421
FXUS65 KBOU 172017
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
217 PM MDT Fri Apr 17 2026

.KEY MESSAGES...

- Snow ending from north to south this afternoon.

- Winter Weather Advisory remains in effect through late afternoon
  for the southern foothills.

- Hard freeze expected across the plains tonight and into Saturday
  morning.

- Elevated fire weather conditions possible for the northern and
  northeastern plains Saturday afternoon.

- Dry and warmer weather returns for early next week.

&&

.DISCUSSION /Through Friday/...
Issued at 209 PM MDT Fri Apr 17 2026

Current radar imagery shows snow showers ongoing for foothills and
plains, with scattered snow showers lingering across the mountains.
CDOT cameras do indicate slick roads across the mountain passes,
however roads across the I-25 Corridor and plains remain wet, as
pavement temperatures have been too warm for snow to accumulate.
Expect snow showers to continue through the late afternoon, before
gradually ending by around 4/5 PM for most of the area. Travel
conditions will gradually improve for the mountains this afternoon
as snow showers continue to taper off, so will let the Winter
Weather Advisory expire at 3 PM. However, will keep the southern
foothills Winter Weather Advisory ongoing through 5 PM due to the
expected lingering travel impacts.

Clearing skies are expected behind this system as it treks east this
evening. This will allow temperatures to dip into the 20s across the
plains (single digits to teens for the mountains and valleys). Given
our recent warm weather allowing plants to bloom, this expected
freeze will likely harm sensitive vegetation. A Freeze Warning
remains in effect from 8 PM tonight to 8 AM Saturday morning. In
addition, any wet roads overnight could freeze, which will result
in slick conditions through Saturday morning.

By Saturday, upper level ridging will begin building over the
western U.S. which will help bring dry and warming conditions over
the region. However, temperatures should remain slightly below
normal, with highs expected to be in the mid-50s. With strong
northwest flow aloft and QG fields indicating deep subsidence,
breezy winds will likely mix down to the surface, with winds gusting
up to 30-35 mph at times in the afternoon across the northeastern
plains. This, combined with relative humidity values in the teens,
will help promote elevated-to-briefly critical fire weather
conditions, particularly for the areas along the CO/WY border.
However, with the recent precipitation, below normal temperatures,
and low confidence of winds gusting above 25 mph for a long
duration, have held off on any fire weather highlights at this time.
If it turns out later this evening that there wasn`t enough
precipitation on the ground, and that winds could be stronger for
a longer duration, then a Red Flag Warning may be warranted.

By Saturday night and into Sunday morning, temperatures will likely
drop again, with most of the plains reaching near freezing or
slightly below freezing. However, have held off on any freeze
headlines for Saturday night due to the uncertainty of widespread
temperatures actually dipping below freezing. Regardless, expect
another cold morning on Sunday.

Warm conditions expected Sunday day through Wednesday as the upper
level ridge dominates the weather pattern. Ensemble guidance is in
good agreement of temperatures reaching up to the high 70s to low
80s, with heat peaking by Wednesday. In terms of precipitation,
aside from weak shortwaves embedded in the upper level flow creating
low chances for showers for the mountains (20-30% chance Monday into
Tuesday), dry conditions will prevail for the region. Daily elevated
fire weather conditions are possible for parts of the plains and
Park county, however winds will be the limiting factor, as weak
flow aloft will keep them mostly below 25 mph. The only exception
would be Wednesday, as winds are expected to increase ahead of an
incoming system.

Ensemble guidance continues to struggle on how to handle the next
system towards the later half of the week. Current models have a 500-
mb shortwave trekking across the U.S. Wednesday through Friday, with
some ensembles indicating the shortwave splitting in two. While we
could get precipitation from this system, it is too early to be sure
exactly where and when. As of now, NBM guidance has daily PoPs
Wednesday through Friday. However, expect this to change as models
continue to resolve the upper level pattern. Stay tuned for
updates!

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 1152 AM MDT Fri Apr 17 2026

A band of moderate snow is currently moving across the Denver
area, dropping visibility to half a mile, and briefly to a quarter
mile in a couple of locations (LMO & EIK). Snow will
continuethrough about 21Z with visibility falling to half amile
under the heavier pockets of snow. Drier air starts to move in
with snow ending between 21Z and 23Z. Ceilings will slowly
improve, climbing to 3,000 to 6,000 feet between 21Z and 23Z, and
then scattered after 00Z. By 03Z, mostly clear skies are
expected. Regarding winds, gusty northeast winds to 30 knots will
slowly decrease through the afternoon hours, becoming light and
variable around or shortly after 00Z. From 03Z to 06Z, winds turn
to a south to southwest drainage direction. WNW to NW winds up to
20 knots are possible between 12Z and 18Z.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 3 PM MDT this afternoon for COZ031-
033.

Winter Weather Advisory until 5 PM MDT this afternoon for COZ034-
036.

Freeze Warning from 8 PM this evening to 8 AM MDT Saturday for
COZ038>051.

&&

$$

DISCUSSION...MAI
AVIATION...12

NWS BOU Office Area Forecast Discussion