Longmont, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

529
FXUS65 KBOU 031617
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
917 AM MST Tue Dec 3 2024

.KEY MESSAGES...

- Quiet pattern today through Saturday, with temperatures above
  normal in most areas.

- Pattern change late next weekend into early next week with
  colder temperatures and a chance of snow.

&&

.UPDATE...
Issued at 910 AM MST Tue Dec 3 2024

Due to satellite imagery and METAR observations, we updated fog in
our grids for the Upper Colorado River Valley/Middle Park Valley.
As the temperatures continue to rise, that fog will dissipate in
an hour or so. Other than that, not much change to the forecast.
The Plains could see high temperatures in the upper 50`s to lower
60`s while the mountains will see temperatures in the 40`s and
valleys in the 30`s. Light winds are expected today with the
northeastern counties seeing some breezy wind gusts up to 20-25
mph late morning to this afternoon.

&&

.SHORT TERM /Through Tonight/...
Issued at 231 AM MST Tue Dec 3 2024

Overall pattern today through tonight will have weak NW flow
aloft over the area. Outside of some higher level clouds today it
will remain dry. At the sfc, a lee trough will be in place which
will allow for downslope warming over the plains. As a result,
will see highs in the mid 50`s to lower 60s. The only exception
will be over portions of Lincoln county where lingering snow over
will keep highs in the 40`s. Meanwhile, across the higher mtn
valleys, inversions will still be hard to break this aftn. Thus
highs in some areas of North and Middle Park will likely struggle
to get above 30 degrees.

For tonight, will keep temps lower than guidance across snow covered
areas of Lincoln county.  In addition, have lowered temps in North
and Middle Park where readings have been well below model
guidance.

&&

.LONG TERM /Wednesday through Monday/...
Issued at 231 AM MST Tue Dec 3 2024

Quiet and mild conditions are expected to continue across the
forecast area through the work week as a broad upper-level ridge
persists over the western CONUS. Within this broad ridging, an upper-
level low is expected to linger over the Desert Southwest, keeping
the ridge centered in the vicinity of Idaho/Oregon. High
temperatures are expected to be above normal through Sunday when we
will likely see our next pattern change. At this time, guidance
solutions continue to show discrepancies with exactly how the
southwestern low evolves, but it will likely stay too far south to
impact northern Colorado.

Afternoon highs are expected to remain in the 50s through the
weekend across the plains, with some downsloping keeping
temperatures at the base of the foothills warmer, and snow cover
still keeping temperatures cooler over Lincoln County. A potent
Arctic airmass to our northeast may brush up against our
northeastern corner on Wednesday, potentially keeping temps a few
degrees cooler in these locations.

There is a signal for a breakdown in the ridge by the end of the
weekend with a potential trough sliding south from the Pacific
Northwest. Increased moisture is advertised in both operational and
ensemble guidance, but there is still a wide spread in just how
much. A change in the pattern is looking likely as temperatures look
to take a decent plunge by the beginning of next week, but with the
overall picture still unclear at this time, have continued with the
NBM output for PoPs and temperatures at this time. It seems
reasonable to go with a slight chance to chance of some light snow
across the CWA, with likely for our northern mountains. Stay tuned
for further details and enjoy the quiet while it`s here.

&&

.AVIATION /12Z TAFS through 12Z Wednesday/...
Issued at 410 AM MST Tue Dec 3 2024

VFR conditions will continue.  Drainage winds will become light
and variable by 18z. By 21Z winds will be light from the NE and
then transition to SE by 01z. Expect drainage winds to redevelop
by 04z this evening.

&&

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

&&

$$

UPDATE...Barjenbruch/Ideker
SHORT TERM...RPK
LONG TERM...Bonner
AVIATION...RPK