281
FXUS65 KPUB 121127
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
527 AM MDT Wed Jun 12 2024

.KEY MESSAGES...

- Warmer and drier today. Isolated showers and thunderstorms
  will be possible this afternoon and evening.

- Record to near record high temperatures Thursday

- Strong to near severe thunderstorm chances increase into
  Friday across northern portions of the southeast plains with
  gusty outflow winds over 60 mph the primary storm risk.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 242 AM MDT Wed Jun 12 2024

Today...

An upper level low positioned off the coast of California will help
to advect up some mid-level moisture later today. Meanwhile, there
will also be some weak troughing to the north with westerly flow in
the mid to upper levels that will interact with the mid-level
moisture and help to aid in the development of convection by later
this afternoon over the higher terrain with orographic lift as the
forcing. These showers and isolated thunderstorms are not expected
to become very strong, given the lack of CAPE and shear over the
region. Still, they could provide some gusty outflow winds as any
showers and storms that do develop will be high based. Isolated
showers and storms will likely remain over the mountains, but then
weaken as they come off over into the adjacent plains and lose
orographic support. A shower or weak storm will still be possible
over the plains, more than likely over El Paso County, otherwise the
plains should remain dry with only some passing mid to high level
clouds. Downsloping winds will also allow for temperatures to warm
quite significantly over the lower elevations, and downright hot for
the plains (especially within the lower Arkansas River Valley),
which some localities could reach the 100 degree mark.

Tonight...

A hot day will lead to a mild night. Mostly clear skies and light
winds will help to cool temperatures a bit more, although it will
only drop into the upper 50s to mid 60s for a majority of the
plains. For high country, temperatures will likely fall into the 40s
for most locations.    -Stewey

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 242 AM MDT Wed Jun 12 2024

Ridging continues over the area on Thursday with very hot
temperatures expected.  Record high temperatures will be challenged
as warm to +18 to +19C.  Record on Thursday are:

KCOS:  95 in 2022
KPUB: 102 in 2022
KALS:  90 in 2021

A frontal boundary drops to near or just north the Palmer Divide
with a narrow axis of higher dew points increasing 40s to near 50 by
afternoon.  How far south this boundary drops could mean the
potential for an isolated strong storm across northern portions of
the southeast plains (Palmer Divide and Kiowa county). Latest
NAMNest has bumped this axis just north of our area with HREF mean
Cape values 500 J/kg or less across the CWA.  Earlier runs did show
higher moisture/CAPE, so will need to monitor trends as we get
closer. Gusty outflow winds in excess of 60 mph would be the primary
risk given high DCAPE values, however some severe hail could also
occur if dew point return is sufficient as deep layer shears to the
north of the boundary could exceed 30 kts given the low level
easterly flow beneath modest westerly flow aloft under the northern
periphery of the upper high. Thunderstorms drop southeastward and
diminish by midnight.

An upper trough will move across the area Friday and Friday night.
The boundary pushes southward into southeast CO Thursday night
likely aided by outflow from thunderstorms across northeast/east
central CO.  Initially this will increase dew points into the 50s
across the southeast plains before southwesterly flow aloft on
Friday mixes dew points eastward again in the afternoon. While the
incoming system brings in Pacific moisture and elevated CAPE across
western areas, the question will be how far east will dew points mix
out across the plains and what will the resultant CAPE be east of
the dry line/surface trough axis. Think main risk Friday will be
gusty outflow winds 60-70 mph given probability for some high DCAPE
values.  However hail isn`t out of the question for the high country
as cooling aloft helps to steepen lapse rates as well.  Across the
far east plains, large hail also can`t be ruled out depending on
position of the dry line/moisture axis.  Overall, shear values look
to stay low across southern CO in the 20-25 kt range which leans
main risks more towards the gusty outflow wind scenario unless
surface winds can stay more southeasterly.  Thunderstorms will
continue into the overnight hours as the upper trough moves slowly
eastward across the state, though storm strengths should come down
with loss of heating. Friday cools off a few degrees though westerly
surface winds should still yield some mid to upper 90s across the
plains before the convective cloud cover/outflows dominate the late
afternoon through evening period.

After a slight cool down for Saturday temperatures soar again to
around the century mark across the plains as southwesterly flow
increases once again into early next week. Critical fire weather
conditions will ramp up as breezy southwest winds mix down in the
afternoon both Sunday and Monday.  GFS is faster with taking the
next trough across northern CO on Tue sending a cold front southward
into the southeast plains on Tue.  EC is slower, less amplified and
farther north with the system, which keeps dry southwest flow across
the area until the front approaching northern portions of the plains
late Tue.  This would spell another hot and breezy day.  Will need
to monitor fuels status closely given the hot and dry trend in the
extended. For now fuels are not deemed critical given the greenup.
-KT

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 526 AM MDT Wed Jun 12 2024

VFR conditions are expected to prevail for all TAF sites (KALS,
KCOS, and KPUB) throughout the forecast period. Winds will be
generally light (mostly less than 10 kts) and primarily influenced
by diurnal effects at all terminals, with only some gusty winds
out of the WSW for KALS during the afternoon hours. There is
very low confidence of VCSH/SHRA and possible VCTS/-TSRA at all
stations this afternoon. If SHRA/TSRA does occur, it could
temporarily reduce CIGs and VIS to MVFR/IFR criteria. It could
also result in periodic windshifts and increased wind speeds for
all terminals.   -Stewey

&&

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

&&

$$

SHORT TERM...STEWARD
LONG TERM...KT
AVIATION...STEWARD