Alert archive / Louisiana / Tornado Watches in 2019

Tornado Watch 14

March 9, 2019Columbia County, Lafayette County, Union County, Arkansas; 5 parishes in Louisiana

The Storm Prediction Center issued this tornado watch at Mar 9, 2019, 11:05 AM CST for Columbia County, Lafayette County, Union County, Arkansas; 5 parishes in Louisiana. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Mar 9, 2019, 11:05 AM CST (17:05 UTC)
Expired
Mar 9, 2019, 3:00 PM CST
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Columbia County, AR, Lafayette County, AR, Union County, AR, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Union Parish, LA, Webster Parish, LA

The radar

The Shreveport radar (KSHV), 88 km from the middle of the area, began a volume at 17:05 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
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
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 9, 11:17 AM CSTSevere Thunderstorm WarningSHVBossier, Caddo, De Soto43 min
Mar 9, 11:20 AM CSTSevere Thunderstorm WarningSHVColumbia, Nevada, Union40 min
Mar 9, 11:24 AM CSTTornado WarningSHVColumbia36 min
Mar 9, 11:59 AM CSTSevere Thunderstorm WarningSHVColumbia, Union37 min
Mar 9, 1:28 PM CSTSevere Thunderstorm WarningSHVLincoln, Union32 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, 5.1 hours before the alert went out and 80 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 2019-03-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 968 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 2019-03-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 226 square meters per square second.1939587897117Sfc1 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
968 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
576 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
226 m²/s²
0-3 km storm-relative helicity
271 m²/s²
Significant tornado parameter
2.0
Supercell composite
7.4

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 9, 1:58 AM CSTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 12 more92 min
Mar 9, 2:31 AM CSTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 11 more7 hr
Mar 9, 3:03 AM CSTMesoscale DiscussionSPCClark, Columbia, Hempstead, Hot Spring, Howard, Lafayette and 8 more117 min
Mar 9, 3:49 AM CSTSevere Thunderstorm WatchSPCSebastian7 hr
Mar 9, 4:45 AM CSTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 12 more60 min
Mar 9, 6:58 AM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Clark, Clay and 60 more2 hr
Mar 9, 7:18 AM CSTSevere Thunderstorm WatchSPCArkansas, Bradley, Calhoun, Clark, Cleburne, Cleveland and 36 more8 hr
Mar 9, 9:45 AM CSTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Jackson and 11 more3 hr
Mar 9, 10:32 AM CSTTornado WatchSPCArkansas, Ashley, Chicot, Clay, Craighead, Crittenden and 15 more8 hr
Mar 9, 10:59 AM CSTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Cleveland, Columbia, Dallas and 6 more2 hr
Mar 9, 1:27 PM CSTMesoscale DiscussionSPCArkansas, Ashley, Chicot, Crittenden, Desha, Drew and 3 more2 hr
Mar 9, 1:58 PM CSTTornado WatchSPCAshley, Chicot5 hr
Mar 9, 2:26 PM CSTMesoscale DiscussionSPCBienville, Caldwell, De Soto, Grant, Jackson, LaSalle and 4 more2 hr

Nearby

Tornado Watches in Louisiana, 2019Tornado Watches in Arkansas, 2019Every tornado watch in 2019

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.