181
FXUS65 KBOU 112341
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
541 PM MDT Mon May 11 2026

.KEY MESSAGES...

- Summerlike warmth and drier weather this week, with highs in the
  80s for the lower elevations.

- Warmest temperatures of the week (mid to upper 80s for the
  plains) on Wednesday and Thursday.

- A few afternoon showers and an isolated thunderstorm possible
  from Tuesday through Friday, mainly across the Front Range
  mountains and foothills.

&&

.DISCUSSION /Through Monday/...
Issued at 1213 PM MDT Mon May 11 2026

The well-advertised ridge across the southwestern CONUS is
gradually strengthening, leaving most of Colorado in a warm but
relatively quiet pattern over the next several days.

We`re well on track to seeing highs in the mid/upper 80s across
the plains today, with 12 PM temperatures already in the low 80s
at most locations. With dry air overhead (shown well by water
vapor satellite), only a few clouds are expected through afternoon
and evening hours.

A weak cold front is still expected to arrive sometime late
tonight or early on Tuesday. The front is expected to bring some
short-lived cooling (highs ~5-10F cooler than today), along with a
modest increase in moisture. Most guidance develops a narrow
corridor of instability across the Front Range during the
afternoon hours, and the weak upslope flow behind the front should
allow for a couple of weak showers and perhaps a brief
thunderstorm despite some capping.

Temperatures should quickly warm back up into mid/upper 80s by
Wednesday, with those well above normal temperatures continuing
into the weekend. Guidance has been slowing warming temperatures
on Wednesday, with ~30% of ECMWF ensemble members now getting DEN
to its first 90F high of the year. However, statistical guidance
remains a few degrees cooler and our current forecast is still
just under 90F for most locations. There is also a weak wave
working through the region Wednesday afternoon, with deeper
moisture aloft and better instability across most of the forecast
area. If we`re going to see any convection/measurable
precipitation this week, Wednesday afternoon would be the time to
do it.

Drier zonal flow by Thursday slowly transitions to southwesterly
flow aloft by the upcoming weekend. Guidance is generally in
better agreement handling the few 500mb shortwaves across western
North America in this time period, and generally keeps things
quite dry through the rest of the forecast period. The pattern
does look like it would turn a little more active by early next
week with a couple stronger shortwaves noted in today`s guidance.

&&

.AVIATION /00Z TAFS through 00Z Wednesday/...
Issued at 535 PM MDT Mon May 11 2026

VFR conditions are expected to last through the forecast period.
NW downslope winds have been present mainly across the west
Denver metro, including at KBJC this afternoon. KBJC has been
gusting between 15 and 25 kts over the last two hours. These
winds have been working somewhat in and out of the western edge of
KDEN over the last hour to 90 minutes. High-res modeling has been
been trending toward KDEN having NNW/NW winds between 10 and 15
kts for the next few hours and thus is our current forecast. There
is still a ~30% chance that winds stay light and variable at
KDEN. KAPA should stay light and variable under 10 kts this
evening. By late this evening around 04z, winds will turn to
drainage at KAPA. At KDEN and KBJC, winds should turn to a more W
and/or WSW direction, but may not turn to a true drainage ahead of
the incoming cold front.

The cold front will move through all three sites between 10z and
12z early tomorrow morning turning winds to be north to slightly
NNE, first moving through KBJC and KDEN before KAPA. A few lower
clouds around 9000 to 10000 ft AGL are possible early tomorrow
after the cold frontal passage, but VFR conditions should
continue. Winds will be at most between 15 and 20 kts immediately
following the cold front, but will then be under 10 kts after
15z.

By tomorrow afternoon, winds will turn to NE/E with only some
sct mid- to high-level clouds. By late Tuesday afternoon, some
virga could develop, especially near KBJC, but has only about a
15-20% chance of occurring. There is an even lower chance (~10%)
for virga at KAPA or KDEN tomorrow afternoon. The possibility is
too low to include in the TAF at this time, but have included bkn
mid-level clouds to account for the increase in moisture.


&&

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

&&

$$

DISCUSSION...Hiris
AVIATION...MV

NWS BOU Office Area Forecast Discussion