Longmont, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

305
FXUS65 KBOU 040710
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1210 AM MST Wed Dec 4 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 825 PM MST Tue Dec 3 2024

Made highly localized adjustments to overnight lows, mainly for
the Fraser valley, to lower below zero given current observations.
Additionally, limited the mention of fog in the forecast to just
patchy occurrences across Middle Park, as high clouds are
relatively expansive tonight and extend well upstream into Utah.
Otherwise, no changes to note this evening.

&&

.SHORT TERM /Through Wednesday/...
Issued at 216 PM MST Tue Dec 3 2024

Pleasant weather is expected as we are stuck between two systems-
Upper level analysis show a mix between northwest flow aloft from
the Polar jet that is well into Canada to our northwest and some
southwest flow with the elongated trough to our southwest. There
will be a weak cold front that passes this evening, but no
precipitation is expected as there is no QPF analysis and cross-
sections show little to no moisture. However, 25-30 mph wind gusts
are expected with this cold front for the northeast Plains.
Temperatures tonight will be between 20-low 30`s for the Plains,
teens-20`s for the mountains and single digits for the high
mountain valleys as the inversions set in again.

Tomorrow`s temperatures, although still above seasonal values,
should be cooler than today`s for the Plains as that cold front
will have pushed through by then. Expect them to be in the 50`s,
even in Lincoln county where that snowpack is finally starting to
not have as much of an effect anymore. We are expecting valley
fog in Middle Park through late morning again, as the inversions
are expected to stay a while due to weak winds and clear skies.

&&

.LONG TERM /Wednesday night through Tuesday/...
Issued at 216 PM MST Tue Dec 3 2024

Dry weather and above normal temperatures will continue across North
Central and Northeastern Colorado through the weekend as a flat
upper level ridge of high pressure remains over the Rocky Mountain
Region. Temperatures through this period are expected to be some 5
to 10 degrees above normal across the CWA. The chance of snow may
return to the Northern Mountains by late Sunday afternoon as an
upper level trough approaches Colorado from the northwest. However,
the models have trended slower which may delay the development of
any snowfall until evening. Cooler unsettled weather is expected
Sunday night into early next week as the upper trough and associated
cold front pushes across the forecast area. Many of the models are
suggesting upslope flow behind the passage of the cold front along
with plenty of QG lift associated with the upper trough and 100KT
upper jet, especially on Monday. This would be a a favorable pattern
for snowfall across the mountains, foothills and adjacent plains.
However, there is still quite a bit of uncertainty in snowfall
amounts due to model differences and run to run inconsistencies.

Cluster analysis shows pretty much a 50/50 split between a deeper
system which would result in a better chance for accumulating snow
while the weaker and more progressive scenario would result in much
lighter amounts across the area. It`s too early to get into the
details on how much snow will fall, but we will need monitor this
storm system for any changes in in it`s track and intensity.

&&

.AVIATION /06Z TAFS through 06Z Thursday/...
Issued at 1201 AM MST Wed Dec 4 2024

VFR through Wednesday. Winds will become more easterly at light
speeds after 18z.

&&

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

&&

$$

UPDATE...Rodriguez
SHORT TERM...Barjenbruch/Ideker
LONG TERM...JK
AVIATION...Gimmestad