Graphic for MPD #0384
MESOSCALE PRECIPITATION DISCUSSION 0384
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
532 PM EDT FRI JUN 23 2017

AREAS AFFECTED...CENTRAL & EASTERN AR...EXT WESTERN TN...EXT
NORTHWEST MS

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

VALID 232130Z - 240100Z

SUMMARY...QUICK HITTING CONVECTION WITH RATES UP TO 2"/HR TO CROSS
COMPROMISED GROUND CONDITIONS AND FURTHER COMPOUND ONGOING
FLOODING CONDITIONS CAUSED BY TROPICAL CYCLONE CINDY.

DISCUSSION...MATURE MCS IS ADVANCING SE FAIRLY RAPIDLY INTO DEEP
WELL OF INSTABILITY (MLCAPE 3000+ J/KG) OVER CENTRAL AR AND AREAS
OF E AR WHERE MIDDAY CLEARING ALLOWED FOR REGENERATION OF
INSTABILITY IN WAKE OF FORMER TD CINDY.  THE MATURE MCS SHOWS
CLASSIC SIGNATURE OF LARGE BOWING SEGMENT ACROSS N CENTRAL AR THAT
SHOWS THE OUTFLOW IS RAPIDLY OUTRUNNING UPPER LEVEL/LEADING TO
HIGHLY SLANTED CONVECTION/WEAKENING THE UPDRAFTS FOR EFFICIENT
RAINFALL PRODUCTION.  THIS LINE NORTHEAST OF I-40 (WEST OF LIT)
CONWAY/FAULKNER AND NORTHEAST TO JACKSON/W POINSETT/CROSS COUNTIES
WILL LIKELY NOT BE A CONCERN FOR FLASH FLOODING DUE TO THIS
OUTFLOW.  FURTHER NORTH NEAR THE MESO-LOW IN GREENE TO CRAIGHEAD
COUNTIES ARE A BIT MORE ROBUST WITH SLOWER OUTFLOW SUPPORTING
BETTER CONVERGENCE IN ADVANCE WITH LESS SHEARED UPDRAFTS WILL BE
MUCH MORE CAPABLE OF RATES UP TO 2"/HR BASED ON RESIDUAL HIGHLY
SATURATED/EVAPORATED LOW LEVEL MOISTURE.  FFG VALUES <1.5"/3HRS IN
COUNTIES ALONG THE MISSISSIPPI RIVER FROM THE MO BOOTHEEL TO JUST
NORTH OF MEMPHIS WILL HAVE A FLASH FLOOD RISK ASSOCIATED WITH
THESE STRONGER CELLS.

ACROSS CENTRAL AR INTO SE AR LATER TONIGHT...ON THE ANTICYCLONIC
SIDE OF THE OUTFLOW JET ORIENTATION OF THE CONVECTION LINE HAS
BECOME A BIT BETTER ORIENTED TO THE MEAN CELL MOTIONS TO THE SE TO
BEGIN TO SUPPORT SOME LOCALIZED TRAINING.  GOES-E VIS LOOP ALSO
DENOTES A MINI-CYCLONIC FEATURE AT THE BOUNDARY LAYER INTERFACE
THAT WOULD SUPPORT WEAKENED NORTHERLY COMPONENTS TO THE WIND TO
HAVE STORM RELATIVE INFLOW SUPPORTING ISENTROPIC ASCENT OVER THE
WEAK SW OUTFLOW BOUNDARY FURTHER ENHANCING MST FLUX AND RAINFALL
EFFICIENCY ALONG THE TRAINING CORRIDOR FOR THE NEXT FEW
HOURS...MAINLY NEAR/ALONG I-40 WEST OF LITTLE ROCK TOWARD LITTLE
ROCK.  AS SUCH A SWATH OF 2-3" WITH POSSIBLE LOCALIZED 4" TOTALS
WOULD NEAR THE HIGHER FFG VALUES IN THE VICINITY MAKING FLASH
FLOODING POSSIBLE.  TOWARD SUNSET (00-01Z) WHEN INSTABILITY WILL
BE REDUCING FAIRLY QUICKLY WITH THE LOSS OF DAYTIME HEATING TO
MAINTAIN STRONGER UPDRAFTS.  HOWEVER CELLS WILL BE APPROACHING THE
COMPROMISED/ONGOING FLOODED REGIONS OF SE AR/NE LA AND WEAKER
THUNDERSTORMS WITH ADDITIONAL 1-1.5" TOTALS WOULD BE EFFECTIVE IN
REAGGRAVATING FLASH FLOODING.

GALLINA

ATTN...WFO...JAN...LZK...MEG...SHV...TSA...

ATTN...RFC...ABRFC...LMRFC...

LAT...LON   36389035 36048939 34568994 33159078 33129264
            34089329 34769384 35229404 35719343 34879178
            35369096 36269078


Last Updated: 532 PM EDT FRI JUN 23 2017