129
FXUS65 KPUB 031803
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1103 AM MST Wed Dec 3 2025

.KEY MESSAGES...

- Snow to occur on  the I-25 corridor and all higher terrain areas
today with impactful accumulations expected, heaviest will fall
during daylight hours which will somewhat limit accumulations on
roadway surfaces.

Heaviest snow will fall in the KCOS region this AM into early
afternoon, with the heavy snow slowly moving south as the day
progresses (See 4th paragraph below for timing)

Northwest flow to prevail through the entire fcst period with
several weaker disturbances moving through bringing on and off snow
to mainly the central mountains.

Gradual warming trend next 10 days.

&&

.UPDATE...
Issued at 1040 AM MST Wed Dec 3 2025

Another update to the winter weather highlights this morning.
High-res guidance continues to hint at a moderate to heavy area
of snow developing across northern parts of the San Luis Valley
and into the eastern slopes of the San Juan Mountains now
through the evening. This seems reasonable given easterly flow
into the eastern slopes of the La Garita and San Juan Mountains,
allowing for efficient upslope into these areas. In addition,
model guidance does shows an area of low level convergence
developing around 700mb as the trough pushes over, which
current mesoanalysis already supports. Given this, have upgraded
northern portions of the San Luis Valleys, portions of the La
Garita Mountains, and the San Juan Mountains to Winter Storm
Warnings to account for the potential of heavier snow, which are
now in effect through early tonight.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 213 AM MST Wed Dec 3 2025


Currently...

Radar at 2 Am was showing snow areas of snow mainly north of
US50, with clusters of snow areas from the northern San Luis
valley east- northeast across EL paso and northern Pueblo
counties. Areas webcams showing snow mostly on grassy areas as
temps relatively warm at this time with mid 20s to mid 30s where
precip is falling. OVer the far eastern plains temps were mild
with mid 30s to mid 40s.

It is going to snow over a good part of the region, with mainly the
far eastern plains seeing the least amount of precipitation. Overall
qpf values should be in the 0.25 to 0.50 amounts, with heavier
amounts approaching an inch over the Sangre De Cristo mountains
and wet mountains.

Although widespread snow is near certain. most of the snow is going
to fall during the daylight hours. Additionally temps are not going
to be overly cold (mainly 29-32 I-25 corridor and larger valleys.
This is likely going to limit accumulations, especially on roadway
surfaces. With that said, some of the snow is likely to be heavy
today, especially late this morning into mid afternoon. Overall, the
heavier activity will spread north to south during the daylight
hours. Storm total accumulations along the I-25 corridor will
generally range from 3 to 9 inches with the heaviest amounts along
the interstate down near the Walsenburg region. Mountains will
see 6 to 12 inch amounts. Interestingly, snowfall amounts over
the northern sections of the central mountains are not expected
to be that high, and the Leadville region may not see any
significant amounts with this event.

Reviewing the statistical DESI guidance, with respect to heavy
precip, the heaviest precip will fall during the morning into the
mid afternoon time period in the KCOS region. For the PUB region
extending down towards Walsenburg, the heaviest snow will fall from
late this morning through the afternoon time period. The Trinidad
region will see the heaviest snowfall from this afternoon into the
evening hours.

By this evening, most of the snow is expected to be generally south
of the US-50 corridor, with the southern mountains and Raton Mesa
region receiving the brunt of the snowfall. By the predawn hours
tomorrow, snow will mainly be along the New Mexico border,
especially the southern San Juans.

Although this will be somewhat of an impactful event, the area is
likely to see beneficial widespread precipitation. Additionally,
it will be the southeast mountains that will benefit the most
with this event, and this will certainly increase the snow pack
over the southeast mtn region. /Hodanish

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 213 AM MST Wed Dec 3 2025

Northwest flow at mid levels will dominate the pattern during the
long term fcst period. Several disturbances will move southeast in
the flow aloft, but none of these systems are expected to be as
strong as the system moving across today. Most of the precip with
these disturbances will occur over the central mountains.
Additionally. the longwave pattern will SLOWLY push eastward during
this period, and this will allow for a slow gradual warming trend
through the weekend into next week. By late next week we may see
temps in the 60s and 70s over the region.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1102 AM MST Wed Dec 3 2025

Snow will continue to impact all of the terminals today into
this evening, with a gradual diminishing trend later this
evening into the overnight hours. Latest radar imagery and
observations showing light to moderate snow in place with
visibility staying right around 1/2 mile at all sites. Given the
overall setup, don`t anticipate much to change with a medium to
high chance for this similar snow intensity and visibility to
continue through this afternoon. While visibility has briefly
dropped to 1/4 mile, mainly at ALS, think there is a low chance
for any persistent heavier snow with this vis to continue. If
this were to occur, think ALS will have the highest chances. IFR
ceilings have moved in place and given the snow trends, don`t
see why any improvement will occur. If anything, ceilings could
trend downward and not up.

Anticipate this snow to diminish this evening, from north to
south with improvement occurring first at COS and then PUB. Do
show this improving trend at all sites, however, it`s possible
that similar snow and intensity could last longer into the
evening at ALS and will continue to closely monitor trends into
the evening. Do have ceilings also improving but my confidence
is not overly high, as it`s possible that IFR ceilings persist
well into the overnight hours. While light snow or flurries may
continue into the overnight hours, any impactful snow should end
after the midnight time frame. Confidence on when the MVFR
ceilings scatter is low, but think a more likely trend will be
for them to remain in place through much of the period. Winds
will generally stay light, however, a period of gustier east
southeast winds is likely at ALS this afternoon.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 8 PM MST this evening for
COZ060>062-076-077-081>086.
Winter Storm Warning until 2 AM MST Thursday for COZ065-
067>070-072>075-078>080-087.
Winter Weather Advisory until 2 AM MST Thursday for COZ066-071-
088.

&&

$$

UPDATE...SIMCOE
SHORT TERM...HODANISH
LONG TERM...HODANISH
AVIATION...RODRIGUEZ