951
FXUS65 KBOU 100059
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
659 PM MDT Mon Jun 9 2025

.KEY MESSAGES...

- Warming trend with above normal temperatures Tuesday through
  Friday. Even warmer weather possible this weekend.

- Chance of afternoon showers and thunderstorms mainly over the
  higher terrain most days. Best chance of rain comes Wednesday
  and Thursday.

&&

.DISCUSSION /Through Monday/...
Issued at 136 PM MDT Mon Jun 9 2025

As expected, most of the afternoon convection has formed just to
the south and west of our CWA. One storm did develop over southern
Park county earlier but quickly drifted into Fremont county. Our
CWA border essentially is on the border of the "moisture" and "no
moisture" line that`s well defined in GOES mid-level water vapor
(CH-09/6.95um) satellite imagery today. That`s led to most
locations across the Denver metro seeing a rather pleasant June
afternoon, with current temperatures in the mid/upper 70s along
with sunny skies and light winds.

Moisture will at least attempt to make a return into our forecast
area as a ridge slowly tries to build across the southwestern
CONUS. We should see at least a few more showers and perhaps a
weak storm or two across the Front Range mountains, but with very
weak steering flow (GFS mean storm motion is <5kt), it will be
hard for anything to develop across the I-25 corridor during the
afternoon or evening hours. Forecast soundings would suggest more
wind than rain anyways. Mid/upper 80s are likely across the plains
with a few low 90s possible east of the urban corridor.

Moisture is expected to increase again on Wednesday, with a better
chance of rain across the higher elevations of the Front Range.
The overall synoptic pattern is still somewhat messy, with one
shortwave tracking across southern Idaho into northern Wyoming
while a weak cutoff low tracks across the TX/OK panhandle. As a
result, a majority of the convection would again be initially
driven by terrain effects. With more moisture to work with over
the plains (surface Tds in the mid 40s) at least a few storms
could survive the slow journey into the lower elevations, but
overall coverage looks to be isolated to scattered.

A gradual drying trend is expected to end the week and continue
through this weekend, as a large ridge builds to our south. At
least some isolated/widely scattered convection is possible again
Thursday before drier southwesterly flow aloft scours out the
remaining mid-level moisture by Friday or Saturday.

Unsurprisingly, the developing ridge and drying conditions will
likely lead to warmer temperatures by this weekend. There is
fairly high confidence that this weekend will feature the warmest
weather of this spring, with temperatures in the 90s across most
of the plains. Both the GFS/ECMWF advertise mid-90s highs for the
Denver metro by Sunday, with broad support from their respective
ensemble systems (~75% of individual GEFS/ECME members >90F).
Above normal temperatures look to generally continue into next
week, with no obvious signal that the ridge will break down in the
longer term period.

&&

.AVIATION /00Z TAFS through 00Z Wednesday/...
Issued at 657 PM MDT Mon Jun 9 2025

Weak normal drainage winds are expected overnight at DIA, commencing
around 04Z this evening. Weak southeasterly winds are likely until
then. There will be no ceiling issues.

&&

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

&&

$$

DISCUSSION...Hiris
AVIATION.....rjk