Graphic for MPD #0696

MESOSCALE PRECIPITATION DISCUSSION 0696
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
907 AM EDT TUE AUG 15 2017

AREAS AFFECTED...N ARKANSAS...NW MISSISSIPPI...W TENNESSEE

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

VALID 151306Z - 151706Z

SUMMARY...HEAVY RAIN WITH EMBEDDED THUNDERSTORMS ASSOCIATED WITH A
VERY SLOW MOVING MCS IS FORECAST TO PERSIST OVER NORTHERN ARKANSAS
AND PARTS OF ADJACENT STATES OVER THE NEXT FEW HOURS.  FLASH
FLOODING REMAINS POSSIBLE OVER THIS REGION AS A RESULT.

DISCUSSION...RADAR IMAGERY CONTINUES TO INDICATE WIDESPREAD
MODERATE TO HEAVY RAIN ALONG WITH NUMEROUS THUNDERSTORMS OVER THE
NORTHERN HALF OF ARKANSAS THIS MORNING. GOES IR SATELLITE IMAGERY
INDICATES A COLD ANVIL CANOPY WITH RADAR ECHO TOPS OVER 45KFT. 
THE CONVECTION IS GENERALLY FORMING WITHIN A BROAD WARM ADVECTION
PATTERN WITH SOUTHWEST LOW TO MID LEVEL FLOW OUT AHEAD OF A
SHORTWAVE TROUGH ADVANCING EAST FROM THE SOUTHERN PLAINS INTO THE
LOWER MS VALLEY. A LOW LEVEL SOUTHWESTERLY JET OF 20 TO 30 KTS IS
ADVECTING DEEP MOISTURE TOWARDS A STATIONARY FRONT OVER NORTHERN
ARKANSAS. PWS ARE ON THE ORDER OF 2 TO 2.25 INCHES, AND THE
CONVECTION HAS BEEN TENDING TO FOCUS ALONG A MODEST INSTABILITY
GRADIENT WITH 500-1000 J/KG OF MLCAPE NOTED OVER CENTRAL ARKANSAS
FROM THE LATEST SPC MESOANALYSIS.

THE LATEST SUITE OF HI-RES MODEL GUIDANCE, INCLUDING THE HRRR AND
ITS EXPERIMENTAL VERSION, ARE IN EXCELLENT AGREEMENT THAT AN AXIS
OF HEAVY RAINFALL WILL CONTINUE OVER THE HIGHLIGHTED REGION
THROUGH 17Z.  ISOLATED TOTALS OF 2 TO 4 INCHES OF ADDITIONAL
RAINFALL ARE INDICATED BY MULTIPLE GUIDANCE SOURCES FROM 13Z TO
17Z. GIVEN THE HEAVY RAINFALL EARLIER THIS MORNING AND THE LOCALLY
REDUCED FLASH FLOOD GUIDANCE VALUES, THE POTENTIAL FOR FLASH
FLOODING REMAINS POSSIBLE THROUGH THE LATE MORNING HOURS.

HAMRICK

ATTN...WFO...LZK...MEG...PAH...SGF...TSA...

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

LAT...LON   36539096 36518918 36218843 35438852 34678887
            34338958 34259062 34219235 34269339 34649409
            35579437 36489393


Last Updated: 907 AM EDT TUE AUG 15 2017