Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 702

May 4, 20126 counties in Oklahoma; 27 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 4, 2012, 7:28 PM CDT for 6 counties in Oklahoma; 27 counties in Texas. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
May 4, 2012, 7:28 PM CDT (00:28 UTC)
Expired
May 4, 2012, 8:30 PM CDT
In force
62 min
Issued by
the Storm Prediction Center
All 33 counties

Carter County, OK, Cotton County, OK, Jefferson County, OK, Love County, OK, Murray County, OK, Stephens County, OK, Archer County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Clay 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, Tom Green County, TX, Wichita County, TX, Wise County, TX, Young County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 103 km from the middle of the area, began a volume at 00:29 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, 0.5 hours before the alert went out and 94 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 2012-05-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2627 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 2012-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
2627 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
1899 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
117 m²/s²
Significant tornado parameter
0.1
Supercell composite
7.1

Open this sounding in Storm Lab

The text

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

049 
ACUS11 KWNS 050029
SWOMCD
SPC MCD 050028
TXZ000-OKZ000-050130-

MESOSCALE DISCUSSION 0702
NWS STORM PREDICTION CENTER NORMAN OK
0728 PM CDT FRI MAY 04 2012

AREAS AFFECTED...SW OK/S CNTRL OK INTO CNTRL AND SW TX

CONCERNING...SEVERE THUNDERSTORM WATCH 240...

VALID 050028Z - 050130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 240
CONTINUES.

SUMMARY...THUNDERSTORMS CAPABLE OF DMGG WINDS AND LARGE HAIL WILL
CONTINUE TO SLOWLY PROGRESS ESEWD INTO S CNTRL OK AND CNTRL TX.
SEVERAL COUNTIES HAVE BEEN ADDED TO THE WW NEAR THE DFW METRO...AND
MORE MAY BE NEEDED TO THE S AND SW LATER THIS EVENING.

DISCUSSION...DRYLINE STORMS CONTINUE TO SLOWLY PROGRESS ESEWD AT
ABOUT 15 KTS...WITH TWO PRIMARY AREAS EMERGING. THE FIRST IS A
SUPERCELL NEAR THE OK/TX BORDER THAT HAS HAD A HISTORY OF PRODUCING
SIGNIFICANT HAIL. THE SECOND AREA IS A CLUSTER OF MULTICELLS AND
SUPERCELLS...PROGRESSING TOWARDS GREATER INSTABILITY. 00Z FWD
SOUNDING IS SHOWING AN EXTREMELY UNSTABLE AIR MASS...WITH VEERING
LOW LEVEL WINDS AND MODEST WLYS ALOFT CONTRIBUTING TO ROTATING
UPDRAFTS. GENERALLY WEAK LOW LEVEL WINDS WOULD SUGGEST THAT ANY
TORNADO THAT CAN DEVELOP WILL BE BRIEF...AND THAT A PREDOMINANT
THREAT OF LARGE HAIL AND DMGG WINDS WILL CONTINUE.

..HURLBUT.. 05/05/2012

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

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

LAT...LON   34529693 33419682 32849683 31989726 31469785 31489863
            31290049 31600071 32769932 33929893 34529867 34799822
            34529693

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 4, 9:53 PM CDTMesoscale DiscussionSPCBosque, Collin, Dallas, Ellis, Grayson, Hamilton and 6 more67 min
May 5, 4:44 PM CDTMesoscale DiscussionSPCBosque, Brown, Burnet, Callahan, Coleman, Comanche and 21 more61 min
May 5, 5:02 PM CDTSevere Thunderstorm WatchSPCBlanco, Brown, Burnet, Coleman, Comanche, Concho and 11 more5 hr
May 5, 6:09 PM CDTMesoscale DiscussionSPCAtascosa, La Salle, Live Oak, McMullen66 min

Nearby

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Oklahoma, 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.