343
FXUS65 KBOU 162359
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
559 PM MDT Sun Aug 16 2026

.KEY MESSAGES...

- Scattered thunderstorms possible through this evening. A few
  of them could become strong to severe, with strong winds, large
  hail, and heavy rainfall.

- Warming and drying trend for Monday and Tuesday, but still
  isolated gusty pm storms/virga.

- More active weather day shaping up for Wednesday with scattered
  severe thunderstorm threat.

- Warmer again through the coming weekend with above normal
  temperatures. Drier Thursday and Friday, but some monsoonal
  moisture likely returns by the weekend.

&&

.DISCUSSION /Through Sunday/...
Issued at 1238 PM MDT Sun Aug 16 2026

Rich, low level air remained in place across the plains this
afternoon. This along with daytime heating is building MLCAPE
into the 1000-1800 J/kg range. Local ACARS soundings still show a
pretty healthy cap in place, but we are warming and should at
least get close to convective temperatures. The most likely area
for convective initiation of course is over the mountains (already
ongoing), but also the higher terrain of the Palmer Divide and
Cheyenne Ridge. Storms will likely move in a southeasterly
direction once they develop, and a weakening cap is expected to
allow propagation across the plains and portions of the I-25
Corridor. Bulk shear will be increasing to 30-35 kts, so enough
shear and instability is present for a few supercells. Thus, large
hail and damaging winds will be a threat with any storms through
mid evening. It should be worth noting that we`ll be under the
right entrance region of an upper level speed max, so weak forcing
should help coverage a bit so we did bump pops up ever so
slightly, with the highest odds of storms over the northeast
plains and Palmer Divide. That upper level speed max could also
aid storms to last a bit longer into the evening than normal.

We still expect clearing skies overnight, and enough lingering low
level moisture for some patchy fog over the plains and in the
high mountain valleys.

Monday will feature warmer and drier weather as the ridge axis
retrogrades to the west-northwest. That puts our forecast into a
drier westerly flow aloft, and mid level temperatures will also be
warming. Highs are expected to reach the upper 80s to lower 90s
over the plains and I-25 Corridor. We`ll still likely have enough
lingering moisture and strong daytime heating to support isolated
late day convection. The airmass along the I-25 Corridor would be
more supportive of just isolated late afternoon/evening sprinkles
and microbursts as DCAPE grows to ~1500 J/kg. Similar weather
conditions although further warming of a few degrees is expected
for Tuesday. Also, a late afternoon frontal passage will likely
be enough to support growing high based shower/storm coverage into
the Tuesday evening and overnight hours.

Wednesday is still on track to be slightly cooler with increased
chances of storms again as the post frontal airmass will be cooler
and more moist. Average MLCAPE from various models suggest
1000-2000 J/kg, while bulk shear is an impressive 40-50 kts so a
growing severe storm threat will be in the picture.

Thursday and Friday are shaping up to be drier again as the ridge
amplifies, this time across Colorado and eastern Utah. That means
a stronger thermal ridge and high temperatures pushing well above
normal...into the lower to mid 90s across the plains and I-25
Corridor. While the ridge should hold fairly steady across the
Central Rockies through at least next weekend, ensembles have good
agreement for an increase in monsoonal moisture under the ridge.
That would support a return to scattered afternoon and evening
shower/storms as well, with the greatest chances holding over the
mountains at least until early next week.

&&

.AVIATION /00Z TAFS through 00Z Tuesday/...
Issued at 541 PM MDT Sun Aug 16 2026

While most of today`s convection has cleared out of the Denver metro
area, some lingering showers and thunderstorms could remain this
evening, prompting us to keep the PROB30s in until 02Z (03Z for
BJC). Following any outflows/variable winds from showers, winds are
expected to turn westerly tonight, reaching S/SW by around 09Z. With
that drainage, clouds are looking to clear out, especially at the
low levels (

NWS BOU Office Area Forecast Discussion