MESOSCALE PRECIPITATION DISCUSSION 0390
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
738 PM EDT SUN JUL 26 2015
 
AREAS AFFECTED...EASTERN CO, SOUTHWEST NE, & NORTHWEST KS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 262338Z - 270538Z
 
SUMMARY...AN ONGOING CONVECTIVE COMPLEX WITH NEW DEVELOPMENT TO
THE SOUTH COULD MERGE INTO AN ELONGATED CONVECTIVE BAND WITH TIME.
 CELL TRAINING AND BACKBUILDING CONVECTION COULD LEAD TO FLASH
FLOODING.

DISCUSSION...A CONVECTIVE COMPLEX WITH OVERSHOOTING TOPS HAS BEEN
MOVING EASTWARD THROUGH CO THIS AFTERNOON, DRAGGING AN OUTFLOW
BOUNDARY SOUTHWARD THROUGH EASTERN CO.  THIS IS OCCURRING AHEAD OF
A WEAK SHORTWAVE MOVING THROUGH EASTERN WY.  HOURLY RAIN RATES
HAVE REACHED 1.5" ON OCCASION WITHIN THESE STORMS.  PRECIPITABLE
WATER VALUES ARE IN THE 1.50-1.75" RANGE PER RECENT RAP FORECASTS.
 LOW-LEVEL INFLOW OUT OF THE SOUTHEAST HAS BACKED TO SOUTHEAST AND
INCREASED TO 25 KTS, WHICH IS FURTHER ORGANIZING FORWARD
PROPAGATING CONVECTION, MOVING ROUGHLY EAST-NORTHEAST AT 25 KTS. 
MLCAPES HAVE BUILT TO 3000-4000 J/KG ACROSS SOUTHWEST AND
NORTH-CENTRAL KS, WITH THE MLCAPE GRADIENT ALIGNED WITH A
LOW-LEVEL WIND SHIFT FROM SOUTH TO SOUTHEAST PER REGIONAL SURFACE
OBSERVATIONS.

THE EXPECTATION IS FOR THE OUTFLOW BOUNDARY TO ALIGN WITH THE ZONE
OF WIND SHEAR WHICH SHOULD ACT FOR THE FOCUS OF CONVECTION LATE
THIS AFTERNOON INTO THIS EVENING.  INFLOW AT 850 HPA IS EXPECTED
TO CONTINUE TO INCREASE, REACHING THE 35 KT RANGE OVER THE NEXT
SEVERAL HOURS, BEYOND THE MAGNITUDE OF THE 850-400 HPA MEAN WIND
AND AT A RIGHT ANGLE.  THIS SHOULD ALLOW FOR SOME CELL
BACKBUILDING, THOUGH CELL TRAINING REMAINS THE MORE SIGNIFICANT
FLASH FLOOD RISK.  ORGANIZED CONVECTION COULD SLOW TO 15-20 KTS
PER THE FORWARD PROPAGATING CONVECTIVE VECTORS.   MOST OF THE
MESOSCALE QPF GUIDANCE APPEARS LOST IN THE WILDERNESS WITH REGARDS
TO QPF PLACEMENT -- THE EXCEPTIONS APPEAR TO BE THE EXPERIMENTAL
12Z HREF MEAN, 18Z NAM CONEST, 21Z EXPERIMENTAL HRRR, AND 21Z RAP
GUIDANCE.  SOME THE GUIDANCE SHOWS THE POTENTIAL FOR LOCAL AMOUNTS
IN THE 3-4" RANGE.  WITH HOURLY RAINFALL RATES AS HIGH AS 2"
POSSIBLE WITH THE MOISTURE AVAILABLE, THIS COULD FALL QUICKLY. 
FLASH FLOODING IS POSSIBLE HERE.

ROTH

ATTN...WFO...ABQ...AMA...BOU...DDC...GID...GLD...LBF...PUB...

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

LAT...LON   41729914 41349871 41039901 40909875 40219883 
            39279891 38839931 38180011 37310168 36860321 
            36760377 36780405 37660421 38290374 39610258 
            40600216 41050220 41190219 41340206 41040065 
            41150022 41320043 41440053 41539985