Alert archive / Louisiana / Mesoscale Discussions in 2004

Mesoscale Discussion 82

February 5, 200433 parishes in Louisiana; 19 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Feb 5, 2004, 5:08 AM CST for 33 parishes in Louisiana; 19 counties in Mississippi. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Feb 5, 2004, 5:08 AM CST (11:08 UTC)
Expired
Feb 5, 2004, 7:45 AM CST
In force
3 hr
Issued by
the Storm Prediction Center
All 52 counties

Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Pointe Coupee 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, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Covington County, MS, Franklin County, MS, Hancock County, MS, Hinds County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pearl River County, MS, Pike County, MS, Simpson County, MS, Walthall 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

Slidell Radar S, LA (KSIL), launched 00:00Z, 11.1 hours before the alert went out and 136 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, Slidell Radar S, LA at 00:00Z on 2004-02-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Slidell Radar S, LA at 00:00Z on 2004-02-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 396 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
590 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
396 m²/s²
0-3 km storm-relative helicity
517 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

216 
ACUS11 KWNS 051108
SWOMCD
SPC MCD 051108 
LAZ000-MSZ000-051345-

MESOSCALE DISCUSSION 0082
NWS STORM PREDICTION CENTER NORMAN OK
0508 AM CST THU FEB 05 2004

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

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 051108Z - 051345Z

CONVECTIVE TRENDS CONTINUE TO BE CLOSELY MONITORED FOR POSSIBILITY
OF WW THIS MORNING.  BRIEF/MARGINAL SEVERE HAIL THREAT WILL EXIST
WITH MOST STRONGER CELLS THROUGH MID MORNING...BEFORE SEVERE
POTENTIAL INCREASES BY 18Z.

A GRADUAL INCREASE IN CONVECTIVE ACTIVITY IS ONGOING IN BROAD ZONE
OF ISENTROPIC ASCENT ON SOUTHERLY LOW-LEVEL JET OFF THE WESTERN GULF
OF MEXICO.  ENHANCED LIFT ALONG/ABOVE SURFACE FRONT FROM NEAR
HOUSTON THROUGH THE FORT POLK VICINITY INTO NORTHEAST LOUISIANA IS
PROVIDING FOCUS FOR DEVELOPING LINE OF CONVECTION.  ADDITIONAL 
ACTIVITY APPEARS TO BE FOCUSING IN CONFLUENT BAND AHEAD OF
FRONT...NEAR/JUST WEST OF LOW-LEVEL JET AXIS...FROM SOUTHWEST INTO
CENTRAL LOUISIANA.

WHILE MARGINAL SEVERE HAIL POTENTIAL WILL REMAIN PRIMARY CONCERN 
WITH ACTIVITY DEVELOPING JUST TO COOL SIDE OF FRONT...SEVERE
POTENTIAL WILL INCREASE IN WARM SECTOR...WHERE SHEAR PROFILES ARE
ALREADY FAVORABLE FOR SUPERCELLS.  AS POLAR UPPER JET STREAK...NOW
PROPAGATING ACROSS THE RIO GRANDE VALLEY...LIFTS NORTHWARD ACROSS
THE SOUTHERN PLAINS THIS MORNING...UPPER FLOW WILL BECOME
INCREASINGLY DIFLUENT/DIVERGENT ACROSS THE CENTRAL GULF COAST
REGION.  THIS WILL ENHANCE CONVECTIVE DEVELOPMENT...WHICH SHOULD
BECOME INCREASINGLY ROOTED IN WARMING/DESTABILIZATION BOUNDARY LAYER
BETWEEN 15-18Z.  AS SURFACE BASED CAPE INCREASES IN EXCESS OF 1000
J/KG BY MID DAY...ISOLATED TORNADIC SUPERCELLS APPEAR POSSIBLE FROM
PARTS OF SOUTHEAST LOUISIANA INTO SOUTHWEST MISSISSIPPI.

..KERR.. 02/05/2004

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

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

29729383 30769301 31419177 32129101 32339045 32118962
31668931 31018933 30448942 29728968 29269002

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, 5:40 AM CSTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 33 more6 hr
Feb 5, 7:35 AM CSTMesoscale DiscussionSPCAcadia, Calcasieu, Cameron, East Baton Rouge, East Feliciana, Evangeline and 11 more115 min
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.