Alert archive / Colorado / Special Weather Statements in 2021

Special Weather Statement, NWS Denver/Boulder, CO

February 3, 2021Douglas County, Elbert County, Colorado

NWS Denver/Boulder, CO issued this special weather statement at Feb 3, 2021, 9:38 PM MST for Douglas County, Elbert County, Colorado. It was in force for 52 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Feb 3, 2021, 9:38 PM MST (04:38 UTC)
Expired: Feb 3, 2021, 10:30 PM MST
In force: 52 min
Issued by: NWS Denver/Boulder, CO

Counties Douglas County, CO, Elbert County, CO

The radar

The Denver radar (KFTG), 57 km from the middle of the area, began a volume at 04:39 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 00:00Z, 4.6 hours before the alert went out and 127 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: 1997 m above ground
0-6 km bulk shear: 73 kt
0-1 km storm-relative helicity: -9 m²/s²
0-3 km storm-relative helicity: 153 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Denver/Boulder, CO wrote its last area forecast discussion before this special weather statement went out at Feb 3, 8:49 PM MST, 49 minutes earlier.

Area forecast discussion, Feb 3, 8:49 PM MST, 49 minutes before

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Hazardous weather outlook, Feb 3, 11:20 AM MST, 10 hours 18 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1120 AM MST Wed Feb 3 2021

COZ030>051-041830-
Jackson County Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer County Below 6000 Feet/Northwest Weld County-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
Central and East Adams and Arapahoe Counties-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-Washington County-Sedgwick County-Phillips County-
1120 AM MST Wed Feb 3 2021

...WINTER WEATHER ADVISORY FOR THE NORTHERN AND CENTRAL MOUNTAINS
THROUGH THURSDAY MORNING...

This hazardous weather outlook is for northeast and north central
Colorado.

.DAY ONE...Today and Tonight

Snow will increase in the mountains this afternoon and continue
tonight. The snow will be heavy at times, mainly this afternoon
and evening, with 6 to 12 inches expected in the higher mountains by
late tonight. In addition winds gusting up to 60 mph will produce
poor visibility over the higher mountain passes. The mountain
valleys and foothills will have less snow, but there could still
be some heavy showers in the late afternoon and evening.
Accumulations of an inch or two will be common, with localized
amounts up to 4 inches.

A cold front will move across the plains by evening, with wind
gusts up to 40 mph. There will be scattered rain showers early
this evening changing to snow by midnight. Some areas could see an
inch or two of snow mainly along and south of a Denver to Akron
line.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Light snow will continue across the mountains into Thursday
afternoon. The next round of mountain snow begins Friday morning
and continues through most of Saturday. Snow and blowing snow
could lead to poor travel conditions. Sunday looks dry with much
improved travel, though blowing snow may become an issue across
the higher mountain passes. A colder pattern is expected for
next week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today or tonight but snowfall
reports will be appreciated.

Gimmestad/RJK

In the hours before

Special weather statement, Feb 3, 8:44 PM MST, 54 minutes before

Special Weather Statement
National Weather Service Denver CO
844 PM MST Wed Feb 3 2021

COZ036-040-041-045-046-040430-
Elbert/Central and East Douglas Counties Above 6000 Feet CO-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County CO-Central and East Adams and Arapahoe Counties CO-
North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe
Counties/East Broomfield County CO-
Jefferson and West Douglas Counties Above  6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet CO-
844 PM MST Wed Feb 3 2021

...Heavy snow band moving across Douglas and Elbert counties...

At 839 PM MST, Doppler radar was tracking a band of heavy snow from
the Cheesman Reservoir towards Byers, moving slowly to the south. An
inch or two of snow is possible with this band. Roads could briefly
become snow covered and slick.

Locations impacted include...
Southern Aurora, southern Centennial, Highlands Ranch, Castle Rock,
Parker, eastern Littleton, Elbert, Lone Tree, Roxborough Park,
Elizabeth, Kiowa, Simla, Larkspur, Perry Park, The Pinery, Louviers,
Franktown, Westcreek, Ponderosa Park and Castle Pines.

LAT...LON 3909 10405 3913 10406 3913 10526 3956 10506
      3968 10414 3909 10396
TIME...MOT...LOC 0339Z 239DEG 49KT 3950 10474

HIRIS

Local storm report, Feb 3, 9:28 PM MST, 10 minutes before

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Special weather statement, Feb 3, 9:38 PM MST, 0 minutes before

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The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 3, 8:44 PM MST	Special Weather Statement	BOU	Arapahoe, Douglas, Elbert	46 min
Feb 3, 10:39 PM MST	Special Weather Statement	BOU	Elbert	36 min
Feb 4, 3:30 AM MST	Winter Storm Warning	BOU	Grand, Jackson	50 hr
Feb 4, 2:39 PM MST	Winter Weather Advisory	BOU	Boulder, Clear Creek, Gilpin, Grand, Jackson, Jefferson and 3 more	38 hr

Nearby

Special Weather Statements in Colorado, 2021 Every special weather statement in 2021

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.