Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 417

April 6, 200327 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2003, 3:00 PM CDT for 27 counties in Texas. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Apr 6, 2003, 3:00 PM CDT (20:00 UTC)
Expired
Apr 6, 2003, 4:30 PM CDT
In force
90 min
Issued by
the Storm Prediction Center
All 27 counties

Anderson County, TX, Brazos County, TX, Cherokee County, TX, Delta County, TX, Freestone County, TX, Grimes County, TX, Henderson County, TX, Hopkins County, TX, Houston County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Madison County, TX, Montgomery County, TX, Navarro County, TX, Rains County, TX, Robertson County, TX, San Jacinto County, TX, Smith County, TX, Trinity County, TX, Van Zandt County, TX, Walker County, TX, Waller County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 157 km from the middle of the area, began a volume at 20:03 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, 8.0 hours before the alert went out and 175 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 2003-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1494 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 2003-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 210 square meters per square second.1939587897117Sfc1 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
1494 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
662 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
210 m²/s²
0-3 km storm-relative helicity
292 m²/s²
Significant tornado parameter
2.0
Supercell composite
8.7

Open this sounding in Storm Lab

The text

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

278 
ACUS11 KWNS 062000
SWOMCD
SPC MCD 062000 
TXZ000-062130-

MESOSCALE DISCUSSION 0417
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT SUN APR 06 2003

AREAS AFFECTED...PARTS OF ERN TX

CONCERNING...TORNADO WATCH 103...

VALID 062000Z - 062130Z

LOW LEVEL FLOW HAS VEERED ALONG/JUST AHEAD OF APPROACHING DRY
LINE THAT EXTENDS ALONG THE I-35 CORRIDOR.  TSTMS HAVE BEEN
TRYING TO DEVELOP ALONG THIS LINE...BUT ARE HAVING A TOUGH TIME
SUSTAINING GIVEN DECREASING SURFACE CONVERGENCE.  THERE IS STILL
A CHANCE THAT TSTMS WILL DEVELOP WITH TIME ALONG THE DRY LINE IN
THE CRS-PRX REGIONS.  IF TSTM CAN BECOME SUSTAINED...VERY LARGE
HAIL AND ISOLD TORNADOES ARE POSSIBLE.



FARTHER SOUTH...FLOW REMAINS BACKED INVOF CONVECTIVE CLUSTER JUST
NORTH OF UTS/W OF LFK WITHIN AN AIR MASS CHARACTERIZED BY SURFACE
DEW POINTS NEAR 70F.  THESE TSTMS...WHILE ALREADY EXHIBITING
SUPERCELLULAR CHARACTERISTICS...MAY PRODUCE TORNADOES AND VERY
LARGE HAIL... PARTICULARLY AS THEY MOVE EWD TOWARD THE SABINE
RIVER INTO WT 101.

..RACY.. 04/06/2003

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

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

31739696 33759596 33659533 31999499 30049476 29999617
30809677

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 5, 6:11 PM CSTMesoscale DiscussionSPCBaylor, Briscoe, Cottle, Crosby, Dickens, Floyd and 9 more64 min
Apr 5, 6:35 PM CSTMesoscale DiscussionSPCArcher, Clay, Collin, Cooke, Dallas, Delta and 23 more115 min
Apr 5, 6:40 PM CSTTornado WatchSPCBriscoe, Childress, Cottle, Crosby, Dickens, Fisher and 16 more5 hr
Apr 5, 8:04 PM CSTMesoscale DiscussionSPCArcher, Baylor, Clay, Collin, Cooke, Dallas and 25 more116 min
Apr 5, 9:20 PM CSTMesoscale DiscussionSPCArcher, Camp, Clay, Collin, Cooke, Dallas and 31 more55 min
Apr 5, 9:35 PM CSTTornado WatchSPCArcher, Bowie, Camp, Cass, Clay, Collin and 38 more5 hr
Apr 5, 10:26 PM CSTMesoscale DiscussionSPCBaylor, Childress, Cottle, Dickens, Fisher, Foard and 11 more64 min
Apr 5, 11:43 PM CSTMesoscale DiscussionSPCArcher, Camp, Clay, Collin, Cooke, Dallas and 31 more92 min
Apr 6, 3:13 AM CDTMesoscale DiscussionSPCArcher, Baylor, Camp, Cass, Cherokee, Clay and 39 more107 min
Apr 6, 3:39 AM CDTMesoscale DiscussionSPCArcher, Baylor, Camp, Cass, Cherokee, Clay and 39 more66 min
Apr 6, 4:50 AM CDTMesoscale DiscussionSPCArcher, Baylor, Brown, Callahan, Coke, Coleman and 27 more115 min
Apr 6, 5:35 AM CDTSevere Thunderstorm WatchSPCWichita4 hr
Apr 6, 9:12 AM CDTMesoscale DiscussionSPCAnderson, Bosque, Camp, Cass, Cherokee, Collin and 41 more2 hr
Apr 6, 10:20 AM CDTMesoscale DiscussionSPCBowie, Cass, Harrison, Marion, Morris, Panola55 min
Apr 6, 10:30 AM CDTTornado WatchSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 14 more6 hr
Apr 6, 12:03 PM CDTMesoscale DiscussionSPCGregg, Harrison, Marion, Panola, Rusk117 min
Apr 6, 12:40 PM CDTTornado WatchSPCAnderson, Brazos, Burleson, Cherokee, Collin, Cooke and 33 more5 hr
Apr 6, 2:55 PM CDTSevere Thunderstorm WatchSPCBowie, Delta, Lamar, Red River5 hr
Apr 6, 3:26 PM CDTMesoscale DiscussionSPCAngelina, Nacogdoches, Sabine, San Augustine, Shelby2 hr
Apr 6, 3:45 PM CDTTornado WatchSPCAngelina, Gregg, Hardin, Harrison, Jasper, Liberty and 9 more5 hr
Apr 6, 5:35 PM CDTMesoscale DiscussionSPCAngelina, Gregg, Hardin, Harrison, Jasper, Liberty and 10 more115 min
Apr 6, 6:23 PM CDTMesoscale DiscussionSPCNewton, Sabine97 min

Nearby

Mesoscale Discussions in Texas, 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.