681
FXUS65 KBOU 081758
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1158 AM MDT Wed Apr 8 2026

.KEY MESSAGES...

- Elevated to critical fire weather conditions over the plains,
  foothills and mountains parks Wednesday afternoon.

- Higher chances for afternoon precip (25-60%) across much of the
  forecast area both Thursday and Friday.

- Unsettled weather pattern Saturday through Tuesday with decent
  chances of precipitation across the CWA.

&&

.DISCUSSION /Through Tuesday/...
Issued at 1149 PM MDT Tue Apr 7 2026

Current satellite imagery shows an upper level low over northern
Montana, which will trek across the northern United States overnight
and Wednesday morning. With the passage of the low, westerly flow
aloft will increase over northern Colorado, with a 40-50 kt 700-mb
jet over the Colorado/Wyoming. Hi-res guidance indicates mountaintop
winds gusting up to 50-60 mph at times through late Wednesday
morning. At this time, models resolve a too unstable atmosphere to
support any mountain wave enhancement. However, with steep lapse
rates, winds will likely mix down to the surface, which will bring
westerly wind gusts up to 25-30 mph to the Urban Corridor through
the afternoon. Breezy winds combined with low dewpoints will allow
for a period of elevated-to-critical fire weather conditions,
particularly for the northern I-25 corridor. However, with marginal
relative humidity values and low confidence of a long duration of
winds greater than 25 mph, have held off on any fire weather
highlights. Another possible limiting factor of prolonged fire
weather conditions is a cold front that will arrive sometime
Wednesday afternoon. If the front arrives earlier, it will cut off
the easterly extent of the westerly winds.

With the arrival of the cold front, another round of isolated virga
showers are possible for the plains and Palmer Divide. DCAPE values
look to range between 400-1000 J/kg, which would support gusty
outflow winds into the evening.

Ensemble guidance continues to indicate our forecast area entering
an active period Thursday and into the weekend, as flow aloft
turn southwesterly ahead of any upper level low, with embedded
shortwaves creating multiple chances of precipitation for the
mountains and plains. Moisture will be continuously advected into
the region with ensemble models indicating PWAT values 150-200% of
normal, particularly Friday and Saturday. For the mountains,
scattered light snow showers are favored each day for elevations
above 8500 ft. However, significant snowfall amounts are not
expected due to low snow-to-liquid ratios with a relatively warm
airmass in place. For the plains, daily scattered
afternoon/evening rain showers (and possibly thunderstorms on
Thursday) will overall produce light rainfall amounts, with
ensemble solutions showing QPF amounts 0.10" or less. However,
localized higher amounts are possible with any stronger showers.

In terms of temperatures for the rest of the week and weekend, the
plains will continue to be about 10-15 degrees above seasonal
normals due to a mid-level thermal ridge over the south/southwestern
U.S. Expect temperatures reaching up to low-to-mid 70s through the
weekend. The only exception will be Friday, as a backdoor cold front
late Thursday/Friday will keep temperatures in the high 60s for most
of the plains.

There continues to be uncertainty in guidance on how the upper level
flow evolves Sunday and towards the beginning of the week. However,
recent model runs do show a shortwave trekking north of Colorado,
which would decrease our chance of precipitation for our forecast
area. However, with models changing between each run, there is
little confidence with this. NBM has slightly decreased PoPs for
the mountains and plains on Sunday, which seems reasonable given
the recent guidance.

Guidance continues to agree on an a more potent upper level low
tracking across Colorado by Tuesday of next week, which would
bring cooler temperatures along with beneficial precipitation to
the forecast area (possibly even snow on the plains!). However,
with the system being this far out, things can change
significantly in terms of track and intensity. Stay tuned for
updates.

&&

.AVIATION /18Z TAFS through 18Z Thursday/...
Issued at 1142 AM MDT Wed Apr 8 2026

The front has moved through much faster than expected this
morning. It is currently positioned between KBDU and KBJC, extending
southeast below KDEN. It looked like it might stall and back
track north for a little while, but it continues to push southwest
now. The front is expected to move through KBJC in the next hour
or two, switching winds to the NE. The front will hit KAPA last
out of our 3 TAF sites. Right now, we have the winds shifting to
NE around 00Z at KAPA, but if the front continues to move at its
current speed, it could be earlier. Winds will start to turn more
SE overnight, eventually turning towards drainage by early
tomorrow morning at KDEN and KAPA. Winds at KBJC will be more
light and variable overnight as a Denver Cyclone potentially sets
up over the area. Winds tomorrow still look tricky as winds shift
more NE to NW tomorrow morning and likely become variable and
gusty in the afternoon. Isolated to scattered showers will be
possible in the afternoon to early evening tomorrow. However, much
of the rain is expected to evaporate before hitting the ground,
leaving gusty winds from virga around the area.

&&

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

&&

$$

DISCUSSION...MAI
AVIATION...AP

NWS BOU Office Area Forecast Discussion