Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 479

April 9, 20127 counties in Oklahoma; 37 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2012, 3:06 PM CDT for 7 counties in Oklahoma; 37 counties in Texas. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
Apr 9, 2012, 3:06 PM CDT (20:06 UTC)
Expired
Apr 9, 2012, 4:00 PM CDT
In force
54 min
Issued by
the Storm Prediction Center
All 44 counties

Beckham County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kiowa County, OK, Roger Mills County, OK, Washita County, OK, Armstrong County, TX, Bailey County, TX, Borden County, TX, Briscoe County, TX, Carson County, TX, Castro County, TX, Childress County, TX, Cochran County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Dawson County, TX, Deaf Smith County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Foard County, TX, Garza County, TX, Gray County, TX, Hale County, TX, Hall County, TX, Hardeman County, TX, Hockley County, TX, Kent County, TX, King County, TX, Lamb County, TX, Lubbock County, TX, Lynn County, TX, Motley County, TX, Parmer County, TX, Potter County, TX, Randall County, TX, Roberts County, TX, Swisher County, TX, Terry County, TX, Wheeler County, TX, Yoakum County, TX

The radar

The Amarillo radar (KAMA), 109 km from the middle of the area, began a volume at 20:06 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

Amarillo Airport, TX (KAMA), launched 12:00Z, 8.1 hours before the alert went out and 108 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 2012-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 505 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 2012-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 square meters per square second.1939587897Sfc1 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
505 J/kg
Mixed-layer CIN
-170 J/kg
Mixed-layer LCL
1025 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
100 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.

585 
ACUS11 KWNS 092007
SWOMCD
SPC MCD 092006
OKZ000-TXZ000-NMZ000-092100-

MESOSCALE DISCUSSION 0479
NWS STORM PREDICTION CENTER NORMAN OK
0306 PM CDT MON APR 09 2012

AREAS AFFECTED...TX PANHANDLE...SWRN TX...ERN NM

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 092006Z - 092100Z

THUNDERSTORMS CAPABLE OF LARGE HAIL AND DMGG WINDS WILL CONTINUE TO
INCREASE IN COVERAGE THIS AFTERNOON. SEVERAL AREAS OF INITIATION ARE
POSSIBLE...WITH STORMS GRADUALLY PROGRESSING EWD/SEWD WITH TIME.

SEVERAL AREAS OF INCREASING CU AND THUNDERSTORM DEVELOPMENT ARE
OCCURRING THIS AFTERNOON...IN RESPONSE TO WEAK LOW LEVEL UPSLOPE
WINDS FARTHER W...AND IN ASSOCIATION WITH SURFACE
CONFLUENCE...NOTABLE ACROSS FAR WRN TX...WITH AN ADDITIONAL BOUNDARY
EXTENDING FROM E CNTRL NM INTO THE TX PANHANDLE. A DISTINCT VORT MAX
IS IMPLIED ON WV IMAGERY AS OF 1945Z OVER ERN NM/WRN TX...LIKELY
CONTRIBUTING TO FORCING FOR ASCENT. ACROSS NM...ALTHOUGH AMPLE
SURFACE HEATING HAS OCCURRED...A DOWNSLOPE COMPONENT TO LOW-MID
LEVEL WINDS IN COMBINATION WITH MIXING HAS LOWERED DEW POINTS ACROSS
THE AREA...LEADING TO ONLY A MARGINALLY UNSTABLE AIR MASS.
NONETHELESS...STEEP MID LEVEL LAPSE RATES MAY ASSIST IN THE
OCCASIONAL DEVELOPMENT OF A STRONG TO SEVERE STORM. FARTHER E ACROSS
THE TX PANHANDLE AND SWD...A MORE UNSTABLE AIR MASS EXISTS...AND
ALTHOUGH MIXING HAS LOWERED DEW POINTS A FEW DEGREES...ADDITIONAL
MOISTENING MAY OCCUR LATER THIS AFTERNOON AS SURFACE WINDS BEGIN TO
BACK TO SELY...FURTHER CONTRIBUTING TO MODERATE INSTABILITY. NEARLY
ALL DETERMINISTIC MODELS INDICATE CONVECTIVE DEVELOPMENT POSSIBLE
ALONG VARIOUS SURFACE FEATURES AS REMAINING CONVECTIVE INHIBITION
ERODES...WITH ONGOING CONVECTION ALSO PROGRESSING INTO GREATER
INSTABILITY FARTHER EWD. THE MOST LIKELY CORRIDOR FOR MORE
SIGNIFICANT SEVERE POTENTIAL REMAINS OVER THE TX PANHANDLE INTO WRN
OK...WHERE MODEST NWLY FLOW WILL LEAD TO THE POTENTIAL FOR SPLITTING
SUPERCELLS.

..HURLBUT.. 04/09/2012

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

ATTN...WFO...OUN...LUB...AMA...MAF...ABQ...

LAT...LON   35890117 35709907 35269860 34709870 33749968 33010075
            32670160 32770233 33540345 34660327 35590211 35890117

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 9, 1:54 PM CDTMesoscale DiscussionSPCAlfalfa, Beaver, Blaine, Custer, Dewey, Ellis and 7 more96 min
Apr 9, 2:28 PM CDTTornado WatchSPCAlfalfa, Blaine, Dewey, Ellis, Harper, Major and 2 more5 hr
Apr 9, 3:23 PM CDTSevere Thunderstorm WatchSPCBeckham, Caddo, Comanche, Custer, Greer, Harmon and 5 more8 hr
Apr 9, 5:37 PM CDTMesoscale DiscussionSPCBeckham, Custer, Greer, Harmon, Jackson, Kiowa and 2 more83 min
Apr 9, 6:27 PM CDTTornado WatchSPCBeckham, Blaine, Caddo, Comanche, Cotton, Custer and 11 more8 hr
Apr 9, 5:03 PM CDTMesoscale DiscussionSPCAndrews, Crane, Dawson, Ector, Gaines, Jeff Davis and 9 more87 min
Apr 9, 5:32 PM CDTSevere Thunderstorm WatchSPCAndrews, Brewster, Crane, Crockett, Culberson, Dawson and 18 more7 hr

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.