MESOSCALE PRECIPITATION DISCUSSION 0712
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
341 AM EDT THU SEP 29 2016
 
AREAS AFFECTED...SOUTHERN NC 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 290740Z - 291200Z
 
SUMMARY...ADDITIONAL HEAVY RAINS ARE EXPECTED OVER THE NEXT FEW
HOURS WITH ADDITIONAL FLASH FLOODING POSSIBLE.

DISCUSSION...A VERY PERSISTENT AND SLOW-MOVING CLUSTER OF
THUNDERSTORMS OVER SOUTHERN NC CONTINUES TO PRODUCE VERY HEAVY
RAINFALL AND IS LIKELY TO PERSIST THROUGH DAWN GIVEN THE PLACEMENT
OF THE CONVECTION WITHIN THE INSTABILITY GRADIENT OVER THE REGION
AND PERSISTENT SOUTHERLY INFLOW. THE FLOW ALOFT OVER THE REGION IS
RATHER DIFFLUENT WHICH IS FOSTERING SOME PERSISTENT LARGE SCALE
ASCENT OVER THE REGION AND THIS IS COURTESY OF THE STRONG UPPER
LOW DROPPING SOUTH OVER THE OH VALLEY.

THE HIGH PWAT ENVIRONMENT OF OVER 1.75 INCHES CONTINUES TO FAVOR
HIGH RAINFALL RATES THAT WITH THE AID OF PERSISTENT INSTABILITY
AND FORCING ALOFT MAY STILL REACH OVER 2 INCHES/HR FOR A COUPLE
MORE HOURS.

THE HIRES GUIDANCE INCLUDING THE HRRR AND HRRR-EXPERIMENTAL
SUGGEST ADDITIONAL AMOUNTS OF AS MUCH AS 2 TO 4 INCHES THROUGH
12Z. THIS WILL CONTINUE TO ENHANCE THE THREAT FOR RUNOFF AND FLASH
FLOODING THROUGH DAWN AS A RESULT. IT IS EXPECTED THAT CONDITIONS
WILL IMPROVE BEYOND THE 12Z TIME FRAME.

ORRISON 

ATTN...WFO...ILM...MHX...RAH...

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

LAT...LON   35617766 35237734 34847761 34577818 34377877 
            34447927 34857958 35257933 35527865