MESOSCALE DISCUSSION 0091
   NWS STORM PREDICTION CENTER NORMAN OK
   0427 AM CST WED JAN 30 2013
   
   AREAS AFFECTED...SOUTH CENTRAL-SERN LA...SERN MS AND PART OF SWRN AL
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 301027Z - 301200Z
   
   PROBABILITY OF WATCH ISSUANCE...60 PERCENT
   
   SUMMARY...POTENTIAL EXISTS FOR AN INCREASING SEVERE WEATHER THREAT
   ACROSS SOUTH CENTRAL AND SERN LA INCLUDING THE BATON ROUGE AND NEW
   ORLEANS METRO AREAS.  A TORNADO WATCH MAY BE NEEDED EARLY THIS
   MORNING...AND TRENDS WILL CONTINUE TO BE MONITORED FOR THIS THREAT.
   
   DISCUSSION...SINCE 09Z...REGIONAL RADAR IMAGERY INDICATED A
   CONSOLIDATING LINE OF TSTMS...WITH THIS ACTIVITY EXTENDING FROM SWRN
   MS SWWD THROUGH SOUTH CENTRAL LA TO OFFSHORE INTO THE NWRN GULF. 
   ANOTHER INDICATION OF THIS INTENSIFYING LINE HAS BEEN AN INCREASE IN
   LIGHTNING ACROSS THIS SAME AREA...ALSO SINCE 09Z.  THIS MARKED
   INCREASE IN TSTMS IS LIKELY IN RESPONSE TO THE SRN EXTENT OF STRONG
   HEIGHT FALLS/FORCING ADVANCING EWD INTO THE LOWER MS VALLEY WHERE
   THE AIR MASS IS QUITE MOIST /SURFACE DEWPOINTS AROUND 70 F AND THE
   06Z SLIDELL SOUNDING INDICATING PW VALUES AROUND 1.5 INCHES/. 
   EFFECTIVE BULK SHEAR STRENGTHENING FROM W-E WITH VALUES AOA 50 KT
   ORIENTED NEARLY PARALLEL TO THE LINE WILL MAIN THE LINEAR STRUCTURE
   THIS MORNING.  A CONTINUED INCREASE IN SLY LOW LEVEL WINDS WILL
   FURTHER ENHANCE LOW LEVEL SHEAR /EFFECTIVE SRH OF 200-400 M2/S2 PER
   OBJECTIVE ANALYSES/ AS THE FAVORABLE THERMODYNAMIC AND KINEMATIC
   ENVIRONMENT SPREADS EWD.
   
   ..PETERS/MEAD.. 01/30/2013
   
   
   ATTN...WFO...MOB...JAN...LIX...LCH...
   
   LAT...LON   29449224 31329092 31418913 31438843 31408789 30448809
               29498858 28888910 28839000 28899084 29019134 29449224