MESOSCALE PRECIPITATION DISCUSSION 0442
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1254 AM EDT SAT JUL 09 2016
AREAS AFFECTED...SOUTHEAST KS...NORTHEAST OK...SOUTHWEST
MO...NORTHERN AR
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 090455Z - 090955Z
SUMMARY...DEVELOPING CLUSTERS OF CONVECTION COULD PRODUCE HOURLY
RAINFALL RATES NEAR 2.00 INCHES...WHICH COULD RESULT IN FLASH
FLOODING EARLY THIS MORNING.
DISCUSSION...CLUSTERS OF THUNDERSTORMS ARE DEVELOPING IN AN AXIS
OF 1.80 TO 2.00 INCH PRECIPITABLE WATER AIR (PER THE LATEST RAP
ANALYSIS)...AND A RIBBON OF 2500-3500 J/KG OF MLCAPE. THE LATEST
IR LOOP SHOWED RAPIDLY EXPANDING AND COOLING TOPS OVER NORTHWEST
AR...WHERE CLOUD TOP TEMPERATURES ARE AS LOW AS -76 C.
THE KSRX RADAR INDICATED POCKETS OF HOURLY RAINFALL RATES GREATER
THAN 2.00 INCHES OVER CRAWFORD AND CONWAY COUNTIES IN AR.
HOWEVER...MESONET OBSERVATIONS HAVE HOURLY RATES LOWER THAN THIS
IN AR...AND BASED ON THE AMOUNT OF DRY AIR IN THE RAP
SOUNDINGS...HAIL CONTAMINATION COULD BE OCCURRING.
THUS FAR THE CONVECTION HAS BEEN SCATTERED...AS THE LOW LEVEL
INFLOW IS SOMEWHAT LIMITED (WITH GENERALLY 15 KNOTS SHOWN ON
REGIONAL VWP). HOWEVER...THERE IS A FAIRLY GOOD SIGNAL IN THE HIGH
RESOLUTION GUIDANCE (INCLUDING THE LATEST HRRR/PARALLEL HRRR/Z0Z
ARW) FOR RAINFALL RATE NEAR 2.00 INCHES AN HOUR... PARTICULARLY
OVER NORTHWEST AR (WHERE THE 00Z WRF ARW SHOWED A 6.00 INCH
RAINFALL BULLSEYE BETWEEN 06Z AND 12Z). IT SHOULD BE NOTED THAT
THE ONE HOUR FLASH FLOOD GUIDANCE VALUES ARE AS LOW AS 1.50 INCHES
ACROSS SOUTHEAST KS AND SOUTHWEST MO.
DUE TO THE SOMEWHAT LIMITED INFLOW...IT IS POSSIBLE THAT THE
CONVECTION REMAINS SCATTERED THROUGH THE EARLY MORNING HOURS.
HOWEVER...DUE IN THE IN SITU MOISTURE AND INSTABILITY...FLASH
FLOODING IS POSSIBLE.
HAYES
ATTN...WFO...ICT...LZK...MEG...SGF...TSA...
ATTN...RFC...ABRFC...LMRFC...MBRFC...
LAT...LON 37669562 36469190 34679094 35029352 36299629
36309629 36359633 37239669
Last Updated: 1254 AM EDT SAT JUL 09 2016