High Wind — Larimer & Boulder Counties Between 6000 & 9000 Feet, Colorado

2025-12-19 · Larimer & Boulder Counties Between 6000 & 9000 Feet, Colorado

Event narrative

Wind gusts of 60-90 mph were common through out the zone with a few gusts topping 100 mph, including a 112 mph wind gust at the NCAR Mesa Lab. Numerous trees and powerline were blown down. In addition to these extreme winds, it was very dry with relative humidity values in the 5 to 15 percent range. A few brief small fires were reported, but no large fires occurred.

Wider weather episode

Extreme winds and fire danger occurred during the morning and afternoon hours of December 19th due to a strong mountain wave. The high winds occurred in and near the foothills of Larimer, Boulder, and Jefferson. The eastward extent of the high winds only reach the western parts of the Denver Metro area and stayed west of Interstate 25. Several (five) fires were reported in the foothills. Numerous power poles and power lines were reported down (at least 28 different reports) across Boulder and the immediate foothills as peak wind gusts hit 90-110 mph. In Gilpin County, there were 100s of trees down and several overhead powerlines down along Gap Road. Several road closures were also noted (some proactively). Public Safety Power Shutoff (PSPS) was enacted early to mid morning by Xcel Energy to approximately 70,000 customers, and a total of approximately 104,000 customers were without power due to additional unplanned outages. The Jefferson County EM reported that there were evacuations for Windy Peak Outdoor Lab, part of the Jefferson County school district. There were difficulties evacuating staff from this location due to the number of downed trees. FlightAware reported more than 1,200 delays at DIA along with more than 80 cancellations.

Source: NOAA Storm Events Database, event_id 1302325. Narrative written by the NWS forecast office that issued the report.