Brighton, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

372
FXUS65 KBOU 241048
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
348 AM MST Tue Dec 24 2024

.KEY MESSAGES...

- Chances for Christmas afternoon snow in the mountains then
  decreasing in the evening. Limited travel impacts for the
  mountains, none for lower elevations.

- Several weak systems will bring additional light snowfall to
  areas above 10 thousand feet through early next week.

- Above normal temperatures continue through this coming weekend.
  Change to colder temperatures likely before the New Year.

&&

.SHORT TERM /Through Tonight/...
Issued at 345 AM MST Tue Dec 24 2024

Clearing appears to be a few hours ahead of schedule this morning.
There is some trapped low level moisture and areas of fog in Grand
County and a few flurries clinging to the mountain ridges, and
these could take a while to dissipate this morning. The rest of
the forecast looks on track with temperatures rebounding back to
near yesterday`s highs. We lowered tonight`s lows in the mountains
a bit anticipating a little slower arrival of the clouds. There
could be some light snow on the ridges again by morning, but more
likely it will start a few hours later than that.

&&

.LONG TERM /Wednesday through Monday/...
Issued at 345 AM MST Tue Dec 24 2024

Holiday overview:
(5)00mb winds shift southwesterly as the next upper level trough
approaches Christmas Day. (4) inches or less total snowfall
expected for areas above ten thousand feet leading to a white
Christmas for a few. (3) more widespread windy days this year
possibly Saturday, Sunday, and most likely Monday. (2) more rounds
of light afternoon snow possible Thursday and Friday for
elevations above ten thousand feet; And (a) pattern change of
cooler temperatures for northeastern Colorado by New Years Eve.

No major changes for the Christmas forecast. Winds aloft shift
southwesterly Wednesday morning as an upper level ridge is replaced
by an upper level trough. QPF fields range between 0.10-0.25 inches
among model guidance for the high country. Additionally, slight
changes in the movement of the upper level forcing moving south
and minimal amounts of precipitation will likely lead to light
snowfall for areas above nine thousand feet. A quick 1-4 inches
will occur for the high country through Christmas evening. It is
possible a delay in snowfall will occur late Wednesday morning and
early afternoon due the drier air aloft thus decided to reduce
PoPs during this timeframe. For the foothills and plains,
temperatures are slightly warmer. There is agreement with the
previous shift for a delay in moistening the environment for
showers thus will keep isolated chances for rain snow showers from
the foothills to the urban corridor. Not a white Christmas but a
cloudy Christmas.

As the holiday trough exits the Central Plains, there isn`t strong
agreement for precipitation chances for the lower elevations
Thursday. Another weak shortwave trough brings meager amounts of
moisture to high country again leading 1-4 inches above 10k feet.

A cold front develops Friday morning and colder air fills in quickly
behind it. 700mb temperatures decrease 1-3C leading to cooler
Friday afternoon highs reaching the mid 40s across the plains and
mid 20s to 30s for the higher elevations. Another round of light
snowfall will occur above 9.5k feet which will likely total to an
additional 1-3 inches by Friday evening. A few mountain passes
will be slick but travel impacts should remain low through the
weekend. Both the GFS and Canadian solutions are in favor of an
upper level jet increasing westerly winds Saturday and Sunday
mainly along the Wyoming Colorado border. The GFS is the strongest
solution of 60-70 kts at 700mb thus this could lead to a small
increase of breezy wind gusts up to 30 mph both Saturday and
Sunday along the plains. Monday, pressure gradients tighten
across the mountains to plains which could lead to a widespread
windy day of gusts up to 30-40 mph for the forecast area. NBM also
highlights this outcome thus this update includes an increased
wind speeds slightly for the plains Monday afternoon.

Both GFS and ECMWF ensembles support cooler temperatures starting
New Years Eve across the entire forecast area. Temperatures appear
well below normal with parts of the plains dropping to the mid to
upper 30s. Although precipitation chances remain uncertain due to
weak shortwave troughs containing insufficient moisture, the
Climate Prediction Center carries above normal precipitation
chances through early January for majority of northeastern
Colorado. It is unlikely to be a drought buster but additional
chances of precipitation are possible.

&&

.AVIATION /12Z TAFS through 12Z Wednesday/...
Issued at 345 AM MST Tue Dec 24 2024

VFR through tonight. Light winds will become east to southeast
after 18z, then return to south (KDEN and KAPA) and west (KBJC)
drainage winds by 03z.

&&

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

&&

$$

SHORT TERM...Gimmestad
LONG TERM...AD
AVIATION...Gimmestad