MESOSCALE PRECIPITATION DISCUSSION 0464
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
838 PM EDT SUN JUL 15 2018

AREAS AFFECTED...CTRL/E-CTRL AL...W-CTRL/NWRN GA

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 160037Z - 160530Z

SUMMARY...THUNDERSTORM CLUSTERS WILL LINGER INTO THE EVENING IN
CENTRAL ALABAMA AND SLOWLY DRIFT TO THE EAST OR NORTHEAST. THIS
WILL LEAD TO AREAS OF LOCALIZED HEAVY RAINFALL. RAIN RATES OF 2-3
IN/HR ARE EXPECTED WITH THE STRONGER STORMS WHICH COULD LEAD TO
AREAS OF FLASH FLOODING.

DISCUSSION...AS OF 0030Z...KBMX RADAR SHOWED CLUSTERS OF
THUNDERSTORMS FROM BIRMINGHAM AL SOUTH TO NEAR MONTGOMERY AL...AND
THEN EAST TO NEAR AUBURN AL. ADDITIONAL ISOLATED THUNDERSTORMS
WERE SITUATED ELSEWHERE ACROSS PARTS OF ALABAMA AND GEORGIA. THE
MORE CONTINUOUS ZONES OF THUNDERSTORM ACTIVITY WERE POSITIONED ON
THE SOUTHWEST PERIPHERY OF A POOL OF UNDISTURBED STRONG
INSTABILITY...WITH MLCAPE VALUES ANALYZED BY THE RAP TO BE ON THE
ORDER OF 2000-3000 J/KG. THE 00Z SOUNDINGS FROM BMX AND FFC TENDED
TO CONFIRM THIS WITH MLCAPE VALUES AROUND 2000 J/KG AND
PRECIPITABLE WATER VALUES AROUND 2 INCHES. KBMX RADAR ALSO SHOWED
A GRADUAL EASTWARD PROPAGATION TO THE CONVECTIVE CLUSTERS IN THE
I-65 CORRIDOR...AND A GRADUAL NORTHWARD PROPAGATION WITH THE
CLUSTERS IN THE I-85 CORRIDOR. SOME INTERSECTING OUTFLOWS WERE
ALSO OBSERVED JUST OUT AHEAD OF THESE THUNDERSTORM CLUSTERS...AND
THIS SHOULD ALLOW FOR CONTINUED PROPAGATION AND FURTHER CONVECTIVE
DEVELOPMENT INTO THE VERY MOIST AND UNSTABLE AIR MASS.

WITH THE SLOW STORM MOTIONS (850-300MB MEAN WIND AROUND 5 KNOTS)
AND DEEP MOISTURE AVAILABLE...VERY HEAVY RAIN RATES ARE
ANTICIPATED. KBMX RADAR DUAL POL ESTIMATES HAVE BEEN AS HIGH AS 3
IN/HR AND KEET AND KMGM SURFACE OBSERVATIONS HAVE CONFIRMED RAIN
RATES AROUND 2 IN/HR. THESE WOULD BE LIKELY TO LEAD TO AREAS OF
FLASH FLOODING...PARTICULARLY IF THEY ALIGN WITH URBAN AREAS.

LAMERS

ATTN...WFO...BMX...FFC...HUN...

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

LAT...LON   34618446 34048375 33148362 32518413 32198489
            32348570 32068656 32568708 33238702 33978714
            34508688 34558582