MESOSCALE PRECIPITATION DISCUSSION 0039
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
257 PM EST SUN JAN 22 2017
 
AREAS AFFECTED...NORTHERN AL/GA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 221956Z - 230156Z
 
SUMMARY...FLASH FLOODING IS POSSIBLE THROUGH THIS AFTERNOON AS
CONVECTION SPREADS NORTHWARD NEAR A DEVELOPING DEEP LAYER LOW.

DISCUSSION...VERY STRONG SYNOPTIC FORCING AHEAD OF THE SHORTWAVE
DIVING SOUTHEAST ACROSS THE LOWER MS VALLEY HAS RESULTED IN
CONTINUED CONVECTIVE DEVELOPMENT OVER THE SOUTHEAST. A CIRCULATION
WITHIN THE CONVECTION HAS BECOME EVIDENT ON RADAR ACROSS CENTRAL
AL NEAR THE TRIPLE POINT LOCATION. THIS CIRCULATION WILL
EVENTUALLY BECOME THE NEW SURFACE LOW AND WILL TRACK INTO NORTHERN
GA BY THIS EVENING...WITH ITS FORWARD SPEED SLOWING. SOUTHEASTERLY
LOW LEVEL FLOW CONTINUES TO ADVECT ABUNDANT MOISTURE BACK IN
TOWARDS THIS CIRCULATION...WITH SOME ELEVATED INSTABILITY AS WELL. 

THOUGHT RECENT RUNS OF THE HRRR WERE HANDLING THE EVOLUTION OF
THIS DEVELOPING LOW PRETTY WELL. CONVECTIVE INTENSITY WILL LIKELY
DECLINE AS THE LOW AND CONVECTION MOVES NORTH OF THE BETTER
INSTABILITY...BUT EMBEDDED HEAVIER CONVECTIVE ELEMENTS WILL LIKELY
CONTINUE THROUGH THE AFTERNOON HOURS ACROSS THE MPD AREA. AS THE
LOW BECOMES MORE WELL DEFINED...DEFORMATION BAND RAINFALL AND
EMBEDDED CONVECTION WILL CONTINUE AROUND THE LOW AS WELL. EXPECT
RAINFALL TOTALS TO LOCALLY APPROACH 1-2" IN AN HOUR...WITH TOTALS
OF 1-4" THROUGH 02Z ACROSS THE MPD AREA. WHILE WE ARE NOT
EXPECTING SIGNIFICANT WIDESPREAD FLASH FLOOD ISSUES...RAINFALL
RATES AND TOTALS OF THIS MAGNITUDE DO BEGIN TO APPROACH AND
LOCALLY EXCEED FLASH FLOOD GUIDANCE. THUS SOME FLASH FLOOD ISSUES
MAY DEVELOP THROUGH THE AFTERNOON HOURS.

CHENARD

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

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

LAT...LON   35018707 34988606 34798527 34388439 33298435 
            32828585 34188778 34288781 34798791