736
FXUS65 KPUB 161013
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
413 AM MDT Mon Sep 16 2024

.KEY MESSAGES...

- More widespread thunderstorm coverage today over the mountains
  and portions of the southeast plains with one or two strong to
  near severe thunderstorms possible.

- Breezy to windy conditions on Tuesday with widespread precipitation
  chances over the higher terrain along with the potential for strong
  to severe storms.

- Warm, dry and breezy Wednesday and Thursday with the potential for
  spotty critical fire weather conditions across the plains.

- Cooler and wetter for the weekend?

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 411 AM MDT Mon Sep 16 2024

Increasing southwest flow today ahead of the southward moving CA low
will pick up shortwave energy from eastern AZ and lift it
northeastward across southern CO this afternoon.  Already seeing
showers and isolated thunderstorms in SW CO ahead of this feature
early this morning, and we should see waves of showers and
thunderstorms through the course of the morning across the western
mountains/interior valleys.  CAMS models are in fair agreement with
showers and embedded thunderstorms increasing in coverage out west
through the late morning and afternoon, spreading eastward into the
southeast plains through this evening.  Best CAPE and shear will be
across western portions of the area today, and if sufficient surface
heating/destabilization can occur between rounds of precipitation, a
few strong to near severe storms will be possible across the
Continental Divide and interior valleys.  Heavy rainfall, isolated
damaging winds, and hail to around 1 inch in diameter would be the
primary risks.  As storms move east of the mountains, low level dew
points will initially start out in the 40s to low 50s before
gradually moistening through the afternoon as showers come off the
mountains.  There probably won`t be as much downdraft CAPE as
yesterday, but storms will start out high based so can`t rule out
some strong gusty outflow winds with thunderstorms as they push off
into the I-25 corridor and adjacent plains.  Wind gusts to around 50
mph look possible. CAPE and shear do not look as great for severe
thunderstorm chances out east, but some locally heavy rainfall could
occur, as well as some brief small hail and gusty outflow winds.

Thunderstorms push eastward but don`t really come to an end out west
along the Continental Divide as the upper low lifts northeastward
into NV and western UT towards 12z. Rounds of showers and isolated
embedded thunderstorms will continue into the overnight hours,
though most will be restricted to the Continental Divide.  Lightning
and locally heavy rainfall will be the primary risks.

Temperatures through the short term will be challenging with the
potential for clouds and showers to limit warming today or send
cooling outflows eastward across the plains just prior to peak
heating.  Guidance shows quite a spread, and have leaned cooler out
west, and warmer out east where there should be a period of mixing
from breezy southwesterly flow to help with a quick warm up during
the morning hours.  Overnight lows should stay relatively warm
overnight with increasing clouds and lee troughing overnight. -KT

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 411 AM MDT Mon Sep 16 2024

Tuesday-Tuesday night...Moderate to strong southwest flow across the
Rockies through the day Tuesday remains progged to become more westerly
and moderate Tuesday night, as a broad upper trough across the Great
Basin lifts out across the Northern Rockies. Latest model data supports
good moisture in place with PWATS around 150 percent of normal. This,
along with increasing uvv ahead of the system through the day Tuesday,
supports likely pops across the higher terrain, especially along and west
of the Continental Divide, with the good orographic flow. Latest DESI
indicates mean surface based CAPE of 400-900 j/kg over and near the higher
terrain late Tuesday morning and afternoon, with 800-1200 j/kg across the
SE plains, greatest east of the I-25 Corridor. With lee troughing and
mixing, will see breezy southerly low level winds across the plains
on Tuesday, leading to increasing wind shear and supporting the chance
of strong to severe storm development Tuesday afternoon and early evening,
especially across the plains, where large hail and damaging wind gusts
would be the main threat from storms. Latest models also continue to
support much drier air filtering into the region behind the passing
trough, with precipitation chances quickly diminishing from west to
east Tuesday evening. Temperatures on Tuesday remain at and above normal,
especially across the plains, with highs in the 80s to lower 90s expected
once again.

Wednesday-Thursday...Moderating westerly flow across the region becomes
southwest and slowly increasing through the end of the work week, as
another eastern Pacific system is progged to dig across the West Coast
and into the Great Basin. Models in good agreement of keeping dry air
in place across the region through Thursday, and with temperatures
remaining at and above seasonal norms, there could be some spotty
critical fire weather conditions popping up across the plains through
this time frame.

Friday-Sunday...Latest model data continues to differ on the timing and
location of the next system moving into the Great Basin by the end of
the work week, which continues to lift out across the Rockies into the
weekend. Latest models are however trending further north with the
system which would keep the best chances of precipitation north of the
Highway 50 Corridor and especially across northeastern Colorado. Time
will tell how this pattern will evolve, however, certainly could see
temperatures cooling to slightly below seasonal levels through the
weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 411 AM MDT Mon Sep 16 2024

Increasing VFR cloud cover expected at the TAF sites through the
next 24 hours. While rounds of showers and afternoon thunderstorms
spread into the southwest mountains and San Luis Valley today,
affecting KALS by late morning/early afternoon, showers and
thunderstorms will be more delayed until mid to late afternoon east
of the mountains for KCOS and KPUB. Heavy rainfall, gusty erratic
outflow winds will be possible with stronger storms out west
including KALS today, while east of the mountains, storms will start
out higher based with gusty erratic outflow winds the primary risk.
Otherwise, expect increasing southerly flow through the 24 hr period
with gusts up to 25 kts.  Winds should tail down some this evening,
but an enhanced and more persistent southerly wind will be likely
overnight as the larger system approaches from the west. -KT

&&

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

&&

$$

SHORT TERM...KT
LONG TERM...MW
AVIATION...KT