Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 334

March 25, 20037 parishes in Louisiana; 12 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 25, 2003, 9:40 PM CST for 7 parishes in Louisiana; 12 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Mar 25, 2003, 9:40 PM CST (03:40 UTC)
Expired: Mar 25, 2003, 11:45 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Red River Parish, LA, Webster Parish, LA, Angelina County, TX, Cherokee County, TX, Gregg County, TX, Harrison County, TX, Houston County, TX, Marion County, TX, Nacogdoches County, TX, Panola County, TX, Rusk County, TX, San Augustine County, TX, Shelby County, TX, Trinity County, TX

The radar

The Shreveport radar (KSHV), 27 km from the middle of the area, began a volume at 03:41 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

Shreveport, LA (KSHV), launched 00:00Z, 3.7 hours before the alert went out and 35 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: 750 J/kg
Mixed-layer CIN: -38 J/kg
Mixed-layer LCL: 1184 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 69 m²/s²
0-3 km storm-relative helicity: 107 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

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

281 
ACUS11 KWNS 260340
SWOMCD
SPC MCD 260340 
LAZ000-TXZ000-260545-

MESOSCALE DISCUSSION 0334
NWS STORM PREDICTION CENTER NORMAN OK
0940 PM CST TUE MAR 25 2003

AREAS AFFECTED...SW AR...NW LA...S-CENTRAL THROUGH NE TX

CONCERNING...SEVERE THUNDERSTORM WATCH 76...

VALID 260340Z - 260545Z

SEVERAL BANDS AND CLUSTERS OF TSTMS WITH POTENTIAL FOR LARGE HAIL
AND ISOLATED DAMAGING WIND WILL CONTINUE MOVING EWD ACROSS WW
AREA THROUGH NEXT FEW HOURS.  THEREAFTER...GENERAL WEAKENING
TREND IS EXPECTED.  ADDITIONAL DEVELOPMENT MAY OCCUR OVER COASTAL
PLAIN ADJACENT TO MIDDLE TX COAST WHEN STRONGER UVM ALOFT MOVES
OVER AREA BETWEEN 4Z-7Z.  ADDITIONALLY...SOME INTENSIFICATION OR
FURTHER DEVELOPMENT MAY OCCUR SE-E OF COT WHERE LEADING
BOUNDARIES FROM WEBB/DIMMIT COUNTY CONVECTION AND ACTIVITY NOW S
OF SAT MERGE...PROBABLY OVER LA SALLE COUNTY BEFORE 5Z.  ELEVATED
MUCAPE INCREASES WITH SWD EXTENT ACROSS AREA AS MIDLEVEL LAPSE
RATES STEEPEN TO AROUND 9 DEG C/KM OVER S TX.  VERTICAL SHEAR
PROFILES ARE MARGINAL AND WILL BECOME INSUFFICIENT TO SUPPORT
ORGANIZED SEVERE POTENTIAL OVER REGION ONCE INSTABILITY WEAKENS
FURTHER...AFTER ABOUT 7Z.

..EDWARDS.. 03/26/2003

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

ATTN...WFO...SHV...HGX...FWD...

33069440 32989386 32969273 32469278 31569357 31039468
31099587

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 25, 7:45 PM CST	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more	2 hr
Mar 25, 8:45 PM CST	Severe Thunderstorm Watch	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 5 more	5 hr
Mar 25, 10:09 PM CST	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more	96 min
Mar 25, 11:25 PM CST	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more	2 hr
Mar 25, 11:45 PM CST	Severe Thunderstorm Watch	SPC	Aransas, Brooks, Calhoun, Cameron, Hidalgo, Kenedy and 6 more	4 hr

Nearby

Mesoscale Discussions in Texas, 2003 Mesoscale Discussions in Louisiana, 2003 Every mesoscale discussion in 2003

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.