MESOSCALE PRECIPITATION DISCUSSION 0070
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1144 AM EST THU MAR 10 2016
 
AREAS AFFECTED...LA/MS...EASTERN AR...SOUTHEAST MO...WESTERN TN/KY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 101644Z - 102031Z
 
SUMMARY...FLOODING CONTINUES ACROSS THE AREA...

DISCUSSION...THE HEAVY RAINFALL SETUP ACROSS THE AREA CONTINUES TO
EVOLVE...WITH A CONVECTIVE LINE BEGINNING TO ORGANIZE ACROSS FAR
WESTERN MS. HEAVIEST RAINFALL CONTINUES TO BE ALONG AND SOUTH/EAST
OF A NEARLY STATIONARY BOUNDARY STRETCHING FROM WESTERN TN
SOUTHWEST INTO LA. AS CONVECTION MOVES NORTH OF THIS BOUNDARY IT
LOSES LOW LEVEL INFLOW AND INSTABILITY...RESULTING IN RAINFALL
RATES DIMINISHING...GENERALLY LESS THAN 0.5" AN HOUR. THESE LOWER
RATES SHOULD CONTINUE THE NEXT SEVERAL HOURS ACROSS NORTHERN LA
AND PORTIONS OF AR. GIVEN THE SATURATED GROUND...EVEN THESE LOWER
RATES WILL LIKELY ALLOW FLOODING TO CONTINUE.

FOCUS FOR THE HEAVIEST ADDITIONAL RAINFALL REMAINS ALONG AND
SOUTH/EAST OF THIS BOUNDARY. HOWEVER HOW THIS BOUNDARY EVOLVES AND
THUS WHERE THE HEAVIEST RAINFALL OCCURS IS A BIT TRICKY. AS THE
CONVECTIVE LINE IS BECOMING MORE ORGANIZED IT IS BEGINNING TO
PROPAGATE OFF TO THE NORTHEAST ALONG FORWARD PROPAGATING CORFIDI
VECTORS. THIS CONVECTIVE LINE WILL PUSH THE EFFECTIVE BOUNDARY
EAST WITH IT. THUS THINK THE 14Z HRRR IS PROBABLY TOO FAR
NORTHWEST WITH THE HEAVIER AMOUNTS ACROSS EASTERN AR...FAR
NORTHWEST MS AND FAR SOUTHWEST TN. INSTEAD THE EASTWARD
PROPAGATING CONVECTIVE LINE APPEARS TO BE FOCUSING THE HEAVIEST
RAINFALL AXIS SLIGHTLY SOUTHEAST OF THIS. THUS A SLIGHTLY
SOUTHEAST SHIFTED HRRR...OR SOMETHING CLOSE TO THE 12Z GEM
REGIONAL...APPEARS TO BE A GOOD STARTING POINT FOR QPF OVER THE
NEXT 6 HOURS OR SO.

THE FORWARD PROPAGATION OF THE LINE SHOULD KEEP ADDITIONAL TOTALS
FROM GETTING TOO EXTREME...BUT 3 HOURLY AMOUNTS OF 2-3" STILL SEEM
POSSIBLE ALONG THIS ENHANCED CONVECTIVE AREA. ACROSS FAR WESTERN
MS AND SOUTHWEST TN WHERE IT HAS ALREADY RAINED QUITE A BIT...THIS
WILL EXACERBATE THE FLOODING ISSUES. TOWARDS CENTRAL MS AND
SOUTHEAST LA WHERE FFG IS HIGHER...STILL MAY SEE AT LEAST ISOLATED
FLASH FLOODING DEVELOP OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE
QUICKER FORWARD PROGRESSION OF THE HIGHER RATES MAKES THE SETUP
MORE MARGINAL ACROSS MS. 

CHENARD

ATTN...WFO...JAN...LCH...LIX...LMK...LZK...MEG...OHX...PAH...
SHV...

ATTN...RFC...ABRFC...LMRFC...OHRFC...SERFC...WGRFC...

LAT...LON   37448758 36878681 34158893 33768914 33118926 
            32568940 31968945 31348978 30669058 30189135 
            29459174 29419242 29589306 30089372 31439401 
            31559420 32049375 33479248 34889192 36708997