Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 2147

August 11, 20036 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2003, 5:29 PM CDT for 6 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 11, 2003, 5:29 PM CDT (22:29 UTC)
Expired
Aug 11, 2003, 7:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Collin County, TX, Dallas County, TX, Ellis County, TX, Grayson County, TX, Navarro County, TX, Rockwall County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 73 km from the middle of the area, began a volume at 22:29 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

Fort Worth, TX (KFWD), launched 12:00Z, 10.5 hours before the alert went out and 54 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 2003-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 638 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 2003-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 square meters per square second.19395878Sfc1 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
638 J/kg
Mixed-layer CIN
-148 J/kg
Mixed-layer LCL
1416 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
60 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.

427 
ACUS11 KWNS 112229
SWOMCD
SPC MCD 112229 
TXZ000-OKZ000-120030-

MESOSCALE DISCUSSION 2147
NWS STORM PREDICTION CENTER NORMAN OK
0529 PM CDT MON AUG 11 2003

AREAS AFFECTED...N-CNTRL TX

CONCERNING...SEVERE THUNDERSTORM WATCH 858...

VALID 112229Z - 120030Z

ADDITIONAL THUNDERSTORM DEVELOPMENT ACROSS THE EASTERN PORTION OF
THE WATCH IS POSSIBLE THE NEXT COUPLE OF HOURS INCLUDING THE AREA
AROUND DALLAS.

STRONG ORGANIZED OUTFLOW BOUNDARY FROM STORMS IN NORTHEASTERN TEXAS
IS CONTINUING TO ADVANCE FROM EAST TO WEST AND IS MOVING INTO THE
EASTERN COUNTIES OF THE WATCH. STORMS MAY FORM ALONG THE BOUNDARY
AND GIVEN THE 30 DEGREE TEMPERATURE DEW POINT SPREAD AT THE SURFACE,
BRIEF DAMAGING WINDS MAY BE POSSIBLE WITH THESE STORMS.  

ONCE THESE STORMS FORM ALONG THE BOUNDARY, THEY SHOULD MOVE
SOUTHWARD ALONG THE BOUNDARY WITH THE POSSIBILITY OF ADDITIONAL
STORM/BOUNDARY INTERACTIONS.

..BOTHWELL.. 08/11/2003

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

ATTN...WFO...FWD...OUN...

31909638 32069672 32509700 33329705 33669704 33789704
33869692 33869678 33649637

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 11:31 AM CDTMesoscale DiscussionSPCAustin, Bastrop, Brazoria, Brazos, Burleson, Caldwell and 27 more89 min
Aug 11, 12:05 PM CDTSevere Thunderstorm WatchSPCAustin, Brazoria, Colorado, Fort Bend, Galveston, Harris and 8 more6 hr
Aug 11, 2:06 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Cooke, Dallas and 31 more54 min
Aug 11, 2:31 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bandera, Bastrop, Bee, Bexar and 44 more29 min
Aug 11, 2:35 PM CDTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bastrop, Bee, Bexar, Blanco and 21 more5 hr
Aug 11, 4:45 PM CDTSevere Thunderstorm WatchSPCBosque, Clay, Collin, Comanche, Cooke, Dallas and 17 more5 hr
Aug 11, 5:16 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Brazoria, Brazos, Chambers and 21 more59 min
Aug 11, 6:09 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Bandera, Bastrop, Bee, Bexar and 42 more96 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.