089
FXUS65 KBOU 132353
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
553 PM MDT Sat Jun 13 2026

.KEY MESSAGES...

- Cool temperatures today and Sunday behind a cold front.

- The best chances for showers/thunderstorms will be Sunday mainly
  along and south of I-70.

- Temperatures heat back up next week.

- Increasing fire weather concerns on Tuesday and Wednesday.

&&

.DISCUSSION /Through Saturday/...
Issued at 145 PM MDT Sat Jun 13 2026

A cold front moved through eastern Colorado last night with cool,
northeast winds behind it. With dry air aloft helping to keep
conditions mostly sunny, it is a pleasant day for June across most
of the northern half of Colorado. Low level convergence over the
Palmer Divide, southern foothills, and South Park may help to
create a few showers in those locations late this afternoon and
evening.

The next round of even cooler air will arrive tonight in our
forecast area. Low clouds currently in Wyoming are associated
with a nearby shortwave trough. Temperatures in Wyoming under
these clouds are mostly in the 40s and low 50s. This will move
into Colorado late this evening. Highs on Sunday are expected to
stay in the 60s across the plains tomorrow with mostly clouds
skies. The upslope flow will likely create some drizzle in the
foothills and adjacent plains. By the afternoon, there will be
enough instability in the central mountains that showers and a few
thunderstorms will form. The best chance for accumulating
rainfall will be along and south of I-70. These storms are not
expected to be severe due to lack of instability.

Ridging aloft will move over Colorado on Monday providing
subsidence. Temperatures will moderate from Sunday`s cool
conditions but will remain below normal.

West-northwesterly flow aloft will increase on Tuesday and
Wednesday as 700 mb temperatures will warm rapidly. 700 mb
temperatures will likely be around 17-18 C over Denver on Tuesday
and near 20 C on Wednesday. This will lead to hot temperatures
around 90 across the plains on Tuesday and the mid 90s on
Wednesday. There will be very dry conditions and moderate
downslope winds. Fire weather concerns will increase Tuesday and
Wednesday with Wednesday potentially reaching critical levels.

A sharp surface cold front will move through Colorado Wednesday
night. This will drop temperatures to more seasonal levels on
Thursday. The CPC and ensembles show a wetter pattern for Colorado
by next weekend and into early the following week. There is some
skepticism that there will be wetter than normal conditions at
this point.

&&

.AVIATION /00Z TAFS through 00Z Monday/...
Issued at 553 PM MDT Sat Jun 13 2026

East-northeast winds gusting to 25 kts are expected to continue
for several more hours at DEN and APA, eventually shifting more
east then east-southeast after 11Z. MVFR CIGs are expected to
develop after 06Z. There is a robust pool of cold air (for June
standards) and stratus making its way south. CAMs have CIGs around
020 pretty much all morning into midday Sunday at all three
terminals. Stratus breakup, even with a near maximum solar
incoming near the summer solstice, may hold off until around 22Z
at all three terminals. Not a high confidence in breakup because
after 00Z Sunday evening, and especially by 02Z, rain showers are
possible (20-40% chance) which would return CIGs to MVFR, though
probably more like 040.

Winds will also be complicated tomorrow afternoon with the
development of a Denver Cyclone that forms near APA or just north
of it late Monday morning, then moves very near or over DEN. For
BJC, this typically results in a straighforward wind forecast,
north 7-11 kts from morning through the early evening. APA and DEN
are far trickier. APA in this scenario would go from east before
sunrise to south around 13Z, then shift to north once the cyclone
moves northeast of APA. For now in the TAF, this is at 21Z but
things often change a lot with Denver Cyclones 24 hours out. DEN
should go ESE by 11Z or so, then east midday, then north after 22Z
when the cyclone is NE of DEN, and the pressure gradient all
across the plains of Colorado favors NE wind. Before 22Z winds
could very well be from every direction if/when the cyclone is
directly on top of the DEN airfield, which is most likely sometime
between 17-21Z. This far out the TAF`s goal is to get the general
trend in wind as the Denver Cyclone moves from southeast to
northeast of DEN.

&&

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

&&

$$

DISCUSSION...Danielson
AVIATION...Schlatter

NWS BOU Office Area Forecast Discussion