MESOSCALE PRECIPITATION DISCUSSION 0182
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1243 PM EDT SAT MAY 07 2016
 
AREAS AFFECTED...CENTRAL/SOUTHERN WY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 071640Z - 072230Z
 
SUMMARY...HEAVY SHOWERS REDEVELOPING AND REPEATING OVER THE SAME
AREA ACROSS THE EASTERN SLOPES OF THE WIND RIVER RANGE MAY RESULT
IN SOME FLASH FLOODING CONCERNS THIS AFTERNOON. ADDITIONAL
EXPANSION OF HEAVY RAIN IS EXPECTED.

DISCUSSION...SHORTWAVE ENERGY LIFTING NORTH AROUND THE EASTERN
FLANK OF A LARGE UPPER LOW OVER SOUTHERN UT WILL BE PROVIDING
PERSISTENT LARGE SCALE ASCENT/DIVERGENT FLOW ALOFT THIS AFTERNOON
OVER MUCH OF CENTRAL AND SOUTHERN WY. THIS COINCIDING WITH A
RELATIVELY MOIST AND PERSISTENT 850/700 MB EASTERLY FETCH SHOULD
HELP MAINTAIN EFFICIENT SHOWER ACTIVITY/PRODUCTION WITH LOCALLY
HEAVY RAINFALL RATES.

THE INSTABILITY PARAMETERS ARE CURRENTLY VERY WEAK...BUT THERE HAS
BEEN SOME MODEST INCREASE IN INSTABILITY SEEN OVER SOUTHERN WY AND
FAR NORTHERN CO WHERE SOME SOLAR INSOLATION IS TAKING PLACE. THE
EXPERIMENTAL GLD-LIGHTNING DENSITY PRODUCT SHOWS SOME UPTICK IN
STRIKE ACTIVITY SUGGESTING THUNDERSTORM EXPANSION AND STRONGER
UPDRAFTS THAT SHOULD SUPPORT HEAVIER RAINFALL RATES OVER THESE
AREAS.

THE PERSISTENCE OF LOW TO MID LEVEL EASTERN FLOW INTO THE
EAST-FACING SLOPES OF THE WIND RIVER RANGE WILL ONLY ENHANCE THE
RAINFALL POTENTIAL MORE...AND THE LAST COUPLE RUNS OF THE HRRR
SHOW ADDITIONAL RAINFALL AMOUNTS OF 1.5 TO 2 INCHES THROUGH ABOUT
21Z. THERE IS SOME POTENTIAL THIS COULD BE UNDERDONE GIVEN THE
AFOREMENTIONED UPTICK IN CONVECTIVE ELEMENTS FARTHER SOUTH WHICH
SHOULD LIFT NORTH AND PIVOT OVER WIND RIVER RANGE AREAS OF
SOUTHERN WY THIS AFTERNOON. 

GIVEN THE EARLIER RAINFALL...THESE ADDITIONAL HEAVY TOTALS MAY
BEGIN TO RESULT IN SOME FLASH FLOODING.  

ORRISON

ATTN...WFO...CYS...RIW...

ATTN...RFC...CBRFC...MBRFC...

LAT...LON   43530884 43330828 43020745 42440666 41960623 
            41470619 41160652 41030752 41360845 42000878 
            42430876 42710888 43090921 43500931