Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 503

April 12, 20127 counties in Oklahoma; 11 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2012, 6:06 PM CDT for 7 counties in Oklahoma; 11 counties in Texas. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued
Apr 12, 2012, 6:06 PM CDT (23:06 UTC)
Expired
Apr 12, 2012, 8:00 PM CDT
In force
114 min
Issued by
the Storm Prediction Center

Counties Beckham County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kiowa County, OK, Roger Mills County, OK, Tillman County, OK, Baylor County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Foard County, TX, Hall County, TX, Hardeman County, TX, Hemphill County, TX, Knox County, TX, Wheeler County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 96 km from the middle of the area, began a volume at 23:08 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

Amarillo Airport, TX (KAMA), launched 12:00Z, 11.1 hours before the alert went out and 183 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, Amarillo Airport, TX at 12:00Z on 2012-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 206 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, Amarillo Airport, TX at 12:00Z on 2012-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 138 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
206 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
840 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
138 m²/s²
0-3 km storm-relative helicity
202 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

724 
ACUS11 KWNS 122306
SWOMCD
SPC MCD 122306 
TXZ000-OKZ000-130100-

MESOSCALE DISCUSSION 0503
NWS STORM PREDICTION CENTER NORMAN OK
0606 PM CDT THU APR 12 2012

AREAS AFFECTED...EASTERN TX PANHANDLE/NORTHWEST TX INTO FAR WESTERN
OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 122306Z - 130100Z

AS A FOLLOW-UP TO MESOSCALE DISCUSSION 500...CONVECTIVE TRENDS ARE
STILL BEING CLOSELY MONITORED FOR CONVECTIVE INITIATION ACROSS
PORTIONS OF NORTHWEST TX/EASTERN TX PANHANDLE INTO FAR WESTERN OK
THROUGH EARLY EVENING. INCIPIENT SIGNS/INCREASING CONFIDENCE OF DEEP
CONVECTIVE INITIATION COULD PROMPT A WATCH ISSUANCE.

AFTER A BOUT OF SHORTWAVE RIDGING OR AT LEAST NEBULOUS FORCING FOR
ASCENT ALOFT...WATER VAPOR/VISIBLE SATELLITE TRENDS /EG. REFERENCE
CIRRUS ACROSS NM INTO FAR WEST TX AND TECUMCARI NM WIND PROFILER/
IMPLY THAT THE LEADING EDGE OF HEIGHT FALLS/FORCING FOR ASCENT WILL
INFLUENCE THE REGION EARLY THIS EVENING. THE DRYLINE HAS RECENTLY
MIXED A BIT EASTWARD ACROSS THE TX PANHANDLE...WITH DEDUCED SIGNS OF
INCREASING MASS CONVERGENCE PER SURFACE OBS ESPECIALLY NEAR THE
DRYLINE AND A NORTHWEST-SOUTHEAST ARCING DIFFERENTIAL HEATING
BOUNDARY/WEAK WARM FRONT ACROSS THE EASTERN TX PANHANDLE/SOUTHWEST
OK/WESTERN PART OF NORTH TX. ACCORDINGLY...VISIBLE SATELLITE TRENDS
DO REFLECT A DEGREE OF DEEPENING/THICKENING OF THE CU FIELD NEAR THE
CDS AND TX/OK BORDER VICINITY.

WHILE THE LIKELIHOOD/EXTENT OF DEEP CONVECTIVE IMITATION IS STILL
UNCERTAIN...THE AFOREMENTIONED CORRIDOR APPEARS CONDITIONALLY MOST
FAVORABLE FOR THE POSSIBILITY OF SEVERE TSTM DEVELOPMENT OVER THE
NEXT FEW HOURS. THIS NOTION IS SUPPORTED BY GUIDANCE SUCH AS THE 18Z
NAM/GFS...WITH EACH INDICATIVE OF CONVECTION PRECIPITATION BETWEEN
00Z-03Z. SHOULD SUCH DEVELOPMENT OCCUR...SUPERCELLS WOULD BE
PROBABLE WITHIN AN UNSTABLE /2000 J PER KG MLCAPE/ AND AMPLE
VERTICAL SHEAR /45 KT EFFECTIVE BULK SHEAR/ ENVIRONMENT...WITH THE
POSSIBILITY OF A LARGE HAIL/TORNADO THREAT.

..GUYER.. 04/12/2012

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

ATTN...WFO...OUN...SJT...LUB...AMA...

LAT...LON   36219978 35709907 33679872 33269941 34160057 35670065
            36219978

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 2:28 PM CDTMesoscale DiscussionSPCBeaver, Texas2 hr
Apr 12, 3:34 PM CDTMesoscale DiscussionSPCBeckham, Caddo, Comanche, Custer, Dewey, Ellis and 7 more86 min
Apr 11, 8:54 PM CDTMesoscale DiscussionSPCArmstrong, Carson, Donley, Gray, Hansford, Hartley and 8 more66 min
Apr 11, 9:12 PM CDTMesoscale DiscussionSPCAndrews, Cochran, Crane, Dawson, Ector, Gaines and 16 more93 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.