Posted by JAC on 4/27/2009, 1:57 pm, in reply to "East OK could fire up early afternoon"

MESOSCALE DISCUSSION 0601 NWS STORM PREDICTION CENTER NORMAN OK 1232 PM CDT MON APR 27 2009 AREAS AFFECTED...NERN OK/SERN KS/SWRN MO/NWRN AR CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 271732Z - 271900Z CONVECTION HAS BEGUN TO INTENSIFY AHEAD OF THE ADVANCING COLD FRONT. WW MAY BE REQUIRED TO COVER THE SLOWLY-INCREASING SEVERE/TORNADO THREAT. LATEST SURFACE ANALYSIS SHOWS A WEAK SURFACE WAVE OVER N CENTRAL OK...ALONG A COLD FRONT MOVING SEWD ACROSS SERN KS AND EWD ACROSS THE WRN HALF OF OK. AHEAD OF THE BOUNDARY...LIMITED HEATING HAS CONTRIBUTED TO SOME DESTABILIZATION...WITH MIXED-LAYER CAPE NOW 500 TO 1500 J/KG ACROSS NERN OK AND VICINITY. IN ADDITION...17Z SGF /SPRINGFIELD MO/ RAOB SHOWS THAT CAP HAS ERODED...AND WITH AMPLE LOW-LEVEL VEERING AND DEEP-LAYER SHEAR NEAR 40 KT...THE OVERALL ENVIRONMENT HAS BECOME MORE SUPPORTIVE OF SEVERE/SUPERCELL STORMS. THOUGH CLOUDS SPREADING NWD FROM CONVECTION OVER TX/SERN OK/WRN AR MAY LIMIT FURTHER DESTABILIZATION...IT APPEARS ATTM THAT WW MAY BE NEEDED. ..GOSS.. 04/27/2009