Alert archive / Louisiana / Tornado Watches in 1999

Tornado Watch 19

January 21, 199922 parishes in Louisiana; 10 counties in Texas

The Storm Prediction Center issued this tornado watch at Jan 21, 1999, 2:45 PM CST for 22 parishes in Louisiana; 10 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jan 21, 1999, 2:45 PM CST (20:45 UTC)
Expired
Jan 21, 1999, 9:00 PM CST
In force
6 hr
Issued by
the Storm Prediction Center
All 32 counties

Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Angelina County, TX, Harrison County, TX, Marion County, TX, Nacogdoches County, TX, Panola County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Trinity County, TX

The radar

The Shreveport radar (KSHV), 73 km from the middle of the area, began a volume at 20:46 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jan 21, 6:33 PM CSTTornado WarningJANMorehouse47 min
Jan 21, 6:33 PM CSTSevere Thunderstorm WarningSHVOuachita42 min
Jan 21, 7:07 PM CSTSevere Thunderstorm WarningJANRichland48 min
Jan 21, 7:35 PM CSTTornado WarningJANWest Carroll50 min
Jan 21, 7:48 PM CSTTornado WarningLCHRapides47 min
Jan 21, 8:40 PM CSTTornado WarningSHVLaSalle50 min

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 8.8 hours before the alert went out and 75 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 1999-01-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 941 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 1999-01-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 289 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
941 J/kg
Mixed-layer CIN
-169 J/kg
Mixed-layer LCL
740 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
289 m²/s²
0-3 km storm-relative helicity
350 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.5

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 21, 2:30 PM CSTTornado WatchSPCBowie7 hr

Nearby

Tornado Watches in Louisiana, 1999Tornado Watches in Texas, 1999Every tornado watch in 1999

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.