Thornton, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

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FXUS65 KBOU 160522
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1122 PM MDT Sun Mar 15 2026

.KEY MESSAGES...

- Mountain snow showers, producing a few inches of accumulation
  for the higher elevations, will continue through Tuesday.

- Steady, continued warming will begin Monday and continue into
  the weekend. Hot/dry/breezy weather will sustain prolonged high
  fire danger for the northern plains each day.

- All-time hottest March temperatures appear increasingly likely
  (>80% chance) for many locations Friday and/or Saturday,
  including for both the mountains and lower elevations.

&&

.DISCUSSION /Through Sunday/...
Issued at 1039 PM MDT Sun Mar 15 2026

A few light snow showers are hanging on mainly west of I-25 along
the base of the foothills owing to weak upslope flow through 3km MSL
per the Table Mountain profiler. With the meridional jet departing
to our east, lingering lift will dissipate over the next couple of
hours and bring an end to the snow across the lower elevations. It
will be a cold night with lows in the teens and single digits for
most locations.

We`ll warm up moderately Monday as heights rise and subsidence
returns to the lee of the Front Range, though did lower highs a
couple of degrees for the lower elevations given signs in some high-
res guidance of continued weak easterly surface flow through the
day. Most areas are thus favored to remain in the 40`s, with
lingering cloud cover also muting the potential to hit 50F. In our
mountains, the approach of a second north/south oriented jet max and
another surge of mid-level moisture should promote redevelopment of
orographic snow showers during the day, and these will continue
intermittently through Tuesday. Have increased PoPs a reasonable
amount over our higher mountains in particular given the quite
unanimous signal for additional light accumulations for the
higher peaks over the next 24-48 hours.

The jet will lift to our northeast by Tuesday as a well-defined
ridge of high pressure emerges over SoCal. More pronounced warming
is expected, with high temperatures set to rebound into the 70`s for
the lower elevations. This ridge will see a gradual eastward
migration through the week, as well as amplification, leading to a
steady warming trend each day through at least Saturday.
Unfortunately, with the ridge centered to our southwest much of the
week, northeast Colorado will remain under an enhanced northwest
flow pattern. With efficient mixing each day, this favors
development of breezy afternoon winds, especially for our northern
plains that are more exposed to this prevailing wind direction. As
such, areas from the Cheyenne Ridge east towards Nebraska and Kansas
will likely see a prolonged period of critical fire weather
conditions from Tuesday through Saturday, exacerbated by building
heat and very low humidity. This is ratified by the elevated
probabilities of exceeding 95th percentile HDWI Tuesday through
Saturday.

As far as temperatures are concerned, little has changed given the
rather consistent signal observed in ensemble guidance. We are
confident in progressively more anomalous heat each day through at
least Friday, with that trend more than likely extending into
Saturday as well (>85% chance). The ECMWF`s EFI exceeds the 95th
percentile each day from Thursday through Saturday, indicating just
how unusual such a prolonged stretch of warm temperatures would be
for our area. There are some factors, such as cloud cover, that
could still influence our chances at setting all-time March records
for some locations such as Denver. However, there are quite a few
locations with extensive historical records for which those records
appear quite easily attainable: Breckenridge (61F), Fort Collins
(81F) and Akron (85F) are some examples of cities with a greater
than an 80% chance of experiencing their hottest March day Friday
and/or Saturday. The probability of that occurring in Denver is
moderately lower, but still significant (~60%).

&&

.AVIATION /06Z TAFS through 06Z Tuesday/...
Issued at 1115 PM MDT Sun Mar 15 2026

Still have some lingering light/snow flurries but this activity
should end by 07z. Ceilings overnight thru Mon morning will be in
the 6000-8000 ft range. The ceilings will scatter out after 18z.

Winds will be light southeast and then light south by 09z. By 12z
will see light and variable winds thru late morning. By 18z winds
will be light east/northeast at DIA with north winds at APA and
northwest winds at BJC.  By 01z, winds will go southeast at DIA
with light northeast winds at APA and light north winds at BJC.

&&

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

&&

$$

DISCUSSION...BRQ
AVIATION...RPK