FXUS65 KPUB 260532

Area Forecast Discussion
National Weather Service Pueblo CO
1032 PM MST Mon Jan 25 2021

Issued at 724 PM MST Mon Jan 25 2021

Based on latest HRRR and 00z NAM, plus persistent snow over nrn El
Paso County, will expand Winter Wx Advisory to include the entire
I-25 corridor and also the srn Sangres. Snow amounts on the low
end of the advisory range, but with heavier snow falling over much
of the area during/near the morning commute, impacts could be more
significant. Other than adding the advisory and making some minor
adjustments to snow amounts, forecast is in pretty good shape and
won`t be making any major changes.


.SHORT TERM...(This evening through Tuesday)
Issued at 250 PM MST Mon Jan 25 2021

...More snow expected across southern Colorado tonight and Tuesday...

First storm has pulled east of the area with wrap around snow
continuing across the northeast portions of the forecast
area...across Kiowa county.  Roads have stayed fairly clear in spite
of some moderate snowfall at times.  This band will pull off to the
northeast late this afternoon through the evening.  Meanwhile,
convective snow showers have developed across the mountains this
afternoon which will continue to expand and become more widespread
as southern Colorado comes under the influence of the next upper low
across southern CA, which will lift northeastward through the Desert
Southwest towards the 4 corners region tonight, then across southern
Colorado on Tuesday. System develops 2 circulation centers as it
crosses the mountains Tuesday morning and the leading impulse
tightens up again across east central CO by mid day.  Once again,
the timing and exact track of this intensification will play a big
role in snowfall amounts.  Overall, this storm looks a little weaker
than the last as far as upglide and development of the wrap around
snow band/trowal.  But this system will also be colder with
persistent light snow expected to continue through Tuesday as
trailing energy moves across.  This could lead towards greater
travel impacts for the urban corridor of southern Colorado. Overall,
snowfall amounts are coming out on the light side of advisory range,
so will issue Winter Weather Advisory for the southeast mountains
and adjacent I-25 corridor from roughly Walsenburg northward.  With
some southeast to easterly upslope flow, expect some snow to spread
up the Arkansas River Valley of Fremont county and perhaps into
southern Chaffee county.  Current advisories do not include the
Sangre De Cristo mountains as of yet but an earlier storm
intensification, or stronger upslope could necessitate upgrades.
Northern El Paso county is another area to watch but for now we are
keeping higher totals on the southern slopes of the Palmer Divide. A
tad farther south track and the southern I-25 corridor down to Raton
could also get in on the action, but with less of an upslope
component down that way, have left them out for now. Expect some
improvement Tuesday afternoon as focus for the heavier snow shifts
eastward across the plains.

Tuesday will be much colder with persistent cloud cover across
southern Colorado.  High temperatures will likely stay in the 20s
across the lower elevations with teens and single digits across the
higher terrain.

.LONG TERM...(Tuesday night through Monday)
Issued at 250 PM MST Mon Jan 25 2021

Tuesday night...

The major shortwave with very cold air associated with it will be
exiting the CWA with only a few lingering snow showers over the
highest elevations of all mountain ranges. Some snow will still be
possible over the plains as well due to the wrap-around moisture
overrunning cold surface temperatures in the deformation zone. All
precipitation should completely exit the region by midnight with
clearing throughout early Wednesday morning.

Wednesday through Friday...

High pressure is going to dominate the area once the low pressure
system exits the region by  early Wednesday morning. Both of the GFS
and ECMWF models are picking up on a weak upper level low from the
subtropical ridge to the southwest over the Pacific Ocean that will
absorb into the ridge and could allow for some higher level
precipitous clouds over the region on Friday, while the mid and
lower levels remain very dry.

Friday night through Sunday...

All of the deterministic models are in relative agreement with the
timing of the next major shortwave trough to influence the CWA late
friday night, except that the ECMWF has this system moving into the
region about 3 hours earlier late Friday night. Due to the
orientation of this trough, most of the precipitation will be
confined to the mountainous areas of the CWA, especially for
Saturday morning, where the greatest amounts of snowfall will be
located on the southwestern facing slopes of the San Juan Mountains.
The low pressure center associated with this trough will propagate
quickly out over the Great Plains and not provide much in the way of
any snowfall for the plains within the CWA.

Sunday night through Tuesday...

A ridge will begin to build back in with warmer and drier conditions
for a majority of the CWA with only a few snow showers over the
Sawatch range due to some troughing to the northwest of the region.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1027 PM MST Mon Jan 25 2021

Upper low pressure system currently over west central AZ will
slide across the Four Corners and CO over the next 24 hrs,
producing widespread IFR to LIFR conditions due to low clouds, fog
and -sn for the area through the forecast period. KPUB and KALS
sites report MVFR to VFR conditions currently but this will be
short-lived, with conditions quickly degrading by 08z. Moore


Winter Weather Advisory until 5 PM MST Tuesday for COZ068-074-

Winter Weather Advisory until 8 PM MST Tuesday for COZ076-077-




NWS PUB Office Area Forecast Discussion