Alert archive / Louisiana / Mesoscale Discussions in 2004

Mesoscale Discussion 83

February 5, 200417 parishes in Louisiana; 12 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Feb 5, 2004, 7:35 AM CST for 17 parishes in Louisiana; 12 counties in Mississippi. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
Feb 5, 2004, 7:35 AM CST (13:35 UTC)
Expired
Feb 5, 2004, 9:30 AM CST
In force
115 min
Issued by
the Storm Prediction Center
All 29 counties

Acadia Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Vermilion Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Jefferson County, MS, Lawrence County, MS, Lincoln County, MS, Pike County, MS, Simpson County, MS, Wilkinson County, MS

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 1.6 hours before the alert went out and 155 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, Lake Charles Mun, LA at 12:00Z on 2004-02-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1499 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, Lake Charles Mun, LA at 12:00Z on 2004-02-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 171 square meters per square second.19395878Sfc1 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
1499 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
509 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
171 m²/s²
0-3 km storm-relative helicity
151 m²/s²
Significant tornado parameter
1.6
Supercell composite
7.0

Open this sounding in Storm Lab

The text

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

289 
ACUS11 KWNS 051336
SWOMCD
SPC MCD 051335 
MSZ000-LAZ000-TXZ000-051530-

MESOSCALE DISCUSSION 0083
NWS STORM PREDICTION CENTER NORMAN OK
0735 AM CST THU FEB 05 2004

AREAS AFFECTED...SRN/CNTRL LA...SW MS

CONCERNING...TORNADO WATCH 5...

VALID 051335Z - 051530Z

SEVERE THREAT WILL INCREASE NEXT FEW HOURS...WITH POTENTIAL FOR
ISOLATED TORNADOES AND DAMAGING WINDS...IN ADDITION TO HAIL. 
CONTINUE REMAINING VALID PORTION OF WW.

MID/UPPER 60S SURFACE DEW POINTS HAVE ADVECTED ACROSS SOUTH CENTRAL/
SOUTHEASTERN LOUISIANA INTO SOUTHWESTERN MISSISSIPPI...AHEAD OF
PRE-FRONTAL CONVECTIVE LINE.  SHALLOW SURFACE INVERSION EVIDENT IN
12Z SOUNDINGS WILL BE MODIFIED WITHIN THE NEXT COUPLE OF HOURS AS
MORE RAPID SURFACE HEATING COMMENCES.  SEVERAL INTENSE CELLS ARE
ALREADY EMBEDDED WITHIN DEVELOPING LINE...AND DESTABILIZATION OF
BOUNDARY LAYER WILL SUPPORT FURTHER INTENSIFICATION.  THIS WILL BE
ACCOMPANIED BY INCREASING RISK FOR TORNADOES...NEAR/WEST THROUGH
NORTH OF LAFAYETTE LA AFTER 15Z.  

INTENSE CELLS WILL CONTINUE TO DEVELOP NORTHEASTWARD INTO VICINITY
OF COLD FRONT NOW ADVANCING EAST OF THE MISSISSIPPI RIVER INTO PARTS
OF WEST CENTRAL/SOUTHWEST MISSISSIPPI. MEANWHILE...REDEVELOPMENT OF
STRONG/SEVERE THUNDERSTORMS WILL CONTINUE ACROSS SOUTH CENTRAL
LOUISIANA THROUGH MIDDAY...AS STRONGEST UPPER DIFLUENCE BETWEEN
POLAR/SUBTROPICAL JETS BECOMES FOCUSED ACROSS THE CENTRAL GULF COAST
AREA BY 18Z.

..KERR.. 02/05/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...JAN...LIX...LCH...HGX...

29529447 30109381 30469290 30899214 31399153 31889115
32289063 32399009 31728981 31239011 30519079 29809137
29549178

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 4, 11:37 PM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Evangeline and 10 more83 min
Feb 5, 1:16 AM CSTMesoscale DiscussionSPCBeauregard, Bienville, De Soto, Grant, Jackson, Lincoln and 6 more119 min
Feb 5, 5:08 AM CSTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 27 more3 hr
Feb 5, 5:40 AM CSTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 33 more6 hr
Feb 5, 8:02 AM CSTMesoscale DiscussionSPCAcadia, Calcasieu, Cameron, East Baton Rouge, East Feliciana, Evangeline and 11 more118 min
Feb 5, 9:52 AM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 11 more113 min
Feb 5, 11:35 AM CSTTornado WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 16 more5 hr
Feb 5, 1:11 PM CSTMesoscale DiscussionSPCAscension, Assumption, Lafourche, Livingston, Orleans, Saint Charles and 5 more2 hr
Feb 5, 3:22 PM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, Iberia, Iberville, Livingston and 8 more113 min
Feb 5, 4:43 PM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 15 more32 min
Feb 5, 4:55 PM CSTTornado WatchSPCAscension, Assumption, East Baton Rouge, Iberia, Iberville, Lafourche and 13 more6 hr

Nearby

Mesoscale Discussions in Louisiana, 2004Mesoscale Discussions in Mississippi, 2004Every mesoscale discussion in 2004

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.