National Weather Service Forecast Discussion

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044
FXUS65 KBOU 230612
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1212 AM MDT Sat May 23 2026

.KEY MESSAGES...

- Warmer and drier this weekend, with only isolated showers and
  storms possible each afternoon/early evening.

- Remaining mild next week, but scattered afternoon and evening
  showers and storms expected most days.

&&

.DISCUSSION /Through Friday/...
Issued at 1212 AM MDT Sat May 23 2026

A shortwave trough is tracking across central andeastern
Colorado at this time. Showers over the eastern plains will
diminish as they track eastward, ending before sunrise. Subsidence
and drier air will prevail behind the exiting shortwave trough.
Temperatures warm up today with highs reaching the 70s across
northeast Colorado. A few high-based showers are possible with
outflow winds reaching 30 mph. The best chance for isolated high-
based showers will be over the higher terrain.

Upper level ridging begins to develop late Saturday and by Sunday
an upper level ridge will prevail over the Central Rockies.
Temperatures will continue to warm for Sunday with highs in the
lower to mid 80s across northeast Colorado. Mostly dry conditions
will continue with only a few high-based showers/thunderstorms
possible. A weak upper level trough approaching from the Desert
Southwest will push the ridge axis east of Colorado on Monday.
However, the ridge will still influence the weather with warm
temperatures continuing. An uptick in moisture is expected to
increase shower and thunderstorm coverage Monday afternoon and
evening. A large upper level low over the Pacific Northwest will
track south-southeast and eject the weak trough out of the Desert
Southwest. The trough then moves across the Central Rockies on
Tuesday. This will lead to slightly cooler temperatures and a
better chance for showers and thunderstorms.

For Wednesday through Friday, the large upper level low stalls
over the western states as ridging blocks its eastward
advancement. South to southwest flow aloft is expected with a
southeast low level flow. This is expected to increase moisture
and lead to cooler temperatures. Daily afternoon and evening
showers and thunderstorms are expected under this pattern. As we
head towards Thursday and more so Friday, the weather pattern
becomes highly uncertain due to the track of the upper level low.
&&

.AVIATION /06Z TAFS through 06Z Sunday/...
Issued at 1212 AM MDT Sat May 23 2026

Showers will continue to move off to the east as a shortwave
trough tracks across Colorado. Drier air will start to move into
the area soon, bringing showers to an end and decreasing clouds.
VFR will persist through the period. Southeast winds will turn
south to southwest overnight and continue into this morning, ~15Z.
Forecasting wind direction will be challenging today. With
ridging forming overhead, opted to lean towards the models showing
light and variable winds. High-based cumulus clouds will develop
this afternoon with bases at 8,000-10,000 feet. Virga and outflow
winds will be possible, but they currently look limited, so
decided against including a tempo or PROB30.

&&

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

&&

$$

DISCUSSION...12
AVIATION...12

NWS BOU Office Area Forecast Discussion