632
FXUS63 KGLD 132017
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
217 PM MDT Sun Sep 13 2026

.KEY MESSAGES...

- Breezy SE to SW winds expected across portions of the area
  Sunday evening into Monday with sustained winds of ~20-25 mph
  may gust to 40 mph

- Scattered storms possible Monday afternoon-evening. A severe
  storm capable of producing brief, localized wind gusts up to
  65 mph and large hail cannot be ruled out, mainly east and
  south of Colby, KS.

- An early morning cold frontal passage will bring much cooler
  temperatures to the area Tue-Tue night. Wed morning lows may
  dip into the upper 40`s in eastern CO and adjacent KS-NE
  border counties.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 128 PM MDT Sun Sep 13 2026

The upper level ridge axis is making it`s way across the High Plains
today ahead of a strengthening area of low pressure over the Pacific
Northwest. At the surface, a surface trough is gradually extending
south over the High Plains from an area of low pressure over Wyoming
and Montana. On Monday, the Tri-State area should be under southwest
flow aloft as the upper level low moves along the Canadian border
with Eastern Montana and North Dakota towards Lake Manitoba. This
will bring our next cold front and precipitation chances to the area
as we start the week.

So far today the forecast for the stratus has panned out as we see
it burn off from the west and south. The big question is whether or
not our northwest corner of counties will see clearing skies or
if they stay socked in with low ceilings through the overnight
hours. SREF guidance is favoring the stratus lingering this
afternoon and once again expanding southeast across the area
this evening and into the overnight hours. Patchy fog could also
occur in the early to late morning hours Monday along the
Kansas/Nebraska border.

This afternoon winds will begin to pick up with southeast winds of
20-25 mph and gusts up to 40 mph possible over the area. The
strongest winds are currently expected to occur over Eastern
Colorado as we see a tightening of the 850 mb height gradient within
the eastern edge of the lee surface trough. The breezy winds could
linger into Monday with winds becoming southwesterly around sunrise
before decreasing to 10-15 mph with gusts up to 30 mph possible
through the afternoon tomorrow.

CAM guidance has been fairly consistent over the last 24 hours in
regards to the development of showers/storms Monday afternoon. Some
CAMs like the HRRR and RAP are trying to have scattered showers
during the late morning to early afternoon, but confidence is
currently low (less than 20%). The middle of the afternoon into the
evening is where I am feeling more confidence at 50-60% for storms
to develop. So far, it has been consistent in the models for
isolated convection to develop along a convergence boundary over the
eastern half of the area. Model soundings continue to favor an
inverted-V profile with 1,500-2,300 J/kg of Surface and Mixed-Layer
CAPE when there are not showers earlier in the day. With favorable
lapse rates and shear of 35-50 kts, we could see large hail and
damaging winds gusts up to 65 mph as the primary concern. We could
still see two areas for initiation impact the CWA. The first could
be over portions of Western Kansas possibly along the convergence
boundary and another over Eastern Colorado closer to the late
afternoon/evening hours. In models with the morning shower activity,
the CAPE generally lowers below 1,000 J/kg with 0-6 km shear and
effective shear of 25-30 kts. Any severe weather should taper down
in the late evening/early overnight hours. However, as a cold front
moves into the area late Monday into Tuesday morning we could see
more showers and sub-severe storms linger over the Tri-State area.
12Z guidance has the front potentially stalling around our southern
CWA border Tuesday, which could lead to more showers and generally
sub-severe storms on Tuesday, especially over the eastern and
southern portions of the area.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 204 PM MDT Sun Sep 13 2026

Wednesday morning, ensembles are favoring a strong 500-mb high
across the Southeastern United States, with troughing to the west.
At the same time, a strong surface high supported by an active jet
stream looks to be located in the Great Lakes Region. These features
are favored to remain in place through Friday. Southerly flow would
be expected across the Great Plains between the southeastern high
and western trough, however the surface high in the Great Lakes
Region is forecast to support easterly surface flow across Kansas.
Warm, wet conditions look to be in place across the area Wednesday
through Friday as a result of this pattern. High temperatures all
three days are in the upper 70s to mid 80s. It`s important to note
that NBM 75th percentile and higher scenarios show highs in the
upper 80s to lower 90s Thursday and Friday. This could occur if the
southerly flow can reach further north into Southern Nebraska, or if
solar heating can develop. Even so, rain is in the forecast, as NBM
24 hr precipitation guidance shows a 40% chance or greater of
receiving more than 0.1 inches of rain both Wednesday and Thursday
across most of the forecast area. These probabilities are highest
along a line from Norton, KS to Tribune, KS Wednesday (50-70%), and
in Northeastern Colorado and far Southwestern Nebraska Thursday (60-
75%). Most of this activity is forecast to be widespread rain rather
than localized convective storms, the exception being Wednesday.
LREF guidance suggests a 40-55% chance across most of the forecast
area of experiencing surface CAPE (a measure of atmospheric
instability) greater than 1000 J/kg Wednesday evening. Some higher
end scenarios (90th percentile and greater) show CAPE may rise above
2000 J/kg. Even so, this convective activity is not favored to be
severe, as GFS and EC soundings show sfc-6km shear remaining below
30 kts during the afternoon and evening hours. Confidence in severe
weather occurring Wednesday is 5% or less.

The forecast begins to become a bit more uncertain by Saturday
morning, specifically regarding the trough to the west of the
forecast area. This feature is expected to be moving slowly eastward
throughout the long term period, though guidance is inconsistent on
when it will move over the forecast area. However, once it moves over
the area, temperatures may drop a bit more, in addition to
precipitation chances. This is represented in the forecast
temperatures for both Saturday and Sunday, with highs in the mid
to upper 70s. Additionally, NBM 24 hr precipitation guidance
drops the probabilities for greater than 0.1 inches of rain
below 40% on Sunday. These probabilities are a little higher on
Saturday, but is likely due to a higher chance that the trough
is still west of the forecast area on Saturday. In other words,
conditions similar to Wednesday through Friday are expected as
long as the trough stays to the west of the forecast area.
However, once it moves in over the region, temperatures and
precipitation would likely drop off a little bit.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1116 AM MDT Sun Sep 13 2026

Stratus is creating more sub-VFR conditions across the Tri-State
area today. Ceilings and cloud cover are expected to improve
over the KGLD terminal through the early afternoon hours. As the
sky clears, winds are expected to pick up over the terminal with
gusts of 25-30 kts possible beginning around 00Z. Overnight,
winds are expected to become more southerly to southwesterly
over KGLD with gusts up to 35 kts possible through the end of
the period. Low-level wind shear is also a concern over the
terminal overnight into Monday morning, primarily from 06-15Z,
at ~200 ft from the south to southwest at 40-45 kts.

KMCK is expected to see the stratus linger potentially through
sunrise Monday morning, creating MVFR to IFR conditions. After
00Z east-southeast winds are expected to increase with gusts of
~25-30 kts possible through ~13Z. Around 13Z, winds are expected
to shift to be out of the southwest with gusts up to 35 kts
possible through the end of the period.

&&

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

&&

$$

SHORT TERM...KMK
LONG TERM...Davis
AVIATION...KMK