922
FXUS65 KBOU 201138
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
538 AM MDT Wed May 20 2026

.KEY MESSAGES...

- Unsettled Tuesday through Friday with scattered to numerous
  showers and a few storms.

- Warming and drying trend for the weekend.

&&

.DISCUSSION /Through Tuesday/...
Issued at 109 AM MDT Wed May 20 2026

Cooler temperatures and rain chances are expected to continue
through the workweek. An upper level trough will remain to our
west/northwest through Thursday. Ahead of the trough, we`ll see
decent large scale lift. And with the moisture already present
thanks to the rain the past few days, this will be enough to
produce some scattered showers and thunderstorms during this time.
For today, instability is on the lower end (MLCAPEs 400 J/kg or
less), so we`re not expecting any severe storms this afternoon.
The one thing we will need to keep an eye on the potential for
landspouts. High res models have a Denver cyclone developing near
the urban corridor this afternoon and we do have some weak
surface CAPEs in that area, so landspouts are not out of the
question. For Thursday, coverage and intensity of storms look a
bit higher. Moisture will be ushered into the area at the surface,
QG lift ahead of the trough will be stronger, and we could see
some breaks in the clouds in the late morning allowing for some
surface heating and increased lapse rates/instability for
Thursday afternoon. The highest chance of stronger storms will be
in our southeastern counties where the better shear and
instability overlap. Right now, the main hazard looks like large
hail, but we can`t rule out an isolated tornado or strong winds as
well.

The upper level trough will move over the area and off to the
northeast overnight Thursday into early Friday. A cold front will
also move through overnight, dropping temperatures a few degrees
for Friday. Rain chances will continue on Friday as a secondary,
weaker trough develops to our northwest and moves over the area
late Friday into Saturday. Coverage and intensity of showers and
storms will be lower than what we`re expecting on Thursday.

After that secondary trough moves through, upper level ridging
will start to build over the area. A warming trend will begin on
Saturday, with highs reaching into the upper 80s for portions of
the plains by Monday. The warming trend will be halted on Tuesday
as another trough approaches from the west, cloud cover increases,
and precip chances return to the mountains and potentially the
plains.

&&

.AVIATION /12Z TAFS through 12Z Thursday/...
Issued at 507 AM MDT Wed May 20 2026

A line of showers extends SW to NE over KAPA and just to the south
of KDEN. These showers are expected to continue for another
couple of hours before moving off to the east. Ceilings this
morning have lifted to VFR for our TAF sites, with some lower
ceilings still hanging around the area. Showers and storms are
forecast to develop between 17Z and 19Z, impacting the terminals
for a few hours before they progress eastward. Once the main push
of showers and storms move east, there is a low chance that we
could see some additional activity into the early evening, but
models seem to be trending away from that solution. Winds this
afternoon will be tricky, as high res models have a Denver cyclone
setting up near the area, so we could see some variation in wind
directions at KAPA and KDEN as the cyclone sets up.

&&

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

&&

$$

DISCUSSION...AP
AVIATION...AP

NWS BOU Office Area Forecast Discussion