MESOSCALE PRECIPITATION DISCUSSION 0219
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1017 PM EDT THU AUG 22 2013
 
AREAS AFFECTED...EASTERN CO 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 230149Z - 230549Z
 
SUMMARY...THERE WERE REPORTS OF SIGNIFICANT FLASH FLOODING ALONG
THE CO FRONT RANGE AS OF 0130Z. THE ENVIRONMENT SHOULD SUPPORT A
CONTINUED FLASH FLOOD THREAT...WITH THE HEAVIEST RAIN DRIFTING
SLOWLY TOWARD THE EAST.

DISCUSSION...POST FRONTAL UPSLOPE HAD FOCUSED A HEAVY RAIN EVENT
ALONG THE CO FRONT RANGE. REPORTS WERE SUGGESTIVE OF POSSIBLE HIGH
END FLASH FLOODING...WITH RAIN TOTALS 1.5 TO 2.8 INCHES PER LOCAL
STORM REPORTS AND COCORAHS. CELLS APPEARED MULTICELLULAR WITH
OCCASIONAL SUPERCELL STRUCTURES...BUT INVOLVEMENT OF SMALL HAIL
APPEARED NEGLIGIBLE IN REDUCING RAIN RATES. 

LOW LEVELS WERE MOSTLY RESPONSIBLE FOR THE SUSTAINED FORCING
BENEATH AN UPPER LEVEL RIDGE...AND UPSLOPE WAS DEEPEST TOWARD
SOUTHEAST COLORADO WHERE KPUX VAD WIND PROFILE INDICATED
ACCELERATED EASTERLY FLOW APPROX. 25 KNOTS THROUGH A DEEP LAYER.
THE POOL OF CAPE THAT DEVELOPED DURING THE DAY WAS ALSO STRONGEST
OVER THIS AREA...AND HIGH RESOLUTION MODELS FOCUSED ACTIVITY IN
SOUTHEAST COLORADO THROUGH 06Z...GENERALLY AHEAD OF THE
CONCENTRATED HEAVY ECHOES THAT WERE MOVING ESE FROM COLORADO
SPRINGS AT 0130Z. OTHER NEW DEVELOPMENT WAS NOTED...HOWEVER...ENE
OF DENVER. LOW LEVEL INFLOW MAY INCREASE OVER NORTHEAST COLORADO
AS AN UPPER LEVEL WAVE BRUSHES THE REGION TO THE NORTHWEST TONIGHT.

SREF AND RUC CAPE FIELDS REMAIN SUPPORTIVE OF DEEP
CONVECTION...EVEN IF BECOMING SLIGHTLY ELEVATED...THROUGH AT LEAST
05-06Z. SLOW STORM MOTIONS WILL BE RESPONSIBLE FOR CONTINUED HEAVY
RAINFALL...1.5-2.5 INCHES BENEATH THE STRONGEST CELLS. MEAN 0-6 KM
WINDS AND SUPERCELL MOTIONS REMAIN 0-10 KT. SMALL SCALE MCS
DEVELOPMENT COULD PUSH CELLS TO EAST A LITTLE QUICKER...BUT THE
SUSTAINED UPSLOPE COULD SUPPORT WESTWARD REDEVELOPMENT AND BRIEF
TRAINING. SUSPECT THAT WITH THE LACK OF MID LEVEL SUPPORT...THE
INTENSITY OF THE RAIN AMOUNTS SHOULD DECREASE BY 05-06Z WITH LOSS
OF CAPE/UPDRAFT STRENGTH.

BURKE

ATTN...WFO...LBF...GLD...PUB...BOU...

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

LAT...LON   40950223 40940373 40590490 39630570 38480531 37680468
            37550361 37990259 38650189 39960165 40950223