SPC Mesoscale Discussion 1893 on 14 October 2014

Multi-day, Potentially Catastrophic Heavy Rainfall and Severe Weather Event

A multi-day, potentially historic heavy rainfall event may produce catastrophic and life-threatening flooding through Saturday from the Ozarks into the Ohio River Valley. Several clusters of strong to severe storms are expected from the Southern Plains, Mid Mississippi Valley to the Ohio/Tennessee Valleys and the Mid Atlantic. Read More >

MESOSCALE DISCUSSION 1893 NWS STORM PREDICTION CENTER NORMAN OK 1231 PM CDT TUE OCT 14 2014 AREAS AFFECTED...WRN INTO NRN GA...WRN SC AND WRN NC CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 141731Z - 142000Z PROBABILITY OF WATCH ISSUANCE...40 PERCENT SUMMARY...WE ARE MONITORING FOR ANY INCREASE IN STORM INTENSITY FOR CONDITIONAL THREAT OF A TORNADO OR DAMAGING WIND GUSTS. DISCUSSION...SURFACE MAP AND SATELLITE SHOW A COLD FRONT ADVANCING EWD ACROSS WRN GA INTO ERN TN/KY WITH A LARGE ZONE OF MAINLY STRATIFORM PRECIPITATION AHEAD ACROSS CNTRL GA INTO THE WRN CAROLINAS. SHEAR PROFILES ARE VERY STRONG ACROSS THE AREA WITH 0-1 KM SRH OVER 250 M2/S2 NEAR ATLANTA AND FAVORABLE DEEP-LAYER SHEAR BENEATH THE UPPER JET. REFLECTIVITY VALUES HAVE INCREASED ALONG THE FRONT ACROSS WRN GA RECENTLY WHERE FORCING FOR ASCENT IS STRONGEST. THE LIMITING FACTOR FOR SEVERE WEATHER CONTINUES TO BE INSTABILITY...WHICH IS MINIMAL GIVEN LACK OF APPRECIABLE COOLING ALOFT AND MINIMAL HEATING. POCKETS OF HEATING DO EXIST FARTHER N ACROSS WRN NC WITH TEMPERATURES NOW ABOVE 80 F. WITH TIME...THIS AREA OF FORCING MAY EVENTUALLY INTERACT WITH SLIGHTLY MORE UNSTABLE AIR FROM NRN GA INTO WRN NC...POSSIBLY PROVING SUFFICIENT FOR A ZONE OF TORNADO OR DAMAGING WIND POTENTIAL. MESOSCALE TRENDS WILL CONTINUE TO BE MONITORED CLOSELY FOR A POSSIBLE WATCH. ..JEWELL/CORFIDI.. 10/14/2014