Red Flag Warning: 18,000 Could Lose Power in Boulder, Jefferson Counties as High Winds Drive Fire Danger
red flag warning conditions are driving emergency power planning across parts of Boulder and Jefferson counties on Saturday, with thousands of residents facing a possible shutoff tied to high winds and elevated fire danger. Xcel Energy said about 18, 000 customers could see electricity cut around 2 p. m. ET as a public safety measure. The National Weather Service set the alert from 11 a. m. to 9 p. m. ET, citing low humidity and strong wind as the critical ingredients.
Power shutoff plan targets foothills, select Boulder areas
Xcel Energy said the potential public safety power shutoff zone includes areas of the Boulder County foothills, the Hill neighborhood in Boulder, and the University of Colorado Boulder campus. Some of Gunbarrel and other areas east of Colorado 119 also appear included on the utility’s outage map, while the Pearl Street Mall and most of north and south Boulder do not appear inside the planned shutoff footprint.
In Jefferson County, Xcel’s map shows parts of the possible shutoff zone near Colorado 93, south of the Rocky Flats National Wildlife Refuge and north of Interstate 70. The utility emphasized that high winds could also trigger unplanned outages through the weekend beyond any planned shutoff.
Xcel originally said 43, 000 customers could be impacted, then reduced that estimate to about 18, 000 in a Friday afternoon release. The release did not explain why the number changed.
Xcel warned that restoration could take “several hours or several days, ” explaining that crews must patrol the entire power line before re-energizing. Work begins once high winds and fire risk have ended, and the utility said it is likely outages could continue into Sunday.
red flag warning conditions: winds, low humidity, and fast-changing weather
The National Weather Service said the red flag warning runs from 11 a. m. to 9 p. m. ET Saturday. NWS tied the alert to low relative humidity and wind, with Saturday winds expected to persist at 20 to 30 mph and gusts up to 50 mph. Relative humidity could fall as low as 10%.
Separately, statewide forecasts describe widespread critical fire danger across Colorado’s lower elevations on Saturday, with humidity levels as low as 7–14% and west winds increasing through the day. Gusts of 40 to 60 mph are expected, and near the foothills—including parts of Boulder County and northern Jefferson County—brief gusts could reach around 70 mph between 1 p. m. and 5 p. m. ET Saturday evening, conditions that can rapidly intensify wildfire spread.
Colorado’s weather is expected to shift late Saturday night, with a cold front moving through around midnight ET in the Denver metro area. Forecasts call for a sudden wind shift and a burst of precipitation, followed by sharply colder air. North winds could gust between 55 and 65 mph overnight and into Sunday, with periods of snow expected into early Sunday morning.
Immediate reactions: utility warns medical-device users to prepare
Xcel Energy urged customers who rely on medical equipment requiring electricity to prepare for potential outages, posting the guidance on social media Friday. The utility also said that even where power is restored, re-energizing lines requires full patrols of the system for safety after extreme wind and fire-risk conditions.
As of 4: 45 p. m. ET Friday, about 1, 441 customers in the Boulder County foothills were still without power after more than 5, 000 in the county lost electricity during high winds on Thursday.
Quick context and what’s next
Saturday’s high winds and low humidity are creating a high-risk fire weather window, while a colder, wind-driven system is expected to follow into Sunday. Xcel’s planned shutoff is aimed at reducing fire risk in targeted areas during the most dangerous conditions.
Customers inside the potential shutoff zone will be watching for updates through Saturday afternoon as conditions evolve, with the possibility that outages—planned or unplanned—extend into Sunday while crews wait for winds and fire danger to ease before safely restoring power.
