MESOSCALE PRECIPITATION DISCUSSION 0257
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
435 PM EDT SUN SEP 15 2013
 
AREAS AFFECTED...COLORADO 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 152032Z - 160000Z
 
SUMMARY...LOW LEVEL NORTHEASTERLY FLOW WILL CONTINUE INTO NORTHERN
COLORADO THROUGH THE REMAINDER OF THE AFTERNOON.  WHILE THIS WILL
GENERALLY LEAD TO LIGHTER RAFL RATES...EMBEDDED AREAS OF MODERATE
TO LOCALLY HEAVY RAINFALL RATES WILL CONTINUE GIVEN ELEVATED
CAPES.  AREAS IN SOUTHERN CO WILL BE MORE LIKELY TO HAVE HIGHER
RAFL RATES WHERE CONVECTION SHOULD BE MORE ROOTED IN THE BOUNDARY
LAYER. 

DISCUSSION...THE 12Z SOUNDING FROM DNR WAS NEARLY SATURATED FROM
THE SURFACE UP TO APPROXIMATELY 600 MB. ACARS FLIGHTS INTO AND OUT
OF DENVER INTL AIRPORT SHOWS LITTLE CHANGE IN THE GEOMETRY OF THE
SOUNDING WITH THE EXCEPTION OF COOLING AT THE LOWER LEVELS.  MOST
OF THE SOUNDINGS SHOWED ELEVATED INSTABILITY ABOVE THE COLDER
AIRMASS WHICH APPEARS TO BE HELPING SUSTAIN SOME MODERATE TO
LOCALLY HEAVY RAINFALL IN NORTHERN CO.  TO THE SOUTH...EARLY
AFTERNOON RADAR SHOWED MORE INTENSE CONVECTION WITH
CORRESPONDINGLY HIGHER RAFL RATES OVER SOUTHERN CO...GENERALLY
ALONG AND SOUTH OF THE RATON MESA.  THIS AREA HAD HIGHER SURFACE
BASED INSTABILITY THAT THE STORMS WERE ABLE TO TAP INTO.  

THINK THE OVERALL PATTERN WILL CONTINUE THROUGH 16/00Z EXCEPT FOR
A PUSH SOUTHWARD OF THE COLDER AIRMASS INITIALLY OVER NORTHERN CO.
 MESOSCALE MODELS FOCUS THE HIGHEST 1 AND 3 HOUR RAFLS SOUTHWARD.
WHILE VALUES FROM THE ARW WERE ON THE ORDER OF 1 TO 1.25 INCHES IN
A 3 HOUR PERIOD...THE PCPN MAX WAS PLACED RIGHT ALONG THE AXIS OF
LOWEST FLASH FLOOD GUIDANCE.  THUS FLASH FLOODING REMAINS POSSIBLE
THROUGH 16/00Z IN THESE AREAS. 

BANN

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

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

LAT...LON   37530487 38150573 39440576 40020579 40570534 40560462
            40210388 39670321 38180392 37530487