128
FXUS65 KBOU 051922
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
122 PM MDT Sun Apr 5 2026

.KEY MESSAGES...

- Dry through Monday with a chance of light showers late day
  Tuesday and Wednesday.

- Elevated to critical fire weather conditions over the plains and
  foothills Wednesday.

- Unsettled weather pattern to end the week.

&&

.DISCUSSION /Through Sunday/...
Issued at 116 PM MDT Sun Apr 5 2026

Northwesterly flow aloft and dry conditions are visible across the
region in this morning`s water vapor imagery. A fairly mild day is
expected across the forecast area today as temperatures hover just
above normal under mostly clear skies. A rather laxed pressure
gradient will keep winds nice and light for a welcomed change. There
have been a few early morning fire starts along the Front Range this
morning that show how susceptible fuels are. Fortunately, the
aforementioned light winds will benefit the fire fighting efforts.

A backdoor cold front will usher in cooler temperatures for Monday,
especially for the northeast corner of the state where afternoon
high temperatures will be 10-15 degrees cooler than today`s. A
tightening pressure gradient will increase winds throughout the day,
but with increasing dewpoints expected with the cold front, RH
values are expected to remain above any critical fire thresholds,
keeping any critical fire weather concerns at bay. Flow aloft
becomes more zonal Monday where it will persist through the majority
of the week. A weak shortwave will pass through the southern tier
Monday night into Tuesday. While the best moisture looks to remain
to our south, we could get a little spillover into our mountains,
with a few hundredths to around a tenth of QPF possible trough
Tuesday, mainly for the Central Mountains and Palmer Divide, though
we could see some very light precipitation over the northeast corner
too. With the zonal flow aloft, temperatures will begin to warm on
Tuesday, bringing us back up to 5-10 degrees above seasonal norms.

An upper-level low will start to slide out of the Pacific Northwest
through the day on Tuesday and cross the northern Rockies on
Wednesday. Downsloping winds will strengthen as lee troughing
deepens ahead of the low, and increasing critical fire weather
conditions are expected across portions of the foothills and plains
where relative humidities will drop into the low to mid teens. There
could be a few hours of mountain wave enhancement Wednesday morning
when cross-barrier flow increases to 45-50 kts with northern
Colorado on the subsident side of a 60 kt, 700 mb jet max. So far,
soundings don`t show an inversion near ridgetop and Sangster
output only shows dp/dn values near 150. However, the RRFS does
show a few hours of 60-70 mph wind gusts for our typical windier
foothills locations of Boulder and Larimer Counties in the
morning, with some fingers of 30-40 mph westerly gusts channeling
their way across the I-25 corridor and Cheyenne Ridge through the
afternoon. We will likely need some fire highlights, but will have
a better idea of what we are looking at once more hi-res guidance
comes into play. Mid-level moisture should increase enough to
bring some light precipitation to the mountains in the afternoon,
and a cold front stemming from the low could bring some light
precipitation to the plains Wednesday evening.

For the end of the week, mid- and upper-level moisture will begin to
increase as flow aloft transitions to the southwest ahead of our
next approaching trough. This will bring better chances for more
widespread precipitation across the forecast area through the
weekend.

&&

.AVIATION /18Z TAFS through 18Z Monday/...
Issued at 1156 AM MDT Sun Apr 5 2026

VFR conditions through the TAF period. Overall light winds through
tomorrow (

NWS BOU Office Area Forecast Discussion