101
FXUS63 KGLD 240720 CCA
AFDGLD

Area Forecast Discussion...CORRECTED
National Weather Service Goodland KS
120 AM MDT Tue Jun 24 2025

.KEY MESSAGES...

- Patchy dense fog may develop late tonight and early Tuesday
  morning.

- Storms are forecast to develop Tuesday afternoon and continue
  into the evening. Severe storms are possible, with slightly
  higher chances in Eastern Colorado. Wind and hail will be the
  primary hazards for initial storms in Colorado, transitioning
  to more of a wind threat as storms congeal and move through
  the rest of the area. There is a very low chance for a
  tornado.

- There is a marginal risk for severe storms Wednesday afternoon
  and evening generally north of Interstate 70 with another
  round of precipitation.

- Storm chances decrease towards the end of the week with
  temperatures warming to above normal.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 1247 AM MDT Tue Jun 24 2025

Current observations show decaying showers around the area close to
the midnight hours as instability continues to lower, likely ending
the storm threat for tonight. The flow in the lowest few
thousand feet remains from the east/southeast, advecting more
moisture into the area. Cloud levels have been dropping, and
will likely lower to a few hundred feet by daybreak. With this,
it should also become moist enough for fog to develop across the
area. Visibility is forecast to generally remain above one
mile, though some pockets of dense fog with visibility around a
quarter of a mile could occur between the 5am to 9am MT
timeframe.

For today, the cloud cover is forecast to slowly break during the
day with daytime heating. The cold front just south of the area
is forecast to change into a warm front and pull north into the
area as a weak surface low develops near the Colorado border. With
the warm air advection and potential breaks in the clouds,
temperatures are forecast to be a bit warmer tomorrow, generally
reaching the low to mid 80s. Winds are forecast to shift from out
of the south at 15-20 mph, though those north of Highway 36 may
remain a bit more from the east at 10-15 mph depending on how far
north the warm front advances.

During the late afternoon and evening hours, chances for storms are
forecast to return to the area. There are two potential areas of
storms development and initiation. The earliest batch would be a
long the warm front. If enough of the cloud cover can break and
instability develop along the warm front, storms should fire up. The
current forecast area is roughly between I-70 and Highway 34. These
storms could be severe, mainly with a large hail threat up to a
couple inches in diameter. Though, forecast soundings look fairly
similar to recent events which would suggest that most would produce
large amounts of small hail, especially if the storms develop and
move off the frontal boundary. Damaging wind gusts and maybe a
tornado would also be possible, but have much lower chances. The
second area of initiation is in East-Central Colorado, west of the
area. Similar to many events recently, storms are forecast to fire
up out of the area over the higher terrain in East-Central Colorado
and progress east. Depending on where the surface low sets up and
how far the warm/stationary frontal boundary extends west, storm
development may be fairly widespread. The question is what happens
to it as it moves east. Most guidance is currently suggesting that
the storms outrun the forcing (both the surface boundary and upper
support provided by an advancing shortwave), leading to storms
gusting and falling apart. However, any cluster that stay with its
outflow will be capable of producing large hail and damaging wind
gusts. Tornadoes become more of a concern if the surface boundary is
over Eastern Colorado and a storm moves along the boundary. Main
window for severe weather occurring if it does is between about 4pm-
12am MT, with storm and severe chances lowering from west to east
across the area.

Tonight, storms are forecast to weaken through the night as
instability begins to lower. That being said, the surface
boundary, surface low, and upper shortwave may persist and
influence the area long enough for storms to last until 3am and
showers until daybreak the next morning. With the cloud cover and
low level moisture lingering, temperatures are forecast to remain
in the 60s and potentially even the low 70s. Patchy dense fog
could form again late in the night.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 130 PM MDT Mon Jun 23 2025

Southwest flow aloft continues on Wednesday with another
shortwave trough coming out of Colorado. Models vary on the
surface pattern and available moisture/instability. GFS has more
of a southwesterly wind which dries out the low levels resulting
in only weak instability, while the NAM and ECMWF show less
downsloping wind and more instability. While some convection
will undoubtedly initiate with the shortwave trough aloft, there
is low confidence in coverage and severe risk. SPC has a
marginal risk north of Interstate 70 where a modest increase in
deep layer shear may slightly favor more organized updrafts.
Storms move east and out of the area overnight. High
temperatures Wednesday afternoon will be in the 80s and 90s and
lows in the 50s and 60s.

Upper flow turns more zonal on Thursday but there is another
shortwave trough with the axis over the forecast area during the
afternoon. GFS is again considerably drier with a westerly
surface wind compared to the NAM and ECMWF which show easterly
winds and more available instability. Deep layer shear ranges
from 10-20kts south of Interstate 70 to 20-30kts north. Storm
chances will be best in eastern areas due to the location of the
upper trough at the time of peak heating and initiation. There
may be a marginal risk for a severe storm, but confidence is
low. Storms should move east and out of the area earlier than
usual, perhaps by early to mid evening. Highs will be in the
upper 80s to around 90 and lows in the 60s.

Friday and Saturday will see a sprawling ridge build across the
southern CONUS. The main storm track will be across the northern
plains. Convection will either not occur at all or be very
isolated and tied to diurnal heating in the afternoon. Saturday
appears to be the better day for convective chances with perhaps
a weak shortwave topping the ridge and lee trough in Colorado
focusing initiation.

Sunday and Monday the ridge amplifies over the northern Rockies
with weak northwest flow developing downstream over the plains.
A cold front is forecast to move through sometime on Sunday. If
it moves through fast enough may see post frontal upslope Sunday
afternoon and convection initiating on the higher terrain to
the west and moving across Sunday night. Models suggest the
front will be far south on Monday and the local area may be too
stable for convection. However, confidence in those kind of
details is low at this time range.

Temperatures will be above normal Friday and Saturday under the
ridge with highs in the mid to upper 90s, then cooling slightly
behind the cold front Sunday and Monday with highs in the 80s
and 90s.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1044 PM MDT Mon Jun 23 2025

For KGLD & KMCK... MVFR ceilings are forecast to start the
period, with IFR conditions forecast starting around 10-12Z.
Current observations across the area show ceilings generally
around 2000-3500ft. Ceilings are forecast to lower through the
night as the continued low level flow from the east/southeast
brings in more moisture and saturates the air. By 10-12Z,
ceilings are forecast to drop to around 200-600ft as the air
mostly saturates. Fog could also develop, though is likely to
remain between 1-5SM. Dense fog is possible, but is currently
around a 15% chance or expected to be brief if it does occur.
Storms and showers remain possible tonight, though chances have
lowered to less than 15%. Best timing would be during the first
few hours of the period. Storms will be possible again tomorrow,
likely between 00-06Z. Current confidence in either site seeing
storms is around 25%, so have opted to not include in the TAFs
at this time. Be advised, if storms do move through late in the
period, they could be severe with large hail and wind gusts
above 50 kts. Winds are forecast to be from the east through
about 15-18Z at 10 kts or less. By 18Z, winds should be around
15-20 kts with gusts up to 30 kts possible.

&&

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

&&

$$

SHORT TERM...KAK
LONG TERM...024
AVIATION...KAK