Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 660

May 1, 20034 parishes in Louisiana; 5 counties in Oklahoma; 69 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 1, 2003, 10:55 AM CDT for 4 parishes in Louisiana; 5 counties in Oklahoma; 69 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 1, 2003, 10:55 AM CDT (15:55 UTC)
Expired
May 1, 2003, 1:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 78 counties

De Soto Parish, LA, Jackson Parish, LA, Red River Parish, LA, Sabine Parish, LA, Bryan County, OK, Coal County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, Anderson County, TX, Angelina County, TX, Bell County, TX, Bosque County, TX, Brazos County, TX, Brown County, TX, Burleson County, TX, Burnet County, TX, Cherokee County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Cooke County, TX, Coryell County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Fannin County, TX, Freestone County, TX, Grayson County, TX, Gregg County, TX, Grimes County, TX, Hamilton County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Houston County, TX, Hunt County, TX, Jack County, TX, Johnson County, TX, Kaufman County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, McLennan County, TX, Milam County, TX, Mills County, TX, Montague County, TX, Nacogdoches County, TX, Navarro County, TX, Palo Pinto County, TX, Panola County, TX, Parker County, TX, Rains County, TX, Robertson County, TX, Rockwall County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Saba County, TX, Shelby County, TX, Smith County, TX, Somervell County, TX, Tarrant County, TX, Travis County, TX, Trinity County, TX, Upshur County, TX, Van Zandt County, TX, Walker County, TX, Washington County, TX, Williamson County, TX, Wise County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 70 km from the middle of the area, began a volume at 15:56 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 3.9 hours before the alert went out and 96 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, Fort Worth, TX at 12:00Z on 2003-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2698 joules per kilogram.LCLLFCEL10008507005003002001001 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, Fort Worth, TX at 12:00Z on 2003-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 248 square meters per square second.193958Sfc1 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
2698 J/kg
Mixed-layer CIN
-157 J/kg
Mixed-layer LCL
614 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
248 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.6

Open this sounding in Storm Lab

The text

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

768 
ACUS11 KWNS 011555
SWOMCD
SPC MCD 011555 
LAZ000-TXZ000-OKZ000-011800-

MESOSCALE DISCUSSION 0660
NWS STORM PREDICTION CENTER NORMAN OK
1055 AM CDT THU MAY 01 2003

AREAS AFFECTED...CNTRL AND ERN TX

CONCERNING...OUTLOOK UPGRADE 

VALID 011555Z - 011800Z

A SLIGHT RISK WILL BE EXTENDED SW AND WILL COVER ALL OF CNTRL AND
NERN TX FOR THE DAY 1 PERIOD. STRONG INSTABILITY HAS DEVELOPED
ACROSS THIS AREA. AS THE CAP WEAKENS ACROSS CNTRL AND NERN TX THIS
AFTERNOON...THE RAPID DEVELOPMENT OF ISOLATED THUNDERSTORMS WILL BE
LIKELY. SOME OF THE STORMS COULD BECOME SEVERE IN THE SLIGHT RISK
AREA. AGAIN...THE SLIGHT RISK WILL BE EXTENDED INTO CNTRL AND NERN
TX FOR THE DAY 1 PERIOD.

..BROYLES.. 05/01/2003

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

ATTN...WFO...LCH...SHV...HGX...FWD...OUN...EWX...SJT...

31219924 31969951 32879869 34079745 34939630 33379598
32349405 32319204 30969455 30219605 30139764 30869913

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 30, 7:30 PM CDTSevere Thunderstorm WatchSPCGarfield, Grant, Kay, Logan, Noble, Osage and 2 more6 hr
Apr 30, 8:17 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Comanche, Cotton and 14 more88 min
Apr 30, 9:52 PM CDTMesoscale DiscussionSPCGarfield, Grant, Kay, Logan, Noble, Osage and 2 more83 min
Apr 30, 11:47 PM CDTMesoscale DiscussionSPCGarfield, Grant, Kay, Logan, Noble, Osage and 2 more118 min
May 1, 12:10 AM CDTSevere Thunderstorm WatchSPCCraig, Garfield, Grant, Kay, Noble, Nowata and 4 more5 hr
May 1, 2:27 AM CDTMesoscale DiscussionSPCCraig, Delaware, Mayes, Nowata, Osage, Ottawa and 2 more2 hr
May 1, 2:13 PM CDTMesoscale DiscussionSPCChoctaw, Haskell, Latimer, LeFlore, McCurtain, McIntosh and 4 more3 hr
May 1, 3:45 PM CDTTornado WatchSPCAdair, Cherokee, Choctaw, Delaware, Haskell, Latimer and 11 more5 hr
May 1, 6:58 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Choctaw, Delaware, Haskell, Latimer and 12 more92 min
May 1, 2:33 PM CDTMesoscale DiscussionSPCBosque, Brown, Burnet, Camp, Comanche, Concho and 34 more117 min
May 1, 2:55 PM CDTTornado WatchSPCBosque, Bowie, Brown, Burnet, Camp, Collin and 35 more5 hr
May 1, 6:10 PM CDTMesoscale DiscussionSPCBosque, Burnet, Camp, Collin, Comanche, Coryell and 31 more95 min

Nearby

Mesoscale Discussions in Texas, 2003Mesoscale Discussions in Oklahoma, 2003Mesoscale Discussions in Louisiana, 2003Every 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.