MESOSCALE DISCUSSION 0680
   NWS STORM PREDICTION CENTER NORMAN OK
   1029 PM CDT MON APR 21 2008
   
   AREAS AFFECTED...PORTIONS CENTRAL/SRN OK
   
   CONCERNING...TORNADO WATCH 212...
   
   VALID 220329Z - 220500Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 212 CONTINUES.
   
   SFC MESOANALYSIS INDICATES QUASISTATIONARY FRONTAL ZONE FROM NEAR
   PNC SWWD TO NEAR CSM THEN WWD GENERALLY ALONG I-40 INTO TX
   PANHANDLE.  WRN OK SFC LOW IS DISSIPATING...BUT MAY REDEVELOP/BLEND
   WITH LEE-SIDE CYCLONE OVER SRN TX PANHANDLE LATER
   TONIGHT...RESULTING IN RESUMPTION OF SWD DRIFT OF FRONTAL ZONE. 
   MEANWHILE...DRYLINE CONTINUES TO RETREAT WWD ACROSS W-CENTRAL AND
   SWRN OK...WITH DEW POINTS RISING AT FSI/LTS.
   
   INITIAL PAIR OF LEFT-/RIGHT-MOVING SUPERCELLS HAS DISSIPATED  AMIDST
   STRENGTHENING SBCINH...AND IR CLOUD TRENDS INDICATE NO OTHER AREAS
   OF GROWING/DEEPENING CONVECTION ATTM.  FAVORABLE SHEAR PROFILES WILL
   CONTINUE...WITH STRENGTHENING LLJ CONTRIBUTING TO 0-1 KM SRH 150-300
   J/KG DERIVED FROM MODIFIED RUC SOUNDINGS AND VWP.  AS CAPPING
   CONTINUES TO INCREASE FOR SFC-BASED EFFECTIVE LIFTED PARCELS...SO
   DOES CONVERGENCE REQUIRED TO OVERCOME IT...WHICH WOULD REFOCUS ANY
   REMAINING DEVELOPMENT POTENTIAL WWD TOWARD FRONTAL ZONE...SFC LOW
   AND DRYLINE.  RETREATING NOCTURNAL DRYLINES WITH WEAK SFC WINDS...IN
   SITUATIONS OF DIABATICALLY STRENGTHENING SBCINH...TYPICALLY RESULT
   IN DECREASING CONVECTIVE INITIATION PROBABILITIES WITH TIME.  IF
   ADDITIONAL CONVECTION DOES NOT DEVELOP WITHIN ANOTHER 1-2
   HOURS...PORTIONS WW MAY BE CANCELED.
   
   ..EDWARDS.. 04/22/2008
   
   
   ATTN...WFO...TSA...OUN...
   
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