MESOSCALE PRECIPITATION DISCUSSION 0465
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
150 AM EDT MON JUL 16 2018

AREAS AFFECTED...SOUTHEAST COLORADO

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 160550Z - 160945Z

SUMMARY...THUNDERSTORMS DEVELOPING IN A BRIEF PERIOD OF UPSLOPE
FLOW TONIGHT MAY PRODUCE LOCALIZED FLASH FLOODING EAST OF THE
HIGHEST TERRAIN CRESTS OF THE SANGRE DE CRISTO MOUNTAINS IN
SOUTHEAST COLORADO. RAIN RATES OF AROUND OR JUST OVER 1 IN/HR WILL
BE POSSIBLE.

DISCUSSION...GOES-16 IR SATELLITE CHANNELS SHOWED A SUDDEN BURST
OF CONVECTION ALONG THE I-25 CORRIDOR IN SOUTHEAST COLORADO IN THE
UPSLOPE REGION OF THE SANGRE DE CRISTO MOUNTAINS WITH SOME
LIGHTNING ACTIVITY AS WELL. THIS WAS LIKELY ASSOCIATED WITH SOME
USPLOPE FLOW...AS THE KPUX RADAR VWP SHOWED E-NE FLOW AROUND 20-25
KNOTS IN THE 850-700MB LAYER. ALTHOUGH THE RAP MODEL DOES NOT SHOW
THIS LASTING MUCH LONGER THAN A COUPLE HOURS...IT MAY BE
SUFFICIENT TO LOCK CONVECTION INTO TERRAIN FEATURES FOR AN HOUR OR
TWO AND PRODUCE LOCALLY HEAVY RAINFALL. THE INFLOW REGION REMAINS
MODERATELY UNSTABLE (MUCAPE 1000-2000 J/KG) AND PRECIPITABLE WATER
VALUES ARE APPROACHING 1.5 INCHES (GPS-PW OBSERVATION NEARBY WAS
1.38 INCHES). SUCH PW VALUES ARE ABOVE THE 90TH PERCENTILE FOR
THIS AREA. THEREFORE... SUFFICIENT MOISTURE AND INSTABILITY EXIST
FOR AT LEAST A SHORT PERIOD OF SUSTAINED AND ORGANIZED CONVECTION.
GIVEN THE OROGRAPHIC FOCUSING MECHANISMS... THIS CONVECTION SHOULD
BE NEARLY STATIONARY. KPUX RADAR SHOWED SMALL AREAS OF 1.0 TO 1.5
IN/HR RAIN RATES BASED ON DUAL POL ESTIMATES... AND IT SEEMS
PLAUSIBLE THAT THIS COULD CONTINUE ANOTHER FEW HOURS IN THE MORE
DEVELOPED I-25 CORRIDOR JUST TO THE EAST OF THE SANGRE DE CRISTO
RIDGES. RAIN RATES THIS HIGH COULD CAUSE FLASH FLOODING...
PARTICULARLY IF THEY ALIGN WITH SOME OF THE BURN SCARS IN THE
REGION.

LAMERS

LAMERS

ATTN...WFO...ABQ...BOU...PUB...

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

LAT...LON   39330437 38800364 37710332 36920338 36580424
            36920518 38390525