000
FXUS65 KPUB 261754
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1154 AM MDT Fri Apr 26 2024

.KEY MESSAGES...

- After a brief lull this morning, moderate to heavy snow will
  spread across the higher terrain today. Impacts from wet,
  heavy snow will be possible over the mountains and in Teller
  County.

- Widespread showers and thunderstorms are expected this
  afternoon into tonight across the eastern plains.

- Snow will continue to increase over the higher terrain
  tomorrow through Sunday. Highest amounts are expected over the
  eastern San Juan Mountains, Sawatch Range, and Pike`s peak
  Region.

- Showers and thunderstorms will move out over the plains
  tomorrow, some periods of heavy rain will be possible along
  portions of the I-25 corridor, especially in El Paso County.

- Another storm later in the week could bring a quick shot of
  precipitation to portions of the area.

&&

.UPDATE...
Issued at 1021 AM MDT Fri Apr 26 2024

Models are trending colder with temperatures across Teller
county and the upper Arkansas River Valley which has bumped up
snowfall amounts.  Have upgraded Winter Storm Watches to Winter
Storm Warnings for those areas and rimmed some of the lower
elevations of the Upper Arkansas River Valley with Winter
Weather Advisories. These go into effect late this afternoon
along the Continental Divide, through this evening for eastern
portions of these areas and will continue through 6 AM Sunday.
Heavy wet snowfall accumulations will be possible above 8500
feet, especially north of highway 50 including the Teller County
region where accumulations in excess of a foot will be possible.
There will be some melt off as snowfall rates lessen at times
across the lower elevations with a tight gradient in snowfall
amounts below 8000 feet, but the heavy snowfall rates could
cause higher impacts with visibility restrictions and broken
tree limbs for trees which have started leafing out.

Also put out a Fire Weather Watch for Baca county Saturday
afternoon and evening to the south of the surface low where dew
points drop into the lower 20s in the afternoon. This will
likely be upgraded to a Red Flag Warning with the afternoon
package issuance. -KT

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 438 AM MDT Fri Apr 26 2024

The first half of Friday will be somewhat calm, with a lull in
precipitation as the upper low quickly moves off to the northeast.
High temperatures will be a bit cooler than yesterday, with 70s
across most of the plains and low-mid 60s over the valleys and the
Palmer Divide. Later on in the day, another upper low will begin to
move into our area from the west, bringing with it more active
weather and more cool air. The limited snow showers across the
mountains that waned Friday morning will increase in coverage and
intensity by late afternoon before starting to spread eastwards. A
surge of north-northwesterly winds will hit our area around late
afternoon as well, allowing for better upslope into parts of Teller
and El Paso Counties. Mixed rain and snow showers will quickly
spread to these areas while rain showers fall further to the south
and east where temperatures are far warmer. While the area will
generally remain above freezing today, the convective nature of
these showers along with cold air advection should still allow for
snow accumulation over the higher terrain. Teller County could
specifically be seeing some impacts due to heavy, wet snowfall,
especially around the northern parts of the county and Pikes Peak.
Moderate to occasionally heavy rain showers and thunderstorms will
be possible across most of our eastern plains, though nothing severe
is expected at this time. The snowfall over the mountains and Teller
County specifically will increase in intensity overnight, with
impactful accumulations already expected prior to Saturday morning.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 438 AM MDT Fri Apr 26 2024

Saturday through Sunday...

A potent major shortwave trough will move over the region, with
increasing snow across the higher terrain and rain, possibly heavy
at times, for the lower elevations. Given the orientation of
this wave, most of the heavier amounts of snow will be confined
to the northern mountains and across the eastern San Juan
Mountains. There could also be some thunder possible, along with
very strong winds and heavy and wet, blowing snow, especially
for the western facing slopes. This could also make travel very
tricky for the Cottonwood and Monarch passes by later in the
evening on Saturday as the intensity of snowfall rates
increases. There will also be some of these showers moving out
into the lower elevations, but likely be in the form of rain for
elevations less than 7500 feet.

As the surface low ejects out over the plains and establishes
itself over northeastern Colorado, it will begin to wrap up and
allow for a TROWAL (trough of warm air aloft) to set up along
the mountains/plains interface of the front range. This will
provide heavy amounts of rain possible along portions of the
I-25 corridor, mainly north of the US-50, over El Paso County.
Model guidance shows that most of the southeastern plains will
be "dry-slotted" initially and then the northeastern
progression of the low will likely keep these areas dry as the
downsloping winds on the backside of the low take over going
into the early morning hours on Sunday. That being said, there
could still be a few showers over Baca County, but the heavier
amounts area going to the north and west. Because of the heavy
amounts of precip anticipated within the TROWAL setup, it cannot
be ruled out to see some localized flooding possible for the
urbanized areas in El Paso County, especially within the city
limits of Colorado Springs.

There will also be a convective element, with CAPE of near 1000 J/kg
showing up over the Palmer Divide by later in the afternoon on
Saturday, which may help to also produce very heavy amounts of
rainfall for the lower elevations and possibly a heavy and wet
accumulation for the higher elevations of the Pike`s Peak/Rampart
Range, as well as Teller County. Due to some uncertainty still as to
exactly where this low will track, these areas have been kept in a
Winter Storm Watch at this time. Which may need to be upgraded if
there is more of a signal that show heavier convective cells
developing over these areas in the higher res rapid refresh models.
There is also going to be steeper lapse rates of 8 to 9C/1km, which
could also help to expedite this process. Colder air advection,
along with the cloud cover will help to cool temperatures off some
15 to 20 degrees. The low does look to increase in speed towards the
northeast as it undergoes weakening, and all moisture will continue
to dissipate temporarily by later in the day on Sunday. However,
westerly flow on the backside of the low in combination with some
instability induced by orographic lifting, will help top re-
trigger thunderstorm development over the mountains, with
another round of heavy snow possible, and then the mid-level
flow will help to push these out over the plains going into the
evening.

Monday through Thursday...

High pressure conditions will subsequently build back in behind the
exiting trough, with drier and warmer conditions returning on
Monday, especially over the plains due to the downsloping winds.
There will be a warming trend continuing through the mid part of the
week. These will be a weaker wave transitioning through which could
allow for another chance of some precip, mainly over the northern
half of the CWA on Wednesday with a cold front moving through that
will cool high temperatures for Thursday. Otherwise, conditions will
remain mostly dry going later part of next week.    -Stewey

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1120 AM MDT Fri Apr 26 2024

Cigs will lower this evening as showers move in across the
mountains and spread into the adjacent plains overnight through
Saturday morning. TSRA will be possible at KCOS after 09z and
even some small hail will be possible along with MVFR to brief
IFR cigs/vis. SHRA will continue through much of the day at KCOS
before decreasing as winds shift out of the north and become
gusty in the afternoon. KPUB will remain VFR with -SHRA possible
late tonight through Saturday morning. Another round will spread
in Saturday afternoon and evening which could bring some brief
MVFR cigs at times. KALS will see the best chance for -SHRA
between 06z and 12z but is more likely to see VFR cigs. Winds
will increase at KALS on Saturday with southerly winds gusting
up to 30 kts. -KT

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 3 PM this afternoon to 6 AM MDT
Sunday for COZ058-060.
Winter Weather Advisory from 6 PM this evening to 6 AM MDT
Sunday for COZ059-061-063.
Winter Weather Advisory from 3 PM this afternoon to 6 AM MDT
Sunday for COZ066-068-073.
Winter Weather Advisory from 9 PM this evening to 6 AM MDT
Sunday for COZ076.
Winter Storm Warning from 9 PM this evening to 6 AM MDT Sunday
for COZ081.
Winter Storm Warning from 6 PM this evening to 6 AM MDT Sunday
for COZ082.
Fire Weather Watch from Saturday afternoon through Saturday
evening for COZ237.

&&

$$

UPDATE...KT
SHORT TERM...GARBEROGLIO
LONG TERM...STEWARD
AVIATION...GARBEROGLIO/KT