517
FXUS65 KBOU 051134
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
534 AM MDT Fri Jun 5 2026

.KEY MESSAGES...

- Warm today with a couple late day thunderstorms mainly south of
  Denver.

- Hot weekend ahead with high temperatures soaring into the mid
  90s across the I-25 Corridor and plains.

- An early season heat wave likely Tuesday and Wednesday, possibly
  lasting into Thursday of next week. Highs near 100 degrees
  possible across portions of the plains.

&&

.DISCUSSION /Through Thursday/...
Issued at 241 AM MDT Fri Jun 5 2026

A weak cool front was pushing southward through southeast Wyoming
and the Nebraska Panhandle in these wee morning hours. Given
surface pressure rises are still organizing to the north, that
front is expected to push across all of the plains early this
morning. Only slight cooling can be expected today, however, as
the front will be rather shallow and offset by warm air aloft and
plenty of morning sunshine. We will see boundary layer moistening,
but also some low level stability given the slightly cooler
temperatures but still very warm airmass aloft. Thus, it will be
hard to reach convective temperatures over the plains and for the
most part they should stay capped off. However, the mountains and
elevated heat sources of the foothills and Palmer Divide will be
more prone to surface based convection given expectations of dry
adiabatic warming. Thus, we expect to see isolated high based
convection originate in the early to mid afternoon hours there.
Despite slight stability in the lower elevations, they will still
attempt to move eastward into the adjacent lower elevations with
perhaps even the southern portions of metro Denver seeing an
isolated late day or early evening storm, although gusty outflow
winds would be more likely than any rain.

Full on summer heat will arrive this weekend underneath upper
level ridging. We`ll be essentially caught in between a weak
upper low drifting north through the Southern and Central Plains
and a deep mid latitude trough over the Pacific Northwest (PNW).
That supports development of southwest mid level flow and warm
advection. High temperatures will warm into the mid 90s over most
of the plains, with potentially a few spots getting into the upper
90s (depending on any influence from the trough to our east).
Denver`s record for Saturday is 95F, and we should be very close
to that. Sunday`s is a bit warmer (98F). While we should stay just
shy of Heat Advisory criteria, the record/near record heat early
in the season could put added stress on people who plan to be
outside for a majority of the day. Stay hydrated and avoid
strenuous outdoor activity during peak heating.

We will see isolated high based convection once again on Saturday
as limited low/mid level moisture remains under the ridge. Sunday
should trend mostly dry.

For Monday, we`ll likely see a brief respite in the heat due to a
weak backdoor cold front - courtesy of the ejecting PNW trough.

We`re confident (>80% chance) that we`ll be right back to the
frying pan, however, for Tuesday and Wednesday. A strong ridge
aloft will develop over the Central Plains while a trough moves
into the western United States. That will lead to increasing
southwest flow across Colorado, further warm advection, and
downslope compressional warming. The combination of these factors
will lead to record/near record heat. Denver`s record high of 95F
on Tuesday seems likely (60% chance) to be tied or broken, while
the record high of 99F on Wednesday has a chance (20-30%) of
being reached. Although recent greenup has been helpful, locally
critical fire weather conditions may start entering the picture
again if fuels dry sufficiently in the hot, dry, and windier
weather.

In contrast to yesterday`s models, there is now some uncertainty
as to how long this heat wave will last, as both the latest EPS
and GEFS have cooled things off for Thursday. There seemed to be
better agreement with a quicker ejecting trough across the
Northern Rockies. Whether this is just a one-off or a meaningful
trend is yet to be seen, so something to watch in upcoming runs.

&&

.AVIATION /12Z TAFS through 12Z Saturday/...
Issued at 534 AM MDT Fri Jun 5 2026

A weak frontal push arrived in the pre-dawn hours, with light
northerly winds to around 6-11 kts behind it to start this TAF
period. There is a 40-50% chance they go light/VRB for an hour or
two before more persistent NE winds expected by 15Z. Winds should
then turn from NE to more E through 22Z and increase to speeds
around 12 kts. The main concern for the TAF period will be
potential for high based convection and outflow, 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 TEMPO of -SHRA (sprinkles) 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...20
AVIATION...20

NWS BOU Office Area Forecast Discussion