MESOSCALE DISCUSSION 0625
   NWS STORM PREDICTION CENTER NORMAN OK
   0552 PM CDT TUE APR 29 2003
   
   AREAS AFFECTED...PORTIONS NRN KS AND EXTREME SRN NEB
   
   CONCERNING...TORNADO WATCH 181...
   
   VALID 292252Z - 292345Z
   
   CAP APPEARS CLOSE TO BREAKING OVER PORTIONS HLC-MCK-HDE TRIANGLE.
   SFC MESOANALYSIS AND CLUSTERED CUMULI ON VIS IMAGERY INDICATE STRONG
   FRONTAL ZONE ALONG GLD-HLC-CNK-MCI LINE...WHICH SHOULD DRIFT NWD TO
   WITHIN 30-50 NM OF NEB BORDER BY 02Z GIVEN INCREASING ISALLOBARIC
   FORCING ACROSS REGION ASSOCIATED WITH DEEPENING LEE-SIDE CYCLONE NOW
   ANALYZED BETWEEN LHX-LIC.  AIR MASS REMAINS CAPPED BASED ON VIS
   IMAGERY...WITH DEEPEST CUMULIFORM TOWERS INDICATED JUST N OF SFC
   WARM FRONT OVER PORTIONS NERN PHILLIPS/SRN HARLAN COUNTIES ALONG
   KS/NEB BORDER...NWD TO NEAR HDE...WHERE APPARENTLY STRONG HCR IS
   MOVING OVER FRONTAL SFC.  THIS APPEARS ATTM TO BE MOST PROBABLE ZONE
   FOR STORM INITIATION NEXT 1-2 HOURS.  OTHER DEEP CU ARE INDICATED
   FARTHER W ALONG SFC FRONT NRN PORTIONS GRAHAM/SHERIDAN/ROOKS
   COUNTIES.  
   
   MODIFIED RAOBS AND RUC SOUNDINGS SHOW ONLY 1-2 DEG C CAP STRENGTH
   AND CINH AOB 50 J/KG...MLCAPE 1500-2000 J/KG...ALONG WARM FRONT FROM
   THERE EWD TOWARD CNK.  STRONG MIXING AND INVERTED-V PROFILES IN
   BOUNDARY LAYER -- WITH DCAPE 1000 J/KG AND ESTIMATED DOWNDRAFT TEMP
   IN MID 50S F...EACH SUGGEST RELATIVELY RAPID TRANSITION TO
   OUTFLOW-LADEN HP STRUCTURES WITH ANY STORMS WHICH DO DEVELOP...AND
   TORNADIC POTENTIAL CONFINED TO RELATIVELY BRIEF WINDOW DURING EARLY
   MATURE STAGE OF SUPERCELL.  MOISTURE FLUX AND KINEMATIC MASS
   CONVERGENCE ARE EACH MAXIMIZED ALONG WARM FRONT BETWEEN HLC-SLN. 
   GREATEST LOW LEVEL SHEAR WHERE THERE ARE NEAR SFC-BASED PARCELS IS 
   BETWEEN WARM FRONT AND KS/NEB BORDER NEAR AND 50-80 NM W CNK...WITH
   0-3 KM SRH 250-350 J/KG.
   
   ..EDWARDS.. 04/29/2003
   
   
   ATTN...WFO...OAX...TOP...ICT...GID...LBF...DDC...GLD...
   
   38930085 40390087 39989672 38509671