MESOSCALE PRECIPITATION DISCUSSION 0193
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
219 PM EDT THU JUN 11 2015
 
AREAS AFFECTED...SECTIONS OF SOUTHEAST WY & EASTERN CO 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 111819Z - 120019Z
 
SUMMARY...THUNDERSTORMS HAVE BEGUN TO DEVELOP ACROSS SOUTHEAST WY
AND EASTERN CO.  WITH THE POTENTIAL FOR HOURLY RAIN RATES UP TO
1.25", FLASH FLOODING IS POSSIBLE.

DISCUSSION...WEAK UPSLOPE FLOW BEHIND A COLD FRONT COMBINED WITH
AN UPPER LOW TO THE WEST AND 500-1000 J/KG MLCAPES HAVE LED TO
THUNDERSTORM DEVELOPMENT ACROSS SOUTHEAST WY AND EASTERN CO. 
PRECIPITABLE WATER VALUES OF ~1" EXIST PER THE 12Z DNR SOUNDING
AND RAP FORECASTS.  SPEED SHEAR BETWEEN 700 HPA (WEST 20 KTS) AND
THE SURFACE (5-10 KTS OUT OF THE EAST) COULD BE LEADING TO 25-30
KTS OF CLOUD BASE INFLOW FOR THE CONVECTION, WHICH WOULD ALLOW FOR
GREATER ORGANIZATION WITH TIME.

THE 06Z SSEO NEIGHBORHOOD PROBABILITIES SHOW THAT THREE HOUR FLASH
FLOOD GUIDANCE VALUES IN THE REGION COULD BE EXCEEDED BY 20Z.  A
1000-500 HPA THICKNESS RIDGE IN THE REGION COULD ALLOW FOR
BACKBUILDING CLOSE TO THE FRONT RANGE, WHILE FORWARD PROPAGATING
CORFIDI VECTORS AND THE MEAN 850-400 HPA WIND SUGGEST AN EAST
MOTION AT 15-20 KTS FOR ORGANIZED CONVECTION.  RAP BOUNDARY LAYER
MOISTURE CONVERGENCE FORECASTS HINT THAT CONVECTION SHOULD DEVELOP
MORE TO THE SOUTH WITH TIME.  THE AVAILABLE MOISTURE ALLOWS FOR
THE POSSIBILITY OF HOURLY RAIN RATES AS HIGH AS 1.25".  THE
MESOSCALE QPF GUIDANCE INDICATES LOCAL AMOUNTS OF 2-3" ARE
POSSIBLE IN THIS REGION.  CONSIDERING MOIST CONDITIONS ACROSS CO
AS OF LATE, FLASH FLOODING IS POSSIBLE ACROSS SATURATED SOILS AND
RUGGED TERRAIN.

ROTH

ATTN...WFO...BOU...CYS...GLD...PUB...

ATTN...RFC...ABRFC...CBRFC...MBRFC...WGRFC...

LAT...LON   42250563 42070426 39800295 38370343 37350483 
            37770563 38510617 39320615 40690622 41780607