MESOSCALE PRECIPITATION DISCUSSION 0241
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
947 AM EDT THU JUN 18 2015
 
AREAS AFFECTED...PORTIONS OF KS, MO, OK, AR, TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 181346Z - 181946Z
 
SUMMARY...HOURLY RAIN RATES UP TO 1" NEAR BILL'S CORE AND UP TO 3"
WITHIN ITS INFLOW BAND(S) WOULD CAUSE FLASH FLOODING OVER
SATURATED SOILS.

DISCUSSION...TROPICAL DEPRESSION BILL CONTINUES MOVING ACROSS
SOUTHEAST OK AT 8-9 KTS, WHICH IS FORECAST TO CONTINUE BY THE
GLOBAL GUIDANCE.  CORE RAINFALL RATES ARE IN THE NEIGHBORHOOD OF
0.25-.5" AN HOUR, WHICH IS EXCESSIVE OVER THE SATURATED SOILS OF
SOUTH-CENTRAL OK PER THE 06Z FLASH FLOOD GUIDANCE VALUES.  WHILE
THE OVERNIGHT INFLOW BAND ACROSS EAST-CENTRAL TX AND NORTHWEST LA
FADES, A NEW BAND IS FORMING JUST TO ITS NORTHWEST NEAR THE
ARKLATEX WHICH IS TAPPING MIXED LAYER CAPES OF 500-1000 J/KG. 
PRECIPITABLE WATER VALUES IN THE AREA ARE 2.1-2.6" PER GPS
INFORMATION.  INFLOW AT 850 HPA REMAINS 25-45 KTS PER VAD WIND
PROFILES, JUST ABOVE THE MEAN 850-400 HPA WIND IN THIS AREA.

DAYTIME HEATING SHOULD ALLOW CONVECTION WITHIN THE NEW INFLOW
BAND, AND ALONG BILL'S TRAILING SURFACE TROUGH, TO STRENGTHEN
TODAY, BRINGING HOURLY RAIN RATES BACK INTO THE 2-3" RANGE EARLY
THIS AFTERNOON.  THE MESOSCALE GUIDANCE GENERALLY AGREES THAT 2-4"
LOCAL AMOUNTS ARE POSSIBLE IN THE BAND, THOUGH IT SHOWS WILD
VARIATION ON WHERE THE INFLOW BAND SETS UP.  BELIEVE RADAR IMAGERY
AND THE CAPE PATTERN ALONG WITH THE SURFACE ANALYSIS ARE REVEALING
WHERE BANDING WOULD OCCUR THIS AFTERNOON, WHICH IS IN BEST
AGREEMENT WITH THE 00Z NMMB AND 00Z SPCWRF.  THE 06Z SSEO
NEIGHBORHOOD PROBABILITIES INDICATE THAT THE RAIN RATES WITHIN
BANDING SHOULD INCREASE MOST AFTER 18Z.  FOR THE CORE RAINFALL, IT
REMAINS TO BE SEEN IF THE OUTFLOW BOUNDARY/CONVECTIVE LINE MOVING
INTO KS WILL BE A FACTOR FOR INCREASING RAIN RATES -- IF SO, SUCH
AN IMPACT REMAINS EIGHT HOURS AWAY.  THE GUIDANCE INDICATES LOCAL
AMOUNTS OF 2-4" BETWEEN EASTERN OK AND SOUTHWEST MO WITH BILL'S
CORE.  SATURATED SOILS COMBINED WITH EXPECTED RAINFALL SHOULD
ALLOW FOR FLASH FLOODING.

ROTH

ATTN...WFO...EAX...FWD...HGX...ICT...LZK...OUN...SGF...SHV...
TOP...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...WGRFC...

LAT...LON   38469469 38369318 37739227 36709214 35209237 
            32829331 31079476 30729530 31449592 31709744 
            32039759 33219740 34139746 34809789 35949769 
            37319670