739
FXUS65 KBOU 182334
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
534 PM MDT Fri Jul 18 2025

.KEY MESSAGES...

- Active pattern continues into the weekend, with scattered
  afternoon showers and storms each day, and a few severe storms
  possible Saturday afternoon/evening.

- Higher chances for rain across the Front Range mountains and
  foothills.

- Warmer and drier trend for early next week.

- 90s continue for the lower elevations through the week.

&&

.DISCUSSION /Through Friday/...
Issued at 224 PM MDT Fri Jul 18 2025

Afternoon convection is currently underway across the higher
elevations. Scattered high-based showers and storms will be
possible through the evening, with gusty outflows to 40 mph
possible across the foothills and plains, and slow moving storms
may bring some localized heavy rainfall. Greater instability is
expected for the northeastern corner of the state where slightly
higher MLCAPE and modest shear would allow an isolated severe
threat for large hail and severe gusts, but Colorado is just on
the fringes of the greatest instability/moisture/shear line,
keeping the threat limited. Cloud cover will help keep temperatures
slightly above normal overnight.

Southwest flow aloft will be in place Saturday, with increasing
moisture expected across the forecast area. PWAT values ranging from
110-150% of normal are expected as an upper-level high over the
southeast helps pull Gulf moisture into the region. While there are
some slight discrepancies between models on how far west the
moisture will make it, dewpoints in the mid 60s are expected on
the east side of a dryline, MLCAPE between 2000-2400 J/kg, and 0-6
km bulk shear between 45-50 kts across the northern corner will
support supercell development by the afternoon. The SPC has put us
in a Slight Risk for severe weather (large hail and damaging
winds) from Logan County eastward, with a Marginal west to I-25,
which seems reasonable at this time. Depending on how far west the
moisture makes it could lead to a few adjustments with the severe
risk.

The rest of the long term forecast period looks to remain fairly active,
with afternoon mountain showers and storms possible each day,
with some spilling onto the plains. Temperatures will remain in
the 90s across the plains through the week as upper-level ridging
over the central US amplifies. Light winds are expected under the
ridge and decreasing moisture to start the week will slowly
increase by mid-week as monsoonal moisture wraps around the
persistent high.

&&

.AVIATION /00Z TAFS through 00Z Sunday/...
Issued at 534 PM MDT Fri Jul 18 2025

Scattered showers and storms have once again plagued the TAF sites
with VRB winds gusting to around 30 kts. There is some backwash
from the first round of storms, but that is being quickly replaced
by more VRB winds from the southwest or west as the next batch of
scattered showers/isolated storms works east. We think this will
be the last round, so winds are expected to settle down post
showers in the 02Z-03Z time frame. Then fairly normal diurnal
winds expected for the rest of the night through 21Z Saturday.
Another round of scattered showers and storms with VRB wind gusts
to ~35 kts expected 21Z Saturday - 02Z Sunday. Ceilings are high
with only light smoke/haze, and thus VFR conditions will persist
through the period.

&&

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

&&

$$

DISCUSSION...Bonner
AVIATION...Barjenbruch