852
FXUS65 KBOU 251117
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
417 AM MST Thu Dec 25 2025

.KEY MESSAGES...

- Warm and dry for the plains through Friday with record high
  temperatures likely

- The mountains will see light snow with the valleys seeing light
  rain/snow showers Thursday into Friday.

- Increased fire danger Friday for the foothills and portions of
  the urban corridor.

- A widespread snow possible for our whole forecast area Saturday
  night into Sunday with light amounts. Much colder temperatures
  expected to accompany the snow.

&&

.UPDATE...
Issued at 246 AM MST Thu Dec 25 2025

Another day of well above normal temps with potential for near
record highs.  However, if mid and higher level clouds develop later
this morning and linger thru the aftn, this could keep temps a
few degrees cooler than forecast. Record high for Christmas is 69
degrees at Denver so it`s possible it could be tied or broken
depending on cloud cover.

Meanwhile, some moisture will move across the mtns today and bring a
good chc of snow showers to the Park Range.  Other mtn areas will
likely have lower coverage of snow shower activity thru the aftn.
The mtn showers may allow for some mixing down of the mid level flow
which could allow for gusty winds to spread across areas in and near
the foothills this aftn.  Cross-barrier flow is in the 40-45 kt
range so winds gusts up to 60 mph may occur for a few hours.

For tonight, cross-sections show a weak mtn wave after midnight with
cross-barrier flow of 50-55 kts thru 15Z Fri.  Thus may see some
gusts up to 70 mph over the mtns and foothill areas with a few
localized higher gusts.  With current cross-sections only showing a
weak mtn wave, will refrain from issuing a High Wind Watch as not
certain about overall coverage of stronger winds should be rather
limited.

In the longer term, it does appear there will be a quick pattern
change from Sat into Sun as an upper level trough moves across the
area in NW flow aloft.  This system will have a decent cold front
associated with it along with a good shot of mid level QG ascent Sat
night into Sun morning. Thus, will likely see a round of
widespread snow from the mtns and foothills, across portions of
the I-25 Corridor and over the Palmer Divide. In addition,
temperatures will be much colder on Sun as well.

&&

.DISCUSSION /Through Wednesday/...
Issued at 214 PM MST Wed Dec 24 2025

Record or near-record highs are forecast on Christmas Day with
most of the urban corridor seeing highs in the upper 60s to low
70s. The record high in Denver is 69 set in 2005 and that will
likely (70% chance) be tied or broken. In the mountains, it will
be mild with a chance of snow as a trough will approach Colorado
from the west. The Park Range may get 2-5" of snow from these
brief but intense snow showers that are expected. Other locations
along the western slope of the Front Range mountains may see 1-3".
Otherwise, a mountain wave will setup over the Front Range
mountains late tonight and will last through much of the day
Thursday. This wave will produce gusts between 50-60 mph over
most of the mountains and foothills with some higher values in the
windy locations of Boulder and Larimer Counties.

On Friday, a similar weather pattern will be in place. Highs will
be similarly warm with record highs possible. Drier air will move
into our forecast area which will limit the snow potential in the
mountains. However, a couple inches of additional snow
accumulation is possible in the Park Range as the best moisture
will stay that far north.

The mild and dry conditions Thursday and Friday along with the
gusty mountain wave will lead to elevated to near-critical fire
weather conditions especially on Friday. This is discussed in
detail in the fire weather section below.

A strong positively-tilted trough will move into western Colorado
on Saturday. There will be cold air advection in the low levels
which will lead to cooler temperatures on Saturday (but still
above normal). On Saturday night, a cold front associated with
this trough will move through our forecast area. This will drop
temperatures significantly with highs on Sunday potentially
staying in the 20s across lower elevations. There will be a brief
period of an over-running snow event Saturday night into Sunday
across the plains and foothills. Southwesterly flow aloft with
good mid-level frontogenesis will develop a couple bands of snow.
Models have been trending toward higher QPF amounts for this
system roughly in the 0.15-0.25" range for the Denver metro. The
confidence of a light snow is increasing with a broad range of
forecast values from 1-4" of snow across the I-25 corridor with
the higher values being closer to the Palmer Divide due to
upslope, northeasterly flow. In the mountains and foothills,
higher amounts are expected potentially exceeding 6" above 10,000
feet.

Sunday night will be cold due to fresh snow cover and clearing
skies. Lows could reach the single digits across the plains.

The pattern returns to warm and dry for the majority of next work
week.

&&

.AVIATION /12Z TAFS through 12Z Friday/...
Issued at 414 AM MST Thu Dec 25 2025

Winds were mainly SSW early this morning except at BJC where
winds were light and variable. Will keep winds SSW at APA
and DIA with a more WSW component by 18z. Winds this aftn
will shift to the WNW or NW by 20z or 21Z.  For this evening
winds will become SW by 02Z and then go the drainage by 05z.
Meanwhile VFR conditions will continue thru the period.

&&

.FIRE WEATHER...
Issued at 214 PM MST Wed Dec 24 2025

Thursday will be windy in the Front Range mountains and foothills
with gusts between 50-60 mph. Winds will be lighter across the
plains with gusts mainly staying below 25 mph. The exception to
that are locations near the Cheyenne Ridge and Palmer Divide where
gusts could reach 35 mph. Relative humidity is expected to
increase as moisture from an approaching low pressure system will
move into Colorado. Minimum relative humidity is expected to stay
above 20 percent across all of our forecast area. Some pockets of
elevated fire weather conditions may develop in the lower
foothills and near the Cheyenne Ridge but no critical conditions
are expected.

Drier air will move in on Friday along with mild conditions.
Minimum relative humidity will drop to 10-15% in the lower
foothills and adjacent plains. Gusty winds will accompany the dry
air and near-critical fire weather conditions are expected for the
lower foothills and I-25 corridor. The magnitude of the wind
gusts are in question so no fire weather highlights were issued at
this time. Wind gusts may reach close to 50 mph in those
locations or, if the mountain wave stays at higher elevations,
gusts could stay around 25-35 mph.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...RPK
DISCUSSION...Danielson
AVIATION...RPK
FIRE WEATHER...Danielson

NWS BOU Office Area Forecast Discussion