884
FXUS65 KBOU 041142
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
542 AM MDT Wed Jun 4 2025

.KEY MESSAGES...

- Scattered to numerous showers and thunderstorms late Wednesday
  afternoon and evening.

- Slow warming trend into the weekend, with chances for showers
  and storms each day through the week.

&&

.UPDATE...
Issued at 357 AM MDT Wed Jun 4 2025

Don`t have a ton of thoughts to add tonight, as things are going
about as expected. The low stratus deck that`s been over the area
for the last 30 hours or so is slowly breaking up, and that trend
should continue through the rest of the morning hours. Some
mid/high cloud cover is likely to persist through most of the day,
which will limit surface heating and instability across the CWA.
As a result, the severe weather threat looks fairly low. A couple
stronger storms are possible this afternoon and evening to the
south and east of the Denver metro, with showers and a few weak
thunderstorms elsewhere.

There`s at least a slightly better chance of more organized
convection on Thursday, but there are still quite a few questions
about how much instability there will be to work with, but most
guidance shows at least a marginally favorable CAPE/shear overlap
along the I-25 corridor into the plains.

&&

.DISCUSSION /Through Tuesday/...
Issued at 218 PM MDT Tue Jun 3 2025

Scattered showers and isolated thunderstorms will remain possible
through mid evening. Most/all of the showers and storms are
expected to form over the higher terrain where it will be unstable
and then drift eastward. Patchy drizzle will be possible in/near
the foothills due to the easterly upslope flow. Drier air moves in
overnight bringing the rain threat to an end.

Longwave upper trough will remain over the western half of the
country through Friday. Each day through Friday, we see a
shortwave trough push through the region, bringing mainly
afternoon/evening showers and thunderstorms. For Wednesday, with
some sunshine tomorrow, temperatures climb into the lower to mid
70s across the Front Range and nearby plains. Clouds hang on most
of the day over the far northeast corner, where it will be cooler.
A Denver cyclone forms and creates a convergence line from the
Palmer Divide northeastward to just east of DIA. Here, MLCAPE
reaches 600-1000 J/kg. This instability combined with decent shear
could produce strong to severe thunderstorms. The best chance for
these stronger storms will be across Douglas, Elbert, and Lincoln
Counties. Lift from the shortwave trough arrives late afternoon
and into the evening hours. Given the expected track of the
shortwave the best chance for showers and storms will be across
the central and southern parts of the area.

For Thursday, we`ll see a similar set up with a shortwave trough
embedded in the westerly flow aloft producing scattered to
numerous showers and thunderstorms. MLCAPE will generally range
500-1000 J/kg so can`t rule out a couple storms just reaching
severe criteria, but most storms are expected to be sub-severe.
Highs take a small step back with temperatures reaching the mid
60s to lower 70s.

On Friday, another shortwave trough will trigger scattered to
numerous showers and thunderstorms. Not much change in
temperatures with highs in the upper 60s to lower 70s over north
Colorado. MLCAPE looks to be a little less, up to 600 J/kg.

For the weekend, an upper level ridge begins to build over the
western states. This will bring warmer temperatures for the
weekend with highs topping 80 degrees across the lower elevations
on Sunday. There will be a decrease in showers and thunderstorms,
with the lack of large scale forcing, but isolated to scattered
showers and thunderstorms are expected during the afternoon and
evening hours, mainly across the higher terrain.

On Monday and Tuesday, the ridging over the region weakens,
though temperatures look to stay near normal. We continue to see
afternoon and evening showers and thunderstorms. No well defined
features on the models at this time to think we will see more than
scattered showers and thunderstorms.

&&

.AVIATION /12Z TAFS through 12Z Thursday/...
Issued at 539 AM MDT Wed Jun 4 2025

Last bit of stratus is lingering near the terminals this morning,
though we`ve generally seen ceilings rise above MVFR thresholds. A
diffuse Denver cyclone/convergence zone has established this
morning, and should lift to the northeast of the terminals later
this morning, leading to a gradual turn of the winds to the
northwest, then northeast by early afternoon.

Quite a bit of uncertainty in the forecast this afternoon and
tonight. Depending on how much instability develops, we could see
widely scattered thunderstorms moving across the terminals. Still
don`t have enough confidence to change from the current
PROB30 (DEN/BJC) and TEMPO (APA) at this point. Second concern is
the potential for stratus to redevelop overnight. Some guidance
drops some IFR cigs back into the area while others keep any
clouds closer to a BKN040-060 deck overnight. Ultimately split the
difference for now, but there is at least some potential for a
return to MVFR/IFR conditions tonight through Thursday morning.

&&

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

&&

$$

UPDATE...Hiris
DISCUSSION...Meier
AVIATION...Hiris