Alert archive / Colorado / Winter Storm Warnings in 2019
Winter Storm Warning 18, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this winter storm warning at Dec 12, 2019, 4:10 AM MST for 9 counties in Colorado. It took effect at Dec 12, 2019, 5:00 PM MST. It was in force for 54 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Dec 12, 2019, 4:10 AM MST (11:10 UTC)
- In effect from
- Dec 12, 2019, 5:00 PM MST
- Expired
- Dec 14, 2019, 11:00 PM MST
- In force
- 54 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Boulder County, CO, Clear Creek County, CO, Gilpin County, CO, Grand County, CO, Jackson County, CO, Jefferson County, CO, Larimer County, CO, Park County, CO, Summit County, CO
The radar
The Denver radar (KFTG), 102 km from the middle of the area, began a volume at 11:10 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
Grand Junction, CO (KGJT), launched 00:00Z, 11.2 hours before the alert went out and 254 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1545 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- 84 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this winter storm warning 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 winter storm warning went out at Dec 11, 7:36 PM MST, 8 hours 34 minutes earlier.
Area forecast discussion, Dec 11, 7:36 PM MST, 8 hours 34 minutes before
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</html>Hazardous weather outlook, Dec 11, 11:02 AM MST, 17 hours 8 minutes before
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 1102 AM MST Wed Dec 11 2019 COZ030>051-121815- 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- 1102 AM MST Wed Dec 11 2019 This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight There will be a chance of light snow in the mountains tonight with accumulations of an inch or two in some areas. Winds will increase over the mountain ridges and higher east slopes of the Front Range. Gusts up to 60 mph will produce localized blowing and drifting snow. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday The next storm system is expected to move into the mountains Thursday night and continue through much of the weekend with snow and winds causing blowing snow issues. Abundant moisture from the eastern Pacific will be brought into Colorado by a strong jet stream which will produce nearly continuous snowfall through most of the weekend. It is difficult at this time to determine snowfall amounts, however significant snow accumulations are possible in the high country as the snow stacks up over a three day period. The plains will have a slight chance of snow from Friday night through Saturday and then an increased chance of snow Saturday night and Sunday with a frontal passage. At this time the snowfall looks light, though there is a bit of uncertainty. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today or tonight. Gimmestad/Schlatter
Nearby
Winter Storm Warnings in Colorado, 2019Every winter storm warning in 2019
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.