Alert archive / Louisiana / Mesoscale Discussions in 2004

Mesoscale Discussion 1007

May 30, 200429 parishes in Louisiana; 16 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 30, 2004, 8:55 PM CDT for 29 parishes in Louisiana; 16 counties in Mississippi. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued: May 30, 2004, 8:55 PM CDT (01:55 UTC)
Expired: May 30, 2004, 10:00 PM CDT
In force: 65 min
Issued by: the Storm Prediction Center

All 45 counties

Avoyelles Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn 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, Lawrence County, MS, Lincoln County, MS, Pike County, MS, Sharkey County, MS, Walthall County, MS, Warren County, MS, Wilkinson County, MS, Yazoo 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

Shreveport, LA (KSHV), launched 00:00Z, 1.9 hours before the alert went out and 130 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: 3106 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 919 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 170 m²/s²
0-3 km storm-relative helicity: 209 m²/s²
Significant tornado parameter: 3.9
Supercell composite: 13.9

Open this sounding in Storm Lab

The text

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

474 
ACUS11 KWNS 310156
SWOMCD
SPC MCD 310155 
MSZ000-LAZ000-TXZ000-310300-

MESOSCALE DISCUSSION 1007
NWS STORM PREDICTION CENTER NORMAN OK
0855 PM CDT SUN MAY 30 2004

AREAS AFFECTED...NRN LA/SWRN MS

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 310155Z - 310300Z

WARM ADVECTION SHOWERS/TSTMS ARE DEVELOPING AHEAD OF THE MAIN
CONVECTIVE LINE ACROSS E CNTRL TX/AR. EVENING SOUNDING FROM LAKE
CHARLES SHOWS AN EXTREMELY UNSTABLE AIRMASS FOR STORMS...WITH MLCAPE
VALUES NEAR 3500-4000 J/KG. DEEP LAYER SHEAR AROUND 30-35 KT IS
SUFFICIENT FOR SUPERCELL DEVELOPMENT. THE LOW LEVEL JET IS FOCUSED
NE ACROSS NRN LA...SO THESE INITIAL STORMS MAY INTENSIFY AS THEY
INTERACT WITH THE LOW LEVEL JET...AND IF THEY DO...A WW MAY BE
NECESSARY LATER TONIGHT.

..TAYLOR.. 05/31/2004

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

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

31019326 31369367 31809401 32629393 32969362 33009156
32939017 31118995 31049221

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 30, 10:35 PM CDT	Tornado Watch	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, East Carroll and 10 more	5 hr
May 31, 1:27 AM CDT	Mesoscale Discussion	SPC	Bienville, Caldwell, De Soto, East Carroll, Franklin, Jackson and 7 more	2 hr
May 31, 9:21 AM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 14 more	54 min
May 31, 10:00 AM CDT	Tornado Watch	SPC	Ascension, East Baton Rouge, East Feliciana, Iberville, Livingston, Orleans and 10 more	6 hr
May 31, 1:06 PM CDT	Mesoscale Discussion	SPC	Ascension, East Baton Rouge, East Feliciana, Iberville, Livingston, Orleans and 10 more	54 min
May 30, 8:54 PM CDT	Mesoscale Discussion	SPC	Alcorn, Attala, Benton, Bolivar, Calhoun, Carroll and 30 more	66 min
May 30, 9:15 PM CDT	Tornado Watch	SPC	Chickasaw, Clay, Itawamba, Lee, Monroe, Prentiss and 1 more	7 hr
May 30, 10:55 PM CDT	Tornado Watch	SPC	Alcorn, Attala, Benton, Bolivar, Calhoun, Carroll and 31 more	5 hr
May 30, 11:05 PM CDT	Mesoscale Discussion	SPC	Itawamba, Lee, Pontotoc, Prentiss, Tishomingo	55 min
May 31, 1:06 AM CDT	Mesoscale Discussion	SPC	Monroe	84 min

Nearby

Mesoscale Discussions in Louisiana, 2004 Mesoscale Discussions in Mississippi, 2004 Every 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.