Four Square Mile, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

456
FXUS65 KBOU 241143
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
443 AM MST Sat Jan 24 2026

.KEY MESSAGES...

- Arctic air over the forecast will continue in place through
  Monday morning, with below zero wind chills for the plains.

- Areas of light snow for the plains through this morning.

- Mountains will see 4 to 12 inches of total snowfall by late
  this afternoon, heaviest along and south of I-70.

- Second round of light snow (with accumulations 0.5-3") Sunday
  afternoon and evening for most areas.

- Warming trend returns Monday, with mostly dry and more seasonal
  conditions through the rest of the work week.

&&

.UPDATE...
Issued at 324 AM MST Sat Jan 24 2026

Radars are showing areas of mainly light snow continuing across
the CWA early this morning. The snowfall may be moderate in
intensity over the southeastern CWA over the eastern Palmer
Divide.  The current forecast and highlights are in pretty good
shape. Will only make a few tweaks to current sky, pop and wind
GFE grids based mainly on current conditions.

&&

.SHORT TERM /Through Saturday/...
Issued at 206 PM MST Fri Jan 23 2026

As expected, it`s cold. Temperatures across the foothills and
plains are generally in the single digits to mid 10s. Wind chill
values are near zero across most of the I-25 corridor and are a
bit lower across the northeast plains. The cold spot of our CWA is
currently an AWOS station northeast of Briggsdale in northeastern
Weld county, where the current temperature is a balmy 0F and the
wind chill is currently -22F. Across the metro, the most notable
feature is a persistent, well-defined Denver cyclone that has
helped produce some very light snow across the Denver metro most
of the day. While we have sufficient near-surface moisture, snow
has been limited by a very strong inversion near 700mb... which is
clearly evident in ACARS soundings today. Finally, snow is
gradually beginning to develop across the mountains. Boundary
layer moisture across the higher elevations is less impressive at
the moment but has been steadily improving through the day.

The general story in the short term period has not changed
significantly. As the shortwave and the accompanying mid-level
front sink southward this evening, moisture depths should increase
dramatically... leading to more widespread light to moderate
snowfall across the mountains. The better lift is still expected
to be along/south of the I-70 mountains tonight. Across the metro,
we`ll likely see a bit more coverage of snow late this evening
through the first half of Saturday morning. I suspect forecast QPF
is a little too low in some places where there could be some
enhanced convergence/upslope from the Denver Cyclone. With
dendritic growth zone depths as deep as around 9-10kft, it
wouldn`t be surprising to see someone in the I-25 corridor come in
with a few inches of very fluffy (high SLR) snow... though most
should only see around an inch.

The moisture axis should shift southward following the departing
shortwave, leading to a gradual decrease in snow from north to
south over the CWA. There`s still some question as to how quickly
we clear out during the day - and how much we manage to warm up as
a result - but in general forecast models haven`t changed
significantly in this period. Our afternoon forecast package was
generally a couple degrees cooler than the previous but did not
lead to any real changes to the overall forecast message.

&&

.LONG TERM /Saturday night through Friday/...
Issued at 206 PM MST Fri Jan 23 2026

Cold temperatures will remain anchored in place Saturday night,
trending colder in the high country given some fresh snow cover and
at least partial clearing, and conversely trending marginally
"milder" along the base of the foothills and I-25 corridor under
weak downslope flow. This flow should allow for locally moderated
daytime temperatures Sunday where west/southwest winds are more
persistent, but an approaching cold front will keep it limited in
scope and duration.

A second and quite robust shortwave will emerge over Montana
Saturday night, accelerating south through the day and driving a
cold front through northeastern Colorado beginning near midday
Sunday. Subtle timing uncertainty with the front reduces confidence
in Sunday`s high temperature forecast, especially for the southern
half of our forecast area where the frontal passage may be more
closely aligned with typical peak heating. In any case, parts of the
northern plains are unlikely to break out of the teens, while areas
roughly along and south of I-70 (outside of our mountains) look to
warm into the 20`s.

The likelihood of accumulating snow with/following Sunday`s front
has risen notably over the past 24 hrs, driven mostly by strong low-
level frontogenesis. Moisture amounts are relatively meager across
the board however (generally 0.05-0.15" of QPF for the mountains,
foothills and I-25 corridor, with upper-end potential of ~0.20" for
the most favored locations in/near the foothills), although healthy
lapse rates and cold temperatures will favor higher snow ratios of
15-20:1 providing a slight boost to accumulations. All that said,
expecting most of the region to see between 0.5-2" of snow, with
localized accumulations to 3" being within reach west of I-25,
falling almost entirely in the afternoon and early evening. Snow
will taper off from north to south and end by midnight. Sunday night
is progged to be the coldest of this arctic stretch thanks to the
frontal reinforcement, fresh snow, and rapidly clearing sky
conditions. Have thus opted to extend the Cold Weather Advisory
through Monday morning, when wind chill values of -10 to -20F will
be relatively widespread across the plains. It will be a
particularly cold night in our high valleys, with low temperatures
falling below -15F in the typical cold pool locations. Breezy winds
Sunday into Monday will also sustain very low wind chills in our
mountains including during daytime hours.

Seasonal temperatures and dry weather make a quick return by Monday
as the shortwave exits to our east and is replaced by weaker
northwest flow aloft and broad subsidence. The warming trend is set
to continue through midweek, with some stabilization as we enter the
latter half of the week. There is no indication of a significant
shift to our predominantly dry pattern through the first week of
February, with ensembles widely favoring generally dry conditions
regionwide and only punctuated by low chances for light mountain
precipitation, the first of which is centered around Thursday night-
Friday night.

&&

.AVIATION /12Z TAFS through 12Z Sunday/...
Issued at 441 AM MST Sat Jan 24 2026

Radars are indicated the light snow is slowly decreasing in
coverage across the CWA including in and around DIA, and upstream
of the airport as well. Will only keep -SN in the TAF through
about 14Z, then I will put a VCSH in through early afternoon.
Visibilities should improve to P6SM after 15Z. Will go with
ceilings in the BKN-OVC035-050 range most of the day based on
model cross sections. Winds will be weak through today either
variable in direction or weak east-northeasterly. Normal drainage
winds are expected tonight with speeds under 10 knots.
&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 5 PM MST this afternoon for COZ034.

Cold Weather Advisory from midnight Sunday night to 9 AM MST
Monday for COZ038-043.

Cold Weather Advisory until 9 AM MST Monday for COZ042-044>051.

&&

$$

UPDATE...66
SHORT TERM...Hiris
LONG TERM...BRQ
AVIATION...66