Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 949

May 28, 201222 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 28, 2012, 9:35 PM CDT for 22 counties in Texas. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
May 28, 2012, 9:35 PM CDT (02:35 UTC)
Expired
May 28, 2012, 10:30 PM CDT
In force
55 min
Issued by
the Storm Prediction Center
All 22 counties

Brown County, TX, Callahan County, TX, Coleman County, TX, Comanche County, TX, Cooke County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Hamilton County, TX, Hood County, TX, Jack County, TX, Johnson County, TX, Mills County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Wise County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 86 km from the middle of the area, began a volume at 02:37 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, 2.6 hours before the alert went out and 82 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 2012-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1125 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 2012-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 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
1125 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
1953 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

873 
ACUS11 KWNS 290236
SWOMCD
SPC MCD 290235
TXZ000-OKZ000-290330-

MESOSCALE DISCUSSION 0949
NWS STORM PREDICTION CENTER NORMAN OK
0935 PM CDT MON MAY 28 2012

AREAS AFFECTED...N-CNTRL TX

CONCERNING...SEVERE THUNDERSTORM WATCH 310...

VALID 290235Z - 290330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 310
CONTINUES.

SUMMARY...CONVECTIVE LINE CONTINUES TO PROGRESS SEWD THROUGH N-CNTRL
TX. LATEST RADAR IMAGERY HAS SHOWN A DECREASING TREND AND THE SEVERE
THREAT IS EXPECTED TO DIMINISH OVER THE NEXT HOUR.

DISCUSSION...KFWS RADAR IMAGERY DEPICTS A TWO DISTINCT LINES OF
TSTMS. ONE LINE IS LOCATED ACROSS WISE AND COOKE COUNTIES AND THE
OTHER IS LOCATED FROM JACK TO COLEMAN COUNTY. THE OUTFLOW BOUNDARY
FROM THE NRN LINE IS APPARENT ON KFWS RADAR IMAGERY...SUGGESTING THE
ACTIVITY BEHIND THIS LINE IS ELEVATED AND THREAT FOR SEVERE WIND
GUSTS IS LOW. OUTFLOW BOUNDARY IS BEGINNING TO EMERGE FROM THE SRN
LINE AS WELL. LOCALIZED ENHANCEMENT OF THE WIND FIELD MAY OCCUR
ACROSS PALO PINTO AND PARKER COUNTIES WHERE THIS TWO OUTFLOW
BOUNDARIES MERGE. OTHERWISE...A DECREASING TREND IS EXPECTED AS THE
LINES REMAIN ELEVATED.

FARTHER W...ISOLATED TSTMS CONTINUE TO INITIATE ALONG MESOSCALE
BOUNDARY INTERACTIONS. STORMS ARE QUICKLY BECOMING OUTFLOW DOMINATED
SO THE PRIMARY THREAT APPEARS TO BE SEVERE HAIL. ADDITIONAL
DEVELOPMENT WELL BEHIND THE MAIN LINE IS ALSO ELEVATED AND MAY POSE
A MARGINAL HAIL RISK.

..MOSIER.. 05/29/2012

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

ATTN...WFO...FWD...OUN...SJT...MAF...

LAT...LON   33619806 33789770 33799725 33619692 33269683 32579711
            31899766 31429857 31669962 32020097 32609928 33619806

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 7:44 PM CDTMesoscale DiscussionSPCBosque, Brown, Coleman, Collin, Comanche, Concho and 18 more91 min
May 28, 11:25 PM CDTMesoscale DiscussionSPCBosque, Brown, Coleman, Coryell, Dallas, Ellis and 10 more35 min
May 29, 3:06 PM CDTMesoscale DiscussionSPCHardeman, Wichita, Wilbarger84 min
May 29, 3:55 PM CDTSevere Thunderstorm WatchSPCClay, Wichita, Wilbarger12 hr

Nearby

Mesoscale Discussions in Texas, 2012Every mesoscale discussion in 2012

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.