013
FXUS65 KPUB 221055
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
455 AM MDT Wed May 22 2024

.KEY MESSAGES...

- Spotty critical conditions possible zone 225 (S mtns) today.

- Very isolated thunder later this afternoon/early evening
  plains mainly S of US50.

- Critical fire weather conditions will be widespread for
  elevations below 7500 ft in vicinity of the Sangres and Wets
  on Thursday during the afternoon and early evening hours.

- Isolated afternoon and early evening thunderstorms will be
  possible over the higher terrain for Thursday and Friday,
  mainly north of Highway 50, with a lesser chance over the
  plains.

- Scattered showers and thunderstorms will become more likely
  this weekend, especially on Sunday, with better chances for
  the plains.

- Isolated thunderstorms possible over the higher terrain on
  Monday and Tuesday.


&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 324 AM MDT Wed May 22 2024

Currently...

A few showers were pushing out of the region over the fare eastern
plains in Baca county at 2 AM. Besides some clouds over the Raton
Mesa, skies were clear across the fcst area. Temps at 2 AM over the
plains ranged from the mid 30s across N El Paso county to upper 40s
over Baca county. Valleys were in the 30s with 10s and 20s in
the high country.

Today and Tonight...

An overall quiet pattern next 24 hours.

In the immediate short term, some frost will be possible over the
northern sections of El Paso county early this AM. Otherwise expect
temperatures to rise into the upper 60s across N El Paso county to
around 80 along the US50 corridor from Pueblo to the KS border. OVer
the Valleys today expect upper 60s, with 40s and 50s over the mtns.

As for any convection today, we may see some isolated high based
convection later this afternoon and early evening over the plains,
with the best chance south of US50. main concerns would be an
occasional isolated CG and brief gusty winds.

As for fire weather, only lower elevations of zone 225 (S Mtns) is
in the critical fuel category, and spotty critical fire weather
conditions will be possible, as winds will be near the 25 mph range
and RH values will down near 15 percent over the lower elevations of
the 225 zone. Over the San Luis Valley meteorological conditions are
imminent today, but fuels are not favorable.

For tonight, a clear night is anticipated with warmer min temps as
compared to this mornings lows. Expect lows in the 40s to L50s
plains and 30s valleys. /Hodanish

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 324 AM MDT Wed May 22 2024

Thursday through Friday...

An upper level low will propagate into Wyoming from upstream, which
will allow for a tightening of the pressure gradient and increasing
southwesterly flow at the surface. This will help to advect in a
drier airmass out of the southwest region and result in dropping
relative humidities for the region on Thursday. Because the fuels
are still critical for the lower elevations (below 7500 ft) in
vicinity of the Sangre de Cristo and Wet Mountains, these areas will
be susceptible to critical fire weather conditions by later in the
afternoon as winds increase and once RH values tank. There will also
be some moisture advection with westerly flow in the mid-levels,
which will allow for afternoon showers and thunderstorms to develop
over the higher terrain with the aid of orographic lifting, although
model data indicates that the majority of this convection will
remain confined to the central mountains where the best swath of mid-
level moisture will be located. High elevation snow will also occur,
mainly over the central mountains. There could also be some
thunderstorms initiating over the Ramparts/Pikes Peak Region (PPR),
that move over into the Palmer Divide area. Downsloping winds over
the lower elevations will also allow for temperatures to become
quite warm, with many locations over the plains and especially
within the lower Arkansas River Valley to top out near the 90 degree
mark on Thursday.

For Friday, as the U/L low continues to propagate eastward and
further away from the region, this will allow for the pressure
gradient to loosen and therefore winds will not be as strong. That
being said, there will still be some spotty areas of fire weather
conditions where fuels are still critical and may need additional
highlights. It will remain mostly dry for most of SE Colorado, with
the only exception being over the higher terrain and especially
north of Highway 50 again, where the best residual mid-level
moisture will be. A weak cold frontal boundary associated with the
exiting U/L low will move through early in the morning and switch
winds to a northerly direction which will help to advect in cooler
temperatures and therefore highs, especially for the plains, will be
notably cooler by some 10 to 15 degrees.

Saturday through Sunday...

It will begin to become more active during this period in the
forecast as a major shortwave trough over well upstream begins to
slowly make its way towards the region and allows for an increase of
moisture and instability. Afternoon and evening showers and
thunderstorms will be more widely scattered over the higher terrain,
with some high elevation snow likely increasing and additional
accumulations likely, especially across the central mountains. As
indicated with increasing PWAT values, chances of showers and
thunderstorms will also increase over the plains, especially for
locations north of Highway 50. As the U/L low associated with this
major shortwave progresses southeastward, it will further increase
chances of precipitation across the region, although there is some
deviation with the deterministic models about the timing and
progression of this. The ECMWF has the progression being quicker and
therefore drying out sooner on Sunday, whereas the GFS has the U/L
low passing just to the north midday on Sunday, resulting in much
more convection. It can be determined which model resolves this
feature the best in the upcoming days.

Monday through Tuesday...

A cold front will move through with the major shortwave on Sunday,
which will result in cooler temperatures for highs on Monday. With
high pressure building back in behind it and a ridge strengthening
upstream, there will be mostly dry conditions, with only a few
isolated afternoon storms over the higher terrain. The ridge moving
over on Tuesday will cause temperatures to rebound quickly with
warmer temps, and mostly dry conditions remaining in place.
-Stewey

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 453 AM MDT Wed May 22 2024

VFR conditions anticipated during the next 24 hours at all 3 taf
sites, KPUB, KALS and KCOS. Diurnal wind flow direction is
expected today but winds will be gusty, especially during the
afternoon time period.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Thursday morning through Thursday
evening for COZ225.
Frost Advisory until 8 AM MDT this morning for COZ084.

&&

$$



SHORT TERM...HODANISH
LONG TERM...STEWARD
AVIATION...HODANISH