014
FXUS65 KBOU 021743
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1143 AM MDT Thu Oct 2 2025

.KEY MESSAGES...

- Dry with warmer than normal conditions through Friday.

- Showers and a few storms enter the picture Saturday and Saturday
  night, but mainly light precipitation amounts expected. A new
  dusting of snow likely (70% chance) for the mountains.

- Turning cooler late Saturday, and staying cool through early
  next week.

&&

.DISCUSSION /Through Wednesday/...
Issued at 136 PM MDT Wed Oct 1 2025

A building upper level ridge from the Central Plains into the
Southern Rockies will bring warm and dry weather through Friday.
The southwest flow in this pattern will bring persistent warm
advection, with high temperatures reaching the lower to mid 80s
across the I-25 Corridor and plains Thursday, and mid to upper 80s
by Friday. The record for Denver is 88F on Friday (10/3), but we
should stay just a couple degrees shy of that. It will become
breezy over the eastern plains and high mountain valleys Friday,
with elevated fire weather conditions there due to the winds and
low humidity.

On Saturday, the weather will be changing as an upper level trough
moves east across the Northern Rockies and Great Basin.
Strengthening low and mid level gradients will bring windier
conditions to the forecast area, especially for the afternoon and
evening hours. It will be relatively warm with above normal high
temperatures expected (quite a strong trend from the NBM in the
last 12 hours, essentially warming it 3-7 degrees across the
forecast area). Thus, the stronger winds combined with still
relatively low but not critical humidity thresholds will bring
elevated fire weather concerns. Mid and upper level moisture
slowly increases through the day, and enough with daytime heating
and instability to produce showers and a few storms. The highest
coverage by far favors the mountains and high valleys, but the
northern border area should also see higher coverage considering
better lift there. There`s reasonable agreement in the ensembles
of that scenario playing out, while Denver would see lower
probabilities of measurable precipitation (20-30% chance).
Mountain areas will also see colder temperatures on the back side
of the trough, enough to produce a light dusting of snow over most
of the mountains above 9,000 feet.

Saturday`s trough weakens quickly and shears out as it heads into
the Northern Plains by Saturday night. Behind that, we`ll be left
in moderate west/southwest flow aloft as yet another trough
enters the Northern Rockies and drops into the Great Basin. This
will allow cool surface high pressure building over the Central
and Northern Plains states to dominate our weather Sunday through
Tuesday. While the airmass will largely be drier and more
subsident, we still can`t rule out a few showers from time to time
in the persistent and cooler upslope regime. It`s almost certain
this will drop high temperatures down into the 60s for Sunday
through Tuesday, with a 30-40% chance that either Sunday or Monday
doesn`t get above 60F on the plains and I-25 Corridor.

We expect gradual moderation toward the middle of next week.

&&

.AVIATION /18Z TAFS through 18Z Friday/...
Issued at 1110 AM MDT Thu Oct 2 2025

VFR conditions through the TAF period. Mostly clear skies and dry
conditions are expected through the TAF period. Current light and
VRB winds are expected to transition to the east by 21Z this
afternoon. Hi-res guidance suggests a shear zone develops to the
southeast of KDEN/KAPA that will shift winds to the NE for a few
hours between 0Z-2/3Z this evening. However, if this
develops/pushes slightly more northwestward, this would result in
winds becoming more S/SE rather than the NE that are currently in
the TAF. Beyond 3Z, wind direction uncertainties diminish as
southerly winds are expected through the overnight hours at
KDEN/KAPA. KBJC will see persistent light and VRB winds for the
evening and overnight hours.

For Friday, drainage winds are expected to become light and VRB
once again before transitioning to the east for the afternoon.

&&

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

&&

$$

DISCUSSION...Barjenbruch
AVIATION...Bonner

NWS BOU Office Area Forecast Discussion