514
FXUS63 KGLD 271727 CCA
AFDGLD

Area Forecast Discussion...CORRECTED
National Weather Service Goodland KS
1127 AM MDT Sun Sep 27 2026

.KEY MESSAGES...

- Dense Fog Advisory in effect for portions of the Tri-State
  area this morning.

- Slightly elevated fire weather concern along/west US-385 this
  afternoon.

- Chances of rain increase Monday evening to as much as a medium
  to likely (40-90%) chance late Monday night, bringing the
  possibility of thunderstorms and heavy rain.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 321 AM MDT Sun Sep 27 2026


A Dense Fog Advisory is in effect this morning from Hitchcock County
to Thomas County to Gove County and counties east. Low visibility of
a half mile or less will make driving conditions hazardous. Fog will
scour out by mid to late morning as winds increase and temperatures
warm.

A weak surface trough over central Kansas will deepen slightly this
morning before getting pushed down into Oklahoma and Red River
Valley by this evening in response to the surface high getting
squished between the deep low along the East Coast and a deepening
trough over the Great Basin. In addition, a shortwave trough lifting
across the Desert Southwest will allow for weak leeside troughing
along the Front Range and Eastern Colorado Plains. This will enhance
southeasterly flow across Kansas and eastern Colorado. Slightly
elevated fire weather conditions for northeast Colorado this
afternoon with relative humidity dropping below 30 percent and
increasing winds with gusts of 30-35 mph. The gusty southeasterly
winds will gradually advect low-level moisture and mitigate fire
weather concerns by early evening.

Looking at the upcoming workweek... A longer duration widespread
rainfall event is setting up across portions of the Southern and
Central Plains from from early Tuesday morning through
Thursday. Models have struggle with the timing and placement of
the frontal boundary and the resultant heavier swath of
rainfall. While there is still some discrepancies with some
details still needing to be ironed out, there is enough
confidence (50-70%) that a good portion of the tri-state area
will see at least a tenth of an inch. Heavier rainfall amounts
of a half inch or higher are looking more likely on over western
Kansas and northeastwards into Nebraska. The system that is
bringing this round of widespread rainfall is currently digging
southwards across the eastern Pacific towards California. This
negatively tilted trough will close off as it moves across the
Great Basin towards the Four Corners region. Strong
southwesterly flow will transport sub-tropical moisture over the
Desert Southwest and into the Plains. Monday afternoon and
evening could see some thunderstorms develop as the front moves
east, but lack of instabilty will keep storms sub-severe. The
front then stalls and heavier rainfall will set-up Monday night
into Tuesday morning, with periods of moderate to heavy rain
possible through Thursday.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 246 PM MDT Sat Sep 26 2026

A trough is favored to be trekking across the Southern and Central
United States Tuesday morning, with an active jet streak to the
north. A cold front is forecast to come through the area sometime
during the morning and afternoon. LREF standard deviation in wind
direction shows large amounts of spread south and east of a line
from Cheyenne Wells, CO to Stratton, NE around noon. This would
indicate that the cold front would be along or southeast of this
line as well. High temperatures are currently forecast in the low to
mid 70s across the forecast area. Precipitation appears likely along
the front, as NBM 24 hr precipitation guidance suggests that most of
the area has greater than a 50% chance of receiving greater than 0.1
inches of rain, with portions of Gove and Graham Counties in Kansas
around an 80% chance. The only area at less than 50% is portions of
Yuma County in Colorado and far northwest Dundy County in Nebraska.
LREF guidance shows all areas having less than a 25% chance of
seeing surface CAPE (a measure of atmospheric instability) greater
than 1000 J/kg Tuesday afternoon and evening, which would suggest
that this precipitation would be linked to widespread rain as
opposed to convective thunderstorms. The exception to this would be
if the cold front can manage to come through during the later
afternoon or evening. NBM 75th percentile and higher solutions show
temperatures in the upper 70s or higher for highs, which could
correspond with this scenario. This would allow for extra
instability and a higher chance for thunderstorms to develop.
However, this is not the favored solution, as rain is primarily
expected to exist ahead of the cold front, which would minimize
temperatures and prevent more significant instability.

Cool and wet conditions are expected to continue going into
Wednesday in association with the trough approaching from the west.
Uncertainty continues to remain as to how fast this feature will
move eastward. Ensembles show the trough centered in one of the 4-
Corners States with a large amount of spread on the trailing edge,
which would indicate a slower progression. Guidance also continues
to show a modest 40-50 kt jet streak curved cyclonically around the
base of the trough, which would favor a surface low developing in
the Southern High Plains. Ensemble and deterministic guidance
indicates this surface low may be very slow moving, and perhaps
stationary Wednesday and Thursday in association with the slow-
moving trough. This would create the potential for several days of
precipitation. NBM 24 hr precipitation guidance shows most of the
area higher than a 70% chance for greater than 0.1 inches of rain
Wednesday, with a 40-45% chance on Thursday. Additionally, higher
end (90th percentile and higher) 48 hr precipitation scenarios show
between 3 and 4 inches of rain between Wednesday and Thursday. This
is a low confidence scenario (5%), but could lead to some localized
flash flooding if it occurs.

It should also be noted that the surface low may deepen enough to
where northerly winds sustained at 15-20 kts are possible Wednesday
and Thursday afternoon, particularly across portions of Eastern
Colorado and far Western Counties in Kansas where NBM guidance shows
a 40% chance or greater for such a solution. While highs are
currently forecast in the upper 60s to lower 70s, we may see a broad
area of highs in the low to mid 60s due to the strong northerly
winds and rain. NBM guidance suggests about a 15-30% chance across
most of the forecast area that highs are below 65 F.

Model guidance begins to diverge by Friday morning, as ensembles are
inconsistent on whether the trough will be through the area or not.
If the trough remains in the area, conditions similar to Wednesday
and Thursday could be experienced. However, if the trough is through
the area, warm and dry conditions are possible. An active jet streak
to the north may also introduce a more active weather pattern to the
forecast area, with EC and LREF ensemble 500-mb mean heights showing
a northwesterly flow coming into the forecast area. This would
suggest the potential for meandering temperatures as well as on and
off precipitation with shortwave systems.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1103 AM MDT Sun Sep 27 2026

GLD: Mainly clear skies and VFR conditions continue into much
of tonight along with gentle east-northeasterly winds, becoming
southeasterly overnight. MVFR is possible by late tonight as
fog begins to develop, further dropping to IFR and potentially
LIFR as fog thickens further and ceilings lower to as low as
300 ft with 1/2SM visibility, possibly lower, during the hours
surrounding sunrise. Fog should clear out by mid-morning
tomorrow while ceilings could linger, maintaining IFR ceilings
into the late morning hours while southeasterly winds pick up to
near 15-20 knots, gusting up to 25 knots.

MCK: Conditions have returned to VFR at this time as fog has
dissipated and clouds continue to scatter. East-southeasterly
winds veer throughout today, becoming southeasterly and
increasing to 10-15 knots, with gusts up to 25 knots by late
morning tomorrow. Meanwhile, fog is expected to develop late
tonight, reducing ceilings and visibility to MVFR, further
deteriorating to LIFR for several hours surrounding sunrise.
Fog should clear out by mid-morning tomorrow while ceilings
could linger, maintaining IFR ceilings into the late morning
hours.

&&

$$

SHORT TERM...Pietrycha
LONG TERM...Davis
AVIATION...Irish