856
FXUS65 KBOU 060142
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
742 PM MDT Sat Oct 5 2024

.KEY MESSAGES...

- Widespread critical fire weather (Red Flag) conditions through
  early this evening, with highest probabilities/strongest winds
  in the mountains, foothills, and northern/eastern plains.

- Elevated to near critical fire conditions Sunday afternoon over
  the Palmer Divide and portions of the east central plains.

- Dry weather through most of nest week with above normal
  temperatures, but odds favor a change in the weather toward next
  weekend.

&&

.UPDATE...
Issued at 736 PM MDT Sat Oct 5 2024

After a record-breaking warm day across the region, temperatures
are cooling off quickly behind a weak backdoor front. This could
prevent Denver from achieving a record high minimum temperature
for the date (would need to remain above 55F through midnight).
Either way, it`ll be close. As mentioned previously, could see
some patchy front in our far northeast plains, but confidence
isn`t there in the spatial extent for any headlines.

Have made a few tweaks to fine-tune the smoke forecast through
Sunday. We can expect some smoke from fires in Wyoming to settle
near the surface overnight into early Sunday morning as it
continues to drift southeast into Colorado. Much of that should
mix out during the day tomorrow, but a transition to westerly flow
aloft will increase the potential for an intrusion of more smoke
from our west (specifically the Yellow Lake Fire in UT) by about
mid-afternoon.

&&

.SHORT TERM /Through Sunday/...
Issued at 140 PM MDT Sat Oct 5 2024

NW flow aloft this aftn will gradually become more westerly late
tonight thru Sun. The overall airmass will remain very dry with
no chance of precip.

Meanwhile, a cool front was moving across the plains this aftn and
will eventually backdoor into the I-25 Corridor by early this
evening.  This front will drop temps back to more seasonal levels
for Sun, however, readings will still be a few degrees above normal.

Temps late tonight will drop into the mid to upper 30s over portions
of the plains, with some potential for scattered light frost.
Finally, there will be some haze due to smoke over portions of the
plains overnight through Sun.  At this time, it appears most of it
will stay to the east of the I-25 Corridor.

&&

.LONG TERM /Sunday night through Saturday/...
Issued at 140 PM MDT Sat Oct 5 2024

Upper level high pressure dominating the Rocky Mountain Region will
result in continued unseasonably warm temperatures and very dry
weather across North Central and Northeastern Colorado over the next
several days. Despite the warm and very dry conditions, fire weather
conditions are expected to stay below critical thresholds due to
relatively light winds, with pockets of elevated conditions in some
areas. The exception may be Monday afternoon across the northern
sections of the plains near the Wyoming border as gusty winds
associated with an upper level disturbance combines with low
relative humidity and dry fuels. The only chance for any
precipitation during the work week may be Wednesday afternoon as
models are hinting at the possibility of a few weak showers,
mainly across the high country.

By next weekend, we could see a change in the weather as the models
are showing an upper level storm system and associated cold front
moving moving across the state. At this time, there is quite a bit
of uncertainty on how the this system will impact the forecast area
due to run to run inconsistencies and model discrepancies. The
consensus of the models is that the CWA should see some cooling by
Saturday with precipitation chances increasing from west to east
across the CWA through the day into the evening, with some
accumulating snow possible over the higher mountains. However, if
the system is a little slower, Saturday could be another
unseasonably warm and dry day across the area.

&&

.AVIATION /00Z TAFS through 00Z Monday/...
Issued at 529 PM MDT Sat Oct 5 2024

Lingering gusty winds across the Denver metro will continue to
diminish over the next couple of hours, and winds have begun to
veer to the north ahead of a likely shift to easterly winds
between 02-03Z this evening. Overnight winds will be light and
under 10 kts, with S/SW drainage flow favored, but potential for
variable directions at times. Prevailing wind directions are quite
uncertain for Sunday, and will be dependent on exact location of
Denver cyclone. Will maintain current lean towards period of NE
winds based on (best) model consensus, although with a far enough
push to the NW, could see an intrusion of SE winds at KDEN after
20Z Sun.

VFR conditions are favored to prevail for all terminals through
the TAF period. However, wildfire activity in WY and UT will
continue to advect some smoke into the region through Sunday
night. At this time, expecting the first intrusion of smoke to
stay far enough NE of the Denver metro early Sunday AM (~04-08Z)
to be of any concern, although minor near-surface vis reductions
to 6-8SM will be possible below the inversion. Suspect the higher
potential for any higher smoke concentrations between 040-060 that
could impact slant visibility would be after 21Z Sun, with an
intrusion of smoke from our west.

&&

.FIRE WEATHER...
Issued at 140 PM MDT Sat Oct 5 2024

Critical fire conditions will continue thru early this evening,
however, winds will decrease along with some increase in humidity
behind a cool front over the plains.  On Sun, will see lighter winds
in most areas.  However, across the Palmer Divide and east central
plains will see south winds increase by early afternoon with low
humidity levels. Thus fire conditions will be near critical levels
for a few hours during the afternoon hours. Elsewhere it will
remain dry with elevated fire conditions in some areas during the
afternoon due to low humidity and continued dry conditions.

Could see elevated to near critical fire weather conditions across
our Northern Plains near the Wyoming border Monday afternoon due
to gusty northwesterly winds, very low relative humidity and dry
fuels. For the remainder of the week, only pockets of elevated
fire weather conditions are expected due to lighter winds.

&&

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

&&

$$

UPDATE...Rodriguez
SHORT TERM...RPK
LONG TERM...JK
AVIATION...Rodriguez
FIRE WEATHER...RPK/JK