Johnstown, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

227
FXUS65 KBOU 030017
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
517 PM MST Mon Feb 2 2026

.KEY MESSAGES...

- Breezy and slightly cooler through Wednesday.

- Quick-hitting light snow showers likely (60-70% chance) for the
  mountains starting Tuesday morning, and Palmer Divide Tuesday
  late afternoon, ending late Tuesday night. Lower chances
  (20-50%) elsewhere. Any accumulations will be light.

- Warm and dry weather will prevail the rest of the week through
  the weekend.

- Pattern change likely next week, finally!

&&

.DISCUSSION /Through Monday/...
Issued at 1255 PM MST Mon Feb 2 2026

Main concern for the short term will be a fast moving disturbance
bringing a chance of light snow to the area. Cross sections show
an increase in mid level moisture in northwest flow tonight, and
further increase Tuesday as a weak disturbance but a 120-130 kt
upper level jet streak race into northern Colorado. The flow
turns more north/northwest in this period, which will be strong
orographics. Unfortunately, moisture is limited. That said, I
wouldn`t be surprised if a couple mountain slopes received at
least a couple inches of snow or more given the strong
orographics. If only moisture was more abundant - seems to be the
theme this season! In the lower elevations, it appears deep
north/northwest flow will strengthen and persist Tuesday afternoon
and night. Again, the biggest challenge will be to saturate the
mid levels sufficiently for any chances of snow. Given the slight
downslope component and weak downward QG forcing, it does not look
favorable especially for the northern plains. However, the EC did
offer up a little more hope with a slightly farther west jet
streak. In addition, while deep northerly flow is not great for
snow production over vast majority of our plains, it does offer up
a pretty healthy upslope component for the Palmer Divide. Thus,
we`ll keep higher PoPs there for late Tuesday afternoon and
especially Tuesday night. Any accumulation there looks light (less
than 1"), although a few of the models would say a couple inches
possible for higher end amounts if the jet streak does end up
farther west. Areas from roughly Denver to the north and east will
see lower chances of any snow and should mostly be flurries to
0.5" for any locations that do see it.

Temperatures stay slightly cooler (but still a few degrees above
normal) into Wednesday. Winds are expected to decrease and
sunshine will return.

For the extended period, we see high confidence in the return to
much above normal temperatures for Thursday through the weekend
with a blocking/high amplitude ridge shifting only slowly east
across the Rocky Mountain region. High temperatures will likely
(>70% chance) reach the 60s on the plains and I-25 Corridor
during this period, with a low probability (20% chance) of hitting
70F by Friday.

If anything changed it was the slight undercutting of the ridge
by a weak disturbance this weekend. At this time, don`t think it
would end up being more than just a slight cooldown and a couple
showers for the mountains.

For those waiting for some more meaningful precipitation or at
least a chance of it, there are changes in the long term. It
appears the blocking ridge that dominated the western U.S. over
the last couple months is finally breaking down early next week.
Most ensembles offer up a change in the weather with increasing
chances of precipitation toward Tuesday and Wednesday of next
week, possibly starting as early as Monday. That`s on the very
edge of our 7 day forecast, but at least we`ll have a better
opportunity to start building onto our minuscule Colorado
snowpack.

&&

.AVIATION /00Z TAFS through 00Z Wednesday/...
Issued at 441 PM MST Mon Feb 2 2026

Light and variable winds are currently in place across the TAF
sites this evening. Guidance continues to struggle to choose a
dominating wind direction through the next several hours, though
wind speeds are consistently light across the board. The only
change to that would likely be if drainage winds take hold sooner
than anticipated, but confidence is low in that happening. For
now, looks like winds should have a more persistent southerly
component by the 6-8Z timeframe, with speeds increasing a few
knots once drainage becomes more dominant (10-12Z).

For tomorrow, there is high confidence in winds transitioning to
the NW by 17Z and increasing in magnitude by 19-20Z. NNW winds are
expected through the afternoon with gusts to 25kts by 19-20Z,
increasing to 25-30kts after 21Z. Ceilings are expected to lower
through the afternoon as the potential for some light rain/snow
showers (20-40%) increases after 22Z. Guidance is fairly
consistent with ceilings dropping to 5,500-6,000 feet AGL at their
lowest, and not until after around 2Z/3Z when temperatures will
be cold enough to support strictly snow vs rain. With the
northerly winds bringing an upslope component, the greatest
impacts and PoPs are expected at KAPA, and less at KBJC.

&&

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

&&

$$

DISCUSSION...20
AVIATION...9