051
FXUS65 KBOU 050535
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1135 PM MDT Thu Jun 4 2026

.KEY MESSAGES...

- Warm and mostly dry for today and Friday with only a slight
  chance of thunderstorms.

- Afternoon high temps to reach the mid 90s across the plains this
  weekend.

- An early season heat wave possible Tuesday through Thursday of
  next week with highs of 100 degrees possible in Denver and
  across the plains.

&&

.DISCUSSION /Through Thursday/...
Issued at 138 PM MDT Thu Jun 4 2026

Temperatures are well above normal with many areas in the mid 80s
this afternoon and on their way to the upper 80s. Across most of
our CWA, the moisture has mixed out and any showers and weak
storms that do form, will generally produce gusty winds and little
rain at the surface. The one exception is the far northeast plains
where moisture hasn`t mixed out. Sterling currently has a
temperature of 90, a dew point of 50, and southeast winds which
indicates moderate surface based CAPE and decent upslope flow.
With northwest winds in Cheyenne and along much of the Cheyenne
Ridge, there is a surface convergence zone that may create strong
storms in northeast Weld, Logan, Phillips, and Sedgwick Counties
later this afternoon/evening. The SPC mesoanalysis page shows
effective bulk shear of around 30 knots which could support a
severe storm or two in that area with large hail and damaging
winds possible.

There is currently a cold front in northeast Wyoming that will
generate strong storms and eventually an outflow boundary that
will reinforce the cold front late tonight. This front will move
across northeast Colorado on Friday morning and it will keep
conditions on Friday afternoon slightly cooler than today and
will increase moisture. There will be moderate instability values
but warm air aloft will result in an inversion that will greatly
limit shower and thunderstorm activity. The best chance for
showers and storms will be over the Palmer Divide and into Lincoln
County where low level convergence will help to produce forcing
that could overcome the cap. It`s possible a few wind gusts around
50 mph are reported from these storms.

The summer heat will begin Saturday and there may be no turning
back. Flow aloft will turn southwesterly with warm 700 mb
temperatures moving over Colorado. With the jet stream to the west
of Colorado, there will be compressional heating that will push
temperatures toward record values. The daily record high is 95 on
Saturday most recently set in 2018 and that has a chance of being
tied. The daily record high is 98 on Sunday set most recently in
2006 and the high may come within a degree or two of that
temperature. This heat is occurring early in the season which
could put added stress on people who plan to be outside for a
majority of the day. Therefore, there was consideration for a Heat
Advisory but no advisory was issued due to temperatures likely
topping out in the mid 90s. If the forecast increases to the upper
90s, there may be a higher chance of an advisory issuance.

There is a wider range of forecast high temperatures in the
ensemble data on Monday due to the uncertainty of a surface
boundary moving through eastern Colorado. Surface boundaries often
move through eastern Colorado when there is strong lee
cyclogenesis and that appears to be the likely scenario.
Therefore, forecast high temperatures are in the upper 80s for
most of the plains with a chance of storms mentioned. However, it
is possible the southwest flow aloft is too strong for much of a
surface boundary to make it through eastern Colorado and another
day of heat occurs with highs in the mid 90s.

There is growing confidence in record-breaking heat Tuesday
through Thursday of next week that may require Heat Advisories. A
strong ridge aloft will develop over the Central Plains of the US
while a trough moves over the West Coast. Colorado will be in-
between these two features which will lead to subsident flow. The
ensemble data is starting to get confident that Denver and most
of the rest of the urban corridor will reach the mid to upper 90s
on Tuesday and Wednesday. The record high of 95 on Tuesday seems
likely to be broken while the record high of 99 on Wednesday is
within reach. The 50th percentile for the high temperature at KDEN
on Thursday is 100 F on the 12Z euro ensembles. That is
significant warmth at this time range and if Denver does reach 100
F, it would tie for the earliest 100-degree day in Denver
history.

&&

.AVIATION /06Z TAFS through 06Z Saturday/...
Issued at 1135 PM MDT Thu Jun 4 2026

The last batch of virga has pushed off the mountains and is
dissipating, so we`re returning to lighter and normal diurnal
winds from the SW to start this TAF period. We do expect a weak
frontal push to arrive 11Z-13Z with a light northerly wind shift,
at least at KDEN. Winds should then turn more NE-E through the day
and increase to speeds around 12 kts. The main concern for the
TAF period will be potential for high based convection and
outflows late in this TAF period - mainly from 23Z Friday to 03Z
Saturday. We think the highest odds will be closer to the
convection over the Palmer Divide, and thus have introduced a
Prob30 of -SHRA and VRBG32kt for KAPA, while also adding enhanced
TEMPO southerly gusts at KDEN for a portion of the evening - as
that would be the most likely direction if we did see outflows off
the Palmer Divide convection. Otherwise look for persistent VFR
with only SCT-BKN clouds above 16,000 ft MSL.

&&

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

&&

$$

DISCUSSION...Danielson
AVIATION...20

NWS BOU Office Area Forecast Discussion