Alert archive / Louisiana / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 47

March 18, 20164 states

The Storm Prediction Center issued this severe thunderstorm watch at Mar 18, 2016, 1:35 PM CDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Mar 18, 2016, 1:35 PM CDT (18:35 UTC)
Expired
Mar 18, 2016, 8:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
55 kt
All 57 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Columbia County, AR, Drew County, AR, Hempstead County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Madison County, MS, Rankin County, MS, Sharkey County, MS, Warren County, MS, Washington County, MS, Yazoo County, MS, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Red River County, TX, Rusk County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 82 km from the middle of the area, began a volume at 18:37 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
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
70%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 18, 1:52 PM CDTSevere Thunderstorm WarningJANRichland, West Carroll23 min
Mar 18, 1:56 PM CDTSevere Thunderstorm WarningSHVRed River64 min
Mar 18, 2:00 PM CDTSevere Thunderstorm WarningJANMorehouse20 min
Mar 18, 2:07 PM CDTSevere Thunderstorm WarningSHVJackson, Lincoln, Ouachita, Union53 min
Mar 18, 2:12 PM CDTSevere Thunderstorm WarningJANEast Carroll48 min
Mar 18, 2:13 PM CDTSevere Thunderstorm WarningJANHumphreys, Issaquena, Sharkey33 min
Mar 18, 3:07 PM CDTSevere Thunderstorm WarningSHVColumbia, Union68 min
Mar 18, 3:10 PM CDTSevere Thunderstorm WarningJANMorehouse, Richland, West Carroll37 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 (KBAD), launched 12:00Z, 6.6 hours before the alert went out and 73 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, Shreveport, LA at 12:00Z on 2016-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 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, Shreveport, LA at 12:00Z on 2016-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 191 square meters per square second.1939587897Sfc1 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
11 J/kg
Mixed-layer CIN
-466 J/kg
Mixed-layer LCL
489 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
191 m²/s²
0-3 km storm-relative helicity
245 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 18, 9:51 AM CDTMesoscale DiscussionSPCClark, Columbia, Garland, Hempstead, Hot Spring, Howard and 8 more84 min
Mar 18, 1:16 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Columbia, Drew and 7 more59 min
Mar 18, 3:47 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Columbia, Drew and 7 more118 min
Mar 18, 10:40 AM CDTMesoscale DiscussionSPCAscension, Assumption, Jefferson, Lafourche, Orleans, Plaquemines and 7 more95 min
Mar 18, 6:04 AM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Collin, Cooke, Cottle and 10 more2 hr
Mar 18, 1:57 PM CDTMesoscale DiscussionSPCBandera, Crockett, Edwards, Gillespie, Kendall, Kerr and 8 more2 hr
Mar 18, 4:09 PM CDTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 31 more7 hr
Mar 18, 6:05 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 23 more55 min

Nearby

Severe Thunderstorm Watches in Louisiana, 2016Severe Thunderstorm Watches in Texas, 2016Severe Thunderstorm Watches in Arkansas, 2016Every severe thunderstorm watch in 2016

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.