782
FXUS63 KGLD 200656
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1256 AM MDT Thu Jun 20 2024

.KEY MESSAGES...

- Chances for showers/thunderstorms continues overnight, mainly
  across the northwest 1/2 of the area.

- Patchy dense fog is also possible across the area overnight.

- Dry and warmer Thursday.

- Hot with highs in the 90s Friday through Sunday then 90s to
  low 100s Monday through Wednesday.

- Dangerous heat index values of 100 to 106 degrees east of
  Highway 25 Monday and Tuesday.

&&

.UPDATE...
Issued at 710 PM MDT Wed Jun 19 2024

Moisture advection is ongoing as SE winds will continue to
stream moist air into the area. Guidance over the past several
runs shows fog development mainly along and south of I-70
starting mid evening and continuing through at least mid
morning. HRRR is the most aggressive with the fog showing a
fairly large area seeing dense fog; I`m however a little
skeptical on this as winds will remain around 10-15 mph through
the night so think this will help keep fog from becoming to
thick. For this reason, I am foregoing any fog highlights at
this time. There continues to be 20-50% chance of showers and
perhaps isolated storms moving across the area with isentropic
lift being the main factor. The best chance for seeing any
rainfall will be along and north of I-70, where a tenth or two
of measurable precipitation looks to occur.

As winds become more more southerly throughout the day tomorrow
some smoke from a large wildfire west of Roswell, New Mexico
may look to move across western portions of Yuma, Kit Carson and
Cheyenne counties in Colorado. Have not introduced haze into
the forecast at this time as would like to see some run to run
consistency but have increased sky coverage a bit to account for
this. At this time any smoke looks to remain elevated just
creating a haze in the sky.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 130 PM MDT Wed Jun 19 2024

Tonight...latest model guidance in general agreement that the
combination of 850-500mb relative humidity and higher pops should
remain focused along and west of Highway 27 through midnight before
continuing to the northwest while weakening. Given the very poor
performance of much of the guidance the past 24 hours, I`m rather
pessimistic in the precipitation forecast. Low temperatures are
forecast to be in the middle 50s to middle 60s. Cant rule out some
fog in spots and next shift may need to update the forecast based on
latest data.

Thursday-Thursday night...drier air in the 850-500mb layer quickly
overtakes the area by mid to late morning, ending any precipitation
chances. Southerly winds strengthen during the day with gusts of 30
to 40 mph, highest west of Highway 25. Breezy winds continue
overnight, mainly west of Highway 27. High temperatures warm back up
into the 85 to 90 degree range with low temperatures in the
60s.

Friday-Friday night...a monsoonal type pattern sets up with an upper
trough to our west and ridge centered over the southeast states.
Unfortunately, moisture from Mexico is skirted to the south of the
area. There is a bit of moisture in the 700-500mb layer that moves
off the Colorado front range and into the northwest 1/4 of the
forecast area during the afternoon and evening, supporting 20%-30%
chances for showers and thunderstorms. High temperatures are
forecast to be in the upper 80s to middle 90s with low temperatures
in the lower 60s to middle 70s. It will continue to be windy with
southerly winds gusting to 40 mph during the day, slowly decreasing
overnight.

Saturday-Saturday night...500mb flow shifts from southwest flow
aloft to zonal with troughing to our north and an elongated ridge to
our south. Presently, dry weather is forecast. There could be a
few thunderstorms flirting with the northwest and western
corner of the forecast area in the afternoon/evening. High
temperatures are forecast to be in the middle 80s to middle 90s
with low temperatures in the 60s.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Issued at 1254 AM MDT Thu Jun 20 2024

Current runs of the GFS/ECMWF continue to amplified 500mb ridge
working northward from the southern to the central Rockies. This
will occur on Sunday into the beginning of next week, providing a
W/NW flow aloft. By the midweek timeframe, the ridge amplification
stretches northward through the Rockies, with a slight eastward trek
towards the Plains region. The amplification/movement, changes the
flow aloft to northwesterly. A few weak shortwaves will traverse the
eastern side of the ridge during the forecast period, mainly during
the afternoon/evening hours.

At the surface, guidance brings a couple troughs/boundaries off the
Front Range and through the central Plains by the afternoon/evening.
Weak instability will have a 15-20% chance for rw/trw. Going into
Tuesday, the second boundary does settle south of the cwa, with a
low extending of the western portion. This front/boundary will be
the focus for increased RH along/in the vicinity, aided by winds
shifting more E/SE. The instability will trigger higher pops (30-
40%) area-wide Tue-Thu. Timing/coverage of the rw/trw chances do
differ each day between the GFS/ECMWF. This will be do to a strong
ridge rolling south behind the front, and eventually pushing east.
The extent of the ridge axis nosing south into the Kansas area could
push high RH further south and limit instability, or focus it more
into southern and western portions of the cwa.

Overall, chances for rw/trw do increase as the week progresses, but
the other concerns will be the return to hot, above normal
temperatures area-wide.

For temps, the latter portion of the upcoming weekend into next week
will see hot conditions return area-wide. Daytime highs on Sunday
will range in the mid to upper 90s. Monday and Tuesday, upper 90s to
low 100s. Wednesday and Thursday, mid to upper 90s.

With these expected highs around the area, concerns for high heat
indices will crop up. Currently looking at the Monday and Tuesday
timeframe where indices along/east of Highway 83 could reach into
the low to mid 100s and possibly need a Heat Advisory as a result.
Will be monitoring for further westward expansion. The remainder of
the extended period will have indices at or below forecasted highs
aided by lower after RH readings.

Overnight lows will range mainly in the 60s for the entire period,
but locales along/east of Highway 83 could only see the 70F mark a
few nights.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1038 PM MDT Wed Jun 19 2024

Stratus and fog has been a bit slow to get going so far but am
seeing signs of development across SE portions of the area, so
forecast expectations remains on track. The slow development has
been from a slower progression of incoming shortwave across SE
CO. Ceilings are forecast to decrease over the next 6 hours with
at least IFR conditions at each terminal and perhaps some LIFR
at KGLD along with some fog potential. Shortwave looks to create
some showers which is favored to impact KMCK which should keep
the fog at bay. Breezy to gusty winds will ensue after the
fog/stratus breaks mid morning with gusts of 30-40 knots across
the area from the south.

&&

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

&&

$$

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