Keenesburg, Colorado Weather Forecast Discussion

818
FXUS65 KBOU 051138
AFDBOU
Area Forecast Discussion
National Weather Service Denver/Boulder CO
538 AM MDT Fri Sep 5 2025
.KEY MESSAGES...
- Still hazy/smoky in/near the mountains today, possibly lasting
  through Saturday.
- Increase in coverage of showers and storms today
  through this weekend, but mainly over the higher terrain.
- Warmer with fewer showers and thunderstorms next week.
&&
.DISCUSSION /Through Thursday/...
Issued at 200 PM MDT Thu Sep 4 2025
A shortwave trough will round the upper level low over Hudson Bay
and travel south across the Northern Plains. This will drive cold
front south across Colorado this evening. ACARS and forecast
soundings show moisture and instability will be limited the rest
of this afternoon and tonight. Isolated to widely scattered
showers and thunderstorms are expected. Gusty winds and mainly
light rainfall is expected from the showers and thunderstorms.
Gusty northeast winds will accompany the front with gusts to 40
mph. Satellite imagery showing a large area of smoke to the north
that will travel southward behind the front. This cold front will
also usher in much cooler air for Friday with highs in the upper
60s to lower 70s across northeast Colorado. Moisture will be a
little higher Friday afternoon, but a strongly capped airmass will
keep showers and storms forming over the lower elevation. The
higher terrain, which will be above the cap, is expected to see a
round of afternoon/evening showers and thunderstorms Friday.
For the weekend, we will see upper level ridging off to the west,
across the Great Basin. Over Colorado, a northwest flow aloft
will prevail. Moisture levels remain high enough for scattered
showers and thunderstorms. On Saturday, most and perhaps all of
the showers and storms will be over the higher terrain. Soundings
still show a capped airmass across the lower elevations. However,
a few showers and storms could move east/southeast off the higher
terrain and onto the nearby lower elevations before dissipating.
On Sunday, it is looking like the lower elevations warm up enough
to break the cap. This will lead to better chances for showers and
thunderstorms across the lower elevations. High temperatures for
the weekend are expected to be in the 70s with lower 80s mixed in
for Sunday.
The upper level ridge slides east across Colorado Monday.
Temperatures warm up more with highs in the 80s across northeast
Colorado. Drier air accompanies the ridging with only a few weak
showers/thunderstorms for the higher terrain.
For Tuesday through Thursday, the ridge slides off to the east,
but then stalls just east of Colorado over the Central Plains. The
ridge is then expected to intensify later in the week. Over
Colorado a weak south/southwest flow aloft is expected. Still a
fair amount of uncertainty on how strong the ridge will be and the
placement of it. Given the expected placement of the ridge, highs
should reach the mid to upper 80s each day with an outside chance
at some lower 90s. Shower and thunderstorm chances should be best
across the western half of Colorado, further away from the
ridging. Can`t rule out storms for eastern Colorado either. That`s
if we can get some sort of an easterly push, to increase low
level moisture.
&&
.AVIATION /12Z TAFS through 12Z Saturday/...
Issued at 538 AM MDT Fri Sep 5 2025
Some light smoke lingers in the area this morning, and winds are
light so dispersion has been slow. It still appears to be enough
to mention in the TAF for slant range visibility concerns, but it
will no longer restrict surface visibility less than 6SM. There`s
still a chance of an elevated layer producing IMC for KDEN off/on
today through this evening with plenty of smoke aloft, so
something to watch for and we`ll have a greater idea of the latest
smoke concentrations after sunrise with new visible satellite
pics (barring cloud cover).
Otherwise, VFR conditions will persist but models still show an
elevated stratus deck for ceilings around 5000 ft AGL for the
Denver TAF sites through 18Z. Although as earlier indicated the
clouds are slow to thicken/become more widespread due to
relatively dry post-frontal airmass. If they do become BKN, then
expect a gradual erosion with peak daytime heating after 18Z. The
chance of showers 20Z-02Z should stay mostly southwest of KDEN,
over the higher terrain or points closer to the Palmer Divide as
the airmass is quite stable over the plains.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Meier
AVIATION...Barjenbruch

NWS BOU Office Area Forecast Discussion