Alert archive / Louisiana / Tornado Watches in 1999

Tornado Watch 4

January 2, 1999Mobile County, Alabama; 28 parishes in Louisiana; 6 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Jan 2, 1999, 3:00 AM CST for Mobile County, Alabama; 28 parishes in Louisiana; 6 counties in Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jan 2, 1999, 3:00 AM CST (09:00 UTC)
Expired: Jan 2, 1999, 9:00 AM CST
In force: 6 hr
Issued by: the Storm Prediction Center

All 35 counties

Mobile County, AL, 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, George County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Stone County, MS

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jan 2, 3:45 AM CST	Tornado Warning	LCH	Saint Landry	65 min
Jan 2, 4:18 AM CST	Tornado Warning	LCH	Lafayette	47 min
Jan 2, 4:29 AM CST	Tornado Warning	LCH	Vermilion	66 min
Jan 2, 4:38 AM CST	Tornado Warning	LIX	Pointe Coupee	32 min
Jan 2, 4:49 AM CST	Tornado Warning	LIX	West Feliciana	31 min
Jan 2, 4:53 AM CST	Tornado Warning	LCH	Iberia	67 min
Jan 2, 5:20 AM CST	Tornado Warning	LCH	St. Mary	65 min
Jan 2, 5:36 AM CST	Tornado Warning	LIX	East Feliciana, Saint Helena	34 min
Jan 2, 6:26 AM CST	Tornado Warning	LIX	Tangipahoa, Washington	34 min
Jan 2, 6:56 AM CST	Severe Thunderstorm Warning	LIX	Lafourche, Saint Charles, Saint John the Baptist	34 min
Jan 2, 7:05 AM CST	Tornado Warning	LIX	Saint Charles, Saint John the Baptist	30 min
Jan 2, 7:53 AM CST	Severe Thunderstorm Warning	LIX	Saint Tammany	32 min
Jan 2, 8:09 AM CST	Tornado Warning	LIX	Saint Tammany	16 min
Jan 2, 8:13 AM CST	Tornado Warning	LIX	Hancock	32 min
Jan 2, 8:37 AM CST	Tornado Warning	LIX	Harrison	33 min
Jan 2, 8:48 AM CST	Severe Thunderstorm Warning	MOB	George, Stone	57 min
Jan 2, 8:54 AM CST	Severe Thunderstorm Warning	LIX	Plaquemines	21 min

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 9.0 hours before the alert went out and 122 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 964 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 137 m²/s²
0-3 km storm-relative helicity: 269 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

999 
WWUS9 KMKC 020816
SEL4  
MKC WW 020816
LAZ000-MSZ000-021500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 4
STORM PREDICTION CENTER NORMAN OK
216 AM CST SAT JAN 2 1999

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   EASTERN LOUISIANA                          
   SOUTHERN MISSISSIPPI                        
   AND ADJACENT COASTAL WATERS

EFFECTIVE THIS SATURDAY MORNING FROM 300 AM UNTIL 900 AM CST.

TORNADOES...HAIL TO 1 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 115 STATUTE MILES EAST AND WEST
OF A LINE FROM 40 MILES SOUTH SOUTHWEST OF HOUMA LOUISIANA TO 65
MILES NORTHWEST OF GULFPORT MISSISSIPPI.

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...  CONTINUE...WW 3...

DISCUSSION...CONVECTIVE CLUSTER WILL CONTINUE MOVING EASTWARD AHEAD
OF STRONG COLD FRONT AND DYNAMIC UPPER TROUGH. DESPITE MARGINAL
INSTABILITY...50 KT LOW LEVEL JET WILL PROVIDE FAVORABLE SHEAR FOR
SUPERCELLS WITH ASSOCIATED WARM AIR AND MOISTURE ADVECTION BRINGING
INCREASING DESTABILIZATION.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. 
MEAN STORM MOTION VECTOR 23040.


...ROGASH

290,0925 310,0914 310,0875 290,0890

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 2, 9:00 AM CST	Tornado Watch	SPC	Baldwin, Butler, Clarke, Coffee, Conecuh, Covington and 8 more	6 hr
Jan 2, 2:15 PM CST	Tornado Watch	SPC	Barbour, Henry, Houston	6 hr
Jan 1, 7:30 PM CST	Tornado Watch	SPC	Bossier, Caddo, Claiborne, De Soto, Red River, Webster	6 hr
Jan 1, 11:00 PM CST	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 28 more	6 hr

Nearby

Tornado Watches in Louisiana, 1999 Tornado Watches in Mississippi, 1999 Tornado Watches in Alabama, 1999 Every 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.