 AM CDTSevere Thunderstorm WarningLCHIberia, St. Mary, Vermilion55 min
Apr 14, 7:07 AM CDTTornado WarningJANHinds, Madison53 min
Apr 14, 7:13 AM CDTTornado WarningLIXAmite, Wilkinson47 min
Apr 14, 7:22 AM CDTSevere Thunderstorm WarningLCHIberia, Saint Martin53 min
Apr 14, 7:27 AM CDTSevere Thunderstorm WarningJANCopiah, Franklin, Lincoln44 min
Apr 14, 7:31 AM CDTTornado WarningLIXEast Feliciana, Saint Helena44 min
Apr 14, 7:43 AM CDTSevere Thunderstorm WarningJANHinds, Madison, Rankin62 min
Apr 14, 7:47 AM CDTTornado WarningJANRankin43 min
Apr 14, 7:51 AM CDTSevere Thunderstorm WarningLCHIberia, Saint Martin, St. Mary54 min
Apr 14, 7:55 AM CDTSevere Thunderstorm WarningLIXEast Feliciana, Saint Helena, Tangipahoa50 min
Apr 14, 7:57 AM CDTTornado WarningLIXEast Baton Rouge, East Feliciana, Livingston, Saint Helena, West Baton Rouge48 min
Apr 14, 7:59 AM CDTSevere Thunderstorm WarningLIXAmite, Pike61 min
Apr 14, 8:01 AM CDTSevere Thunderstorm WarningLIXAscension, Assumption, East Baton Rouge, Iberville, Lafourche, Livingston and 3 more59 min
Apr 14, 8:03 AM CDTTornado WarningLIXSaint Helena, Tangipahoa42 min
Apr 14, 8:18 AM CDTTornado WarningLIXAscension, East Baton Rouge, Livingston, Tangipahoa42 min
Apr 14, 8:22 AM CDTTornado WarningLIXSaint Helena, Tangipahoa38 min
Apr 14, 8:24 AM CDTSevere Thunderstorm WarningJANSimpson, Smith51 min
Apr 14, 8:28 AM CDTSevere Thunderstorm WarningJANLeake, Scott, Smith62 min
Apr 14, 8:28 AM CDTTornado WarningJANRankin, Simpson, Smith17 min
Apr 14, 8:30 AM CDTSevere Thunderstorm WarningLIXEast Baton Rouge, Livingston, Saint Helena, Tangipahoa, Washington45 min
Apr 14, 8:33 AM CDTSevere Thunderstorm WarningJANCovington, Jefferson Davis, Lawrence57 min
Apr 14, 8:41 AM CDTSevere Thunderstorm WarningLCHIberia, Saint Martin, St. Mary64 min
Apr 14, 8:45 AM CDTSevere Thunderstorm WarningLIXLivingston, Saint Helena, Saint Tammany, Tangipahoa, Washington45 min
Apr 14, 8:49 AM CDTTornado WarningLIXSaint Tammany, Tangipahoa, Washington41 min
Apr 14, 8:55 AM CDTTornado WarningLIXTangipahoa, Washington35 min
Apr 14, 9:00 AM CDTSevere Thunderstorm WarningLIXAscension, Assumption, Lafourche, Livingston, Saint Charles, Saint James and 3 more45 min
Apr 14, 9:01 AM CDTTornado WarningLIXWalthall29 min
Apr 14, 9:07 AM CDTSevere Thunderstorm WarningJANMarion68 min
Apr 14, 9:11 AM CDTSevere Thunderstorm WarningJANJasper, Smith79 min
Apr 14, 9:16 AM CDTSevere Thunderstorm WarningJANCovington, Jefferson Davis, Jones89 min
Apr 14, 9:16 AM CDTSevere Thunderstorm WarningJANChoctaw, Neshoba, Oktibbeha, Winston59 min
Apr 14, 9:17 AM CDTTornado WarningLCHSaint Martin13 min
Apr 14, 9:22 AM CDTSevere Thunderstorm WarningLIXAssumption, Lafourche, Terrebonne38 min
Apr 14, 9:27 AM CDTTornado WarningLIXAssumption, Lafourche, Saint James33 min
Apr 14, 9:30 AM CDTSevere Thunderstorm WarningLIXSaint Tammany, Tangipahoa, Washington45 min
Apr 14, 9:44 AM CDTSevere Thunderstorm WarningLIXAssumption, Lafourche, Livingston, Saint Charles, Saint James, Saint John the Baptist and 1 more46 min
Apr 14, 9:52 AM CDTSevere Thunderstorm WarningJANClay, Lowndes, Noxubee, Oktibbeha68 min
Apr 14, 9:53 AM CDTSevere Thunderstorm WarningJANClarke, Jasper97 min
Apr 14, 9:54 AM CDTSevere Thunderstorm WarningJANForrest, Lamar, Marion81 min
Apr 14, 10:03 AM CDTSevere Thunderstorm WarningJANKemper, Neshoba, Noxubee57 min
Apr 14, 10:06 AM CDTTornado WarningJANClay, Lowndes, Oktibbeha54 min
Apr 14, 10:10 AM CDTTornado WarningJANForrest, Lamar65 min
Apr 14, 10:26 AM CDTSevere Thunderstorm WarningLIXJefferson, Lafourche, Orleans, Saint Charles, Saint John the Baptist, Terrebonne49 min
Apr 14, 10:40 AM CDTSevere Thunderstorm WarningJANJones65 min
Apr 14, 10:49 AM CDTSevere Thunderstorm WarningJANKemper, Lauderdale56 min
Apr 14, 10:51 AM CDTTornado WarningJANLowndes24 min
Apr 14, 10:52 AM CDTTornado Warning Tornado observedLIXSaint Tammany12 min
Apr 14, 11:00 AM CDTTornado WarningJANKemper, Lauderdale45 min
Apr 14, 11:22 AM CDTSevere Thunderstorm WarningJANClarke53 min
Apr 14, 11:24 AM CDTSevere Thunderstorm WarningJANKemper, Noxubee32 min
Apr 14, 11:37 AM CDTSevere Thunderstorm WarningLIXSaint Tammany22 min
Apr 14, 11:39 AM CDTTornado WarningLIXPearl River22 min
Apr 14, 11:51 AM CDTSevere Thunderstorm WarningJANForrest, Lamar39 min
Apr 14, 12:10 PM CDTTornado WarningJANForrest20 min
Apr 14, 12:11 PM CDTFlash Flood WarningLIXSaint Tammany3 hr
Apr 14, 12:13 PM CDTFlash Flood WarningLIXJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 1 more3 hr
Apr 14, 1:25 PM CDTFlash Flood WarningLIXHancock, Harrison, Jackson9 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 00:00Z, 12.0 hours before the alert went out and 89 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 00:00Z on 2018-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 92 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 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 00:00Z on 2018-04-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.193958Sfc1 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
92 J/kg
Mixed-layer CIN
-56 J/kg
Mixed-layer LCL
1418 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

121 
WWUS20 KWNS 141155
SEL7  
SPC WW 141155
LAZ000-MSZ000-CWZ000-141900-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 47
NWS Storm Prediction Center Norman OK
655 AM CDT Sat Apr 14 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Eastern and southern Louisiana
  Southern to east-central Mississippi
  Coastal Waters

* Effective this Saturday morning and afternoon from 655 AM until
  200 PM CDT.

* Primary threats include...
  A few tornadoes likely with a couple intense tornadoes possible
  Scattered damaging wind gusts to 70 mph likely

SUMMARY...Line of storms has intensified from central Louisiana to
southwest Mississippi. This will move steadily eastward through
midday with potential for a few tornadoes and strong to isolated
severe wind gusts.

The tornado watch area is approximately along and 65 statute miles
east and west of a line from 70 miles north northwest of Meridian MS
to 55 miles southwest of Houma LA. 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.

&&

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 22035.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 13, 7:22 PM CDTTornado WatchSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more3 hr
Apr 13, 8:54 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 10 more66 min
Apr 13, 9:53 PM CDTTornado WatchSPCBeauregard, Bienville, Bossier, Caddo, Caldwell, Claiborne and 14 more8 hr
Apr 13, 10:12 PM CDTTornado WatchSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more10 hr
Apr 14, 2:10 AM CDTMesoscale DiscussionSPCAllen, Avoyelles, Beauregard, Bienville, Caldwell, Catahoula and 20 more2 hr
Apr 14, 6:37 AM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 20 more83 min
Apr 14, 4:35 AM CDTMesoscale DiscussionSPCAlcorn, Attala, Benton, Calhoun, Carroll, Chickasaw and 32 more115 min
Apr 14, 9:40 AM CDTMesoscale DiscussionSPCGeorge, Greene, Jackson95 min
Apr 14, 10:36 AM CDTTornado WatchSPCGeorge, Greene, Harrison, Jackson, Perry, Stone and 1 more8 hr
Apr 14, 12:41 PM CDTMesoscale DiscussionSPCGeorge, Greene, Jackson94 min
Apr 14, 2:56 PM CDTMesoscale DiscussionSPCJackson94 min
Apr 14, 6:17 PM CDTMesoscale DiscussionSPCGeorge, Jackson118 min
Apr 14, 6:55 PM CDTTornado WatchSPCGeorge, Greene6 hr

Nearby

Tornado Watches in Mississippi, 2018Tornado Watches in Louisiana, 2018Every tornado watch in 2018

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.