MESOSCALE PRECIPITATION DISCUSSION 0262
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
225 PM EDT SUN MAY 29 2016
 
AREAS AFFECTED...EASTERN GA/SC 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 291824Z - 300024Z
 
SUMMARY...INSTABILITY ACROSS EASTERN SC/NC CONTINUES TO LEAD TO
HEAVY RAIN NEAR AND WEST OF BONNIE'S CENTER.  HOURLY RAIN RATES UP
TO 2.5" COULD LEAD TO FLASH FLOODING.

DISCUSSION...OCCASIONAL HEAVY RAIN CORES CONTINUE TO PULSE NEAR
AND WEST OF BONNIE'S CENTER, WHICH MEANDERED WESTWARD THROUGH 1
PM/17Z AROUND THE NORTHEAST SIDE OF AN UPPER LEVEL CIRCULATION IN
SOUTHEAST GA AND A LOW-LEVEL VORTICITY MAXIMUM WHICH HAS SWEPT
OFFSHORE THE GA COAST.  THERE ARE INDICATIONS THAT THE CENTER MAY
HAVE DRIFTED BACK TO THE EAST IN THE 2 PM/18Z SURFACE OBSERVATIONS
FROM SC. THE VERTICAL WIND SHEAR OVER THE SYSTEM APPEARS TO BE
DISRUPTING THE USUAL DIURNAL CYCLE AND ALLOWING AFTERNOON
CONVECTION NEAR THE CENTER.  SPC MESOANALYSES CONTINUE TO INDICATE
CIN NEAR AND WEST OF THE CENTER, WHICH IS ALLOWING THE 1000-3000
J/KG MUCAPE IN NORTHEAST SC AND SOUTHERN NC TO ADVECT IN AND SPARK
NEW CONVECTION.  PRECIPITABLE WATER VALUES ARE BETWEEN 1.6-1.9"
PER GPS VALUES AND RAP MASS FIELDS.  LOW-LEVEL INFLOW CONTINUES TO
BE CYCLONIC AT 20-35 KTS PER VAD WIND PROFILES.

THE 06Z SSEO NEIGHBORHOOD PROBABILITIES OF EXCEEDING THE THREE
HOUR FLASH FLOOD GUIDANCE SHOW A SPIKE IN HEAVY RAINFALL ACROSS
PORTIONS OF SC THROUGH 00Z.  THE 12Z MESOSCALE/CAM GUIDANCE SHOWS
POCKETS OF 2-4" OF RAINFALL OVER THE NEXT SEVERAL HOURS, WHICH
COULD FALL QUICKLY.  THE AVAILABLE MOISTURE AND INSTABILITY COULD
ALLOW FOR HOURLY RAIN RATES UP TO 2.5".  OVERALL MOTION OF THE
SYSTEM COULD CONTINUE TO BE ERRATIC THIS AFTERNOON AND EVENING,
PRESUMABLY TO THE NORTH OR NORTHEAST EVENTUALLY.  CONSIDERING THAT
5-9" OF RAIN WHICH HAS ALREADY FALLEN ACROSS EXTREME EASTERN GA
AND SOUTHERN SC PER RADAR ESTIMATES AND COCORAHS OBSERVATIONS,
FLASH FLOODING REMAINS POSSIBLE DUE TO SATURATED SOILS.  DUE TO
THE UNCERTAINTY CAUSED BY DISPERSION IN THE MESOSCALE GUIDANCE AND
BONNIE'S ERRATIC MOTION TODAY, CHOSE THE POSSIBLE OVER THE LIKELY
CATEGORY.

ROTH

ATTN...WFO...CAE...CHS...ILM...

ATTN...RFC...SERFC...

LAT...LON   34088098 33817985 32827968 32228053 31918109 
            32678161 33468158