412
FXUS63 KGLD 301646
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1046 AM MDT Sun Jun 30 2024

.KEY MESSAGES...

- Low confidence with regard to thunderstorm development today
  through the overnight hours.

- Much cooler highs today due to cloud cover all day.

- Hot weather returns Monday behind a warm front with highs
  returning to the low 100s east of the Colorado border.

- Chances for storms each day, mainly during the evening.

&&

.UPDATE...
Issued at 1044 AM MDT Sun Jun 30 2024

Update to going forecast to add in a few hours of patchy fog in
the Burlington CO area based on local obs/CDOT webcams. Also
adjusted pops in the east to account for the slow moving shower
activity, especially in Graham and Norton counties.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 319 AM MDT Sun Jun 30 2024

This morning, showers and thunderstorms are continuing to move east-
northeast over Southeast Colorado and Southwest Kansas along the
northern edge of a 500 mb high. CAM guidance suggests that
during the mid morning hours (around 7-9 am) the showers and
sub-severe storms should begin to clip across the Tri-State area
as the high nudges north. This round should taper off from west
to east by the mid afternoon before another round of isolated
supercells to clusters of thunderstorms develops along and east
of the Front Range. Confidence is low to medium for severe
weather this afternoon into the evening, with the best potential
for anything severe mainly along and east of the Colorado
border. MLCAPE values are currently expected to be around
1000-1500 J/kg with decent shear of 20-30 kts. With scattered to
broken cloud cover expected to linger across much of the area
today, it will be a bit challenging for the atmosphere to
further destabilize as highs will only reach the mid 70s to
lower 80s. Hazards today, any strong to severe storms develop,
include up to quarter sized hail and thunderstorm wind gusts up
to 60 mph. Heavy rainfall may pose a concern depending on storm
coverage/track as PWs sit in the 1-2" range. Should storms move
into the area later today, we should see them exit to our east-
northeast overnight. Overnight lows are expected to fall into
the 60s tonight.

A hot one is in store on Monday as the upper high sits over the
Southern Plains. Shortwave disturbances will strengthen a lee
surface trough along the Front Range while the cold front from
Saturday comes back as a warm front. Another day of marginally
decent CAPE is anticipated at 1000-2000 J/kg; however, shear is
quite low. During the afternoon and evening hours, the lee trough
will move across the area, which is when storms should begin to
develop. While there is some uncertainty with coverage, we are
looking at another day of discrete to clusters of storms that will
move east to northeast. SPC has placed majority of the area in a
marginal risk with Dundy, Hitchcock, and Red Willow counties in a
slight risk. The main hazards include hail and damaging wind gusts.
As a line eventually develops over the northern half of the area,
heavy rain also becomes a concern. High temperatures tomorrow will
unfortunately bring back some triple digits for the area with
temperatures in the 90s to low 100s. Locales east of the Colorado
border could see Heat Index values up to ~105 degrees possible,
especially east of Hwy 83. Overnight lows should fall into the 60s
to lower 70s tomorrow night.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Issued at 200 AM MDT Sun Jun 30 2024

Tuesday...the forecast area will be in between an upper level trough
moving through the area with an upper level ridge centered over the
southeast United States. Moisture, mainly in the 700-300mb layer
will move across the area from the southwest during the day then
west-southwest during the night. PWAT values of 1-1.7" during the
day slowly decrease into the 0.9-1.3" range overnight. It appears
we`ll have just a 20% chance for thunderstorms across parts of far
eastern Colorado in the afternoon with a 30%-50% chance overnight.
High temperatures are forecast to be in the middle 80s to lower 90s
with low temperatures in the upper 50s to middle 60s.

Wednesday...there is fairly good agreement between the GFS/ECMWF/GEM
models in bringing a weather system through the area from the west
during the typical mid to late afternoon hours through much of the
overnight hours. Presently, we have 20%-30% chances for afternoon
thunderstorms, peaking in the 30%-50% range during the evening
before decreasing from west to east. With evening GFS PWAT values of
0.70-1.0" and storm motions of 25 to 30 mph, the threat for
excessive rainfall should be rather low. High temperatures are
forecast to be in the middle 80s to lower 90s with low temperatures
in the middle 50s to middle 60s.

Thursday...an upper level low pressure area is forecast to move east-
southeast across the northern and central plains with the flow aloft
from the west-northwest. It appears that we`ll have a weather system
move through during the overnight hours from the northwest with 30%-
40% chances for thunderstorms. GFS PWAT values arent terribly high
in the 0.8-1.1" range with storm motions generally around 25 to 30
mph. High temperatures are forecast to be in the middle 80s to lower
90s with low temperatures in the middle 50s to lower 60s.

Friday...the forecast area should be under northwest flow aloft with
some ridging moving on to the west coast. Although we currently have
20% chances for thunderstorms across the entire area during the
night, the better chance of that could be across the southwest 1/3-
1/2 of the area as weather systems move off the Colorado front
range, moving toward the southeast. With PWAT values around 0.80"
across the entire area, only light amounts of rainfall are possible.
GFS/ECMWF/GEM 850mb temperatures support high temperatures in the
upper 70s to middle 80s. Low temperatures are forecast to be in the
55 to 60 degree range.

Saturday...currently, we have a 20% chance for overnight
thunderstorms. High temperatures are currently forecast to be in the
85 to 90 degree range with low temperatures in the middle 50s to
middle 60s.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 956 AM MDT Sun Jun 30 2024

For KGLD, there will be an IFR/MVFR mix(OVC008-015) of ceilings
through at least 09z Monday before shifting to VFR for the
remainder of the forecast period. There is a chance for
thunderstorms to come near/impact the terminal, but with low
confidence on timing, have kept to VCSH and will update as
things develop. 09z-13z Monday has chance for lingering showers
with no reduction to visibility at this time. Winds, southeast
15-25kts through 13z Monday, then southwest around 20-30kts.
LLWS 09z-13z Monday 180@45kts.

For KMCK, current VFR conditions will trend to an IFR/MVFR mix
by at least 00z Monday. Some lower ceilings possible from
20z-00z. From 00z-05z Monday there is low confidence on the
potential timing for thunderstorms, so have left as VCSH for
now and update as needed. Light showers and low ceilings
expected from 05z to 16z before going VFR again. Winds,
southeast at least through 14z Monday 15-25kts, before going
more southerly from 16z onward.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.

&&

$$

UPDATE...JN
SHORT TERM...KMK
LONG TERM...99
AVIATION...JN