333
FXUS65 KBOU 022102
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
202 PM MST Mon Mar 2 2026

.KEY MESSAGES...

- Warm and dry today, with near-critical fire weather conditions
  across the Palmer Divide.

- Mountain snow and low-elevation rain likely (>70% chance) tonight
  into Tuesday evening, favoring areas north of I-70.

- Potential for colder storm system with more widespread snow
  Thursday night through Friday, although uncertainty in amounts
  remains.

&&

.DISCUSSION /Through Monday/...
Issued at 135 PM MST Mon Mar 2 2026

It`s warm again across most of our forecast area. Temperatures in
the plains are generally in the 60s, with a few spots in the metro
near or just above 70F at the time of this discussion. Thankfully,
this has come without much wind. ACARS soundings from early this
afternoon show very little wind through the lowest 1-2km of the
boundary layer. There are still some stronger winds near the top
of the PBL (~550mb), and every once in a while we`re still seeing
a few gusts of 30-35 mph over the lower foothills and adjacent
plains.

We`ll have a brief pause in our stretch of above normal
temperatures on Tuesday, as a weak storm system arrives. That
shortwave is currently near the NV/ID border per water vapor
satellite, and should continue to progress eastward tonight into
tomorrow. As the lee cyclone over southeastern Colorado deepens
during the morning hours, there should at least be a weak frontal
surge moving across the plains. The "cold" air isn`t particularly
impressive, but should be reinforced as the 850-700mb low
redevelops near the CO/KS/NE border and upslope flow deepens a
bit. The main questions remaining are (1) how much stratus
develops over the area... and similarly what will that do to high
temperatures, and (2) how much moisture will we see across the
lower elevations? For temperatures, most guidance has a pretty
robust/deep post-frontal stratus deck, keeping temperatures in the
mid to upper 40s. There is still a rather large spread across the
12z model suite to sort out... though we did lower temperatures a
few degrees in the grids. For precipitation, again its a rather
mixed signal. The 500mb vort max passes almost right over the
area, but that shortwave is in the process of almost completely
shearing apart by the time it`s over our CWA. Like previous
forecasts, the current one still favors the northern Front Range
and Cheyenne Ridge, with little to no precipitation south of I-70
and east of I-25. The overall precipitation and snow forecasts
were not changed significantly from previous forecasts... with a
few inches for the higher terrain and mostly rain below around
7-7.5 kft.

Ridging will make another appearance for Wednesday and Thursday,
with south-southwesterly flow increasing ahead of a more organized
trough. Temperatures should warm back into the 60s by Wednesday,
with low 70s possible Thursday. Depending on how much wind
translates down to the surface, there could be elevated to
critical fire weather conditions across portions of the plains
Thursday afternoon.

The forecast gets far more complicated late Thursday into Friday.
Guidance generally is in good agreement that the shortwave trough
will transition towards a closed low at 500mb, settling over
eastern Utah by Friday morning. The favored solution from
deterministic models today is to break that low into two very
distinct pieces - a weaker shortwave the ejects into the Central
Great Plains, while the other piece is shoved southwestward and
eventually turns back into a closed low off the southern
California coast. As a whole, the ECMWF and its respective
ensemble and AI ensemble are wetter across the reason than the
GFS/GEFS/AIGEFS, but neither solution offers much in the way of
confidence. There are some scenarios where the ejecting shortwave
would be enough for some meaningful precipitation (and maybe even
snow) for the lower elevations, but given the highly complicated
setup here, it`s difficult to provide many details. We`ll see how
this evolves over the next couple of days.

By the upcoming weekend, it looks fairly likely that we`ll end up
split between the cutoff low to our south and the primary
jetstream to the north... leading to another period of mild and
dry weather.

&&

.AVIATION /18Z TAFS through 18Z Tuesday/...
Issued at 1102 AM MST Mon Mar 2 2026

Winds have turned to more W-NW to start off this TAF, although
indications are muddled for any clear trends through 21Z-00Z since
mixing has been limited by a high cloud deck. We have seen a
stronger W-SW component push across KAPA, but with lack of
organized heating the wind fields may just turn more N-NW (60-70%
chance) and stay lighter through most of the afternoon, or even
become VRB at times (30% chance). KBJC would have the best
opportunity (50-60% chance) of gusty WNW winds to ~25 kts, while
KDEN and KAPA any gusts should stay under 20 kts, even if we do
mix better. The signals for any clear direction through this
evening are even more uncertain, so we`ve opted for a few hours of
VRB winds until the first surge of a front occurs (toward
06Z-08Z) when winds should turn more northerly. A stronger
frontal surge is likely by 15Z-16Z Tuesday, with a higher
certainty that we`ll see stratus and MVFR ceilings developing by
then. The stratus deck will have support from increasing shower
coverage and narrower T/Td spread to the north, combined with a
weak upslope component developing. That stratus deck will be hard
to erode with continued N-NE flow through the day and showers
becoming more widespread - enough to go TEMPO -RA for the
afternoon hours. We think the most likely range for ceilings will
be in the 1200-2000 ft range for most of the day, although a
slight chance (20-30%) that ceilings briefly drop to 1000 feet
depending on extent of showers.

&&

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

&&

$$

DISCUSSION...Hiris
AVIATION...20

NWS BOU Office Area Forecast Discussion