173
FXUS65 KBOU 011126
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
526 AM MDT Mon Jun 1 2026

.KEY MESSAGES...

- A chance for strong and severe thunderstorms this afternoon and
  again Tuesday afternoon, with locally heavy rain possible.

- Thunderstorm chances will continue on Wednesday with lower
  threat for severe storms, however, locally heavy rain will be
  possible.

- Trending warmer and drier by the end of the week.

&&

.DISCUSSION /Through Sunday/...
Issued at 231 AM MDT Mon Jun 1 2026

Already seeing sct high based showers and a few weak tstms across
portions of nern CO early this morning.  This appears to be
associated with some mid level instability and along the srn portion
of an upper level jet.  Latest data suggest this activity will
continue thru mid morning with a few stronger storms possible closer
to the WY-NE border area.

By aftn, SW flow aloft will remain over the area as easterly flow in
the lower levels occurs behind a weak cool front.  SBCAPE over the
plains will range from 1500-2000 j/kg by aftn with a favorable shear
profile.  Sct tstms will develop near Denver by 20z and then move
rapidly ENE across the plains by 00Z.  Damaging winds and large hail
will likely occur with a few of the storms, with a brief tornado or
two possible initially, before storms consolidate into a solid line.
Meanwhile, across the higher terrain tstm coverage will be more
widely sct.  Highs today will be in the upper 70s to lower 80s
across the plains.

On Tue, the flow aloft will remain SW with the low level flow
becoming more SSE across the plains.  Once again, SBCAPE will range
from 1500-2000 j/kg with a favorable shear profile.  However, not
sure where best focus for tstms will be in the aftn.  If a Denver
cyclone were to develop, then storms may fire off the DCVZ and then
move ENE across the plains, with a few svr storms possible.  Once
again over the higher terrain expect tstm coverage will be more
isold to wdly sct.  As for highs, readings will be in the upper 70`s
to mid 80`s over the plains.

By Wed, the flow aloft will become more zonal and weaken. Meanwhile,
will still see SSE low level flow across the plains with possibly a
Denver cyclone and associated DCVZ.  SBCAPE will still be in the
1500-2000 j/kg range by aftn so there will still be some threat of
isold svr storms.  In addition, storm motions will be slower so may
see some heavier rainfall in those areas that get storms.   Across
the higher terrain, storm coverage will generally remain widely sct.
Highs over nern CO will be in the lower to mid 80`s.

For Thu and Fri, the flow aloft will remain nearly zonal as an upper
level trough moves across the nrn Rockies.  SBCAPE over the plains
will likely stay in the 1500-2000 j/kg range both days.  Overall,
focus for tstm development is hard to pinpoint this far out so will
just keep pops in the chc category.  Highs across the plains will
be in the 80`s on Thu with mid 80`s to lower 90`s by Fri.

Looking ahead to next weekend, an upper level trough is fcst to
develop over the wrn US with the flow aloft becoming more SSW.  For
now it looks drier with warmer temps.

&&

.AVIATION /12Z TAFS through 12Z Tuesday/...
Issued at 518 AM MDT Mon Jun 1 2026

Winds were light and variable early this morning but should trend
to a ESE direction by 15z and maintain that general direction
thru the aftn. Still expect sct tstms to develop by 20z and then
quickly move east of the airports by 23z. At this time, DIA
appears to have the best chc of getting hit by a stronger storm
but confidence is still to low to have a tempo group as of now.
If a stronger storm were to occur at DIA, brief wind gusts to 50
mph along with some hail would be possible. After 23z, believe
tstm threat will diminish but can`t rule out a slight chc of
showers until 02z. Winds, outside of outflow boundaries, will
become more SE by early evening and then SSE by 06z. For late
tonight, if a Denver cyclone were to develop near DIA some stratus
could affect BJC and possibly DIA by 12z Tue. However, confidence
in this is rather low so have not included in 12z taf.

&&

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

&&

$$

DISCUSSION...RPK
AVIATION...RPK

NWS BOU Office Area Forecast Discussion