SPC MD 2055

MD 2055 CONCERNING TORNADO WATCH 664… FOR PORTIONS ERN OK…EXTREME SERN KS…SRN MO…WRN/NRN AR…EXTREME N-CENTRAL/NE TX.


MESOSCALE DISCUSSION 2055
NWS STORM PREDICTION CENTER NORMAN OK
0937 PM CDT SAT OCT 13 2012

AREAS AFFECTED...PORTIONS ERN OK...EXTREME SERN KS...SRN
MO...WRN/NRN AR...EXTREME N-CENTRAL/NE TX.

CONCERNING...TORNADO WATCH 664...

VALID 140237Z - 140430Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 664 CONTINUES.

SUMMARY...BAND OF STG-SVR TSTMS WITH EMBEDDED BOW/LEWP FORMATIONS
WILL CONTINUE TO POSE PRIMARY DAMAGING GUST THREAT...AND SECONDARY
TORNADO RISK...AS IT MOVES EWD THROUGH REMAINDER WW AREA.  SVR
POTENTIAL COULD PERSIST FAR ENOUGH E OF WW...INTO FAVORABLY MOIST
AIR MASS FROM ARKLATEX TO OZARKS...TO WARRANT ANOTHER WW.

DISCUSSION...PRIMARY CONVECTIVE BAND WAS EVIDENT AT 230Z FROM SGF
AND SLG AREAS TO JUST W OF FSM...SWWD THROUGH DUA/GLE AREAS...MOVING
ENEWD AT VARIABLE SPEEDS GENERALLY WITHIN 35-45 KT RANGE.  GIVEN
ALIGNMENT OF MEAN-WIND AND DEEP-SHEAR VECTORS NEARLY PARALLEL TO
THIS ACTIVITY...QUASI-LINEAR CONVECTIVE MODE SHOULD REMAIN DOMINANT.
 SFC DEW POINTS AND PW EACH DECREASE WITH EWD EXTENT ACROSS AR AND
ARKLATEX REGION...AND ACCORDINGLY...FCST SOUNDINGS SUGGEST
STRENGTHENING MLCINH AND DECREASING BUOYANCY EWD TOWARD MS RIVER
ATTM.  HOWEVER...BENEATH 50-60 KT SWLY LLJ...SUFFICIENT AIR MASS
RECOVERY MAY OCCUR IN NARROW PRECONVECTIVE CORRIDOR TO SUSTAIN
STG-SVR CONVECTION E OF WW.  EFFECTIVE SHEAR MAGNITUDES ARE
MAXIMIZED AT ABOUT 50 KT OVER ERN OK AND WRN AR WHERE CAPE LAYER
REMAINS DEEPEST.  FOR NRN END OF COMPLEX...MOVING NEWD INTO
CENTRAL/ERN MO...SVR THREAT SHOULD DIMINISH GRADUALLY WITH TIME AND
NEW EXTENT AS TSTMS OUTPACE LOW-LEVEL DESTABILIZATION AND MOVE INTO
PROGRESSIVELY LOWER-THETAE AIR MASS.  STILL...ISOLATED DAMAGING
GUSTS CANNOT BE RULED OUT INTO ERN MO...ESPECIALLY ON LOCAL SW- OR
W-FACING SLOPES.

..EDWARDS.. 10/14/2012

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

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

LAT...LON   33789654 34509549 35279479 35849533 36689550 37219462
            37719306 37279165 36409158 34969250 33329458 33259829
            33789654

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md2055.html