Graphic for MPD #0377
 
MESOSCALE PRECIPITATION DISCUSSION 0377
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1205 PM EDT THU JUL 23 2015
 
AREAS AFFECTED...CENTRAL AND SOUTHEAST NC 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 231605Z - 232105Z
 
SUMMARY...VERY INTENSE SHOWERS AND THUNDERSTORMS WILL EXPAND IN
COVERAGE THROUGH THE MID-AFTERNOON HOURS. SLOW
MOVEMENT...CELL-MERGERS AND BACKBUILDING OF CELLS WILL FOSTER SOME
FLASH FLOOD POTENTIAL GIVEN THE EXPECTED HIGH RAINFALL RATES.

DISCUSSION...AN AREA OF LOW PRESSURE FOCUSED ALONG A WAVY
STATIONARY FRONT IS MOVING GRADUALLY INTO SOUTHERN NC BASED ON
LATEST SURFACE OBSERVATIONS. MEANWHILE...CONVECTION HAS BEEN
GRADUALLY INCREASING JUST AHEAD OF THE LOW CENTER OVER EASTERN NC
AND GENERALLY ALONG THE NORTH SIDE OF THE FRONTAL ZONE. THE
CONVECTION IS ENHANCING WITH AN UPTICK IN LOW LEVEL
FORCING/MOISTURE CONVERGENCE COUPLED WITH STRONG DIURNAL HEATING
WHICH IS HELPING TO FOCUS A MARKED INCREASE IN SURFACE-BASED
INSTABILITY. 

THE LATEST GOES-SOUNDER/GPS-DERIVED PWATS ARE 1.75 TO 2
INCHES...WITH SOUNDER DRIVEN LI/S NOW AS LOW -5 TO -7 JUST AHEAD
OF THE SURFACE WAVE. CONVECTION OVER THE NEXT FEW HOURS SHOULD
CONTINUE TO INCREASE AND EXPAND IN COVERAGE AS STRONGER MOISTURE
CONVERGENCE AND INSTABILITY FOCUSES OVER EASTERN NC. SOME MODEST
UPPER LEVEL FORCING ASCENT IS EXPECTED TO AS WEAK VORT ENERGY
ADVANCES EAST ACROSS THE REGION AS DENOTED SUBTLY IN THE GOES-RGB
AIRMASS IMAGERY.

THE 00Z ARW/00Z NMMB AND CONSECUTIVE RUNS OF THE HRRR SUGGEST SOME
VERY IMPRESSIVE RAINFALL POTENTIAL THIS AFTERNOON WITH FOCUSED
AMOUNTS OF 3 TO 6 INCHES...AND LOCALLY HEAVIER AMOUNTS AS HIGH AS
8 INCHES. WHILE FFG VALUES ARE HIGH ACROSS THE REGION...THE
RAINFALL RATES POTENTIAL IS VERY HIGH AND MAY LOCALLY EXCEED 3
INCHES/HR. THE ENVIRONMENT IS CONDUCIVE FOR CELL-MERGERS AND
BACKBUILDING WHICH WILL ONLY ENHANCE THE RAINFALL RATE POTENTIAL.
THEREFORE...EXPECT SOME FLASH FLOODING AND RUNOFF PROBLEM CONCERNS
THROUGH THE AFTERNOON.

ORRISON

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

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

LAT...LON   35917760 35617683 35137636 34757646 34657664 
            34417734 34057782 33977828 34077858 34607917 
            35077927 35467928 35897865 


Last Updated: 1205 PM EDT THU JUL 23 2015