Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 976

June 7, 200921 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 7, 2009, 4:00 PM CDT for 21 counties in Texas. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Jun 7, 2009, 4:00 PM CDT (21:00 UTC)
Expired
Jun 7, 2009, 5:00 PM CDT
In force
60 min
Issued by
the Storm Prediction Center
All 21 counties

Coke County, TX, Crockett County, TX, Fisher County, TX, Glasscock County, TX, Howard County, TX, Irion County, TX, Jones County, TX, Kent County, TX, Mitchell County, TX, Nolan County, TX, Reagan County, TX, Runnels County, TX, Schleicher County, TX, Scurry County, TX, Sterling County, TX, Stonewall County, TX, Sutton County, TX, Taylor County, TX, Terrell County, TX, Tom Green County, TX, Val Verde County, TX

The radar

The San Angelo radar (KSJT), 40 km from the middle of the area, began a volume at 21:00 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

Midland Regional, TX (KMAF), launched 12:00Z, 9.0 hours before the alert went out and 136 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, Midland Regional, TX at 12:00Z on 2009-06-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 50 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, Midland Regional, TX at 12:00Z on 2009-06-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 290 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
50 J/kg
Mixed-layer CIN
-393 J/kg
Mixed-layer LCL
2592 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
290 m²/s²
0-3 km storm-relative helicity
249 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.

000 
ACUS11 KWNS 072101
SWOMCD
SPC MCD 072100 
TXZ000-072200-

MESOSCALE DISCUSSION 0976
NWS STORM PREDICTION CENTER NORMAN OK
0400 PM CDT SUN JUN 07 2009

AREAS AFFECTED...PORTIONS OF W-CNTRL/SWRN TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 072100Z - 072200Z

ISOLATED TSTMS FORMING ACROSS THE HIGHER TERRAIN OF SWRN TX WILL
POSE AT LEAST A SHORT-TERM DURATION SEVERE HAIL/WIND THREAT.
UNCERTAINTY OVER LONGEVITY AND POTENTIAL COVERAGE OF CONVECTION AS
IT ATTEMPTS TO EVOLVE E/NEWD INTO W-CNTRL TX. OBSERVATIONAL TRENDS
WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

AS OF 2055Z...RADAR IMAGERY DEPICTED AN ISOLATED SUPERCELL AROUND 40
E FST...WITH A SPLITTING CELL EVOLVING NWD. INTERPOLATED SURFACE
OBSERVATIONS SUGGEST AIR MASS IS DEEPLY MIXED ALONG DRYLINE/TROUGH
AXIS WITH TEMPERATURES IN THE MIDDLE 90S AND DEW POINTS IN THE
MIDDLE 50S. GIVEN THE STEEPNESS OF LAPSE RATES COMBINED WITH NEAR 40
KT EFFECTIVE SHEAR...SEVERE HAIL AND WINDS WILL BE THE PRIMARY
THREATS. OPERATIONAL AND HI-RES MODEL GUIDANCE SUGGEST OVERALL
CONVECTIVE COVERAGE WILL BE SUBSTANTIALLY LESS THAN IN PREVIOUS
DAYS. WITH MODEST CONVERGENCE ALONG THE DRY LINE AND APPARENT LACK
OF LARGER-SCALE FORCED ASCENT...UNCERTAINTY REMAINS HIGH REGARDING
OVERALL COVERAGE AND LONGEVITY OF CONVECTION.

..GRAMS.. 06/07/2009

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

ATTN...WFO...EWX...SJT...LUB...MAF...

LAT...LON   31000019 29020070 29750142 29760265 30750236 32090159
            32850117 33280090 33390037 33349990 32709956 31869970
            31000019

Nearby

Mesoscale Discussions in Texas, 2009Every mesoscale discussion in 2009

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.