Arvada, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

767
FXUS65 KBOU 301744
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1144 AM MDT Sun Mar 30 2025

.KEY MESSAGES...

- Light rain showers for the plains later this afternoon with snow
  mixed in later this evening and tonight. Light snow showers in
  the mountains.

- Occasional showers, mostly rain at lower elevations and snow at
  higher elevations, this week. Highest chance of precipitation is
  on Tuesday. Temperatures will be near seasonal normals.

- Small potential for a larger snowfall across our forecast area
  next weekend but there is high uncertainty in the track of this
  system.

&&

.UPDATE...
Issued at 1004 AM MDT Sun Mar 30 2025

Cloudy and cool day for most of the area. Areas of drizzle, mainly
west of the I-25 will decrease and end early this afternoon. East to
southeast low level flow across the plains will keep areas from
Denver north socked in with clouds for today. Lowered temperatures a
few degrees here with highs only expected to reach the mid 40s.
There is some clearing to the south of Denver. This will result in
slightly warmer temperatures. Models have favored this area for
showers, and perhaps a few storms this afternoon. This appears on
track due to the partial clearing leading to a little instability.
Increased PoPs across this area for late this afternoon and early
evening. No other changes to the forecast are planned.

&&

.SHORT TERM /Through Tonight/...
Issued at 414 AM MDT Sun Mar 30 2025

Precipitation is on the decrease over the CWA at this time. There
are two areas left, one across the north central CWA just getting
into the plains along the northern border moving eastward. It is
mainly light snow. The other area is mainly over Washington and
Morgan Counties. It is also light snow and moving eastward about
20 mph. There is plenty of fog across the plains at this time.
Some places have visibilities down to 1/2 mile.

Models have moderate zonal flow aloft for the CWA today into this
evening.  After 06Z tonight, strong northwesterly flow at jet level
moves into the CWA.  There is synoptic scale subsidence over the
forecast area today, but later this afternoon, weak upward motion
moves in. Models keep an easterly component to the low level
winds through the day into this evening, then weak drainage wind
patterns are indicated.

There is ample moisture around today and tonight.  Convection should
kick early to mid afternoon, with the best coverage over the
southern CWA. The showers look to produce just light rainfall.
There is tad a CAPE progged this afternoon, mainly over the Palmer
Ridge and Southern Front range Foothills. Will leave the 20-50%
pops going for much of the CWA late this afternoon and tonight.
The plains will see rain and maybe some snow mixed in tonight.
Light snow in the mountains with limited accumulations. Will leave
the mention of thunder out for now as it too cool.

For temperatures today, readings look 10 to 15 degrees F cooler than
yesterday`s highs with the increased low level moisture around from
the recent precipitation, plenty of cloudiness expected today and
the cooler airmass in place from last evening`s cold front.

&&

.LONG TERM /Monday through Saturday/...
Issued at 414 AM MDT Sun Mar 30 2025

There`s a break between systems for Monday, though there`s still
some moisture and instability especially over the northern and
western edges. So we`ll keep some low PoPs, but amounts should be
light. With some warm advection and more sun, temperatures will
pop up about 10 to 15 degrees, near or a little above normals. The
next shortwave trough will move through Tuesday. There will be
some moistening ahead of it with winds picking up and some
mountain moisture Monday night, then more lift and what should be
a decently organized batch of showers Tuesday afternoon and
evening. This should be mostly rain on the plains, with the snow
level likely dropping from 7-8 thousand feet down to 5-6 thousand
feet behind the trough Tuesday night.

There`s another break Wednesday into early Thursday, though once
again, some lingering instability and moisture precludes a
completely dry forecast.

Models continue to have good agreement on a large trough
developing over the southwest by Friday. But details on the
interaction between numerous shortwaves and the large scale
pattern vary a lot. There`s been a trend towards additional
shortwaves digging the mean trough deeper, slower, more westward
going into the weekend. In addition to the trough location, the
way shortwave energy lifts out of the trough, or rotates northward
around the east side of it, will affect precipitation chances for
us. Current model runs still mostly have a weak lead trough
lifting north on Thursday in a warm environment, and then some
kind of lift Friday into Saturday. This takes a variety of forms
from a deformation zone on the edge of the broad low, to
shortwaves lifting northeast, to slight warm/moist low level
advection that is eventually enough to saturate. So given the
current set of forecasts, it looks like there`s a pretty good
chance of plains rain and mountain snow in the Friday/Saturday
time frame. It`s not out of the question to have it cold enough
for snow on the plains, but the early parts will be fairly warm.

There is the nagging question of potential further digging/slowing
which could put the whole thing west of us and under a blocking
pattern and the upper air features never even get here. So yes, a
prolonged precipitation event or potentially nothing over the
weekend. We still think there`s a pretty good chance of some
forcing for lift in a favorable environment, but it seems early to
latch on to the more aggressive solutions given a decent chance
the focus for prolonged lift won`t be over us.

&&

.AVIATION /18Z TAFS through 18Z Monday/...
Issued at 1145 AM MDT Sun Mar 30 2025

Low clouds to persist through the day with ceilings mainly
2000-4000 feet. Scattered showers develop after 21Z with the best
chance for showers to the south of DEN and towards APA. Thus went
with a tempo for showers at APA and just a PROB30 at DEN and BJC.
Once the showers progress east of the area (~06Z), clouds are
expected to lower.

For late tonight and into Monday morning (10Z to 15Z), there will
be a good chance for fog. A cyclone forms overnight, with
southerly winds initially prevailing at DEN. Low clouds are
expected to be in place, but southerly winds prevail through the
night and may prevent fog from forming. However if winds shift to
the west, northwest or any northerly component, fog will likely
develop at DEN. Added a tempo for the fog, but could be moved into
the prevailing group if wind direction confidence to the west or
north grows.


&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Monday evening through late Tuesday
night for COZ031.

&&

$$

UPDATE...Meier
SHORT TERM....rjk
LONG TERM.....Gimmestad
AVIATION...Meier