Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 270

March 17, 200326 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 17, 2003, 10:27 PM CST for 26 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Mar 17, 2003, 10:27 PM CST (04:27 UTC)
Expired
Mar 18, 2003, 1:30 AM CST
In force
3 hr
Issued by
the Storm Prediction Center
All 26 counties

Archer County, TX, Brown County, TX, Callahan County, TX, Coleman County, TX, Comanche County, TX, Concho County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Hamilton County, TX, Hood County, TX, Jack County, TX, Kerr County, TX, Kimble County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Mills County, TX, Palo Pinto County, TX, Parker County, TX, San Saba County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Wise County, TX, Young County, TX

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 4.5 hours before the alert went out and 187 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 00:00Z on 2003-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 401 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 00:00Z on 2003-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 40 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
401 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1196 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
40 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.8

Open this sounding in Storm Lab

The text

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

437 
ACUS11 KWNS 180428
SWOMCD
SPC MCD 180427 
TXZ000-180730-

MESOSCALE DISCUSSION 0270
NWS STORM PREDICTION CENTER NORMAN OK
1027 PM CST MON MAR 17 2003

AREAS AFFECTED...CENTRAL/NRN TX

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 180427Z - 180730Z

...THUNDERSTORMS MAY REDEVELOP ACROSS PORTIONS OF NORTH
CENTRAL/WEST CENTRAL TX AFTER MIDNIGHT.  LARGE HAIL...OR PERHAPS
DAMAGING WINDS COULD EVOLVE FROM THIS ACTIVITY.  WW MAY BE
REQUIRED AFTER MIDNIGHT...



RECENT SATELLITE IMAGERY SUGGEST LEADING EDGE OF UPSTREAM FORCING
HAS REACHED 100 LON...SPREADING ENEWD AT ROUGHLY 40 KT PER
EXPANDING MID-UPPER LEVEL CLOUDINESS.  THIS ACTIVITY APPEARS
CONVECTIVE IN NATURE AND WILL SOON SPREAD ACROSS MOIST BOUNDARY
LAYER EAST OF THE DRY LINE.  THERE IS SOME CONCERN THUNDERSTORMS
WILL EVOLVE FROM THIS ELEVATED ACTIVITY...THEN INTENSIFY AND ROOT
DOWNWARD INTO MORE UNSTABLE AIR MASS.  IN ADDITION...MID LEVEL
COOLING SHOULD AID DESTABILIZATION AS EXIT REGION OF UPPER JET
SPREADS INTO NORTH CENTRAL TX.	LATEST THINKING IS TRAILING LINE
OF THUNDERSTORMS ACROSS OK MAY GRADUALLY LIFT ENEWD WITH RENEWED
DEVELOPMENT TO THE WEST OF DFW...PERHAPS FROM NEAR BWD TO NEAR
SPS.  LARGE SCALE PATTERN STRONGLY FAVORS LINEAR DEVELOPMENT WITH
POSSIBLE SQUALL LINE EVOLUTION WELL AFTER MIDNIGHT.  WW MAY BE
REQUIRED AFTER MIDNIGHT.

..DARROW.. 03/18/2003

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

ATTN...WFO...FWD...OUN...EWX...SJT...

30880014 33689875 33479669 31689781 29959937

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 17, 8:19 PM CSTMesoscale DiscussionSPCArcher, Bosque, Clay, Cooke, Denton, Eastland and 13 more86 min
Mar 18, 2:03 AM CSTMesoscale DiscussionSPCBell, Bosque, Burnet, Collin, Coryell, Dallas and 23 more3 hr
Mar 18, 9:36 AM CSTMesoscale DiscussionSPCAngelina, Bowie, Camp, Cass, Cherokee, Franklin and 22 more3 hr
Mar 18, 11:40 AM CSTTornado WatchSPCAngelina, Brazoria, Chambers, Galveston, Hardin, Harris and 13 more5 hr

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.