811
FXUS65 KPUB 201118
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
518 AM MDT Sun Apr 20 2025

.KEY MESSAGES...

- Patchy fog into early Sunday morning, otherwise warming up
  again for Sun and Mon.

- Overnight lows around or below freezing possible again
  tonight.

- Strong to severe thunderstorm potential increases across the
  Plains Wednesday into Thursday.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 318 AM MDT Sun Apr 20 2025

Upper low over the TX panhandle will depart through the southern
plains today. Precipitation over the southern CO will be done early
this morning with patchy low clouds and fog across the San Luis
Valley and perhaps portions of the southeast plains where winds
become light enough to limit mixing and allow radiational fog to
develop.  Otherwise, temperatures will rebound today under dry
northwest flow aloft.  High temperatures will top out in the 60s
across the plains with 50s for the high valleys and 30s and 40s for
the mountains.

Winds across the high country increase overnight as flow aloft
becomes more westerly and lee troughing takes hold across the
adjacent plains.  Enhanced westerly drainage winds will develop
along the eastern slopes and portions of the I-25 corridor Sunday
night, which will bring a return of above freezing temperatures.
Meanwhile, valley locations will see another cold night under clear
skies with good radiational cooling.

Monday will be breezier with critically low day time relative
humidity values returning, though recent precipitation likely
brought sufficient moisture along the I-25 corridor to dampen fuels
and mitigate the fire weather threat from gusty afternoon winds. An
open wave passes to the north, spreading a brief round of moisture
and possibility of showers into the central mountains to the
afternoon.  But the plains will stay dry with increasing mid/high
clouds during the late afternoon and evening. -KT

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 318 AM MDT Sun Apr 20 2025

Models are in general agreement through Friday, with differences
popping up for next week. A few strong, to possibly severe
storms may be possible Wednesday and Thursday.

Monday night through Tuesday...broad westerly flow aloft with
weak embedded energy is forecast through this period. A few
lingering showers will be possible over the Central Mountains
Monday evening, dissipating after sunset. Any snow will remain
confined to the highest peaks with no to little snow
accumulations expected. Another piece of energy will move across
Colorado on Tuesday. This will lead to another round of showers
and isolated thunderstorms across the higher terrain by Tuesday
afternoon. A couple of thunderstorms may move across the Palmer
Divide late Tuesday afternoon and evening. The main risks for
thunderstorms will be lightning and outflow wind gusts near 40
mph. This shower and thunderstorm activity will dissipate
overnight as the embedded energy lifts off to the northeast. Any
snow will be confined to the highest peaks. Overnight lows
Monday night will fall into the 30s to 40s across the Plains,
and 20s across the San Luis Valley. Highs on Tuesday will reach
the upper 60s to mid 70s for the lower elevations.

Wednesday into Friday...the potential for severe weather ramps
up on Wednesday across the Plains and will continue into
Thursday. An upper trough over the northern Rockies with a
trough axis stretching south across Colorado is expected to
provide the focus for shower and thunderstorm development across
the Plains on Wednesday. Moisture is forecast to work northward
into the Plains, with forecast dewpoints rising into the upper
40s, with a few lower 50 readings possible near the Kansas
border. SBCAPE values around 1200 j/kg and sufficient shear
should allow for a few strong to severe storms. Hail near 1 inch
in diameter and wind gusts near 60 mph may be possible with
stronger storms Wednesday afternoon and evening.

The upper trough will continue to move east into the Northern
Plains on Thursday, and will send a cold front south across the
Plains by midday Thursday. This will help spark another round of
showers and thunderstorms across the region. Dewpoints look to
remain elevated in the 40 degree range, however, SBCAPE values
will likely struggle to reach 1000 j/kg. This may limit storm
strength Thursday. Most model guidance does have decent
precipitation by late Thursday into the overnight hours along
the Eastern Mountains and I-25 corridor as low level flow turns
northeasterly upslope.

An upper vort max is forecast to lift northeast out of New
Mexico on Friday, which will provide additional support for
continued rounds of showers and thunderstorms on the Plains.
Southeasterly surface winds will help keep moisture in place,
but temperatures will be cool, likely limiting instability
potential. But there could be pockets of decent rainfall along
the Eastern Mountains Friday.

Temperatures look to be warm Wednesday with upper 70s across the
Plains. Cooler air behind the cold front will bring slightly
cooler temperatures for Thursday with mostly mid 70s across the
Plains. Highs Friday will continue to cool, with 60s to lower
70s across the region.

Saturday and Sunday...forecast uncertainty increases next
weekend with the development, movement and timing of the next
upper low over the Pacific Northwest. The GFS takes the upper
low north across Montana, with broad southwesterly flow across
Colorado with warm conditions and increased fire weather
potential, especially Sunday. The ECMWF has a broad, slow moving
low over Utah over the weekend. That would keep unsettled
weather across Colorado. The Canadian solution has a much
stronger, deeper low over the Great Basin by Sunday, which is
slower than the ECMWF, and much further south/stronger than the
GFS. Given the uncertainties in the forecast, did not move away
from the NBM guidance with broad low pops across the region for
next weekend.  Mozley

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 515 AM MDT Sun Apr 20 2025

KALS...VFR conditions through the next 24 hours. Patchy fog
across the San Luis Valley may impact this terminal through 14z
with reduced CIGS and VIS. Overall, fog has been slow to
develop, but remains possible.

KCOS and KPUB...VFR conditions through the next 24 hours. There
is a very low probability (10-20%) of fog development through
14-15z this morning. If it does develop, VIS and CIGS could be
reduced. Mozley

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...KT
LONG TERM...MOZLEY
AVIATION...MOZLEY