216
FXUS65 KBOU 160030
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
630 PM MDT Wed Apr 15 2026

.KEY MESSAGES...

- Locally critical fire weather conditions over the plains
  Thursday afternoon.

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

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

&&

.DISCUSSION /Through Wednesday/...
Issued at 153 PM MDT Wed Apr 15 2026

Flow aloft backs to the southwest tonight and increases Thursday
ahead of an approaching upper level trough currently centered over
the Pacific Northwest. Temperatures warm back up into the 70s
across northeast Colorado and relative humidities fall into the
teens. This will lead to elevated to locally critical fire weather
conditions Thursday afternoon, mainly for areas south of I-70. A
surface low develops over northeast Colorado and into Wyoming in
response to the southwest flow aloft.

The main upper level troughtracks eastward across the Northern
Rockies on Thursday and into the Northern Plains onFriday.
Additionally, a shortwave trough will travel southeast across the
Great Basin on Thursday and the Central Rockies on Friday. The
cold front associated with this system will dive south across
Colorado Thursday night and early Friday. Much colder air moves
into the area with highs only reaching the upper 30s to lower 40s
across northeast Colorado. Like most systems this season, it will
be somewhat moisture starved. Snow moves into the mountains late
Thursday night and early Friday morning and then progresses
eastward across the urban corridor and eastern plains. Snowfall
amounts are expected to be light, less than 3 inches across the
lower elevations and 2 to 7 inches over the mountains. Since most
of the snow is expected to fall during the daytime hours, roads
will mainly just be wet. Roads in the mountains may become snow-
covered in places, mainly over the mountain passes.

A possible greater impact than the snow will be cold
temperatures.The temperatures will not be extremely cold for this
time of year, but it has been about 5 weeks since we last saw air
this cold. Since then many irrigation systems have been turned on
and perennials have bloomed. The prolonged cold temperatures
(upper teens and lower 20s) Friday night and Saturday night could
damage above ground irrigation systems and bloomed perennials. It
is best to drain and/or protect irrigation systems before the cold
air arrives.

Cool northwest flow aloft will prevail behind the exiting system
on Saturday with highs expected to reach the 50s across northeast
Colorado. Breezy northwest winds up to 30 mph are possible over
the northeast plains.

Warmer temperatures are expected for Sunday as flow aloft backs
to the southwest ahead of an upper level ridge to the west. Highs
are expected to reach the upper 60s to lower 70s across northeast
Colorado. The warming trend continues into Monday and Tuesday as
the upper level ridge moves over the Central Rockies. This pattern
is expected to bring dry conditions on all three days. The
forecast becomes less clear on Wednesday as the ridge is expected
to move east of the region. Will southwest flow aloft or an upper
level trough/low replace the ridge? Models are still showing a
wide variety of solutions.

&&

.AVIATION /00Z TAFS through 00Z Friday/...
Issued at 624 PM MDT Wed Apr 15 2026

VFR conditions through the end of the forecast period. Winds have
started to weaken but remain primarily from the west across the
region with a few NW gusts lingering at KAPA. Winds will
gradually become variable around sunset before transitioning to
the usual SW-SSW drainage flow this evening. Drainage winds will
be in place through Thursday morning and likely remain southwest
for most of the day before taking on more of a westerly component
around 20Z-23Z. Brief periods of 20KT gusts could be possible late
in the afternoon as well. We expect a cold frontal passage to
bring a northerly wind shift to the area sometime between 05Z and
07Z on Thursday evening.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM to 9 PM MDT Thursday for COZ214-216-
241-246-247.

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

Fire Weather Watch from Thursday morning through Thursday
evening for COZ245-249.

&&

$$

DISCUSSION...12
AVIATION...AA

NWS BOU Office Area Forecast Discussion