National Weather Service Forecast Discussion

Thornton Weather Forecast   
Today's Forecast Story   
726
FXUS65 KBOU 251154
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
454 AM MST Sun Jan 25 2026

.KEY MESSAGES...

- Continued arctic cold to continue through Monday morning.

- Additional light snowfall expected Sunday, 0.5-3" Urban Corridor
  and plains with 3-5" for the mountains.

- Warming and drying trend kicks back in on Monday just because...

&&

.UPDATE...
Issued at 324 AM MST Sun Jan 25 2026

Satellite, radar and surface observations are showing partly
cloudy to cloudy skies for much of the CWA this morning. There may
even be some snow flurries over the northern Urban Corridor here
and there. Temperatures were mainly -5 to +5 F over most of the
plains, but a tad warmer right near the foothills. Weak drainage
winds were in place for most areas.

Latest model runs indicate a light snowfall is expected across
most of the CWA later this morning through evening. So the
forecast there is in pretty good shape. Will make grid adjustments
to sky conditions this morning for sure based on reality. Will
lower high temperatures somewhat with thickness grids and
current & expected sky cover in mind. Will leave the Cold Weather
Advisory going as well.

&&

.SHORT TERM /Through Sunday/...
Issued at 203 PM MST Sat Jan 24 2026

Between waves of snow today, outside the Palmer Divide and the
mountains, with some clearing skies made it feel several degrees
warmer than on Friday over the urban corridor and the plains. It
really stopped snowing in the mountains or along the Palmer but I`m
not sure I hear anyone complaining.

Skies continue to clear for the most part tonight into Sunday
morning, though some cirrus may overspread around midnight tonight
and then wane a tad by sunrise. Reason this is brought up, overnight
temperatures. A little wind/mixing will continue, like it did
Saturday morning, so we will radiate nicely with the lighter winds
and clearing skies, but may not end up as cold as we did on Saturday
morning. Still single digits to negative single digits from the
urban corridor into the plains and the mountains.

Sunday, fun-day in terms of forecasting temperatures, reinforcing
shot of arctic air, and snow banding. Confidence is high, 80+%, of
accumulating snowfall over the urban corridor and the adjacent
plains Sunday afternoon into the evening as another arctic front
barrels through the region. High temperatures could easily occur
right around noon and then the cold air starts to ooze in from the
north, along with higher level clouds, with a bigger punch by
mid/late afternoon. This is when the moisture convergence, albeit
less than ideal moisture content, will be at it`s highest and we see
a 3-4 hour window of wind driven snow showers and some resemblance
of weak upslope in the foothills and Palmer Divide. We did bump up
the snow ratios across much of the region by an inch or two, just
given how cold the air coming into the region will be. Even with
paltry 0.01-0.03" of liquid we could squeeze out a little over an
inch in the urban corridor and adjacent plains.

Sunday night into Monday morning, in the wake of the fresh snowfall
and clearing skies behind the front will definitely be the coldest
thus far this winter. EFI is showing a higher EFI and a slightly
high SOT over much of the region leading to a much colder than
normal, outside of the reforecast climatology, for overnight lows.
We could easily have numerous locations drop to -10F over the

&&

.LONG TERM /Sunday night through Saturday/...
Issued at 203 PM MST Sat Jan 24 2026

Monday we start the warming trend as stronger winds aloft begin to
shove the arctic airmass to the east and away from our region. We`re
expecting high temperatures to be right around seasonal averages
which would be about 20 to 25F degrees above where we end up on
Sunday. Building ridge to our west, where have we heard this before,
keeps north-northwest flow aloft with little in the way of embedded
vort maxes riding down the east side. Not to discount Thursday with
a slightly better chance, 20-30%, of higher elevation snow,
otherwise it`s dry mist places. Each day next week we add a few
degrees onto the previous days highs - back into the low-50s F by
Wednesday through the remainder of the work week.

&&

.AVIATION /12Z TAFS through 12Z Monday/...
Issued at 451 AM MST Sun Jan 25 2026

Models continue indicating a cold front with upslope flow behind
it to move across DIA around 19Z early this afternoon. There may
be BKN050 ceilings at DIA this morning along with light and
variable winds. After the front passes, ceilings will be in the
BKN-OVC010-030 range with visibilities in the 1-3SM -SN range.
Winds will generally be northeasterly after the front passes with
speeds in the 10-22 knot range into early evening, decreasing
after that and eventual becoming normal drainage patterns by 06Z.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Cold Weather Advisory from midnight tonight to 9 AM MST Monday
for COZ038-043.

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

&&

$$

UPDATE...66
SHORT TERM...Heavener
LONG TERM...Heavener
AVIATION...66

NWS BOU Office Area Forecast Discussion