Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 2192

September 18, 201130 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Sep 18, 2011, 7:58 PM CDT for 30 counties in Texas. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
Sep 18, 2011, 7:58 PM CDT (00:58 UTC)
Expired
Sep 18, 2011, 9:00 PM CDT
In force
62 min
Issued by
the Storm Prediction Center
All 30 counties

Bosque County, TX, Brown County, TX, Collin County, TX, Comanche County, TX, Concho County, TX, Cooke County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Erath County, TX, Fannin County, TX, Grayson County, TX, Hamilton County, TX, Hood County, TX, Hunt County, TX, Johnson County, TX, Kimble County, TX, Lamar County, TX, Lampasas County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Mills County, TX, Parker County, TX, Rockwall County, TX, San Saba County, TX, Somervell County, TX, Sutton County, TX, Tarrant County, TX, Wise County, TX

The radar

The Dyess AFB radar (KDYX), 108 km from the middle of the area, began a volume at 01:00 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

Fort Worth, TX (KFWD), launched 00:00Z, 1.0 hours before the alert went out and 185 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 2011-09-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2236 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 2011-09-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 square meters per square second.193958Sfc1 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
2236 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1912 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.2

Open this sounding in Storm Lab

The text

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

167 
ACUS11 KWNS 190058
SWOMCD
SPC MCD 190058 
TXZ000-OKZ000-190200-

MESOSCALE DISCUSSION 2192
NWS STORM PREDICTION CENTER NORMAN OK
0758 PM CDT SUN SEP 18 2011

AREAS AFFECTED...PORTIONS OF N AND CNTRL TX

CONCERNING...SEVERE THUNDERSTORM WATCH 853...

VALID 190058Z - 190200Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 853
CONTINUES.

WITH EXCEPTION TO NRN PORTIONS OF THE WW NEAR THE RED
RIVER...CONVECTION HAS LARGELY STRUGGLED TO INTENSIFY AND INCREASE
IN AREAL COVERAGE ACROSS MUCH OF THE WW AREA. THIS IS PROBABLY DUE
TO RATHER WEAK LOW-LEVEL CONVERGENCE ALONG A SLOW-MOVING SFC COLD
FRONT...AS WELL AS THE ABSENCE OF ANY SIGNIFICANT FORCED ASCENT
ALOFT AS PRIMARY UPPER WAVE REMAINS SITUATED ACROSS ERN OK. LATEST
RADAR IMAGERY CONTINUES TO INDICATE STRONGEST CLUSTER OF TSTMS IS
LOCATED N/E OF THE DFW METROPLEX AND IS PROGRESSING ESEWD...WITH
CONTINUED POTENTIAL FOR DMGG WINDS AND LARGE HAIL. FARTHER
S...ISOLATED TSTMS ARE PERSISTING WITHIN AN UNSTABLE AIR MASS...BUT
WITH THE LOSS OF DIABATIC HEATING THE ENVIRONMENT SHOULD GRADUALLY
BECOME LESS FAVORABLE FOR SUSTAINING A THREAT FOR DMGG WINDS/LARGE
HAIL. COLD FRONT IS NOW SITUATED FROM NEAR 6R6-10 W BWD-20 N FTW
/PER 00Z SUBJECTIVE ANALYSIS/...WITH DRIER/MORE STABLE AIR SLOWLY
ADVECTING SEWD IN ITS WAKE.

..ROGERS.. 09/19/2011

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

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

LAT...LON   30260105 33829714 33829507 30259928 30260105

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 18, 10:31 PM CDTMesoscale DiscussionSPCAnderson, Bosque, Cass, Cherokee, Ellis, Freestone and 17 more59 min

Nearby

Mesoscale Discussions in Texas, 2011Every mesoscale discussion in 2011

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.