Mesoscale Discussion 384

Issued

Apr 15, 2016, 1:25 PM MDT (19:25 UTC)

Expired

Apr 15, 2016, 7:30 PM MDT

In force

6 hr

Issued by

the Storm Prediction Center

Counties Boulder County, CO, Clear Creek County, CO, Gilpin County, CO, Grand County, CO, Jackson County, CO, Larimer County, CO, Park County, CO, Summit County, CO

The Denver radar (KFTG), 125 km from the middle of the area, began a volume at 19:28 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

530 
ACUS11 KWNS 151926
SWOMCD
SPC MCD 151925 
COZ000-160130-

MESOSCALE DISCUSSION 0384
NWS STORM PREDICTION CENTER NORMAN OK
0225 PM CDT FRI APR 15 2016

AREAS AFFECTED...PORTIONS OF CENTRAL/NORTH-CENTRAL COLORADO

CONCERNING...HEAVY SNOW 

VALID 151925Z - 160130Z

SUMMARY...A LONG-DURATION SNOW EVENT IS INITIATING OVER THE
CNTRL/N-CNTRL CO MOUNTAINS...WITH SNOW BECOMING LOCALLY HEAVY IN THE
20-22Z TIME FRAME AND CONTINUING INTO THE EVENING AND OVERNIGHT.
SNOWFALL RATES MAY LOCALLY REACH 2 INCHES PER HOUR AT TIMES...
AFFECTING ELEVATIONS ABOVE 6-7 KFT.

DISCUSSION...A RECENT WATER VAPOR LOOP INDICATES A PROMINENT
MID-LEVEL SPEED MAX CROSSING THE DESERT SW...APPROACHING THE SRN
ROCKIES...WITH A CYCLONE BECOMING DEFINED W OF THE FOUR CORNERS
REGION. THIS CYCLONE WILL GRADUALLY EDGE EWD THROUGH THE REMAINDER
OF THE DAY INTO TONIGHT WHILE CLOSING OFF AT H7...YIELDING AN
INCREASE IN UPSLOPE FLOW TO ITS NE OVER PARTS OF THE CO ROCKIES.
DIURNALLY STEEPENED LAPSE RATES COUPLED WITH LARGE-SCALE ASCENT E OF
THE CYCLONE ARE PRESENTLY SUPPORTING AN INCREASE IN CONVECTION OVER
PARTS OF CNTRL/WRN CO. THIS ACTIVITY WILL GRADUALLY CONGEAL INTO
PERSISTENT PRECIPITATION BANDS EVOLVING WITHIN A DEFORMATION ZONE
RELATED TO THE MATURING H7 CYCLONE THROUGH THE EVENING/OVERNIGHT
HOURS.

THERMAL PROFILES WILL BE SUFFICIENTLY COLD FOR SNOW TO FALL OVER THE
MOUNTAINS...WITH SNOW LEVELS FORECAST TO FALL TO AROUND 7 KFT
THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS AS ADIABATIC
COOLING RELATED TO LARGE-SCALE ASCENT CONTINUES TO OVERSPREAD THE
REGION. FURTHER REDUCTION IN SNOW LEVELS WILL LIKELY OCCUR LATER IN
THE EVENING INTO THE OVERNIGHT -- TO AROUND 6 KFT -- AS LOW-LEVEL
COLD ADVECTION OCCURS. FRONTOGENETIC ASCENT IN THE LOW/MID
LEVELS...COMBINED WITH UPSLOPE TRAJECTORIES IN MANY AREAS...WILL
INTERSECT SUFFICIENTLY DEEP DENDRITIC GROWTH ZONES FOR PERIODS OF
SNOWFALL RATES LOCALLY REACHING 2 INCHES PER HOUR THROUGH TONIGHT.
THIS ACTIVITY WILL LIKELY AFFECT PORTIONS OF THE CO FRONT RANGE WWD
TO THE PARK RANGE.

..COHEN.. 04/15/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

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

LAT...LON   39060577 39360636 39780663 40490682 40920670 40940573
            40720545 40030535 39360533 39060577

Mesoscale Discussions in Colorado, 2016Every mesoscale discussion in 2016

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.