147
FXUS65 KBOU 241916
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
116 PM MDT Sat Oct 24 2026

.KEY MESSAGES...

- Cooler and unsettled for the rest of the weekend. A couple
  rounds of showers, one late this afternoon and evening and
  another tomorrow late afternoon through the night.

- Some snow accumulation (considerable spread in potential
  accumulations) for mountains above 9,000 feet, but generally
  minor travel impacts expected over the high mountain passes.

- Warming trend and mostly dry much of next week.

- Unsettled weather potentially returning next weekend.

&&

.DISCUSSION /Through Saturday/...
Issued at 116 PM MDT Sat Oct 24 2026

Satellite shows a broad upper low over the Desert Southwest with a
couple of embedded vorticity maximums circulating around it, the
most pronounced one in southwest Arizona. This latter feature
will end up being the main low which will drift slowly northeast
into eastern Utah on Sunday. Ahead of that, weak lift will be
present both from the QG aspect and an upper level speed max
ahead of this trough. One wave of energy is currently organizing
with a considerable amount of convection in southwest and south
central Colorado, and that will arrive late this afternoon/
evening as it advects north/northeast in the mean flow. While our
instability is marginal and S/SW flow is generally downslope for
us, the earlier frontal passage has brought deepening upslope to
about 11,000 ft MSL east of the Front Range. That will help offset
the substantial drying we`ve seen in this flow pattern over the
last couple days, and thus showers will have a greater chance of
surviving as they roll off the higher terrain and onto the plains
and I-25 Corridor. We`ve bumped PoPs up just a tad thanks to the
upslope component. We still think most precipitation amounts will
be light (0.10-0.20 inch or less), although the Mosquito Range and
south facing mountains along the Summit County/Park County line
including Hoosier Pass could easily pick up 3-5" of snow with some
travel impacts through this evening. Snow amounts tonight would
taper off rather quickly along/north of I-70 to just an inch or
so. One other location that stands a higher chance (30-60%) of
more meaningful precipitation near 0.5 inch rain would be over the
far eastern plains, roughly east of a line from Holyoke to Limon.

On Sunday and Sunday night, synoptic scale lift will gradually
increase as the upper level low moves east across the forecast
area. Models were still highly variable, with the synoptic scale
models still pointing toward better chances of more widespread
showers than today. However, we will be fighting a deeper
downslope component than today, as flow just off the deck is more
southerly. The only upslope component would be quite shallow and
north of a Denver Cyclone. Thus, the highest chances of rain late
Sunday afternoon and especially Sunday night will likely shift
toward the northern half of the forecast area. Probabilities of
>0.50" of rain are 30-50% near the Wyoming/Nebraska border, with
much lower probabilities farther south. In the mountains, snow
levels will likely hover near 9,000-10,000 feet which would
support a few more inches of snow for the high country. Again,
that favors the northern tier of mountains so another 1-5" is
expected there, but some high end solutions still show a small
chance (10-15%) of as much as 8-10".

By Monday morning, there is good agreement that the upper trough
will be moving east and northeast of the forecast area, taking the
precipitation with it. Temperatures will start to moderate with
Monday`s highs pushing back into the 60s for the lower
elevations. We`ll turn to a more zonal flow Tuesday which means
further warming and mostly dry weather, although a couple of the
ensemble members have just enough moisture for a few rain/snow
showers in the northern mountains.

Wednesday through Friday are shaping up to be dry and warmer as
southwest flow aloft and flat ridging develops across the
forecast area. Highs could push back to near 70F as ensembles
continue to trend to a warmer solution.

We`re still watching the next potential trough and/or return of
subtropical moisture as we head toward next weekend. While there
is considerable uncertainty in the details, it does appear we are
shaping up for more unsettled weather but again quite a bit of
blocking by the southern CO mountains.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1215 PM MDT Sat Oct 24 2026

Current satellite shows a cloud deck against the foothills
causing lower ceilings at KBJC. Clouds have started to decrease at
KDEN and KAPA within the last hour, but we expect some cloud
decks to fill back in once again in the next few hours. Behind
this morning`s cold front, winds were gusting to about 20 mph at
times. Wind gusts should rapidly decrease over the next hour and
we only expect gusts around 15 mph at most through this
afternoon.

Some rain showers look increasingly possible late this
afternoon through the early evening. Given the latest CAMs, there
is now a TEMPO at KDEN where these showers could briefly lower
ceilings. Winds tonight should have a southerly component and
remain light (under 12 kts). Bufkit soundings are in good
agreement that low clouds stick around at KDEN and KAPA with
ceilings around 2000-3000 ft AGL through much of the overnight.
There is the potential for even lower ceilings, but confidence is
low. As we approach Sunday morning, the ceilings at KDEN and KAPA
start to lift but likely stay around 5000 to 7000 ft AGL for much
of the day before lowering once again tomorrow evening. Some
clouds below these heights still look likely for much of Sunday.
KBJC likely stays with a ceilings around 2000 ft AGL from this
evening through tomorrow morning, but there could be some slight
improvements towards late Sunday morning.

Finally, the winds tomorrow look highly uncertain at this time.
Guidance has been in good agreement for several runs that a
Denver Cyclone/DCVZ will form north of the terminals. We are most
confident that KBJC will stay with north winds tomorrow. At this
time, KDEN looks to have light northerly winds for the afternoon
due to the DCVZ staying just to the east of the airport. There is
a ~40% chance that the DCVZ makes it west of KDEN/KAPA bringing
some gustier southerly winds into those terminals tomorrow
afternoon. Showers look to increase from south to north once again
late Sunday afternoon.

&&

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

&&

$$

DISCUSSION...20
AVIATION...MV

NWS BOU Office Area Forecast Discussion