688
FXUS65 KBOU 301800
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1200 PM MDT Thu Apr 30 2026

.KEY MESSAGES...

- Mountain snow expected Thursday morning through Friday morning,
  with travel impacts likely for high mountain passes.

- Rain showers likely (>70% chance) for Urban Corridor and
  adjacent plains, with highest coverage of beneficial
  precipitation Thursday afternoon.

- Warmer and drier conditions expected for the weekend.

- Chance of showers returns early next week, with potential
  (50-60% chance) of more meaningful precipitation toward late
  Tuesday or Wednesday.

&&

.DISCUSSION /Through Wednesday/...
Issued at 1158 PM MDT Wed Apr 29 2026

The unsettled stretch of weather this week continues... Current
radar imagery shows showers located near and south of Denver.
Showers will continue in this vicinity overnight, especially for
southern and eastern portions of the metro, with light snow possible
for the mountains. There will be a lull in the showers for the early
morning on Thursday due to some dry air intrusion affecting most of
the area, except for the Palmer Divide and southern Front Range
Mountains.

A 500 mb low will track over Baja California and far northern Mexico
on Thursday into Friday. The latest model trends are continuing to
keep this low to the south of the US-Mexico border for the duration
of the event, though we are expecting decent QG lift and
frontogenesis over our area. Additionally, we are expecting some
upslope flow with cross sections showing around 10 to 20 kt winds
and moderately deep moisture- up to 600 to 700 mb- enhancing QPF for
the Palmer Divide and southern Front Range Foothills. This will
result in showers and snow showers returning around midday Thursday
and lasting into the evening. The cloud cover and showers will keep
it feeling more like an early spring day with temperatures
struggling to make it out of the 40s across the Urban Corridor and
only reaching the 50s in the eastern plains.

The biggest uncertainty in the forecast still remains the QPF for
Thursday. Models have still been trending drier with this system,
especially for areas north and east of Denver. The southern Front
Range mountains (south of the I-70 corridor) and western areas of
the Palmer Divide are expected to see the highest QPF due to a
longer duration of more favorable upslope flow in these areas. These
areas could receive 0.50" to 0.75" QPF with isolated higher amounts
possible. Due to the aforementioned dry air, we expect a sharp
cutoff in QPF with locations north and east of a line from Fort
Collins to Greeley likely to only receive up to 0.20". The Denver
area should receive 0.20" to 0.40" with the higher amounts in the
western and southern portions of the metro.

In general, we expect 5 to 13 inches of snowfall in the mountains,
with the highest amounts south of I-70. Thus, a Winter Weather
Advisory will continue for those locations on Thursday and early
Friday morning. The snow level is expected to be near 6500-7000
feet. The Palmer Divide and foothills will receive snow, but
pavement temperatures will likely be too warm for the snow to
significantly affect travel. The greatest impacts will be confined
to the higher passes and higher elevations, especially on Thursday
afternoon and evening. Additionally, have lowered PoPs for Friday
due to more dry air moving in behind a front. Some light rain (snow
for the mountains) will remain possible on Friday, though precip
amounts will be very low. Friday will be a warmer day than Thursday
will high temperatures still about 10 degrees below average with
cloud cover still in place.

For the weekend, warmer and drier weather is expected as an upper
level ridge builds over the Rockies. Ensemble guidance continues to
be in good agreement of temperatures rising above seasonal normals
Saturday through Monday, with temperatures reaching up to the low
70s on Sunday and Monday.

Precipitation chances return to most of the forecast area as
guidance hones in on a stronger upper level shortwave trough
(possibly strengthening into a closed low) trekking across southern
Colorado Monday night into Tuesday. As of right now ensembles show
about a 50-60% chance for 24-hr QPF amounts of 0.50" or more for the
Front Range mountains and southern foothills, and 20-30% chance for
Denver and adjacent plains. Unfortunately for the northern and
northeastern plains, it looks like they will miss out on much of the
precipitation. However, will continue to monitor, as changes in the
track of the system will change precipitation chances for our area.

&&

.AVIATION /18Z TAFS through 18Z Friday/...
Issued at 1201 PM MDT Thu Apr 30 2026

The lower ceilings finally settled over the airport at about 16Z
earlier this morning. Will keep ceilings down in the BKN-OVC012-022
range the rest of today and much of this evening and maybe a tad
lower with the showers. Will mainly keep a PROB30 in for -SHRA the
rest of today. Models are still hanging on to better chances of
rain this evening at DIA so will go with a TEMPO group from
0100/0103 for -SHRA. Ceilings should lift significantly around 07Z
tonight. For winds, the current northeasterlies are expected to
go due easterly later this afternoon, maybe even southeast by
early evening. Speeds look to be under 10 knots by late afternoon
onward. Some sort of weak drainage, or a downslope/drainage mix is
expected by 07Z.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 AM MDT Friday for COZ033-034-037.

&&

$$

DISCUSSION...MAI/MV
AVIATION...66

NWS BOU Office Area Forecast Discussion