687
FXUS65 KBOU 302339
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
539 PM MDT Sat May 30 2026

.KEY MESSAGES...

- Strong to severe thunderstorms through early evening with gusty
  winds and isolated large hail as the primary concerns, over far
  northeast Colorado.

- Drier weather will prevail for all areas on Sunday.

- A chance for strong thunderstorms returns for Monday and Tuesday
  afternoon, with locally heavy rain possible on Monday.

&&

.DISCUSSION /Through Saturday/...
Issued at 213 PM MDT Sat May 30 2026

The previous near-term convective environment forecast seems to be
on track for this afternoon, with the main difference being the
western extent of NNE flow and dewpoints in the 50s. Current
observations show a well-defined N-S theta-e boundary or pseudo
dryline extending southwards from the Nebraska panhandle through
Fort Morgan, down to Limon. Satellite imagery shows an increase in
cumulus east of Denver as well as well as convective initiation
already taking place over the foothills, I-25 corridor, and high
terrain. To the northeast, dewpoints are sitting in the upper 50s,
low stratus has begun to dissolve, and SBCAPE is already >1000 J/kg
and increasing.

The latest SPC convective outlook for this afternoon has placed
Colorado`s northeastermost counties under a slight (level 2/5) risk
for severe storms, as well as a marginal (level 1/5) risk that
extends as far west as Weld County and DIA. The primary hazards
associated with this risk will be gusty winds and hail, with the
strongest storms (and the better chance for large hail) occurring
east of Morgan County and far NE Colorado. A few landspouts cannot
be ruled out given the surface vorticity present, as well as
relatively low (~900-1300ft AGL) LCLs in NE Colorado. Storm motion
will initially be northwards, with more organized convection
taking on a northeast-east motion component.

Tomorrow appears to be uneventful as the shortwave trough dissipates
and zonal flow aloft returns. Afternoon temperatures will be near-
average, with low 80s over the Denver metro area. An afternoon
shower or isolated thunderstorm cannot be ruled out over the highest
mountain peaks, as is typical for this time of year.

Low-level moisture will return on Monday as easterly winds advect
precipitable water (PW) values in the 0.50-0.80 inch range into
north central Colorado. There will be 40-60% chance for scattered
showers and thunderstorms to develop Monday afternoon. Model
soundings suggests a deeply moist and unstable vertical profile,
hinting at the potential for locally heavy rainfall, as well as
isolated large hail. Tuesday afternoon will bring another chance for
afternoon showers and thunderstorms although uncertainty remains
regarding the development of low level stratus, which would hinder
instability. However, if low stratus are able to clear off early
enough on Tuesday, there will be plenty of moisture and SBCAPE
(>1000 J/kg) for a few strong thunderstorms to develop.

Uncertainty enters the picture on Wednesday given that it is unclear
if a shortwave trough will develop over the Pacific northwest, or if
flow aloft will turn zonal. Nevertheless, there will be additional
chances for afternoon showers and thunderstorms through the end of
next week.

&&

.AVIATION /00Z TAFS through 00Z Monday/...
Issued at 539 PM MDT Sat May 30 2026

Thunderstorms have progressed northeast of the Denver area, ending
the threat of storms for the rest of today. Outflow from the
storms is expected to result in northwest to northeast winds. At
DEN and APA, winds are expected to gradually turn to the south-
southwest in the 03Z to 06Z time range. Clouds will decrease this
evening becoming mostly clear tonight and for Sunday. South-
southwest winds continue into Sunday morning and then slowly turn
to the west-northwest 16-18Z. Most models show west-northwest
winds gusting to 25 knots after 18Z. Though the GFS throws a
curve ball with an easterly anti-cyclonic flow after 18Z Sunday.
Opted to go with the west-northwest winds that most of the models
show.

&&

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

&&

$$

DISCUSSION...AA
AVIATION...12

NWS BOU Office Area Forecast Discussion