MESOSCALE PRECIPITATION DISCUSSION 0508
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
854 PM EDT TUE JUL 18 2017

AREAS AFFECTED...CENTRAL/SOUTHERN NC...CENTRAL/NORTHERN SC

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 190052Z - 190430Z

SUMMARY...A PERSISTENT BAND OF THUNDERSTORMS WILL CONTINUE TO
GRADUALLY DROP SOUTHWARD WITH INTENSE RAINFALL RATES. SOME
ADDITIONAL FLASH FLOODING IS POSSIBLE.

DISCUSSION...A RELATIVELY COMPACT UPPER LOW OVER THE SOUTHERN
MID-ATLANTIC REGION CONTINUES TO WORK OFF DIURNALLY ENHANCED
BOUNDARY LAYER INSTABILITY AND A RELATIVELY MOIST ENVIRONMENT FOR
CLUSTERS OF STRONG THUNDERSTORMS WHICH ARE PRODUCING RAINFALL
RATES OF AS MUCH AS 2 TO 2.5 INCHES/HR.

EXPERIMENTAL GOES-16 10.3 MICRON/IR SATELLITE DATA HAS SHOWN SOME
ADDITIONAL COOLING OF CONVECTIVE TOPS OVER THE LAST 30 MINUTES IN
VICINITY OF MECKLENBURG AND UNION COUNTIES OF SOUTHERN NC NOT FAR
FROM CHARLOTTE...AND ALSO DOWN INTO FAR NORTHEAST SC INVOLVING
CHESTERFIELD COUNTY.

THESE THUNDERSTORMS ARE BEING DYNAMICALLY SUPPORTED BY THE DPVA OF
THE UPPER LOW AND ALSO RELATIVELY STEEP MID LEVEL LAPSE RATES AND
SHOULD TEND TO PERSIST A FEW MORE HOURS WHILE SHIFTING GRADUALLY
SOUTHWARD INTO NORTHERN/CENTRAL SC.

EXPECT AS MUCH AS 3 TO 4 INCHES OF RAIN WITH ISOLATED 5 INCH
AMOUNTS NOT OUT OF THE QUESTION. THE ACTIVITY SHOULD WEAKEN LATE
IN THE EVENING AS INSTABILITY IS EXHAUSTED...BUT THESE TOTALS MAY
RESULT IN SOME ADDITIONAL FLASH FLOODING CONCERNS.

ORRISON

ATTN...WFO...CAE...CHS...GSP...ILM...RAH...RNK...

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

LAT...LON   36547918 36177835 35277831 33897904 33178001
            33108087 33678152 34478161 35348102 36138016