371
FXUS65 KBOU 101844
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1244 PM MDT Fri Jul 10 2026

.KEY MESSAGES...

- Isolated to scattered showers and a few thunderstorms with
  gusty winds into early this evening.

- Prolonged period of hot temperatures arrives Saturday, lasting
  through most of next week.

- Hints of monsoon moisture reaching the high country by late next week,
  but considerable uncertainty depending on positioning of upper
  level ridge.

&&

.DISCUSSION /Through Friday/...
Issued at 1244 PM MDT Fri Jul 10 2026

One last somewhat active weather day before a prolonged dry and
hot spell sets in. Isolated to scattered convection is developing
along the Front Range early this afternoon. These showers and
storms will be moving generally east-southeast across the plains
through late afternoon and early evening, before finally ending in
the Lincoln County area closer to 10 pm. There is some low level
moisture advection into east central Colorado on the heels of
easterly winds, so MLCAPE should build toward around 1000 J/kg.
Thus a couple strong to severe storms would be possible southeast
of Denver, currently where a Marginal Risk of severe storms is in
place from SPC.

On Saturday, the upper level ridge that will dominate our weather
for the week ahead will start to build northward. That means
hotter temperatures and drier weather. Isolated high based
showers/virga or a lone storm is still possible in the afternoon
due to strong diurnal heating, but these should be confined to
the Palmer Divide and Park County area as other areas remain
drier. High temperatures will warm several degrees from those
observed today as the heat dome builds in. High temperatures are
expected to climb into the 90s across almost all of the plains,
with the hottest readings (upper 90s) along the I-25 Urban
Corridor into Greeley.

Heat will remain the main concern through much of the upcoming
week. There is strong model agreement that the anomalously strong
upper high (500 mb heights near 601 decameters, or ~3 standardized
anomalies) builds from Wyoming into North & South Dakota. The
highest 850 mb temperature anomalies are still forecast to stay
well to our north, while the heart of the mid level thermal ridge
stays off to our north and west. As ironic as this sounds, we`ll
have weak "cool" advection across the plains with deep southeast
flow in place. By all means, that does not suggest we will be
cool, but instead we won`t be approaching all time record highs
east of the Rockies and will also likely stay a couple degrees shy
of daily records. However, the same can`t be said for our high
mountain valleys west of the Front Range. Those locations will be
underneath the mid level thermal ridge and also have a downslope
component to aid compressional heating. Thus, near all time record
highs can be expected at least early this coming week for places
like Dillon (89F), Kremmling (93F), and Grand Lake (88F). With
regard to potential highlights, highs are expected to hold in the
upper 90s across most of the plains and I-25 Corridor, so we`ll
at least be approaching Heat Advisory conditions by Monday. Skies
will be all but clear, so sunshine will add to the heat load/
component. However, at the same time decent radiational cooling
and recovery is expected overnight. There is some uncertainty on
those cooler temperatures however, where enhanced drainage winds
could hold in this southeast flow regime - especially for the
south/east parts of metro Denver.

The only, and slight, chance of an afternoon shower/storm would
be over the Park County area in this flow regime Sunday into
early next week. Some models show a little mid level moisture into
the mountains as early as Wednesday, with a further increase of
monsoonal moisture building under/just west of the ridge axis
through late next week. However, we are uncertain as to whether or
not that ridge retrogrades too much and shunts the deeper
monsoonal moisture further to our west. So, something to keep an
eye on as wherever the plume does shift should see a significant
uptick in daily showers/storms and chances for wetting rains. For
now, it appears that stays mostly west of the Front Range until
potentially the following weekend. Until that changes, hot/mainly
dry weather will prevail given this monster of a ridge.

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 1117 AM MDT Fri Jul 10 2026

VFR conditions will prevail for all terminals through the TAF
period. Winds have begun to shift to the NE and will take on an
increasingly easterly component through mid to late afternoon.

Primary concern today remains the potential for high-based
convection. The window has shifted slightly later, focused between
23Z and 03Z this evening, with the highest chances of impacts to
KDEN between 01-03Z. Confidence in true TSRA impacts is lower than
that for outflow winds (~30% vs 50-60% respectively). Winds will
swing to the southeast this evening before settling into drainage
flow for the overnight period.

&&

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

&&

$$

DISCUSSION...20
AVIATION...BRQ

NWS BOU Office Area Forecast Discussion