986
FXUS65 KBOU 251058
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
458 AM MDT Sat Jul 25 2026

.KEY MESSAGES...

- Record or near record heat this weekend

- Heat Advisory for the I-25 Corridor today, expanding to all of
  the plains for Sunday as heat builds

- Scattered afternoon/evening thunderstorms this weekend, most
  numerous over the higher terrain

- Increasing chances for thunderstorms with locally heavy rain
  Monday, Tuesday, and Wednesday.

&&

.DISCUSSION /Through Friday/...
Issued at 239 AM MDT Sat Jul 25 2026

Hot weather is locked in for this weekend as a dominating ridge
of high pressure remains centered across the Central Rockies. Mid
level temperatures warm another 1C today and potentially another
0.5-1C on Sunday. That means we`ll be pushing to near 100F across
all of the I-25 Corridor and plains this afternoon, and likely to
or exceeding the century mark on Sunday when a few of the lower
elevations on the plains could be very close to 105F. The Heat
Advisory remains in effect for the I-25 Urban Corridor for today,
but based on further warming and building heat impacts we have
expanded the Advisory to all of the northeast plains for Sunday.
Denver`s records of 99F today (set in 1963 and 1931) and 100F
tomorrow (set in 1910) could both be tied or broken.

Regarding convective potential, mid level water vapor imagery has
juiced up rather quickly after yesterday`s brief drying. In fact,
the latest models and ensembles boost our precipitable water (PW)
to near 1.20-1.25" for the Denver area by 00Z, or a good 150% of
normal. With such strong surface heating, we don`t see much
evidence of a cap in/near the I-25 Corridor and mountains.
Therefore, we expect scattered coverage of storms along the I-25
Corridor, with numerous showers and thunderstorms over the Front
Range mountains and Park County. The airmass is weakly capped over
the plains so we`ll gradually taper off the chances of any rain
to the east. With those relatively high PW values, warm cloud
depths up to 3,000 ft, and mean storm motion less than 15 mph,
locally heavy rain will be possible. That said, most areas will
only see gusty winds and light rain as typical in these scenarios.
On Sunday, there area signs of some slight drying although that
may be overdone given little if any moisture advection under the
ridge.

On Monday, the ridge center is forecast to shift slightly
southward. That would allow a better push of monsoonal moisture to
stream into the forecast area. It will still be hot, as latest
models have backed off on any meaningful cooling. At least there
will be more heat relief due to late day outflow from showers and
storms. We think coverage will be boosted as better moisture
arrives, and with PW increasing further to 150-175% of normal
locally heavy rainfall can be expected with the stronger storms.
Similar if not even higher monsoonal moisture will hold across
the forecast area Tuesday and Wednesday per latest ensemble
guidance. Thus, a couple more active weather days are expected
along with just slight cooling. Again, the main threats will be
locally heavy rainfall and localized flooding. At this time, we
see flood threats comparable to last Wednesday when spotty but
very intense rainfall occurred. Warm cloud depths have a chance to
deepen as temperatures cool slightly Tuesday into Wednesday, so
something to watch over the next few days.

For the latter portions of the week through next weekend, the
upper level ridge is forecast to retrograde into the Great Basin.
This puts more of a northwest flow aloft across Colorado, which
could lead to some mid/upper level drying. However, at the same
time we have opportunity for a backdoor weak "cool" front or two
which could aid low level moisture and instability over the
plains. Temperatures will still average a few degrees above normal
during this period, while chances of storms gradually decrease
toward next weekend.

&&

.AVIATION /12Z TAFS through 12Z Sunday/...
Issued at 458 AM MDT Sat Jul 25 2026

We`ll start this TAF period with southwest winds at KDEN and KAPA,
and more W-NW at KBJC. Those winds are expected to transition more
S-SE 15Z-18Z (may be briefly VRB), and increase with a few gusts
to 20 kts ahead of developing scattered showers and storms
this afternoon. There is a relatively high confidence of gusty
outflows with sufficient shower/storm coverage - enough for
VCTS/VCSH and TEMPO VRB G30+ kts in the most likely time frame of
21Z-24Z. There`s a slight chance (20%) that storms could begin as
early as 20Z, and a 30% chance of some gusty outflows/light
showers lasting to around 04Z. Outside of showers and storms, an
enhanced S-SW wind component is expected after 00Z, with speeds
of 10-14 kts with G20 kts, eventually settling to lighter winds
06Z-12Z Sunday.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 10 AM this morning to 9 PM MDT this evening
for COZ038>040-043.

Heat Advisory from 10 AM to 9 PM MDT Sunday for COZ038>040-
042>051.

&&

$$

DISCUSSION...20
AVIATION...20

NWS BOU Office Area Forecast Discussion