826
FXUS65 KBOU 161132
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
532 AM MDT Thu Apr 16 2026

.KEY MESSAGES...

- Critical fire weather conditions and Red Flag Warning south and
  southeast of Denver today.

- Next system moves in Friday with much colder temperatures and
  some snow for most locations.

- Hard freeze Friday night and into Saturday morning with lows in
  the upper teens to mid 20s.

- Dry and warmer weather returns for early next week.

&&

.DISCUSSION /Through Wednesday/...
Issued at 1105 PM MDT Wed Apr 15 2026

Temperatures will warm into the mid 70s to near 80 degrees for much
of the plains on Thursday. Winds will turn more to the
south/southwest, with gusts around 20 to 35 mph. Breezy winds
combined with RHs in the single digits to low teens across the
plains will lead to another day of elevated to critical fire
weather conditions. A Red Flag Warning will be in effect for
tomorrow afternoon for the southern Foothills, Palmer Divide, and
areas generally east of the Urban Corridor and south of US 34.

A strong cold front will move through late Thursday through early
Friday. Winds behind the front will be strong from the north, with
gusts around 35 to 50mph overnight. Much colder temperatures and the
potential for some snow accumulations will follow behind the front.
Snow chances will increase for the mountains overnight Thursday into
Friday, with snow chances spilling into the plains early Friday into
Friday afternoon as an upper level trough moves into the area. We`re
a little concerned about the potential for anticyclonic upslope and
convergence against the southern Foothills and Palmer Divide. This
combined with strong 700mb frontogenesis in these areas for the late
morning and early afternoon could lead to heavier snowfall than
currently forecast. We increased snowfall amounts in these areas to
account for this potential, but amounts may need to be adjusted up
further if banding potential becomes more prominent. Most likely
snowfall totals across the urban corridor, northern I-25 corridor,
and east is a trace to around 2 inches of snow. The most likely
amounts in the Foothills and Palmer Divide area are more in the 1 to
4 inch range, however there is a low chance (~10%) that amounts
could approach around 8 inches in portions of this area. The
mountains are looking at most likely accumulations around 2 to 8
inches. With how warm the road temperatures will be to start this
event in the Foothills and plains (and the more borderline freezing
temperatures during the afternoon), accumulations on roadways should
be limited.

Snow chances will begin to taper off in the evening as the upper
level trough moves through and subsidence builds in behind it. At
the surface winds will begin to weaken and temperatures are forecast
to drop significantly overnight. Minimum temperatures will likely be
in the low to mid 20s across the plains Saturday morning, with
colder temperatures in the mountains and across the Palmer. This
will lead to a hard freeze, potentially impacting sprinkler systems
and plants which have started to bud. A Freeze Watch is in effect
for all of the plains for Saturday morning.

Upper level ridging will begin to build into the area between the
exiting trough and a strong upper low over the West Coast. A warming
trend will begin Saturday, with highs increasing into the lower 80s
for portions of the plains by Tuesday afternoon. Conditions are
expected to remain mostly dry through this period. Things start to
get a bit more uncertain on Wednesday as models try to figure out
how that upper low will move into the central U.S., but a majority
of the ensemble members keep the plains dry and give a low chance of
precip for the mountains.

&&

.AVIATION /12Z TAFS through 12Z Friday/...
Issued at 532 AM MDT Thu Apr 16 2026

Change in the weather coming, with a strong cold front arriving
midnight tonight or shortly thereafter. Some light snow for
Friday. The main concern in the shorter term will be winds.

We`ll start this period with the typical S-SW winds at the TAF
sites, continuing through at least 15Z. Then, as diurnal heating
and mixing occurs, we`ll start to see uncertainty enter the
forecast. In this southwest flow pattern, it`s not unusual to see
a shear zone develop, and today could be the same especially with
expected increase in high level clouds. Although, latest check of
satellite shows the cloud arrival may be a little later. In any
case, we should still see differential heating (weaker inversions
south than north) and corresponding development of a shear zone
off the Palmer Divide. There are some hints of this in the HRRR,
keeping a small area of light/VRB winds near or just north of KDEN
and KBJC mid morning - early afternoon, and that could potentially
last into mid to late afternoon (models now starting to hint at
this) depending on development and amount of opaque cloud cover.
KAPA will have the highest odds (80-90%) of getting properly
mixed and staying south of the shear zone, and thus we`ll start
winds increasing there by 15Z with a further well mixed G24-28kt
scenario 20Z-02Z. For KDEN, we think a more southerly component
is most likely through 19Z, but a 20-30% chance of light E or NE.
After that, we`ll see higher chances of a mixed SW flow wind
pushing through KDEN but the lee troughing is rather weak and
thus it may take as late as 22-24Z before those stronger W-SW
winds with gusts near 25 kts develop. The same can be said for
KBJC. Winds should start to relax again by 01Z-02Z with loss of
daytime heating.

Then, a strong cold front will bring gusty north winds (30-40 kts
possible at KDEN), most likely 05-07Z Friday. Low clouds could
start to develop within a few hours of that but most likely
holding off til closer to 12Z Friday. Snow is most likely to
develop in the area by 14Z-16Z with restrictions to visibility and
MVFR ceilings.

&&

.FIRE WEATHER...
Issued at 524 AM MDT Thu Apr 16 2026

Breezy winds combined with RHs in the single digits to low teens
across the plains will lead to another day of elevated to critical
fire weather conditions. A Red Flag Warning will be in effect for
this afternoon and early evening for the southern Foothills,
Palmer Divide, and areas generally east of the Urban Corridor and
south of US 34.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM this morning to 9 PM MDT this
evening for COZ214-216-241-245>247-249.

Freeze Watch from Friday evening through Saturday morning for
COZ038>051.

&&

$$

DISCUSSION...AP
AVIATION...20
FIRE WEATHER...AP

NWS BOU Office Area Forecast Discussion