"URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
508 PM MST Thu Dec 18 2025

...THIS IS A PARTICULARLY DANGEROUS SITUATION FOR IN AND IMMEDIATELY
ADJACENT TO THE FOOTHILLS, BETWEEN 5500 AND 9000 FEET, FOR BOULDER
AND JEFFERSON COUNTIES ON FRIDAY...

Strong west winds, sustained 45-55 mph with gusts upwards of 85-105
mph, are expected in the foothills of Boulder and Jefferson Counties
beginning early Friday morning. Relative humidity values are
expected to drop into the low teens, possibly upper single digits.
While Red Flag conditions, critical fire weather, are expected
across a larger area in northern Colorado, the most extreme
conditions are expected to be along Highway 93 from Jefferson County
into Boulder County and along US-36 north of Boulder to the Larimer
County line and westward. There will be a high potential for fast
moving wildfires, should any new starts occur.

Winds toward I-25 and eastward will be slower to develop, and also
speeds will be considerably lighter. That said, gusts of 25-40 mph
are still expected to combine with very low humidity and cured
grasses to support critical fire weather conditions. Areas farther
east into eastern Adams, Arapahoe, Elbert, and Lincoln counties have
more uncertainty if those winds even develop, so those locations
remain under a Fire Weather Watch.

Such conditions may be a longer duration than usual, with potential
for low humidity to extend well into the evening hours." #COwx #wildfires