000 FLUS74 KOUN 162341 CCA AWUOUN AREA WEATHER UPDATE NATIONAL WEATHER SERVICE NORMAN OK 641 PM CDT THU JUN 16 2005 ...WARNING DECISION UPDATE... ..THIS WARNING DECISION UPDATE CONCERNS NORTHWEST OKLAHOMA... TWO CLOSELY-SPACED INTENSE SUPERCELL STORMS LOCATED TO THE NORTHWEST OF BUFFALO AND ROSSTON IN FAR NORTHWEST OKLAHOMA CONTINUE TO EXHIBIT LARGE AND DEEP CORES WITH EXCELLENT VOLUMETRIC Z/V STRUCTURES. GIVEN EXTREME INSTABILITY AND INCREASING DEEP LAYER SHEAR... EXPECT GIANT HAIL THREAT TO PERSIST FOR AT LEAST ANOTHER HOUR OR TWO. STORM TO MOVE INTO WESTERN HARPER COUNTY MAY POSE A RISK OF BASEBALL TO SOFTBALL SIZE HAIL. STORMS HAVE ALSO REMAINED NEARLY STATIONARY OVER NORTHERN HARPER COUNTY FOR OVER AN HOUR... AND FLASH FLOOD THREAT WILL PERSIST THIS AREA. TWO RIGHT MOVING SUPERCELLS HAVE ALSO SHOWN A TENDENCY TO ACCELERATE A SOUTHEASTWARD MOVEMENT OVER THE PAST 30 MINUTES... PERHAPS SUGGESTING THAT STORM-SCALE COLD POOL PRODUCTION MAY BE BEGINNING TO DRIVE UPDRAFT PROPAGATION. ALTHOUGH SUPERCELLS ALONG THE WARM FRONTAL BOUNDARY THAT LIES FROM SOUTHWEST KANSAS INTO CENTRAL OKLAHOMA MAY POSE A MINIMAL SPIN-UP TYPE TORNADO RISK THROUGH ABOUT 8 PM... THE OVERALL TORNADO THREAT IS EXPECTED TO REMAIN VERY LIMITED BY VERY WEAK SURFACE TO 1 KM AGL SHEAR AND RATHER LARGE TEMPERATURE/DEWPOINT SPREADS IN THE INFLOW AIR SOURCE REGION. OF MUCH GREATER CONCERN IS THE POTENTIAL FOR UPSCALE COLD POOL GROWTH AND SEVERE FORWARD PROPAGATING MCS DEVELOPMENT WITH EMBEDDED SUPERCELLS ACCOMPANIED BY VERY LARGE HAIL AND POTENTIAL FOR DESTRUCTIVE AND WIDESPREAD NON-TORNADIC WINDS THROUGH 9-10 PM. $$ MILLER NOTE: THIS PRODUCT IS MEANT TO INCREASE INFORMATION EXCHANGE ON THE STORM SCALE. TERMS DEFINED: Z = REFLECTIVITY V = VELOCITY (GROUND- OR STORM-RELATIVE) VOLUMETRIC Z = REFLECTIVITY AT LOW, MID AND HIGH LEVELS VIL = VERTICALLY INTEGRATED LIQUID TDA = ALGORITHM TO DETECT STRONG CYCLONIC SHEAR POSH = PROBABILITY OF SEVERE HAIL ALGORITHM SCIT = STORM CELL IDENTIFICATION AND TRACKING TBS = THREE-BODY SCATTER = REFLECTIVITY FLARE SIGNATURE FROM HAIL AP = ANOMALOUS PROPAGATION MESO = MESOCYCLONE RFD = REAR FLANK DOWNDRAFT BWER = BOUNDED WEAK ECHO REGION MT = MAX STORM TOP TVS = TORNADIC VORTEX SIGNATURE LP = LOW PRECIPITATION SUPERCELL HP = HIGH PRECIPITATION SUPERCELL GIANT HAIL = HAIL 2 INCHES OR GREATER RDA = WSR-88D RADAR SITE VCP = VOLUME COVERAGE PATTERN OF WSR-88D TDWR = TERMINAL DOPPLER RADAR (LOCATED IN NORTHWEST NORMAN) POLARIMETRIC RADAR/DUAL POL=SEE: WWW.NSSL.NOAA.GOV/~SCHUUR/RADAR.HTML ZDR = DIFFERENTIAL REFLECTIVITY KDP = DIFFERENTIAL PHASE HCA = POLARIMETRIC HYDROMETEOR CLASSIFICATION ALGORITHM $$