410
FXUS65 KBOU 141751
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1151 AM MDT Tue Oct 14 2025

.KEY MESSAGES...

- Precipitation chances return late Wednesday into Thursday across
  the mountains and plains. Cold enough for snow in the higher
  mountains.

- Turning warmer and drier again by the weekend.

&&

.UPDATE...
Issued at 403 AM MDT Tue Oct 14 2025

Drier air is moving in from the southwest with some clearing south
of Denver. However, it looks like moisture will linger over the
mountains this morning. While the deeper convection will remain
west of the Continental Divide, there will continue to be weak
showers for a little while longer. We expect the drying to be more
widespread by this afternoon with only a few isolated showers.
Updated PoPs and cloud cover in line with the above.

&&

.DISCUSSION /Through Monday/...
Issued at 238 PM MDT Mon Oct 13 2025

A weak shortwave should race across the region this evening into
tonight, with scattered rain showers across the plains and
rain/snow showers over the higher elevations. We should quickly
clear behind the shortwave tomorrow, with warmer temperatures
likely in the continued south-southwesterly flow aloft.

A large upper low is expected to drift from the central California
coast into central Utah from Tuesday afternoon into Wednesday
night, with the upper flow aloft gradually strengthening.
Wednesday looks to be the warmest day of the week - coinciding
with the stronger mid-level flow and warmer 700mb temperatures
(near 10-12C) - with highs likely reaching the mid/upper 70s. A
few spots in the plains may see some low 80s. Despite the
approaching trough, moisture is fairly limited and there shouldn`t
be much more than a few light rain or snow showers across the
higher terrain.

The upper trough axis is then expected to weaken and lift
northeastward into Wyoming from Wednesday night into Friday
morning, with one stronger shortwave rotating around the base of
the trough into our CWA sometime on Thursday. Guidance for the
most part is in agreement that this should provide a brief shot of
snow across the northern mountains, perhaps with some upslope
precipitation across the Front Range behind a cold front. Still,
the limited amount of moisture to work with along with the brief
period of favorable lift will keep any snowfall accumulations
fairly light.

The upper trough should lift well into the northern Great Plains
by this weekend. Northwest flow aloft on Saturday will keep
temperatures near normal, and could also bring some orographic
snow to portions of the northern mountains (mainly Park Range) if
enough moisture lingers in the area. A ridge is expected to build
into the region Sunday and Monday, with a good signal for above
average temperatures.

By early next week, most guidance tries to bring in a strong
shortwave/trough axis into the region, though there are fairly
large differences in timing/strength. Either way, that potential
storm system would bring us back to cooler than normal
temperatures, along with a chance of some rain and snow into the
region.

&&

.AVIATION /18Z TAFS through 18Z Wednesday/...
Issued at 1151 AM MDT Tue Oct 14 2025

Denver cyclone/shear boundary beginning to show up nicely on the
TDEN radar. It extends from near APA (just north) to CFO. The
boundary has been fairly stationary over the past hour. It is
farther south than most of the models show, so will continue with
north/variable winds through the afternoon. However, there is
still a chance (30-40%) that the boundary drifts northward through
DEN bringing gusty southwest winds. After 00Z, the cyclone
weakens and winds eventually return to a southerly drainage
direction by 06Z (or sooner if the boundary moves through).

For Wednesday, southerly flow increases ahead of an approaching
upper level trough. Most models show fairly strong south winds
(gusts greater than 25 knots) after 18Z Wednesday. Feel the models
are underplaying the Denver cyclone. Usually we will see a well
developed Denver cyclone through early afternoon in these set ups
and then it slowly mixes out during the afternoon. Expect gusty
south winds to arrive at DEN, but may not occur as soon as the
models show. Another thing to watch for Wednesday will be
thunderstorms after 20-21Z. HRRR is bullish with thunderstorm
development, while other models show drier air and fewer to no
storms for the Denver area. Drier air typically wins out,
especially with the southerly downslope winds off the Palmer
Divide, so will leave the mention of storms out of the TAFs at
this time.

&&

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

&&

$$

UPDATE...Gimmestad
DISCUSSION...Hiris
AVIATION...12

NWS BOU Office Area Forecast Discussion