640
FXUS65 KPUB 171007
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
407 AM MDT Sat May 17 2025

.KEY MESSAGES...

- Isolated thunderstorms possible across the Pikes Peak region
  and eastern plains this afternoon and early evening, with
  potentially one or two strong to severe storms near the
  eastern border.

- Elevated meteorological fire weather conditions will be
  present across the San Luis Valley, and the valley floors of
  Chaffee, Fremont and Custer counties this afternoon.

- Windy and warm on the plains Sunday, increasing shower/t-storm
  chances mountains.

- Cooler with more widespread showers and thunderstorms Monday
  into Tuesday morning.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 328 AM MDT Sat May 17 2025

Currently...Generally lighter westerly flow aloft across the state
as a weak upper low sits over the California Baja. Mid and high
level cloud cover roughly over the northern half of CO was starting
to thin and erode to the north, but this cloud cover has kept temps
somewhat mild so far with readings in the 40s for the high valleys,
and mid 40s to mid 50s for the plains, as of 1 AM.

Today...Flow aloft becomes more southwesterly today as the next
incoming low pressure trough pushes inland from the Pacific NW into
the Intermountain West. A few snow showers will be possible across
the central mts by midday, but any snow is forecast to be a dusting
at best. A little further south and at the lower elevations drier
air will advect into the San Luis Valley, as well as the valley
floors of Chaffee, Fremont and Custer counties. Combines with
increasing west-southwest surface winds for those areas, critical
fire weather conditions will be likely during the afternoon hours.
Since fuels continue to be going through green-up, no fire weather
highlights will be issued at this time.

More importantly, with southwest flow aloft is increasing, steady
southeasterly surface flow is forecast across the eastern plains up
to along the I-25 Corridor. There will be enough llvl moisture to
work with, as well as some favorable shear, for isolated convection
to develop by 1 or 2 PM across the Pikes Peak region. The main
threat from these storms initially will be cloud to ground lightning
and gusty winds to 50 mph. However, hi-res model guidance indicates
healthier CAPE farther east which makes sense due to mid 40
dewpoints hovering right along the KS border. Anywhere from 1000 to
1500 j/kg of CAPE will be on tap as well as 40-50 kts of 0-6 km bulk
shear, so one or two strong to severe storms will be possible across
the far eastern plains today between 3 PM and 9 PM, and SPC has
brought the Marginal area for severe storms back into the eastern CO
plains. Main threats from these storms will be hail up to 1 inch in
diameter and 60 mph wind gusts.

Plan on highs today in the mid 60s to lower 70s for the high
valleys, and 70s to lower 80s for the plains.

Tonight...the upper trough to our west nears as it slides into the
Great Basin, and south-southwest flow aloft increases even moreso.
Activity across the eastern should be diminishing by midnight, but
the next round of mt snow will be fast approaching by sunrise
Sunday. Increased mid and high level cloudiness is expected to keep
overnight temps somewhat more mild, with predicted lows in the 30s
for the high valleys, and 40s to near 50F for the plains. Moore

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 328 AM MDT Sat May 17 2025

First piece of upper energy ejects out of the western U.S.
trough Sunday, moving e-ne across Colorado during the day. Track
looks unfavorable for widespread convection across the area
Sunday, as best energy and moisture stay north and east, while
strong swly flow and low/mid level dry slot spread over the
sern plains in the afternoon. Will keep some pops over the
mountains and along the Palmer Divide to account for
instability showers/t-storms as cold pool aloft moves across,
though threat of strong/severe storms will be east and north of
the area as surface low/trough push quickly eastward into KS by
late day. Some snow is possible over the higher peaks along the
Continental Divide, with a local inch or two above 12k feet.
Winds will be strong and gusty most locations Sunday, and while
fire danger will be high, fuels across the region continue to
green-up, precluding and fire highlights.

On Monday, trailing piece of upper energy slides across CO, as
upper level low wraps up over Nebraska and surface low shoots
east across KS. While easterly upslope flow will be lacking,
increased moisture/modest instability/dynamic lift will be
enough to generate fairly widespread showers/weak t-storms at
many locations, especially in the afternoon/evening. Rainfall
amounts look light, though eastern mountains could pick up a
tenth or two by late evening. Showers taper off by early Tuesday
morning, though cool temperatures will linger. For the
remainder of the week, flat upper ridge slowly builds across the
area, leading to dry conditions and slowly warming temperatures
into next weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 328 AM MDT Sat May 17 2025

VFR conditions are expected at KCOS, KPUB, and KALS for the next 24
hours. Plan on increasing mid-high level cloud cover by midday into
the evening. Gusty west and southwest winds are likely over KALS
today, with gusts to 25kt expected between 18z and 01z. Winds will
be out of the east-southeast at both KCOS and KPUB tomorrow,
beginning early in the morning hours. Gusts to 25kt will be likely
at KCOS between 17z and 02z, with gusts to 30kt possible at KPUB
between 20z and 04z. Isolated thunderstorms will be possible across
the eastern plains starting by 20z and lasting through 04z, but
affect on KCOS and KPUB questionable so did not mention.


&&

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

&&

$$

SHORT TERM...MOORE
LONG TERM...PETERSEN
AVIATION...MOORE