Alert archive / Louisiana / Mesoscale Discussions in 2004

Mesoscale Discussion 1011

May 31, 200413 parishes in Louisiana; 10 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 31, 2004, 1:27 AM CDT for 13 parishes in Louisiana; 10 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 31, 2004, 1:27 AM CDT (06:27 UTC)
Expired: May 31, 2004, 3:30 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 23 counties

Bienville Parish, LA, Caldwell Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, West Carroll Parish, LA, Attala County, MS, Choctaw County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Madison County, MS, Oktibbeha County, MS, Sharkey County, MS, Warren County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 117 km from the middle of the area, began a volume at 06:26 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 6.5 hours before the alert went out and 107 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: 4361 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 814 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 156 m²/s²
0-3 km storm-relative helicity: 215 m²/s²
Significant tornado parameter: 3.4
Supercell composite: 17.5

Open this sounding in Storm Lab

The text

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

073 
ACUS11 KWNS 310627
SWOMCD
SPC MCD 310627 
ALZ000-MSZ000-LAZ000-ARZ000-310830-

MESOSCALE DISCUSSION 1011
NWS STORM PREDICTION CENTER NORMAN OK
0127 AM CDT MON MAY 31 2004

AREAS AFFECTED...NRN LA/MS

CONCERNING...HEAVY RAINFALL...TORNADO WATCH 346...347...

VALID 310627Z - 310830Z

LINE OF INTENSE CONVECTION HAS BECOME ALIGNED WITH LARGE SCALE DEEP
LAYER WSWLY FLOW ACROSS NRN LA AND MS. COLD FRONT WAS DRIFTING SEWD
ACROSS THE ARKLATEX BEHIND THE PREFRONTAL STORMS AND SHOULD MAINTAIN
CONVERGENCE AND ASCENT ACROSS THE REGION. APPARENT LINE INTERSECTION
WITH BOWING STORMS OVER HUMPHREYS COUNTY IN NWRN MS MAY BE THE
LOCATION OF MOST ENHANCED LOW LEVEL SHEAR AND SHORT-TERM
WIND/TORNADO POTENTIAL. STRONG/DAMAGING WIND SHOULD SPREAD ACROSS
NCNTRL MS COUNTIES OF HOLMES...ATTALA...WINSTON...
KEMPER...AND NOXUBEE OVER THE NEXT 1-2 HOURS.

ELSEWHERE...STRONGER DEEP LAYER SHEAR APPEARS TO BE LAGGING THE
CONVECTIVE LINE AND STORM CHARACTER MAY TRANSITION TO MULTICELLULAR
ACROSS PARTS OF NRN LA. AIRMASS FEEDING THE STORMS REMAINS VERY
UNSTABLE AND MOIST AND THICKNESS DIFFLUENCE...LLJ/LIFT INTO THE
TRAILING LINE SHOULD SUPPORT BACKBUILDING AND TRAINING THROUGH THE
MORNING WITH ATTENDANT THREAT OF FLOODING.

..CARBIN.. 05/31/2004

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

ATTN...WFO...BMX...JAN...SHV...

32159089 31969398 32349379 33169107 33558908 33598823

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 30, 8:55 PM CDT	Mesoscale Discussion	SPC	Avoyelles, Bienville, Bossier, Caddo, Caldwell, Catahoula and 23 more	65 min
May 30, 10:35 PM CDT	Tornado Watch	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, East Carroll and 10 more	5 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; radar from the NEXRAD Level II archive.