National Weather Service Forecast Discussion

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403
FXUS65 KBOU 041151
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
551 AM MDT Sun Oct 4 2026

.KEY MESSAGES...

- Dry and unseasonably warm weather for the week ahead.
  Record/near record warmth on Monday.

- A few showers possible Tuesday as a weak disturbance moves
  across.

&&

.DISCUSSION /Through Saturday/...
Issued at 1049 PM MDT Sat Oct 3 2026

An upper level high will be centered over the Great Basin on Sun and
then will weaken some on Mon.  Cross-sections show just enough mid
level moisture with favorable lapse rates to allow for isold high
based showers mainly over Park county Sun aftn.  Otherwise it will
be dry with above normal temperatures.

On Mon, once again there is some mid level moisture embedded in weak
NW flow aloft.  As a result, can`t rule out isold high based showers
over the high terrain.  Meanwhile, with rising 850-700 mb temps
along with downslope low level flow, highs will be near record highs
across portions of the plains as readings reach the mid 80`s to
around 90.

On Tue, a weak disturbance may affect the area with some increase in
mid level moisture.  Thus may see a slightly better chc of high
based showers/isold tstms over the higher in the aftn.  Over nern
CO, it will remain dry with highs remaining 10 to 15 degrees above
normal.

By Wed, the flow aloft will remain weak WNW. The ECMWF still shows
some lingering mid level moisture over the higher terrain while the
GFS doesn`t.  Overall, any high based shower activity should be
rather isold.  Once again highs will be 10 to 15 degrees above
normal.

For Thu and Fri, the flow aloft will become more zonal by Fri with
mainly dry conditions expected.  Highs both days will continue 10 to
15 degrees above normal over much of the area.

By next Sat, the flow aloft will increase from the WSW as an upper
level trough develops over the Pacific NW.  Meanwhile, there are
significant disagreements between the ECMWF and GFS as to where this
system will be by late Sun.  The ECMWF intensifies the upper level
trough and keeps it near the West Coast while the GFS moves it
quickly into the nrn Rockies and Great Basin.  At this point, really
hard to say which solution will pan out.  However, it looks warm and
dry on Sat with highs from 10 to 15 degrees above normal.  For Sun,
there could be a chc of precip in the mtns late in the day based on
the faster GFS solution.  Meanwhile, will likely see another day of
above normal temperatures as well.

&&

.AVIATION /12Z TAFS through 12Z Monday/...
Issued at 525 AM MDT Sun Oct 4 2026

VFR conditions expected through the TAF period. South-
southeasterly winds have dominated through the overnight hours
tonight. A gradual increase in speeds is expected over the next
few hours, with a few hours of 15 to 20 kt gusts possible between
roughly 15Z-17Z at KDEN/KAPA. After that, winds should transition
to the south-southwest before becoming light and variable between
18Z-19Z at KDEN/KAPA, with a north to northeasterly shift
expected at KBJC. Winds are expected to remain generally light
through the afternoon (

NWS BOU Office Area Forecast Discussion