820
FXUS65 KBOU 301959
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
159 PM MDT Sat Aug 30 2025

.KEY MESSAGES...

- Scattered showers and thunderstorms will form this afternoon
  and early evening. Brief heavy rain, gusty winds, and small hail
  with the stronger storms.

- Slightly warmer and drier Sunday through Tuesday.

- Wednesday and Thursday will see a chance of storms with a cold
  front passage at some point during the two days.

&&

.DISCUSSION /Through Saturday/...
Issued at 150 PM MDT Sat Aug 30 2025

Water vapor imagery shows a shortwave trough over western
Nebraska and South Dakota with Colorado under slight subsident
flow behind this trough. Water vapor imagery also shows much drier
air aloft than yesterday. Despite the drier air and subsidence,
cooler temperatures aloft has allowed some low level instability
to form with up to 1,500 j/kg of surface based CAPE across the
eastern plains. This instability from daytime heating had lead to
the development of scattered showers and storms across our
forecast area. These storms may produce brief heavy rainfall,
small hail, and lightning. Around sunset, the showers and storms
will dissipate due to the loss of instability and the rest of the
night will be dry.

A ridge over the Intermountain West will strengthen and become
more broad Sunday through Tuesday. This will provide subsident
flow to our area. With northwest winds in the low levels, the
moisture will mostly leave our forecast area as afternoon relative
humidity will drop to 20-30%. Therefore, dry weather is expected
for the vast majority of our forecast area although the mountains
could see a few raindrops each afternoon. Temperatures will remain
a few degrees below normal but will trend warmer.

A very strong trough will be over the Great Lakes on Wednesday and
Thursday. The trough may produce small shortwaves that will near
northeast Colorado and provide weak forcing to our area. In
addition, a cold front will move through our forecast area at some
point on Wednesday or Thursday. This will push cooler air into the
area along with better moisture. Isolated showers and storms will
develop each afternoon.

The ridge over the Intermountain West will strengthen again on
Friday and will move more directly overhead. This will lead to
warmer temperatures that may reach the upper 80s across the
plains.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1231 PM MDT Sat Aug 30 2025

ACARS soundings show CAPE is building over the Denver metro and
will soon reach 1,000 j/kg. Scattered showers and storms will
develop this afternoon as a result and may move over the
terminals. Wind gusts up to 35 knots are possible with visibility
around 2 SM. The best chance for storms is between 20-02Z this
afternoon/evening.

For the rest of the TAF period, VFR conditions are expected with
light winds.

&&

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

&&

$$

DISCUSSION...Danielson
AVIATION...Danielson