167
FXUS65 KBOU 190547
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1147 PM MDT Sun Oct 18 2026

.KEY MESSAGES...

- Warm and mostly dry conditions continuing to start the week.

- Isolated mountain rain and snow showers early this week.

- A more organized system by late week, with light rain/snow
  showers increasingly likelyacross the high country.

&&

.DISCUSSION /Through Sunday/...
Issued at 1143 PM MDT Sun Oct 18 2026

The above-average temperatures and mostly dry weather looks to roll
on for the next few days for the vast majority of the forecast area.
High temperatures should not approach record territory this week,
though we expect high temperatures generally 5-10 degrees above
average for the plains. Model guidance including ensemble clustering
data remains in relatively good agreement through Friday on the
evolution of the overall upper-level pattern.

A weak front has pushed through the area this evening, which will
lead to high temperatures a touch cooler for Monday. There will be
increased cloud cover overnight through Monday morning. The
mountains could see some isolated rain/snow showers on Monday
afternoon as moisture increases. The central mountains look to have
the highest chances overall, though PoPs remain low. Little to no
accumulation is expected. It will be rinse and repeat on Tuesday and
Wednesday with some isolated rain/snow showers (at best) possible
for the southern half of the high country. Temperatures should bump
up a touch on both days as an upper-level ridge builds.

An upper-level low over the Pacific Ocean is expected to start to
approach California on Wednesday, move inland, and be centered over
Utah by Friday morning. The latest data shows a broadening trough
moving into WY and MT on Friday afternoon. As this low approaches,
flow aloft is expected to turn to the southwest for our area and
stay southwest as the trough moves off to our northwest. Late
Wednesday into Thursday, we expect deeper moisture to approach our
southern and western high country. Precipitation chances should
increase from south to north across the high country starting
Wednesday evening and lasting through at least Friday morning with
some low-impact snow possible (i.e. below advisory level) mainly
above 11,500 ft or higher. By Thursday afternoon, we could start to
see some low rain chances creep into the plains before drier
conditions return for Friday. Southwest flow aloft is generally an
unfavorable setup for the metro to receive any significant rainfall,
so any rain would likely be light and scattered in nature. This is
reflected in the latest ensemble data with mean QPF amounts under
2/10 inch for KDEN and higher QPF confined to the high country.
Deterministic runs are even drier than that.

For the weekend, model disagreement continues. There are some signs
in the ensemble data that temperatures could dip to near-average or
even a tick below average for Saturday onward. This would be
courtesy of a cold front moving in from the north. Some low PoPs
could continue on Saturday and Sunday for the high country, though
confidence is low this far out.

&&

.AVIATION /06Z TAFS through 06Z Tuesday/...
Issued at 1143 PM MDT Sun Oct 18 2026

VFR conditions expected through the TAF period. A weak boundary has
helped winds stay from the northwest this evening but these winds
are light. Light and variable winds are expected from 08-09Z through
the rest of the night.

Southeast to east winds will develop during the late morning hours
on Monday and continue through the afternoon. Winds will
eventually veer towards the southeast in the evening and to
drainage overnight.

&&

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

&&

$$

DISCUSSION...MV
AVIATION...Danielson

NWS BOU Office Area Forecast Discussion