MESOSCALE DISCUSSION 0053
   NWS STORM PREDICTION CENTER NORMAN OK
   0549 PM CST SAT JAN 13 2007
   
   AREAS AFFECTED...PORTIONS EXTREME E-CENTRAL/NE TX...NWRN
   LA...SRN/ERN AR.
   
   CONCERNING...HEAVY RAINFALL 
   
   VALID 132349Z - 140245Z
   
   BAND OF TSTMS WITH HEAVY RAINFALL IS FCST TO MAINTAIN INTENSITY AS
   IT MOVES EWD ACROSS CORRIDOR NEAR LINE FROM
   GGG...SHV...ELD...PBF...50 SW MEM.  RAIN RATES COMMONLY 1-1.25
   INCH/HOUR ARE EXPECTED...LOCALLY/BRIEFLY TOPPING 2 INCHES/HOUR IN
   MOST INTENSE CORES.
   
   23Z SFC MESOANALYSIS SHOWS FRONTAL-WAVE LOW BETWEEN SHV-GGG...WHICH
   SHOULD LIFT NEWD INTO SWRN AR DURING NEXT FEW HOURS.  STRONGEST
   CONVERGENCE AND STORM-RELATIVE/SFC-BASED INFLOW LIKEWISE IS FCST TO
   SHIFT NEWD AHEAD OF LOW...WITH COLD FRONT UNDERCUTTING SFC-BASED
   BUOYANCY FOR DEVELOPMENT OCCURRING SW OF LOW.  STILL...ACTIVITY MAY
   FORM ATOP SHALLOW FRONTAL LAYER IN ENVIRONMENT OF ELEVATED MOISTURE
   TRANSPORT AND WAA...AIDING PROPAGATIONAL MAINTENANCE OF SWRN PORTION
   OF PRECIP/TSTM BAND.  GIVEN NEARLY PARALLEL ORIENTATION OF ACTIVITY
   RELATIVE TO AMBIENT MEAN FLOW...TRAINING OF CORES IS LIKELY TO
   FURTHER AUGMENT HEAVY RAIN HAZARD.  ALTHOUGH 73 F DEW POINT AT SFC
   STATION IER IS BOGUS...GPS SENSOR DATA AND NEAR-TERM FCST SOUNDINGS
   AHEAD OF FRONT INDICATE FAVORABLY RICH MOISTURE WITH NARROW ZONE OF
   PW 1.4-1.7 INCH THROUGH NEARLY SATURATED DEEP-LAYER
   PROFILE...PORTENDING EFFICIENT PRECIP PROCESSES IN MOST INTENSE
   CONVECTION.  HEAVIEST RAIN SHOULD REMAIN S OF FREEZING LINE ACROSS
   PORTIONS OZARKS.  ADDITIONAL DETAILS ON FREEZING/FROZEN PRECIP
   POTENTIAL FARTHER N WILL BE DISCUSSED IN UPCOMING SPC WINTER WEATHER
   MESOSCALE DISCUSSIONS.
   
   WARM SECTOR VERTICAL SHEAR PROFILES ALSO ARE FAVORABLE FOR SOME SVR
   POTENTIAL WITH 0-1 KM SRH AROUND 200 J/KG...AND WEAK SBCAPES OF
   200-300 J/KG.  BRIEF TORNADO OR DAMAGING GUST CANNOT BE RULED OUT. 
   HOWEVER...LACK OF MORE ROBUST BUOYANCY AND OF DISCRETE CONVECTIVE
   MODE SHOULD KEEP THIS THREAT MRGL AT MOST.
   
   ..EDWARDS.. 01/13/2007
   
   
   ATTN...WFO...MEG...JAN...LZK...SHV...
   
   32999409 33439346 34499237 34799096 34139083 33769120
   32389241 31929448