Arvada, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

142
FXUS65 KBOU 091732
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1132 AM MDT Wed Apr 9 2025

.KEY MESSAGES...

- Critical fire weather conditions for much of the plains for
  today. Areas of elevated to critical possible through next
  weekend, mainly toward Saturday and Sunday.

- Above normal temperatures and dry weather through Saturday, with
  high temperatures reaching near record levels Saturday.

- Cooler temperatures and a chance of showers for early next week,
  but odds of any significant precipitation remain quite low.

&&

.UPDATE...
Issued at 943 AM MDT Wed Apr 9 2025

Main concern remains fire weather today. Winds are starting to
increase along the foothills and Wyoming border area at this time,
and those are on course to spread across all of the plains later
this morning through the afternoon with additional daytime heating
and mixing. We nudged daytime highs up a degree or so based on
the latest short term guidance and plenty of sunshine (mainly just
a few bands of wave clouds), and made minor adjustments to winds
in a few spots. Overall forecast is on track.

&&

.SHORT TERM /Through Tonight/...
Issued at 242 AM MDT Wed Apr 9 2025

WNW flow aloft will be over the area today.  Cross-sections continue
to show varying amounts of mainly mid and high level moisture
embedded in the flow, with drier air, in the lower levels.  Once
again there could be some virga in the nrn mtns but measurable
precip appears on the low side.  Across the plains, there will be
periods of clouds with dry conditions.

Meanwhile, gusty WNW to NW winds will develop late this morning and
continue thru the aftn. Gusts from 35 to 45 mph will occur across
the nern plains this aftn. It will also be windy over the higher
terrain as well. As far as temps, 850-700 mb temps are 2-3 degrees
c lower than Tue. Thus aftn highs will be slightly cooler over
the plains with readings in the upper 60s to lower 70s.

For tonight, the flow aloft will become more NW.  There is minimal
moisture embedded in the flow so will keep a dry fcst in place.  A
cold front will move across the plains after midnight bringing
cooler lows for Thu morning.

&&

.LONG TERM /Thursday through Tuesday/...
Issued at 242 AM MDT Wed Apr 9 2025

There will be decreasing northwest flow aloft on Thursday as the
upper level ridge continues to build over the central Rockies.
Breezy conditions are possible for the far eastern plains due to
tightening of pressure gradients from a surface high pressure in the
Dakotas and a low pressure in the eastern US. Areas like Sedgwick,
Phillips and Washington counties could see northwest wind gusts
up to 25 mph. Sometime in the late afternoon, a backdoor cold
front is expected to push through the plains, which should keep
temperatures in the mid-high 60s. However, depending on how
quickly the cold front arrives, temperatures could be slightly
cooler.

Friday and Saturday will be our warmest days of the period as both
days are expected to see temperatures in the 80s. On Friday, the
broad upper level ridge will shift east and settle over Colorado. At
the surface, there could be breezy south/southwest winds along the
eastern plains due to tighter surface pressure gradients. On
Saturday, the upper level ridge will flatten, resulting in
increasing westerly flow aloft. With this increased flow aloft,
strong winds are possible in the mountains, with a 40% chance of
gusts exceeding 55 mph. For the plains, westerly downslope winds
will aid in compressional heating, allowing temperatures to reach
up to the mid-high 80s. Current high temperature forecast for
Denver is 85 degrees, which would tie the record that was set in
2023.

Guidance has continued to indicate an upper level trough traversing
just north of Colorado sometime Sunday into Monday. However, there
is still some uncertainty between ensemble runs in terms of exact
timing and intensity. The most recent solutions have trended towards
a faster-moving trough, with a cold front limiting temperatures
to the high 60s/low 70s for Denver on Sunday. Ahead of the cold
front, widespread strong westerly wind gusts are possible across
the region, with a 20% chance of gusts exceeding 50 mph across the
plains and a 30% chance of gusts >60 mph in the mountains.

Precipitation chances return to the region on Monday, although
ensemble output does not indicate anything significant. Light
orographic snow showers are possible across the Front Range
mountains with minimal accumulations. For the plains, light rain
showers are possible, with a small chance of temperatures getting
cold enough for a rain/snow mix. However, little if any travel
impacts are expected.

&&

.AVIATION /18Z TAFS through 18Z Thursday/...
Issued at 1132 AM MDT Wed Apr 9 2025

Main concern are the gusty northwest winds today, and those are
now increasing. Peak gusts near 30 kts can be expected from the
northwest through much of the afternoon, decreasing by 01Z. After
01Z, look for a further decrease in winds to around 10 kts and a
slight turn more north/northeast through 03Z-06Z. Winds could then
become light and variable overnight, but odds would favor light
southeast flow around 5-8 kts through 16Z Thursday, turning more
easterly by 18Z. VFR will persist.

&&

.FIRE WEATHER...
Issued at 242 AM MDT Wed Apr 9 2025

Critical fire danger will be over most of the plains late this
morning through the early evening hours. Gusty northwest winds
from 35-45 mph will occur along with humidity levels around 15
percent.

The winds will gradually decrease by early evening along with an
increase in humidity levels.

There could be localized elevated fire weather conditions in
South Park and the far northeastern plains on Thursday and Friday.
Relative humidity values should reach down to the mid teens and
wind gusts up to 25 mph are possible. However, these conditions
are expected to be brief.

Widespread elevated to critical fire weather conditions are expected
both Saturday and Sunday. Temperatures 20+ degrees above normal are
possible for Saturday, with a dry air mass allowing humidity values
to dip to critical thresholds. The plains and mountains could see
relative humidity values less than 10% with 35+ mph wind gusts
across the high country and 25+ mph gusts along the plains. On
Sunday, relative humidity values are expected to be in the low-mid
teens with 40+ mph wind gusts across the mountains and 30+ mph gusts
along the plains. However, depending on the timing of the cold front
on Sunday, cooler temperatures and high relative humidities are
possible.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 7 PM MDT this evening for COZ238>240-
242>246-248>251.

&&

$$

UPDATE...Barjenbruch
SHORT TERM...RPK
LONG TERM...Ideker
AVIATION...Barjenbruch
FIRE WEATHER...Ideker/RPK