849
FXUS65 KBOU 231159
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
459 AM MST Fri Jan 23 2026

.KEY MESSAGES...

- Arctic air now over the forecast area and to continue in place
  into Sunday, with below zero wind chills for the plains.

- Areas of light snow for the plains mainly Friday evening,
  lingering into Saturday morning.

- Mountains to see 4 to 12 inches of snow Friday through
  Saturday, heaviest along and south of I-70.

- Lots of uncertainty regarding any potential moderation Sunday.
  Stronger signal of temperatures returning to near normal for
  Monday through much of next week.

&&

.UPDATE...
Issued at 304 AM MST Fri Jan 23 2026

Satellite pictures are showing Stratus moving into the northeast
corner at this time. A bit earlier, radars indicated a passing
area of light snow showers over Logan, Sedgwick and Phillips
Counties moving eastward and out of the CWA. Consensus of latest
models indicate very little light snow to no snow for the plains
much of today. Will reduce pops, especially this morning and for
the western half of the plains.

Thickness grids indicate continued cold air advection all day today
and there should also be a decent cloud cover in place.  I will
lower today`s daytime highs, based partially on current readings and
no warming expected through the day. Today`s high in Denver may
well have been the reading at midnight three hours ago.

Will increase sky cover grids today and tonight based on current
satellite pictures and forecast cross sections.

In the low levels, there is a circulation centered right over the
southern half of DIA. It certainly isn`t helping forecast winds
in the TAF.

Will leave the highlights as is for this updates.

&&

.SHORT TERM /Through Friday/...
Issued at 235 PM MST Thu Jan 22 2026

Northeast low level flow has transported cooler air into eastern
Colorado with temperatures in the 30s. Strong surface high over
southern Canada associated with the arctic air will sink southeast
into the Northern Plains overnight. Cold air advection will
continue overnight with temperatures falling into the single
digits. As the colder air moves into the area, light snow/flurries
will be possible Friday, mainly over the eastern plains. Little
to no accumulation is expected. Looking upstream, temperatures
across central Montana are generally in the teens. Expect this air
and similar temperatures to be over eastern Colorado Friday.
Surface winds turn east and southeast Friday across the plains and
is expected to produce a Denver Cyclone. Southerly downslope
winds off the Palmer Divide dries the air enough so snow doesn`t
form and likely pushes temperatures into the 20s.

For the mountains, this first surge of cold only reaches 9,000 to
10,000 feet MSL, so it is expected to stay east of the divide.
Snow forms over southwest Colorado Friday morning due to lift from
a jet and frontogenesis. The snow spreads northeastward during
the day and into the north central mountains mid to late
afternoon. Mountain roads likely become slick around sunset due
snowfall and falling pavement temperatures.

&&

.LONG TERM /Friday night through Thursday/...
Issued at 235 PM MST Thu Jan 22 2026

Perhaps our best shot of snow across the I-25 corridor comes late
Friday night into the first half of Saturday. For snow
enthusiasts, the setup leaves a lot to be desired, with weak
upslope but a limited amount of boundary layer moisture as very
cold air starts to settle into the plains. Guidance also maintains
some sort of Denver cyclone... which may limit upslope along the
base of the foothills where shallow upslope would generally favor
the better accumulations. All in all, nearly every piece of
guidance produces less than a tenth of an inch of QPF here and
totals across the lower elevations should generally be around an
inch or two.

Across the mountains, light to moderate snow should continue
through most of the day as the mid-level trough (and its
associated moisture) slowly dips southward into southeastern
Colorado. QPF and snow grids are still fairly bullish across our
I-70 mountains, where total snow amounts are forecast in the 5-12"
range.

This weekend will also feature this winter`s coldest temperatures
of the year, as we sit on the western edge of an impressively cold
airmass settling over the Midwest. Saturday`s highs will struggle
to reach the mid teens, with overnight lows in low single digits
to several degrees below zero. Sunday`s forecast is a little more
uncertain, as another shortwave swinging across the region brings
another chance for some light snow, along with a brief
reinforcing shot of cold air. Highs may be a couple degrees warmer
than Saturday but won`t be noticeably warmer.

There is good agreement that the final shortwave on Sunday will
also help scour out most of the cold air by Monday, as the flow
turns more to the west-northwest and mid-level temperatures warm
considerably. Depending on how much snow cover is left across the
plains, some areas near the river valleys (e.g., Greeley) may
struggle to fully mix out, but most of the I-25 corridor should
see highs back in the 40s. Most of next week looks fairly quiet
and dry with temperatures near or a little above normal... before
a somewhat more active pattern attempts to return by Thursday or
Friday.

&&

.AVIATION /12Z TAFS through 12Z Saturday/...
Issued at 454 AM MST Fri Jan 23 2026

Stratus is virtually surrounding the entire airport at this time.
The pesky circulation right over the airport is likely the cause
of this. Radar is showing some weak echoes developing into a
circle around the airport. Pretty interesting. Will go with OVC015
in the TAF as it is bound to fill in shortly. May also need to
put some -SN in but not reduce VSBYs much at all. The winds will
continue to be difficult with the pesky circulation at hand. Many
of the models show the circulation to slide south and southeast
this morning bringing fairly light north or northeast winds to
all the airport. Not all the models show this; with some having
the circulation to push northward this morning. I guess I will
start off with west to northwest winds, then perhaps lean towards
some sort of weak east or northeasterlies. I will keep the
ceilings in the OVC010-015 with something a bit lower in a TEMPO
or PROB30 group later this evening and overnight with the best
chances of -SN.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 11 AM this morning to 5 PM MST
Saturday for COZ034.

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

&&

$$

UPDATE...66
SHORT TERM...12
LONG TERM...Hiris
AVIATION...66

NWS BOU Office Area Forecast Discussion