Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 971

May 14, 20034 states

The Storm Prediction Center issued this mesoscale discussion at May 14, 2003, 10:55 AM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 14, 2003, 10:55 AM CDT (15:55 UTC)
Expired
May 14, 2003, 1:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 40 counties

Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Pike County, AR, Sevier County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Webster Parish, LA, Bryan County, OK, Choctaw County, OK, Johnston County, OK, Marshall County, OK, McCurtain County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Collin County, TX, Delta County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Gregg County, TX, Harrison County, TX, Hopkins County, TX, Hunt County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Titus County, TX, Upshur County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 104 km from the middle of the area, began a volume at 15:55 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

Shreveport, LA (KSHV), launched 12:00Z, 3.9 hours before the alert went out and 106 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, Shreveport, LA at 12:00Z on 2003-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 480 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, Shreveport, LA at 12:00Z on 2003-05-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 84 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
480 J/kg
Mixed-layer CIN
-383 J/kg
Mixed-layer LCL
842 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
84 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

958 
ACUS11 KWNS 141555
SWOMCD
SPC MCD 141555 
LAZ000-ARZ000-TXZ000-OKZ000-141800-

MESOSCALE DISCUSSION 0971
NWS STORM PREDICTION CENTER NORMAN OK
1055 AM CDT WED MAY 14 2003

AREAS AFFECTED...SERN OK / NERN TX / SWRN AR / NWRN LA...

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 141555Z - 141800Z

THUNDERSTORMS DEVELOPING ACROSS SERN OK SHOULD INCREASE / EXPAND EWD
INTO SWRN AR OVER THE NEXT 1 TO 2 HOURS...AND EVENTUALLY BUILD SEWD
INTO NERN TX / NWRN LA BY EARLY AFTERNOON.  WW WILL LIKELY BE
REQUIRED FOR THIS AREA BY NOON.

LATEST DATA INDICATES INCREASINGLY WARM / VERY MOIST BUT CAPPED
BOUNDARY LAYER BENEATH ELEVATED MIXED LAYER / VERY STEEP MID-LEVEL
LAPSE RATES.  OUTFLOW BOUNDARY FROM EARLIER CONVECTION APPEARS TO
EXIST ACROSS SERN OK WHERE NEW STORMS ARE DEVELOPING ATTM.  FURTHER
SOUTH INTO NERN TX...SECOND BOUNDARY / WARM FRONT IS ANALYZED SOUTH
OF THE DFW METROPLEX EWD TOWARD GGG.  LOW-LEVEL JET IS VEERED TO
WSWLY ACROSS MUCH OF THIS AREA ATTM / ROUGHLY PARALLEL TO SURFACE
BOUNDARIES...BUT SHOULD BACK TO A MORE SLY DIRECTION OVER THE NEXT
COUPLE OF HOURS AS MID-LEVEL SHORT-WAVE TROUGH APPROACHES.  THIS
WOULD RESULT IN AN INCREASE IN WARM ADVECTION / LIFT INVOF SURFACE
BOUNDARIES...WHICH COMBINED WITH CONTINUED HEATING SHOULD ALLOW
BOUNDARY LAYER TO DESTABILIZE / CAP TO WEAKEN.

ALTHOUGH LOW-LEVEL WIND FIELD HAS BEEN DISRUPTED BY CONVECTION...
MID-LEVEL FLOW -- AND THUS DEEP-LAYER SHEAR -- REMAINS FAVORABLE FOR
STORM ORGANIZATION / ROTATION GIVEN MODERATE INSTABILITY ABOVE THE
BOUNDARY LAYER.  SEVERE THREAT ACROSS SERN OK / SWRN AR -- PRIMARILY
IN THE FORM OF LARGE HAIL ATTM -- SHOULD SHIFT SEWD WITH TIME AND
INCREASE TO INCLUDE LOCALLY DAMAGING WINDS AS BOUNDARY LAYER
DESTABILIZES AND LOW-LEVEL JET BACKS.

..GOSS.. 05/14/2003

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

ATTN...WFO...LZK...SHV...TSA...FWD...OUN...

34219341 33189264 32159278 32239450 32799644 34339705

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 13, 8:05 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Lafayette, Miller, Nevada55 min
May 14, 5:50 AM CDTMesoscale DiscussionSPCHoward, Little River, Miller, Sevier115 min
May 14, 10:26 AM CDTMesoscale DiscussionSPCDesha, Phillips94 min
May 14, 11:10 AM CDTSevere Thunderstorm WatchSPCPhillips6 hr
May 14, 2:30 PM CDTTornado WatchSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 10 more6 hr
May 14, 5:17 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Lafayette, Little River, Miller, Nevada and 1 more118 min
May 14, 6:10 PM CDTSevere Thunderstorm WatchSPCAshley, Columbia, Lafayette, Nevada, Union6 hr
May 13, 8:30 PM CDTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 15 more5 hr
May 13, 10:45 PM CDTTornado WatchSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more5 hr
May 13, 9:58 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Cleveland, Custer and 20 more3 hr
May 13, 10:20 PM CDTSevere Thunderstorm WatchSPCAlfalfa, Atoka, Beckham, Blaine, Caddo, Canadian and 39 more7 hr
May 14, 1:34 AM CDTMesoscale DiscussionSPCAtoka, Blaine, Caddo, Canadian, Cleveland, Coal and 32 more116 min
May 14, 3:49 AM CDTMesoscale DiscussionSPCAtoka, Blaine, Bryan, Caddo, Canadian, Carter and 38 more116 min
May 14, 4:05 AM CDTSevere Thunderstorm WatchSPCAlfalfa, Blaine, Bryan, Caddo, Canadian, Carter and 23 more5 hr
May 14, 7:40 AM CDTMesoscale DiscussionSPCBeckham, Bryan, Carter, Comanche, Cotton, Custer and 11 more95 min
May 14, 3:23 PM CDTMesoscale DiscussionSPCCotton, Jefferson, Love, Tillman2 hr
May 14, 4:52 PM CDTMesoscale DiscussionSPCAlfalfa, Garfield, Grant, Kay, Noble, Payne and 1 more113 min
May 14, 6:28 PM CDTMesoscale DiscussionSPCGreer, Harmon, Jackson2 hr

Nearby

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