420
FXUS65 KBOU 231902
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
102 PM MDT Sat May 23 2026

.KEY MESSAGES...

- Isolated threat for severe storms this afternoon in the far
  northeast corner of Colorado. Wind and hail would be the primary
  hazards.

- Warmer and drier this weekend, with only isolated showers and
  storms possible each afternoon/early evening.

- Remaining mild next week, but scattered afternoon and evening
  showers and storms expected most days.

&&

.DISCUSSION /Through Saturday/...
Issued at 1253 PM MDT Sat May 23 2026

This morning`s upper-air charts show an upper-level low situated
along the Canadian border over North Dakota and Minnesota, with the
associated trough axis still stretching across eastern Colorado. 700
mb dewpoints show some lingering moisture remains east of the
Rockies, but a swath of higher dewpoints remains just south and east
of Colorado. The trough is expected to progress eastward through
today with upper-level ridging expected to move overhead on it`s
backside. A brief warming trend is expected to kickoff today, with
afternoon high temps expected to hover near-normal across the
forecast area, reaching values roughly 10 degrees warmer than
yesterday`s highs. Expect low to mid 70s along the urban corridor,
with 60s forecast for the high mountain valleys today before
temps warm by another 10 degrees or so for Sunday. Precipitation
chances are primarily anchored to the higher elevations today in
the form of some high-based virga showers, and for the far
northeast plains where the SPC has placed a sliver of our
northeast corner in a marginal (1/5 risk level) for isolated
strong to severe thunderstorm potential for wind and hail. The
main severe potential will likely remain east of our forecast area
where the majority of the hi-res guidance continues to show the
higher dewpoints remaining, but if these slide a bit more westward
like portrayed in a few of the deterministic models, with 35-45kt
500mb flow aloft, can`t rule out the potential for isolated
severe hail or wind. There will also be potential for any of the
aforementioned high-based showers that develop to bring gusty
winds as they move off the terrain as DCAPE values between
800-1000 J/kg will be possible through the afternoon hours that
could produce gusts up to 35-40 mph. Mild temps (mid to upper 40s)
are expected across the majority of the lower elevations for the
overnight hours, with the base of the foothills expected to be in
the low 50s and the mountain valleys dropping into the 30s.

For Sunday, it will be warm and mostly dry as the aforementioned
warming trend continues. 700 mb temps are expected to increase to 9-
11C under a fairly zonal upper-level ridge. Temperatures are
forecast to climb into the 80s along the urban corridor, approaching
90 across our northeast plains, and 60s to 70s for the high mountain
valleys. We could see a few afternoon high-based showers/weak storms
develop over the higher terrain that will likely be accompanied by
some gusty outflows once again.

From Monday onward, ensembles show a gradual increase in PWAT each
day through the week, with the best moisture expected over the
higher elevations. An upper-level low is likely to move ashore
Southern California Sunday, progressing eastward and turning flow
aloft over Colorado to the southwest by Monday morning, despite
the broad upper-level ridge axis remaining in place across the
Rockies. Monday is expected to be the warmest day of the week,
with afternoon highs expected to reach 10-15 degrees above-normal
across the plains. This will bring an uptick in showers and
thunderstorms for the afternoon as PWAT values reach roughly
120-140% of normal along the mountains and up to 120% of normal
for the plains, as the ridge axis shifts off the spine of the
Rockies through the day. By Monday evening, an upper-level low
will move ashore the Pacific Northwest and help amplify the ridge
now over the Central Plains. This low is expected to drop
southward and into the Great Basin where it`s expected to remain
blocked (stationary) through the long term forecast period.
Temperatures will turn back towards near normal as we have daily
chances for showers and thunderstorms as the low remains just to
our west through the week and PWAT values remain above normal
through at least Thursday.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1230 PM MDT Sat May 23 2026

Current observations show light winds (

NWS BOU Office Area Forecast Discussion