MESOSCALE DISCUSSION 0249
   NWS STORM PREDICTION CENTER NORMAN OK
   0215 PM CDT THU APR 09 2015

   AREAS AFFECTED...CNTRL/SRN AR...NE TX...FAR NW LA...EXTREME SE OK

   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

   VALID 091915Z - 092115Z

   PROBABILITY OF WATCH ISSUANCE...80 PERCENT

   SUMMARY...WHILE THERE IS SOME UNCERTAINTY AS TO WHEN SURFACE-BASED
   STORMS DEVELOP...CONFIDENCE IS THAT DEVELOPMENT WILL EVENTUALLY
   OCCUR AND POSE A SEVERE RISK ACROSS THE AREA. A SVR TSTM WATCH WILL
   LIKELY BE NEEDED TO COVER THE THREAT.

   DISCUSSION...VISIBLE SATELLITE IMAGERY CONTINUES TO SHOW A LARGE
   AREA OF AGITATED CU OVER THE REGION WITH A FEW ELEVATED TSTMS OVER
   SW AR. SURFACE OBSERVATIONS THROUGHOUT THE REGION REPORT
   TEMPERATURES IN THE UPPER 70S AND LOW 80S WITH DEWPOINTS IN THE MID
   TO UPPER 60S. BOTH THE LZK AND SHV 18Z SOUNDINGS REVEALED THAT EML
   CAPPING REMAINS IN PLACE BUT MLCINH VALUES OF -36 AND -5
   J/KG...RESPECTIVELY...SUGGEST THAT CONTINUED HEATING WILL RESULT IN
   AN EROSION OF THAT INHIBITION. GIVEN THIS INHIBITION AS WELL AS
   FAIRLY NEBULOUS FORCING FOR ASCENT...THERE IS SOME UNCERTAINTY AS TO
   WHEN SURFACE-BASED CONVECTIVE INITIATION ACTUALLY OCCURS.
   HOWEVER...CONFIDENCE IS HIGH THAT CONVECTIVE INITIATION WILL OCCUR
   WITHIN AT LEAST A PORTION OF THIS WARM SECTOR AHEAD OF THE FRONT.
   ONE POSSIBLE SCENARIO IS FOR THE ELEVATED ACTIVITY CURRENTLY OVER SW
   AR TO BECOME SURFACE-BASED AS IT TRAVELS INTO THE WARMER ENVIRONMENT
   OVER CNTRL AR. DEVELOPMENT COULD ALSO OCCUR WITHIN BANDS OF
   LOW-LEVEL CONFLUENCE IN THE WARM SECTOR. 

   ONCE DEVELOPMENT OCCURS...THE ENVIRONMENT APPEARS SUPPORTIVE OF AT
   LEAST STRONG MUTLICELLS CAPABLE OF LARGE HAIL AND DAMAGING WINDS.
   STORM PROXIMITY MAY LIMIT A TRULY DISCRETE SUPERCELL MODE BUT IT IS
   NOT OUT OF THE QUESTION AND...IF IT OCCURS...THE POTENTIAL FOR VERY
   LARGE HAIL AND A TORNADO EXISTS.

   ..MOSIER/GRAMS.. 04/09/2015


   ATTN...WFO...MEG...LZK...SHV...FWD...

   LAT...LON   34099482 35319350 35869233 35559130 34639096 33089227
               32129479 33079548 34099482