200
FXUS65 KBOU 030658
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1158 PM MST Mon Mar 2 2026

.KEY MESSAGES...

- Mountain snow and low-elevation rain likely through Tuesday
  evening, with highest rainfall amounts north of I-76.

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

&&

.DISCUSSION /Through Monday/...
Issued at 1152 PM MST Mon Mar 2 2026

Current water vapor imagery shows an upper level shortwave trough
over southwestern Wyoming/northeastern Utah. This weak system
will trek into Colorado by Tuesday morning, with moisture
advecting into the region. Scattered mountain snow showers will
continue overnight tonight and throughout the day Tuesday. Given
how warm we have been lately, snow levels will be around 8000-8500
ft overnight, before dipping down to 7000-7500 ft with the
arrival of cooler air from the shortwave. The overall snowfall
forecast for the mountains were not changed significantly from the
previous forecast, with highest snow accumulations limited to
elevations above 10,000 ft.

The biggest change to the forecast is the precipitation amounts for
the northern plains. Recent guidance now favors the 500-mb
vorticity max right over the plains Tuesday, with good mid-level
forcing throughout the day (mid-level lapse rates will be around
7-8 dg/km). The surface lee cyclone continues to trend farther
south than previous runs, which will allow moisture to be pulled
further south into the northern plains. Hi-res guidance now favors
some areas receiving upwards of 0.50" of QPF by throughout
Tuesday, with a few solutions indicating 1.00". Due to this, have
increased amounts for areas north of I-76. Unfortunately, Denver
area will not see the bulk of this precipitation, as guidance
still favors ~0.10" of QPF. Expect rain showers across the
foothills and plains throughout the day Tuesday before gradually
ending northwest to southeast overnight.

Upper level ridging will return to the state Wednesday and Thursday,
with increased southwest flow aloft on Thursday ahead of an incoming
trough. Temperatures will rebound to the 60s by Wednesday and
possibly lower 70s by Thursday. ECMWF ensemble has consistently been
warmer than the GEFS, with 36 out of 50 members showing max
temperatures between 70-72 (compared to the GEFS, where all 30
members show max temperatures between 62-68 degrees). With these
warm temperatures and dry conditions, elevated to critical fire
weather conditions are possible on Thursday, particularly the Palmer
Divide and eastern plains, where lee cyclogenesis could promote
gusty winds.

Guidance continues to be in good agreement of a shortwave trough
breaking into two pieces of energies on Friday, with the weaker one
ejecting into the northern Great Plains, and the other one trekking
towards southern California and becoming a closed low. Cold air will
advect into the region, with 700-mb temperatures dipping to -6 to -9
dg C. Moisture will begin to stream into the region by late Thursday
night into the mountains, and Friday morning across the plains. At
the surface, a lee cyclone will strengthen slightly and trek
northwest, with a cold front pushing through the plains.
Precipitation is possible across the forecast area, as GEFS and
ECWMF ensembles have consistently shown measurable QPF with the
latest few runs (and even snow!). However, how much moisture is
still the question, as it will depend on the exact track of the
ejecting trough. As of now, the ECMWF has a slightly southerly track
than the GFS, which brings more moisture and colder air into the
region.

By the weekend, we will likely have weak flow aloft as Colorado
looks to be in between the two systems. Dry conditions and warmer
temperatures should prevail for the mountains and plains.

&&

.AVIATION /00Z TAFS through 00Z Wednesday/...
Issued at 548 PM MST Mon Mar 2 2026

VFR conditions are expected through at least tomorrow morning. A
front will pass through the area starting around 05-07z bringing N
winds with it, especially at BJC and DEN. Ceilings will start to
lower at this time with a stratus deck moving into place. At APA,
we expect the winds to be from SW to NW throughout the night
tonight. A stronger push of N winds will occur with the frontal
passage around 15-16z Tuesday affecting all 3 sites. Gusts could
be as high as 25 to 30 kts as the front passes. There is a low
possibility that rain could occur tomorrow morning at BJC. There
is high confidence (50-80%) that rain will accompany the front
during the late morning and afternoon hours tomorrow. PROB30
groups were added to account for uncertainty in the timing of the
onset of the rain. Ceilings could be as low as between 500 and
1000 feet AGL, especially in the afternoon tomorrow with any
showers that pass through according to BUFKIT soundings and cross
sections. We accounted for this with TEMPO groups at all 3 sites
for lower ceilings and lower visibility (as low as 4 SM at BJC and
5 SM at DEN and APA). There is agreement across several hi-res
models that the ceilings will gradually rise Tuesday evening as
the rain clears.

&&

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

&&

$$

DISCUSSION...MAI
AVIATION...MV

NWS BOU Office Area Forecast Discussion