Graphic for MPD #0638
 
MESOSCALE PRECIPITATION DISCUSSION 0638
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1230 AM EDT SUN SEP 04 2016
 
AREAS AFFECTED...NORTH CENTRAL KS...EXT SOUTHERN NEB 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 040430Z - 040930Z
 
SUMMARY...CONGEALING COMPLEXES CONTINUE TO POSE FLASH FLOODING
THREAT ACROSS NW/NC KS THROUGH EARLY MORNING HOURS. 

DISCUSSION...SLOW MOVING SUPER CELLS ACROSS RED WILLOW AND
NORTON/GRAHAM COUNTIES HAVE DEVOLVED AND CONSOLIDATED INTO A
LARGER MATURING MCS THAT HAS KICKED AN OUTFLOW SSW ACROSS AT OR
ALONG I-70.  STRENGTHENING LOW LEVEL JET SAMPLED BY VWP INDICATES
45-50 KT 850MB DUE SLY INFLOW THAT ISENTROPICALLY TO THE LFC NEAR
AREAS ALREADY AFFECTED WITH MUCAPES AT THIS LEVEL IN THE 1500 J/KG
RANGE.  CONTINUED WAA LOW LEVEL PROFILE AND ADVECTION IN THE
MID-LEVELS A FORECAST TO REMAIN FAIRLY UNSTABLE THROUGH THE EARLY
MORNING HOURS UNTIL LLJ SLACKENS AND VEERS TOWARD 09-10Z.  CELL
MOTION VECTORS TOWARD THE NORTHEAST AT 20-25KTS  OPPOSED TO
FORWARD PROPAGATION VECTORS TOWARD THE SOUTHEAST...SUPPORT SLOW
EASTWARD MIGRATION OF THE COMPLEX BUT ALSO REPEAT CONVECTIVE
DEVELOPMENT ALONG THIS INTERFACE SUPPORTING COMPOUNDED TOTALS. 
MST PROFILES AND STRONG FLUX SUPPORT TPWS OVER AROUND 1.75"
ALLOWING FOR EFFICIENT RAINFALL RATES AROUND 2"/HR WITH LIMITED
LOSSES TO EVAPORATION SUB-CLOUD BASE. 

UPPER LEVEL SUPPORT HAS BEEN SLACKING OVER THE LAST FEW HOURS AS
HEIGHT FALLS WELL WEST ARE LIFTING THE JET AXIS AND THEREFORE THE
RIGHT EXIT REGION FURTHER NORTH REDUCING THIS ADDITIONAL
BOLSTERING AFFECT THAT SUPPORTED THE CONVECTION EARLIER.  

SURFACE ANALYSIS/GOES-E AND RADAR REFLECTIVITY ALSO SHOW THE
ADVANCE OF A WESTERN CONVECTIVE CLUSTER WITH TOPS WITH CONTINUED
COOLING TOPS TO -70C INTO FAR NW KS...ALONG A SW-NE
BOUNDARY...THAT IS QUICKLY ADVANCING.  THIS CLUSTER IS A
DEMARCATION OF THE END OF FLASH FLOOD THREAT AS IT SLIDES ESE
COLLECTING/MERGING WITH AFOREMENTIONED ISENTROPIC INDUCED MCS. 
THIS MAY POSSIBLY ACT A INTENSIFYING FACTOR WITH INCREASED RATES
FOR A SHORT DURATION FURTHER COMPOUNDING RAINFALL TOTALS AND FF
THREAT IF IT DOES NOT WEAKEN PRIOR TO REACHING THE AREAS MOST
AFFECTED BY EARLIER ROUNDS.    

GALLINA

ATTN...WFO...DDC...GID...GLD...ICT...

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

LAT...LON   40240056 40119867 39359822 38939860 38899925 
            38970018 39410136 39740151 40090127 


Last Updated: 1230 AM EDT SUN SEP 04 2016