Alert archive / Colorado / Mesoscale Discussions in 2003

Mesoscale Discussion 2579

December 8, 200316 counties in Colorado; 15 counties in Nebraska; Goshen County, Laramie County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Dec 8, 2003, 10:18 AM MST for 16 counties in Colorado; 15 counties in Nebraska; Goshen County, Laramie County, Wyoming. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Dec 8, 2003, 10:18 AM MST (17:18 UTC)
Expired: Dec 8, 2003, 4:15 PM MST
In force: 6 hr
Issued by: the Storm Prediction Center

All 33 counties

Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Clear Creek County, CO, Denver County, CO, Elbert County, CO, Gilpin County, CO, Jefferson County, CO, Larimer County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Weld County, CO, Arthur County, NE, Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Kimball County, NE, McPherson County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Goshen County, WY, Laramie County, WY

The radar

The Cheyenne radar (KCYS), 102 km from the middle of the area, began a volume at 17:15 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.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 5.3 hours before the alert went out and 132 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1747 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

145 
ACUS11 KWNS 081719
SWOMCD
SPC MCD 081718 
NEZ000-COZ000-WYZ000-082315-

MESOSCALE DISCUSSION 2579
NWS STORM PREDICTION CENTER NORMAN OK
1118 AM CST MON DEC 08 2003

AREAS AFFECTED...NE CO/SE WY/NW NEB

CONCERNING...HEAVY SNOW 

VALID 081718Z - 082315Z

HEAVY SNOW WILL LIKELY DEVELOP BY 21Z IN THE FOOTHILLS AND PLAINS TO
THE EAST OF THE FRONT RANGE AND MEDICINE BOW MOUNTAINS. SNOWFALL
RATES OF 1 TO 2 INCHES PER HOUR WILL BE LIKELY.

A COLD FRONT IS CURRENTLY MOVING SWD ACROSS CNTRL CO AND IS
POSITIONED NEAR THE PALMER DIVIDE. AS A RESULT...NELY LOW-LEVEL FLOW
HAS INCREASED ACROSS NERN CO OVER THE LAST SEVERAL HOURS. WV IMAGERY
SHOWS AN UPPER-LEVEL DISTURBANCE MOVING NEWD ACROSS SRN WY AND NRN
CO. AS THIS FEATURE MOVES OUT ONTO THE PLAINS THIS
AFTERNOON...LARGE-SCALE ASCENT WILL INCREASE CAUSING BANDS OF SNOW
TO DEVELOP. COLD AIR ADVECTION AT THE SFC BEHIND THE FRONT SHOULD
KEEP TEMPS IN THE LOWER TO MID 30S ALONG THE URBAN CORRIDOR. ONCE
PRECIPITATION STARTS...TEMPS SHOULD COOL QUICKLY TO NEAR FREEZING
DUE TO EVAPORATIONAL COOLING. THIS COMBINED WITH SFC DEWPOINTS IN
THE UPPER 20S F AND INCREASING LIFT...WILL BE FAVORABLE FOR PERIODS
OF HEAVY SNOW WITH 1 TO 2 INCH PER HOUR SNOWFALL RATES. LATE THIS
AFTERNOON...AS THE SYSTEM MOVES FURTHER NEWD...HEAVY SNOWFALL WILL
ALSO BE POSSIBLE ACROSS WRN NEB AND FAR NERN CO.

..BROYLES.. 12/08/2003

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

ATTN...WFO...LBF...GLD...BOU...CYS...

39630583 40200608 41570526 42710397 42910332 42800213
42240110 41760099 40980190 40320253 39340336 39210445

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 8, 2:17 AM MST	Mesoscale Discussion	SPC	Archuleta, Delta, Garfield, Hinsdale, Mesa, Mineral and 5 more	4 hr
Dec 8, 4:46 AM MST	Mesoscale Discussion	SPC	Clear Creek, Eagle, Grand, Lake, Park, Summit	3 hr
Dec 8, 4:11 PM MST	Mesoscale Discussion	SPC	Boyd, Brown, Cedar, Dixon, Holt, Keya Paha and 2 more	5 hr

Nearby

Mesoscale Discussions in Colorado, 2003 Mesoscale Discussions in Nebraska, 2003 Mesoscale Discussions in Wyoming, 2003 Every mesoscale discussion in 2003

Sources

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.