SPC MD 2052

MD 2052 CONCERNING TORNADO WATCH 661…664… FOR N TX…OK EXCEPT WRN PORTIONS…EXTREME SERN KS…SWRN MO…NWRN AR.


MESOSCALE DISCUSSION 2052
NWS STORM PREDICTION CENTER NORMAN OK
0659 PM CDT SAT OCT 13 2012

AREAS AFFECTED...N TX...OK EXCEPT WRN PORTIONS...EXTREME SERN
KS...SWRN MO...NWRN AR.

CONCERNING...TORNADO WATCH 661...664...

VALID 132359Z - 140200Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 661...664...CONTINUES.

SUMMARY...ALTHOUGH PREDOMINANT STORM MODE SHOULD REMAIN RATHER
MESSY/QUASI-LINEAR...A FEW SUPERCELLS REMAIN POSSIBLE IN
PRECONVECTIVE ENVIRONMENT STILL CHARACTERIZED BY RICH MOISTURE AND
FAVORABLE LOW-LEVEL SHEAR AND DEEP-TROPOSPHERIC WIND PROFILES.
ADDITIONAL WW ISSUANCE MAY BE NEEDED AS ACTIVITY NEARS ERN END OF
EXISTING WWS...ESPECIALLY OVER PORTIONS N TX.

DISCUSSION...23Z SFC MESOANALYSIS SHOWED PAC COLD FRONT EXTENDING
SWD FROM LOW OVER N-CENTRAL KS...ACROSS W-CENTRAL OK...THEN SWWD
OVER MAF AREA.  FRONT WAS OVERTAKING DRYLINE ACROSS NW TX.  SOME
TSTMS STILL MAY DEVELOP ALONG FRONT IN AIR MASS AT LEAST PARTIALLY
AFFECTED BY EARLIER TSTMS.  HOWEVER...BULK OF CONVECTION HAS BEEN
AND WILL REMAIN IN PREFRONTAL DEEP-LIFT ZONE CURRENTLY SHIFTING EWD
ACROSS SERN KS...NERN THROUGH S-CENTRAL OK AND NWRN/N-CENTRAL TX.
WIDELY SEPARATED BOW ECHOES IN THAT ZONE HAVE PRODUCED MEASURED SVR
GUSTS IN OSAGE AND JEFFERSON COUNTIES OK AT 2204 AND 2245Z
RESPECTIVELY.  GIVEN STRENGTH OF AMBIENT WIND FIELDS...HIGH-PW
INFLOW LAYERS ESPECIALLY FROM ERN OK SWD...AND POTENTIAL FOR BOTH
DOWNWARD MOMENTUM TRANSFER AND PRECIP LOADING IN DOWNDRAFTS...SVR
GUSTS WILL REMAIN PRIMARY THREAT.  NEARLY PARALLEL ALIGNMENT OF
DEEP-SHEAR AND MEAN-WIND VECTORS WITH DEEP-CONVERGENCE SHOULD FAVOR
QUASI-LINEAR AND BOWING STRUCTURES.  HOWEVER...BROAD AREA OF 250-400
J/KG EFFECTIVE SRH AND 45-50 KT EFFECTIVE SHEAR MAGNITUDES COVERS
THIS AREA...SUPPORTING SUPERCELL POTENTIAL.  A FEW TORNADOES REMAIN
POSSIBLE...WHETHER FROM QLCS/BOW CIRCULATIONS OR SUPERCELLS.

..EDWARDS.. 10/13/2012

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

ATTN...WFO...LZK...SGF...SHV...TSA...ICT...FWD...OUN...SJT...

LAT...LON   32279996 34459828 35989693 36539553 37659489 37359303
            36589275 35449320 33739458 32429651 32209821 32279996

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md2052.html