Posted by JAC on 4/25/2009, 10:34 pm, in reply to "OK Under the Gun Today"

MESOSCALE DISCUSSION 0571 NWS STORM PREDICTION CENTER NORMAN OK 0923 PM CDT SAT APR 25 2009 AREAS AFFECTED...NRN MO...SERN IA...W CNTRL AND NWRN IL CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 260223Z - 260330Z THUNDERSTORMS DISPLAYING HP SUPERCELL STRUCTURE HAVE RECENTLY INTENSIFIED OVER WRN PORTIONS OF WW 184 ...POSSIBLY IN RESPONSE TO STRENGTHENING LLJ INTERACTING WITH NEARLY STATIONARY FRONT LOCATED FROM NERN KS TOWARD NRN IL. ANOTHER CLUSTER OF STORMS MOVING E THROUGH NERN MO/SERN IA IS BEGINNING TO SHOW SIGNS OF INCREASING ORGANIZATION...WITH CELLS CONSOLIDATING INTO A LINE. THIS CONVECTIVE SYSTEM MAY CONTINUE TO EVOLVE INTO A BOW ECHO AS IT ENCOUNTERS A SLIGHTLY MORE UNSTABLE AIRMASS OVER IL. THE PRIMARY UNCERTAINTY REGARDING SVR POTENTIAL FROM NWRN MO INTO IL IS INCREASING CAPPING INVERSION/CINH. LOW LVL SHEAR IS QUITE STRONG ACROSS THE REGION...WITH AREA VWP/S DISPLAYING LARGE LOOPING STRUCTURES. THIS SHEAR ENVIRONMENT...COMBINED WITH MESOSCALE FORCING AND INFLUX OF MOISTURE ASSOCIATED WITH LLJ MAY CONTINUE TO FAVOR SEVERE STORM DEVELOPMENT ALONG SW-NE BOUNDARY. THUS...A LOCAL EXTENSION OF WW 184 MAY BE REQUIRED...OR A REPLACEMENT WATCH MAY BE ISSUED BY 03Z. ..GARNER.. 04/26/2009