Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 473

April 7, 2012Cotton County, Jefferson County, Stephens County, Oklahoma; 27 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 7, 2012, 2:29 PM CDT for Cotton County, Jefferson County, Stephens County, Oklahoma; 27 counties in Texas. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued
Apr 7, 2012, 2:29 PM CDT (19:29 UTC)
Expired
Apr 7, 2012, 3:30 PM CDT
In force
61 min
Issued by
the Storm Prediction Center
All 30 counties

Cotton County, OK, Jefferson County, OK, Stephens County, OK, Archer County, TX, Baylor County, TX, Brewster County, TX, Callahan County, TX, Clay County, TX, Coke County, TX, Crane County, TX, Fisher County, TX, Glasscock County, TX, Haskell County, TX, Howard County, TX, Irion County, TX, Jones County, TX, Midland County, TX, Mitchell County, TX, Nolan County, TX, Pecos County, TX, Reagan County, TX, Runnels County, TX, Shackelford County, TX, Stephens County, TX, Sterling County, TX, Taylor County, TX, Throckmorton County, TX, Upton County, TX, Wichita County, TX, Young County, TX

The radar

The Dyess AFB radar (KDYX), 82 km from the middle of the area, began a volume at 19:29 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Midland Regional, TX (KMAF), launched 12:00Z, 7.5 hours before the alert went out and 217 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 2012-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 993 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 2012-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 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
993 J/kg
Mixed-layer CIN
-242 J/kg
Mixed-layer LCL
1189 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
148 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

265 
ACUS11 KWNS 071930
SWOMCD
SPC MCD 071929
OKZ000-TXZ000-072030-

MESOSCALE DISCUSSION 0473
NWS STORM PREDICTION CENTER NORMAN OK
0229 PM CDT SAT APR 07 2012

AREAS AFFECTED...WRN/N CNTRL TX INTO S CNTRL OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 071929Z - 072030Z

THUNDERSTORMS WILL GRADUALLY INCREASE IN COVERAGE THIS
AFTERNOON...WITH SUPERCELLS CAPABLE OF LARGE HAIL AND DMGG WINDS
BECOMING INCREASINGLY POSSIBLE WITH TIME.

CU FIELD IS BEGINNING TO INCREASE ALONG A COLD FRONT...LOCATED AS OF
19Z FROM CNTRL OK SWWD TOWARDS MARFA TX...WITH A TOWERING
CU/DEVELOPING STORM OVER FISHER COUNTY TX. ADDITIONAL STORMS ARE
DEVELOPING ALONG THE DRYLINE FARTHER SOUTH. ALTHOUGH SUBTLE HEIGHT
RISES MAY INITIALLY HINDER A GREATER COVERAGE OF STORMS...FRONTAL
FORCING IS EXPECTED TO COMPENSATE SUFFICIENTLY TO LEAD TO A WELL
DEFINED LINE OF STORMS BY THIS EVENING. AMPLE DIURNAL HEATING HAS
NEARLY ERODED ANY REMAINING CONVECTIVE INHIBITION...WITH
MESOANALYSIS SHOWING A MODERATE TO VERY UNSTABLE AIR
MASS...PARTICULARLY FROM S CNTRL OK SWWD WHERE DEW POINTS HAVE RISEN
INTO THE LOWER TO MID 60S. THE MODEST FLOW ALOFT/PARTICULARLY ACROSS
NRN PORTIONS OF THE MD AREA IN NWRN TX/S CNTRL OK /AND STEEP MID
LEVEL LAPSE RATES MAY BE SUFFICIENT FOR SUPERCELLULAR DEVELOPMENT
WITH THE STRONGER UPDRAFTS.

..HURLBUT.. 04/07/2012

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

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

LAT...LON   34849770 34099749 32779864 31430048 29340382 29780420
            30650333 32210173 33519950 34719839 34869816 34849770

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 7, 10:17 AM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Cleveland, Comanche, Garfield and 12 more88 min
Apr 7, 3:01 PM CDTSevere Thunderstorm WatchSPCBrewster, Callahan, Coke, Coleman, Concho, Crane and 27 more9 hr
Apr 7, 6:41 PM CDTMesoscale DiscussionSPCArcher, Brewster, Brown, Callahan, Clay, Coke and 26 more64 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.