453
FXUS65 KBOU 231141
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
441 AM MST Sun Nov 23 2025

.KEY MESSAGES...

- Light snow in the mountains and foothills above 7000 feet
  mainly south of I-70 later this afternoon and tonight. Minimal
  accumulations

- Light rain late this afternoon and tonight for the plains,
  especially the eastern half.

- Becoming windy Monday to Tuesday, and turning colder.

- Some moderation with diminishing chances of any snow through
  Thanksgiving.

&&

.UPDATE...
Issued at 254 AM MST Sun Nov 23 2025

Satellite pictures are showing the center of an upper low over
south central Arizona at this time. The latest models to this
feature to move northeastward across central Colorado by 00Z late
this afternoon, then east of state over western Kansas by 12Z
Monday morning. The best synoptic scale energy will be over the
CWA from 18Z-00Z this afternoon. Models continue to indicate the
best QPF over the eastern plains, which still looks to fall as
rain. Models continue to show minor snowfall amounts in the
mountains, mainly south of I-70. I did increase sky cover grids
over much of the CWA with the upper low moving right across the
CWA through Sunday night.

&&

.DISCUSSION /Through Saturday/...
Issued at 257 PM MST Sat Nov 22 2025

Shortwave ridging over Colorado has brought dry conditions and
slightly above normal temperatures over the forecast area for the
day. With relatively light winds aloft, expect a quiet night ahead
of an approaching system.

Models are in good agreement of an upper level low trekking across
the forecast area Sunday afternoon/evening, with the trough axis
centered over east central Colorado. Due to this track, the best
areas for measurable precipitation will be the southern Front Range
mountains and southern/eastern plains. Ensemble`s 25th-75th
percentiles range between 0.1"-0.4" of QPF, but can`t rule out a
narrow band of localized higher amounts due to frontogenetical
forcing under the deformation zone. Recent ensemble and
deterministic runs have continued to trend downwards in
precipitation across the northern Front Range mountains and northern
I-25 corridor- have lowered PoPs Sunday through Monday for that
reason. In terms of precipitation type, rain is expected for
elevations below 7,000 ft. Snowfall amounts will most likely range
from T-4", with highest amounts confined to the high passes. Areas
along and south of I-70 will see slick roads Sunday evening and into
Monday morning.

By Monday afternoon, flow aloft will turn west/northwesterly as a
fast-moving upper level shortwave crosses just north of the forecast
area. This system could bring light orographic snow showers to
the northern Front Range mountains, with minimal accumulation and
travel impacts. However, the rest of the forecast area will likely
remain dry due to the northerly track of the system. Model
guidance has trended towards weaker cross-barrier flow, with only
a couple of Sangster runs showing a 20% chance of winds reaching
above 60 kts. We will continue to monitor model trends, but at
this time no high wind highlights are expected.

A potent cold front associated with the upper level system will
travel across the forecast area Monday night and into Tuesday
morning. Morning lows will range from 20s to the low 30s along
the plains and teens to low 20s in the mountains and valleys.
Wednesday morning temperatures are expected to be colder, with
most of the plains in the mid teens-low 20s and mountains and
valleys ranging from single digits to mid-teens.

A warming trend will return for Thanksgiving and Friday as flat
ridging settles over the southwestern United States. Cross-barrier
flow could create windy conditions along the higher terrain,
however expect generally mild, albeit quiet weather days late
this week. The only exception would be if an embedded shortwave
crosses the state, which would bring orographic snow showers to
the northern mountains. Towards the end of the holiday weekend,
ensemble guidance has continued to indicate a disturbance bringing
colder temperatures and a chance of our first snow showers to the
plains. However, there are still many discrepancies between
model runs on exactly how this system will evolve. We will
continue to monitor any changes in guidance.

&&

.AVIATION /12Z TAFS through 12Z Monday/...
Issued at 433 AM MST Sun Nov 23 2025

Models are still showing a surge of cooler air and weak upslope
getting into DIA late this morning. The latest models shifted the
precipitation a bit further east and south of DIA. I went with a
PROB30 for -RA and BKN030 this evening instead of the previous
TEMPO group.  Cloudiness should decrease after 07Z.

&&

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

&&

$$

UPDATE.......66
DISCUSSION...MAI
AVIATION.....66