National Weather Service Forecast Discussion

Thornton Weather Forecast   
Today's Forecast Story   
763
FXUS65 KBOU 101920
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
120 PM MDT Sat Oct 10 2026

.KEY MESSAGES...

- Unseasonably warm and mainly dry weather this weekend.

- Isolated to scatteredshowers (15-35% coverage) and a couple
  weak storms over themountains this afternoon and Sunday
  afternoon. Any precipitation would be light.

- Elevated fire weather conditions as southwest breezes increase
  this afternoon on the eastern plains.

- Pattern change next week, with cooler temperatures
  finallyarriving by Tuesday. Main precipitation chances hold off
  until at least late Tuesday, but uncertainty remains.

&&

.DISCUSSION /Through Saturday/...
Issued at 112 PM MDT Sat Oct 10 2026

Radar shows light showers across the higher terrain at this hour.
Today will continue our streak of above-average days with high
temperatures in the 80s for the plains. SW flow aloft has
increased over the last 24 hours. Thus, winds could be breezy in
our mountains and the eastern plains this afternoon. With relative
humidity dropping into the teens across the eastern plains, we
expect a few hours of elevated to near-critical fire weather
conditions for those locations this afternoon. Some isolated to
scattered showers will continue to remain possible in the higher
terrain today, with a low (~10-20%) chance for these to push off
into the urban corridor and the adjacent plains. Little measurable
rainfall is expected and this would only be widely scattered in
the higher terrain. Some showers could continue through the
overnight for far western portions of our area including Jackson,
Grand, and Summit counties. Given increasing high-level cloud
cover overnight, it will be another unseasonably warm night with
another record warm minimum for the day possible. 57 degrees
(1881) is the record warm minimum for Sunday.

On Sunday, the remnants of Tropical Storm Rachel move into the
western US with any notable precipitation staying well to the west
of our forecast area. For our area, high temperatures should take a
slight dip, but will remain in the 80s for most of the plains.
Another round of isolated to scattered showers will be possible for
the high country, mainly west of the Continental Divide. The
forecast starts to become more uncertain by Monday. It is becoming
more likely that a backdoor cold front will stall somewhere
over/just north our northeastern counties. South of the front,
temperatures should stay in the upper 70s to near 80, but north of
the front, temperatures could drop into the low 70s. Regardless, we
expect this front to push through the area by Tuesday morning
bringing a "cool" down with highs into the upper 60s to low 70s on
the plains (except for our far southeastern counties) for Tuesday
afternoon- still a few degrees above average for this time of year.

There are still significant differences in the forecast across the
latest model suite starting Tuesday night through the end of the
week. The position/speed/strength of the trough and upper-level
low(s) remains uncertain. The ECMWF has trended slower and further
west over the last few runs while the GFS moves a somewhat weaker
low over or north of our area. In general, we expect PoPs to
increase starting late Tuesday and peak on Wednesday with Thursday
continuing to trend drier. Note that a vast majority of ensemble
members (~90%) give Denver some measurable rainfall, with amounts
generally under 1/2 inch. Some of the moisture associated with the
remnants of Hurricane Simon could be pulled into the flow aloft,
mainly affecting areas to our east. As snow levels drop through the
week and moisture increases, the mountains and high country (mainly
above 10,000 feet) could see a few inches of snow. Our northern
mountains in particular look most favorable.

From Thursday onward, the GFS progresses the upper-level low off to
the east with another low moving from Canada into the Great Lakes
region towards the end of the week and into the weekend. The ECMWF
keeps the upper-level low hung up over the Four Corners through the
end of the week. Regardless, high temperatures look to finally stay
near to below average through at least next Saturday with at least
some low PoPs in the mix.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1126 AM MDT Sat Oct 10 2026

VFR conditions will prevail for all terminals through the TAF
period. The corridors of gustier W winds over the western metro
have almost entirely vanished per latest TDEN returns, in favor of
weaker southerly flow, although a corridor of more robust S/SW
flow remains evident in the vicinity of KAPA. Will need to monitor
this area given at least some potential to push towards KDEN in
the coming hours. For now though, opting to retain weaker WSW/SW
flow in the KDEN TAF.

Guidance continues to indicate potential for isolated high based
light SHRA (predominantly virga) over the I-25 corridor mid to
late afternoon, however have pushed back the start time for PROB30
groups to 21Z to reflect latest timing confidence. A few gusts to
around 20 kts or briefly slightly higher will be possible with
passing virga. Expect a return to drainage flow this evening.

&&

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

&&

$$

DISCUSSION...MV
AVIATION...BRQ

NWS BOU Office Area Forecast Discussion