Alert archive / Louisiana / Tornado Watches in 2003
Tornado Watch 957
The Storm Prediction Center issued this tornado watch at Nov 18, 2003, 2:25 AM CST for 38 parishes in Louisiana; 24 counties in Mississippi. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 18, 2003, 2:25 AM CST (08:25 UTC)
- Expired
- Nov 18, 2003, 8:00 AM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 62 counties
Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Livingston Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Richland Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Vermilion Parish, LA, West Baton Rouge Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Issaquena County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Neshoba 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, Yazoo County, MS
Warnings issued inside it
24 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 18, 3:05 AM CST | Severe Thunderstorm Warning | SHV | LaSalle | 40 min |
| Nov 18, 3:26 AM CST | Severe Thunderstorm Warning | JAN | Catahoula | 59 min |
| Nov 18, 4:04 AM CST | Severe Thunderstorm Warning | JAN | Franklin | 61 min |
| Nov 18, 4:05 AM CST | Severe Thunderstorm Warning | JAN | Concordia | 45 min |
| Nov 18, 4:28 AM CST | Severe Thunderstorm Warning | JAN | Tensas | 42 min |
| Nov 18, 4:31 AM CST | Severe Thunderstorm Warning | LCH | Avoyelles | 29 min |
| Nov 18, 4:57 AM CST | Severe Thunderstorm Warning | JAN | Madison | 28 min |
| Nov 18, 5:00 AM CST | Severe Thunderstorm Warning | JAN | Adams, Jefferson | 60 min |
| Nov 18, 5:14 AM CST | Severe Thunderstorm Warning | JAN | Claiborne, Issaquena, Jefferson, Warren | 31 min |
| Nov 18, 5:16 AM CST | Severe Thunderstorm Warning | LIX | Wilkinson | 44 min |
| Nov 18, 5:28 AM CST | Tornado Warning | JAN | East Carroll | 47 min |
| Nov 18, 5:32 AM CST | Tornado Warning | JAN | East Carroll | 43 min |
| Nov 18, 6:03 AM CST | Severe Thunderstorm Warning | LIX | Amite, Wilkinson | 42 min |
| Nov 18, 6:14 AM CST | Severe Thunderstorm Warning | JAN | Hinds, Madison, Yazoo | 61 min |
| Nov 18, 6:27 AM CST | Severe Thunderstorm Warning | JAN | Jefferson | 23 min |
| Nov 18, 6:34 AM CST | Severe Thunderstorm Warning | JAN | Copiah | 61 min |
| Nov 18, 7:04 AM CST | Severe Thunderstorm Warning | JAN | Holmes, Yazoo | 46 min |
| Nov 18, 7:05 AM CST | Severe Thunderstorm Warning | LIX | Saint Helena | 40 min |
| Nov 18, 7:15 AM CST | Severe Thunderstorm Warning | JAN | Hinds, Rankin | 60 min |
| Nov 18, 7:17 AM CST | Severe Thunderstorm Warning | JAN | Attala, Madison | 58 min |
| Nov 18, 7:18 AM CST | Severe Thunderstorm Warning | LIX | East Baton Rouge, Iberville, Livingston | 42 min |
| Nov 18, 7:25 AM CST | Severe Thunderstorm Warning | LIX | Ascension, Assumption | 35 min |
| Nov 18, 7:45 AM CST | Severe Thunderstorm Warning | LIX | Livingston, Saint Helena, Tangipahoa, Washington | 45 min |
| Nov 18, 7:55 AM CST | Severe Thunderstorm Warning | LIX | Ascension, Assumption, Iberville, Lafourche, Saint James, Terrebonne | 50 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
Lake Charles Mun, LA (KLCH), launched 00:00Z, 8.4 hours before the alert went out and 151 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.
- Mixed-layer CAPE
- 877 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 631 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- 200 m²/s²
- 0-3 km storm-relative helicity
- 222 m²/s²
- Significant tornado parameter
- 1.2
- Supercell composite
- 7.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 180824
SEL7
SPC WW 180825
LAZ000-MSZ000-CWZ000-181400-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 957
NWS STORM PREDICTION CENTER NORMAN OK
225 AM CST TUE NOV 18 2003
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
CENTRAL AND EASTERN LOUISIANA
CENTRAL AND SOUTHERN MISSISSIPPI
COASTAL WATERS
EFFECTIVE THIS TUESDAY MORNING FROM 225 AM UNTIL 800 AM CST.
TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS ALONG AND 90 STATUTE MILES EAST AND WEST
OF A LINE FROM 50 MILES NORTH NORTHWEST OF JACKSON MISSISSIPPI TO
25 MILES WEST SOUTHWEST OF INTRACOASTAL CITY LOUISIANA.
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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 954...TORNADO WATCH NUMBER 955. WATCH NUMBER 954 955
WILL NOT BE IN EFFECT AFTER 225 AM CST. CONTINUE...WW 956...
DISCUSSION...LA CONVECTIVE BAND EXPECTED TO CONTINUE E AT 25-30 KT.
COMBINATION OF RICH BOUNDARY LAYER MOISTURE INFLOW...50-60 KT DEEP
SHEAR AND MODEST LOW LEVEL DIRECTIONAL SHEAR LIKELY TO REMAIN
FAVORABLE FOR EMBEDDED SUPERCELLS AND ISOLATED TORNADOES AS S TX
SHORTWAVE TROUGH ACCELERATES NNE TOWARD REGION.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 22035.
...CORFIDI
325,0885 293,0910 293,0940 325,0915SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 17, 7:48 PM CST | Mesoscale Discussion | SPC | Bossier, Caddo, Claiborne, Webster | 87 min |
| Nov 17, 8:10 PM CST | Mesoscale Discussion | SPC | Beauregard, Calcasieu, Natchitoches, Sabine, Vernon | 95 min |
| Nov 17, 9:25 PM CST | Tornado Watch | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 12 more | 7 hr |
| Nov 17, 10:53 PM CST | Mesoscale Discussion | SPC | Beauregard, Calcasieu | 97 min |
| Nov 17, 11:44 PM CST | Mesoscale Discussion | SPC | Bienville, Bossier, Caldwell, Claiborne, De Soto, Grant and 11 more | 91 min |
| Nov 17, 11:50 PM CST | Tornado Watch | SPC | Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 2 more | 5 hr |
| Nov 18, 2:08 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Avoyelles, Catahoula, Concordia, East Baton Rouge and 25 more | 97 min |
| Nov 18, 4:48 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Concordia, East Baton Rouge, East Feliciana, Iberville and 17 more | 117 min |
| Nov 18, 6:08 AM CST | Mesoscale Discussion | SPC | Ascension, Jefferson, Lafourche, Livingston, Orleans, Plaquemines and 8 more | 2 hr |
| Nov 18, 6:55 AM CST | Tornado Watch | SPC | Ascension, Assumption, East Baton Rouge, Jefferson, Lafourche, Livingston and 11 more | 5 hr |
| Nov 18, 10:30 AM CST | Mesoscale Discussion | SPC | Saint Bernard | 90 min |
| Nov 18, 1:29 AM CST | Mesoscale Discussion | SPC | Bolivar, Coahoma, DeSoto, Leflore, Marshall, Panola and 5 more | 3 hr |
| Nov 18, 1:55 AM CST | Tornado Watch | SPC | Bolivar, Coahoma, DeSoto, Holmes, Humphreys, Leflore and 7 more | 6 hr |
| Nov 18, 11:25 AM CST | Tornado Watch | SPC | George, Greene, Jackson | 6 hr |
| Nov 18, 2:50 PM CST | Severe Thunderstorm Watch | SPC | Bolivar, Washington | 5 hr |
Nearby
Tornado Watches in Louisiana, 2003Tornado Watches in Mississippi, 2003Every tornado watch in 2003
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.