958
FXUS65 KBOU 100420
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1020 PM MDT Fri Oct 9 2026

.KEY MESSAGES...

- Unseasonably warm through at least Sunday.

- Mainly dry weather continues, with only isolated to
  scatteredshowers (15-30% coverage) and a couple weak storms
  over themountains through Sunday. Any precipitation would be
  light.

- Elevated fire weather conditions as southwest breezes
  increase,especially on Saturday.

- Pattern change next week, with cooler temperatures
  finallyarriving by Tuesday. Main precipitation chances hold off
  untilthe middle of next week, but even then much uncertainty.

&&

.DISCUSSION /Through Friday/...
Issued at 1014 PM MDT Fri Oct 9 2026

There is good agreement thru the weekend that an elongated upper
level trough will extend from the Pacific NW southward into
California. This will allow for mainy SW flow aloft across the
area thru Sun. Ahead of this trough, moisture from Rachel will
move northeast with the best PW`s staying over wrn CO into the
Great Basin. Thus precip chances will stay on the low side across
much of the area, except west of the Divide, where there will be a
a chc of showers and a few tstms each aftn. As far as temps,
readings will remain well above normal, across much of the area on
Sat, with highs in the mid to upper 80`s over nern CO. For Sun,
depending on how much higher level cloud cover there is, readings
may end slightly cooler over the plains with highs in the lower
to mid 80`s.

Looking ahead to Mon, an upper level low will develop over
California and Nevada with SW flow aloft over the area. Once
again, any tropical moisture with the remnants of Rachel will stay
west of the area. Thus, any chc for showers/tstms will remain
west of the divide. Meanwhile, there is still some disgreement as
to whether a cool front will backdoor into nern CO. The latest
data has it stalling out over the far nern plains. As a result,
this would lead to another day of above normal temps over much of
the area.

By Tue, the upper level low will move into the Great Basin with SW
flow aloft remaining over the area. There is agreement that a
cool front will move across nern CO Mon night into Tue. As a
result, should see highs drop back to more seasonal levels across
the plains. Meanwhile, as far as precip chances, once again it
appears best chance will stay mainly to the west of the area with
any shower/tstm activity focused west of the divide.

For Tue night thru Wed, there remains a lot of uncertainty on how
quickly the upper level low will move to the ENE.  The GFS has this
system moving from Utah into central WY by Wed aftn while the ECMWF
keeps the system stalled over Utah.  Overall, should see a gradual
increase in precip chances for the higher terrain late Tue night
into Wed, unless the system slows down even further.  In addition,
would likely see accumulating snow in the mtns as well. Across nern
CO, it will be cooler as highs stay in the 60`s with a good chc of
showers and a few tstms, especially on Wed.

By Thu, the ECMWF has an elongated weakening upper level low
extending from sern WY into swrn CO.  Meanwhile, the GFS has the
upper level low over central South Dakota.  If the ECMWF is correct
then it would remain cool and unsettled over the area.  On the other
hand, the GFS solution would lead to dry conditions with seasonal
temperatures.

&&

.AVIATION /00Z TAFS through 00Z Sunday/...
Issued at 542 PM MDT Fri Oct 9 2026

VFR conditions expected through the TAF period. Expecting to see
wind speeds continue to slacken over the next hour, with an
easterly progression of the shear zone that has been in place west
of KDEN/KAPA in the next hour to bring winds around to the NW.
Winds are expected to settle into a SSW flow for the overnight
hours at KDEN/KAPA (by 3-5Z), but there could be a brief period of
light and variable winds behind the boundary or a gradual
counterclockwise turn before they settle in. KBJC is expected to
maintain more of a SW to westerly flow for the overnight hours.

For Saturday, winds should start to turn to the SW around 19/20Z
at KDEN, slightly sooner at KAPA. Forecast soundings show DCAPE
approaching 1,000 J/kg in the afternoon that would bring potential
for some passing virga showers (gusty winds with no precipitation)
beginning around 21Z. A PROB30 has been introduced at KDEN and
KBJC from 21Z-24Z to account for some gusty outflows from any
virga that could move across the TAF sites, with winds between
20-25 kts possible if they do move overhead.

&&

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

&&

$$

DISCUSSION...RPK
AVIATION...9

NWS BOU Office Area Forecast Discussion