Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 2048

October 13, 201239 counties in Oklahoma; 14 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 13, 2012, 2:55 PM CDT for 39 counties in Oklahoma; 14 counties in Texas. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Oct 13, 2012, 2:55 PM CDT (19:55 UTC)
Expired
Oct 13, 2012, 4:30 PM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 53 counties

Atoka County, OK, Blaine County, OK, Bryan County, OK, Caddo County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Creek County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Kingfisher County, OK, Kiowa County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Major County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Noble County, OK, Okfuskee County, OK, Oklahoma County, OK, Pawnee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Cooke County, TX, Haskell County, TX, Jack County, TX, Jones County, TX, Knox County, TX, Montague County, TX, Shackelford County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX, Young County, TX

The radar

The Norman radar (KTLX), 92 km from the middle of the area, began a volume at 19:54 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

Norman, OK (KOUN), launched 12:00Z, 7.9 hours before the alert went out and 75 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, Norman, OK at 12:00Z on 2012-10-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 885 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, Norman, OK at 12:00Z on 2012-10-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 341 square meters per square second.19395878Sfc1 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
885 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
683 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
341 m²/s²
0-3 km storm-relative helicity
365 m²/s²
Significant tornado parameter
0.3
Supercell composite
8.7

Open this sounding in Storm Lab

The text

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

296 
ACUS11 KWNS 131955
SWOMCD
SPC MCD 131955 
OKZ000-TXZ000-132130-

MESOSCALE DISCUSSION 2048
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT SAT OCT 13 2012

AREAS AFFECTED...CNTRL/SRN OK...NWRN TX

CONCERNING...TORNADO WATCH 661...

VALID 131955Z - 132130Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 661 CONTINUES.

SUMMARY...BAND OF SEMI-DISCRETE CELLS AND CLUSTERS FROM SWRN OK TO
THE TX BIG COUNTRY IS EXPECTED TO EVOLVE E/NEWD WITH AN INCREASING
RISK FOR SEVERE HAIL/WIND AND A FEW TORNADOES. CONCERN IS ALSO
INCREASING OVER THE POTENTIAL FOR INTENSIFICATION OF PRE-FRONTAL
TSTMS IN S-CNTRL OK. WFO WW EXTENSION OR A DOWNSTREAM TORNADO WATCH
ISSUANCE ARE POSSIBLE.

DISCUSSION...19Z SURFACE ANALYSIS PLACED THE PACIFIC COLD FRONT FROM
NEAR AVK TO BGS. TSTMS HAVE INCREASED IN COVERAGE AND INTENSITY
ALONG THE FRONT AS SURFACE TEMPERATURES HAVE SURGED THROUGH THE 80S
IN A NARROW CORRIDOR AHEAD OF IT ACROSS WRN OK INTO THE BIG COUNTRY.
ALTHOUGH STORM-SCALE INTERFERENCE/CLUSTERING MAY TEND TO LIMIT A
MORE INTENSE THREAT...DEEP-LAYER SHEAR PROFILES REMAIN FAVORABLE FOR
ALL TYPES OF SEVERE. 

ON/NEAR THE ERN FRINGE OF THE WW...A TSTM CLUSTER HAS INTENSIFIED IN
S-CNTRL OK. ALTHOUGH INSTABILITY IS NOT AS GREAT AS FARTHER
WEST...STRONG LOW-LEVEL S/SWLYS SAMPLED IN THE PURCELL OK PROFILER
HAS YIELDED AROUND 30 KT 0-1 KM SHEAR AMIDST A RICH PW AIR MASS OF
1.75 IN THE 18Z OUN RAOB. THIS WILL SUPPORT POTENTIAL FOR AN
EMBEDDED SUPERCELL STRUCTURE OR TWO AND AN ATTENDANT RISK OF A
TORNADO.

..GRAMS.. 10/13/2012

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

ATTN...WFO...TSA...FWD...OUN...SJT...LUB...

LAT...LON   36469852 36839791 36859735 36579692 35929630 35369589
            34969570 34449564 34029609 33369794 32709896 32529954
            32679995 32890015 33280005 34579931 36469852

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 12, 10:11 PM CDTMesoscale DiscussionSPCBeaver, Cimarron, Texas94 min
Oct 12, 11:52 PM CDTMesoscale DiscussionSPCBeaver, Cimarron, Harper, Texas83 min
Oct 13, 2:06 AM CDTMesoscale DiscussionSPCBeaver, Harper84 min
Oct 13, 12:23 PM CDTMesoscale DiscussionSPCCaddo, Comanche, Custer, Greer, Jackson, Kiowa and 2 more3 hr
Oct 13, 1:00 PM CDTTornado WatchSPCAlfalfa, Atoka, Blaine, Bryan, Caddo, Canadian and 36 more8 hr
Oct 13, 5:57 PM CDTTornado WatchSPCAdair, Cherokee, Choctaw, Craig, Creek, Delaware and 19 more6 hr
Oct 13, 6:59 PM CDTMesoscale DiscussionSPCAdair, Atoka, Bryan, Carter, Cherokee, Choctaw and 35 more2 hr
Oct 12, 9:19 PM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Carson, Castro, Cochran and 20 more56 min
Oct 12, 11:34 PM CDTMesoscale DiscussionSPCAndrews, Bailey, Cochran, Crosby, Dawson, Floyd and 9 more86 min
Oct 13, 1:10 PM CDTMesoscale DiscussionSPCCoke, Concho, Crockett, Irion, Menard, Reagan and 7 more95 min
Oct 13, 1:37 PM CDTSevere Thunderstorm WatchSPCBrown, Coke, Coleman, Concho, Crockett, Edwards and 19 more9 hr
Oct 13, 3:42 PM CDTMesoscale DiscussionSPCCoke, Crockett, Irion, Kinney, Maverick, Reagan and 6 more93 min
Oct 13, 6:30 PM CDTMesoscale DiscussionSPCAngelina, Austin, Bastrop, Bexar, Brazos, Burleson and 27 more60 min

Nearby

Mesoscale Discussions in Oklahoma, 2012Mesoscale 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.