Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 147

February 23, 200312 counties in Arkansas; 11 parishes in Louisiana; 13 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 23, 2003, 2:14 PM CST for 12 counties in Arkansas; 11 parishes in Louisiana; 13 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Feb 23, 2003, 2:14 PM CST (20:14 UTC)
Expired: Feb 23, 2003, 4:15 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center

All 36 counties

Bradley County, AR, Calhoun County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Hempstead County, AR, Lafayette County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Angelina County, TX, Harrison County, TX, Jasper County, TX, Nacogdoches County, TX, Panola County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 8.2 hours before the alert went out and 20 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1249 m above ground
0-6 km bulk shear: 73 kt
0-1 km storm-relative helicity: 208 m²/s²
0-3 km storm-relative helicity: 335 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

030 
ACUS11 KWNS 232015
SWOMCD
SPC MCD 232014 
ARZ000-TXZ000-LAZ000-232215-

MESOSCALE DISCUSSION 0147
NWS STORM PREDICTION CENTER NORMAN OK
0214 PM CST SUN FEB 23 2003

AREAS AFFECTED...SRN AR...ERN TX...WRN LA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 232014Z - 232215Z

CONVECTIVE TRENDS ARE BEING MONITORED FOR POSSIBILITY OF
INCREASING SEVERE THREAT.



INTENSE CYCLONIC MID/UPPER JET STREAK CONTINUES TO DIG ACROSS THE
RED RIVER VALLEY ARKLATEX REGION.  STRONGEST MID-LEVEL COOLING/
FORCING FOR UPWARD VERTICAL MOTION IN EXIT REGION OF JET STREAK
IS SHIFTING INTO THE OZARKS...AND PROGGED TO BEGIN ACCELERATING
WITH UPPER JET...INTO THE MIDDLE MISSISSIPPI/LOWER OHIO VALLEY
REGION THIS EVENING.  HOWEVER...LOW-LEVEL WARM ADVECTION ALONG 50
KT SOUTHERLY LOW-LEVEL JET AXIS FROM EAST TEXAS INTO CENTRAL
ARKANSAS IS CONTRIBUTING TO LOWER TROPOSPHERIC DESTABILIZATION
AND INCREASING SHALLOW CONVECTIVE ACTIVITY IN STRONGLY SHEARED
ENVIRONMENT.



MOISTURE AVAILABLE TO SYSTEM IS STILL QUITE MARGINAL FOR DEEP
CONVECTIVE DEVELOPMENT...AND MID-LEVEL TEMPERATURES SOUTH OF
UPPER JET AXIS ARE WARM RELATIVE TO LIFTED PARCELS.  THUS
CONSIDERABLE UNCERTAINTY EXISTS WITH REGARD TO WHETHER SUSTAINED
THUNDERSTORM ACTIVITY IS POSSIBLE.  BUT...WITH MID 50S SURFACE
DEW POINTS EVIDENT IN 20Z SURFACE ANALYSIS ADVECTING ACROSS THE
UPPER TEXAS COAST...THERE APPEARS TO BE A NARROW WINDOW OF
OPPORTUNITY FOR DEEP CONVECTION AS LOW-LEVEL FORCING INCREASES
ALONG COLD FRONT IN AN ARC FROM SOUTHWEST ARKANSAS INTO SOUTHEAST
TEXAS FROM 23/22Z-24/00Z.  DESPITE...MAXIMUM CAPE VALUES ON THE
ORDER OF A FEW HUNDRED J/KG...THERMODYNAMIC ENVIRONMENT IN WARM
SECTOR NEAR SURFACE LOW/JUST AHEAD OF SURFACE FRONT WILL BE
SUPPORTIVE OF HAIL/GUSTY WINDS IN ENVIRONMENT WITH MORE THAN
SUFFICIENT SHEAR FOR UPDRAFT ROTATION.

..KERR.. 02/23/2003

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

32909421 33709388 34299339 34069220 33239203 32779234
31799292 30349435 30229526 30939576 31389520 31949472

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 23, 10:41 AM CST	Mesoscale Discussion	SPC	Baxter, Benton, Boone, Carroll, Fulton, Madison and 3 more	5 hr
Feb 23, 5:25 PM CST	Mesoscale Discussion	SPC	Sabine	95 min

Nearby

Mesoscale Discussions in Texas, 2003 Mesoscale Discussions in Arkansas, 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.