-- Discussion containing changed information from previous version are highlighted. --
475
FXUS65 KPUB 070417
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1017 PM MDT Mon May 6 2024

.KEY MESSAGES...

- Strong and gusty winds will continue to weaken slightly going
  into the evening hours, but then increase tomorrow morning
  and could reach to near High Wind Warning criteria for some
  locations.

- Critical fire weather conditions will continue into the early
  evening hours for the San Luis Valley and portions of the
  plains. These conditions are expected to return again tomorrow
  afternoon and possibly Wednesday.

- A few showers, and high elevation snow showers, will be
  possible over locations mainly north of Highway 50.

- Temperatures at or just below freezing are possible across El
  Paso county Tuesday night.

- Cooler and wetter weather is expected by the end of the week
  into the weekend, along with the possibility for accumulating
  snow across the higher terrain.

&&

.UPDATE...
-- Changed Discussion --
Issued at 1013 PM MDT Mon May 6 2024

With increasing humidity values and overall decreasing winds,
critical fire weather conditions are no longer expected for this
evening. Given this, the Red Flag Warning for today has been
allowed to expire.
-- End Changed Discussion --

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 239 PM MDT Mon May 6 2024

Currently and through tonight...

Very strong and gusty winds due to a post-frontal density current
and deep mixing will continue to slightly weaken going into the
evening hours for most areas as winds begin to decouple, although
likely remaining quite strong across the highest elevations due to
stronger winds aloft. There Critical fire weather conditions
currently for the San Luis Valley, and portions of the plains where
fuels are still critical, should subside by early this evening as
winds begin to decouple and RH values recover above the 15 percent
threshold. There could still be some areas reaching close to High
Wind Warning criteria for the next couple of hours, although not
expecting to this to persist and be widespread. There could still be
some areas of blowing dust through the early evening hours, mainly
over the eastern plains. A few showers will continue to be possible
for the central mountains, although these should be light and brief,
with little in the way of additional accumulations expected.
Although, there could still be some temporarily reduce visibilities,
especially through the passes, due to blowing snow. Low temps will
be quite modified and not as cold for lower elevations, due to
mixing, yet they will be cooler than the previous night because of
colder air advection in

Tomorrow...

Stronger winds are going to return by early tomorrow morning,
shortly after sunrise when winds begin to mix down from the 700 mb
level. Confidence is still lacking with there being widespread areas
of High Wind Warning criteria, given that x-sections show only
forward shear as being the driving force, and little in the way of
any mountain wave action. The only way this is likely to be achieved
is if there is a sufficient amount of deep layer mixing and 700 mb
winds which are forecast to exceed 50 kts, makes it down to the
surface. Higher terrain is also questionable, as most locations
remain right on the cusp of High Wind Warning criteria.
Nevertheless, severe crosswinds are still possible, especially over
portions of the southern I-25 corridor. For this reason, I have
issued a High Wind Warning for tomorrow, which covers all of the
areas most vulnerable to the potential for high wind criteria
occurrence.

There could also be some areas of blowing dust, especially shortly
after sunrise when soils are initially lifted. There will be some
snow showers with blowing snow over the central mountains, with
additional snow amounts of a few inches possible, especially for the
western facing slopes of the northern Sawatch and Mosquito ranges.
There could be some temporary reduced visibilities due to blowing
snow, especially for the Cottonwood and Fremont passes. In addition,
to the strong winds, there will be low RH values for the San Luis
Valley (SLV) and plains. Due to this, critical fire weather
conditions are expected for the SLV, as well as portions of the
plains where fuels are still critical.   -Stewey

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 239 PM MDT Mon May 6 2024

Large upper low situated across the central CONUS will continue
to influence the weather across the area during the mid week
time frame. Trough and jet axis do begin to dip south Tuesday
night into Wednesday, helping to end any snow development across
the central mountains and also providing a diminishing trend
with the winds. With this diminishing trend along with a cooler
air mass filtering in, will see temperatures fall into the 30s
across the plains. Temperatures do look to drop to or just below
freezing across El Paso county and with higher confidence in
place, have opted to issue a Freeze Watch. Elsewhere across the
plains, temps should stay above freezing, and where winds really
drop off, frost could develop. Will keep an eye on trends and
the possible need for additional freeze/frost headlines. While
winds will not be as strong on Wednesday, they will still be
gusty in some locations. These winds along with high
temperatures in the 50s and 60s and RH values in the 10 to 15
percent range, will see another day of high fire danger. The
current Fire Weather Watch on Wednesday for the San Luis Valley,
southeast mountains, and portions of the plains still looks to
be on track at this time.

By late Wednesday into Thursday, will likely see another low
take shape across the region, which will then slowly meander
back west/southwest through the end of the work week. This
system will bring some complexity to the forecast, especially
into the start of the weekend, with some lower confidence on
exact trends. That being said, cooler temperatures with
increasing precip chances will be the main trend during this
time. At this time, highest precip chances will be over the
mountains, where there are increasing chances for accumulating
snow. Once again, do have lower confidence in place, but will
need to monitor the potential for some impacts across the higher
terrain along with the need for possible winter weather
headlines. Other locations over the lower terrain, mainly along
and west of I-25, will likely see periods of rain showers along
with a few thunderstorms. For the remainder of the weekend into
early next week, should see this upper low slowly shift to the
south with precip chances lowering and temperatures warming.
It`s quite possible that it takes a slower track and if so, will
see continued precip chances and cooler temperatures for
southern Colorado.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 239 PM MDT Mon May 6 2024

VFR conditions are expected to prevail for all TAF sites (KALS,
KCOS, and KPUB) throughout the forecast period. Winds will be
synoptically influenced throughout the entire duration of the
forecast. They will be very strong and gusty through the evening
out of the west to northwest direction at all terminals. These
winds will decouple and weaken going into the late evening
hours, but then return to being very strong and gusty shortly
after sunrise tomorrow morning, towards the end of the forecast
period. There could also be some areas of BLDU at KALS after 17Z
and KPUB after 16Z, which may temporarily reduce VIS down to
IFR criteria. Winds will further increase towards the end of the
forecast period. -Stewey

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
Red Flag Warning from 9 AM to 10 PM MDT Tuesday for COZ224-225-
232-233-237.
High Wind Watch from 9 AM MDT Tuesday through Tuesday evening
for COZ069>075-077>080-083-086>088.
Fire Weather Watch from Wednesday morning through Wednesday
evening for COZ224-225-232-233.
Freeze Watch from late Tuesday night through Wednesday morning
for COZ084-085.
-- End Changed Discussion --

&&

$$

UPDATE...SIMCOE
SHORT TERM...STEWARD
LONG TERM...RODRIGUEZ
AVIATION...STEWARD