Alert archive / Colorado / Winter Storm Warnings in 2023

Winter Storm Warning 7, NWS Denver/Boulder, CO

February 20, 20237 counties in Colorado

NWS Denver/Boulder, CO issued this winter storm warning at Feb 20, 2023, 2:08 PM MST for 7 counties in Colorado. It took effect at Feb 21, 2023, 11:00 AM MST. It was in force for 33 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: Feb 20, 2023, 2:08 PM MST (21:08 UTC)
In effect from: Feb 21, 2023, 11:00 AM MST
Expired: Feb 22, 2023, 8:22 PM MST
In force: 33 hr
Issued by: NWS Denver/Boulder, CO

Counties Boulder County, CO, Broomfield County, CO, Grand County, CO, Jackson County, CO, Jefferson County, CO, Larimer County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 90 km from the middle of the area, began a volume at 21:07 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 12:00Z, 9.1 hours before the alert went out and 290 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: 1771 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 357 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

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 Feb 19, 3:10 PM MST, 22 hours 58 minutes earlier.

Area forecast discussion, Feb 19, 3:10 PM MST, 22 hours 58 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 20, 2:18 AM MST	Winter Storm Watch	BOU	Boulder, Broomfield, Grand, Jackson, Jefferson, Larimer and 1 more	26 hr

Nearby

Winter Storm Warnings in Colorado, 2023 Every winter storm warning in 2023

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.