582
FXUS65 KBOU 200550
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1150 PM MDT Tue May 19 2026

.KEY MESSAGES...

- Unsettled Tuesday through Friday with scattered to numerous
  showers and a few storms, most numerous in/near the Front Range.

- Warming and drying trend for the weekend.

&&

.DISCUSSION /Through Tuesday/...
Issued at 1259 PM MDT Tue May 19 2026

Water vapor satellite imagery showsan upper level trough over
the Great Basin with southwest flow across Colorado. The right
entrance of a 100-110 knot jet will provide lift for bands of
showers. Radar and satellite imagery indicate this jet lift is
increasing with showers currently forming. Showers will continue
through the rest of the afternoon and into the overnight hours.
Best jet lift exits the area this evening, but upslope flow and
ascent ahead of the trough should provide enough lift for light
showers to continue tonight. The best chance for showers shifts
over eastern Colorado by sunrise Wednesday morning. Additional
showers and isolated thunderstorms are expected Wednesday
afternoon and evening as upslope flow persist and lift ascent from
the trough continues.

Colorado will be between systems late Wednesday night and
Thursday morning. We finally see some sunshine, which will push
temperatures into the 60s. This will help destabilize the
airmass, with SBCAPE climbing to 500-1000 J/kg. Lift increases
throughout the day ahead of an upper level trough moving east-
southeast across Wyoming. Showers and thunderstorms are likely
Thursday afternoon and evening. Depending on the amount of
instability, a few of the storms could be severe. Something to
monitor over the next two days. Areas of rain are expected to
linger into the overnight hours Thursday and by Friday morning,
rain showers will exit the eastern plains. Most of Friday is
expected to be dry with temperatures in the 60s across northeast
Colorado. A weak wave embedded in the flow aloft will bring
scattered showers late Friday and early Saturday.

An upper level ridge begins to build over the Central and Southern
Rockies Saturday. Chances for showers and thunderstorms decrease,
but there may be enough moisture for isolated to scattered showers
and thunderstorms. Temperatures will warm into the upper 60s to
mid 70s across northeast Colorado. Ridging will be centered over
the Central Rockies Sunday and the first half of Monday.
Temperatures will continue to warm under the ridge with highs in
the 70s to lower 80s across northeast Colorado. Chances for
showers and thunderstorms will be very low Sunday, but increase
Monday as the ridge slides off to the east late in the day. For
next Tuesday, models show an upper level trough digging south
across the northwest part of the country. Ahead of this, we should
see a round of showers and thunderstorms Tuesday afternoon and
evening.

&&

.AVIATION /06Z TAFS through 06Z Thursday/...
Issued at 1143 PM MDT Tue May 19 2026

Light rain and mist will continue near the TAF sites through the
early morning. Rain will likely clear out of the KBJC area first
and KAPA last. We`ll see a brief break in rain chances in the mid
to late morning, before they return. Showers and storms are
expected to form in the area around 17Z to 19Z and then progress
eastward over the next couple of hours. This will be the best
chance of showers and storms. There is potential for some
lingering rain after the initial push, but models are starting to
trend further south with that activity, so the best chance for
additional rain in the afternoon and evening will be at KAPA. MVFR
CIGs are present this evening and will continue through tomorrow
morning, before they start to lift around 14Z to 16Z to low end
VFR for the afternoon (4000ft to 6000ft).

&&

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

&&

$$

DISCUSSION...12
AVIATION...AP

NWS BOU Office Area Forecast Discussion