496
FXUS63 KGLD 211941
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
141 PM MDT Sat Sep 21 2024

.KEY MESSAGES...

- Showers and thunderstorms will develop over majority of the
  Tri-State area this weekend. Both severe weather and flooding
  chances are very low (<5%).

- Low temperatures in the mid to upper 30s are forecast for
  eastern Colorado by Monday morning, potentially allowing for
  some patches of frost. There is a concern for fog formation
  Monday morning, too.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 141 PM MDT Sat Sep 21 2024

Current observations show moisture streaming in from the south with
cloud cover over almost all of the area. Temperatures are now
holding steady in the 70`s with the cold front through the area and
the cloud cover holding temperatures. Winds are beginning to lower a
tad as the front moves further away and mixing has been cut off by
the cloud cover. These conditions should hold through the afternoon.

Going into the evening and overnight hours, precipitation is
forecast to begin for southeastern portions of the area as the
moisture continues to stream in and shift to the northeast. An area
of surface convergence is also forecast to set up in the southeast
which will develop the bulk of the storms and precipitation. The
rest of the area may not see precip until later in the evening as a
dry streak cuts through the area. However, as the upper trough
swings through, additional storms are forecast to fire up along the
higher terrain and move east into and hopefully through the area.
The main issue again will be the dry air intrusion and how saturated
the air column is. Current forecasts are not very optimistic with
most having the area with rain totals around a tenth or two.
However, larger amounts can be expected if the surface convergence
boundary stays near the area in the south and if enough moisture can
rotate around the whole system in the area before the higher
pressure and upper feature push it all to the east (max amounts
around an inch or two).

Tomorrow, a much cooler day is forecast as cloud cover lingers
through much of the day along with some lingering showers. Will need
to keep an eye on how much dry air moves in from the north and how
much streams in through the mid-levels. If too much dry air is
present, the cloud cover would dissipate earlier than forecast and
temperatures likely warm to around 60. Winds are forecast to remain
around 10 to 15 mph from the north as the higher surface pressure
moves into the area.

Tomorrow night, any linger cloud cover is forecast to dissipate as
drier air continues to advect into the area. Winds are also forecast
to become calm or light as the high pressure broadens out over the
area. These conditions will allow for much cooler temperatures in
the area with 30`s and 40`s possible. Eastern Colorado and the Tri-
State border area may even see frost potential. With the clear skies
and calm winds, it`ll be up to how much dry air moves in and how
much dewpoints lower. Dewpoints in the low to mid 30`s are possible
with temperatures a few degrees warmer forecast.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 106 PM MDT Sat Sep 21 2024

Going into next week, the latest runs of the GFS/ECMWF continue to
show an amplified 500mb ridge over the western portion of the
country work eastward into the Rockies. The weak system that had
been forecast the past couple of days to traverse the eastern side
of this ridge Monday night into Tuesday has now weakened further.
The two models are not consistent now with this system affecting the
western portion of the CWA. With its passage now only Monday night,
weak instability present to warrant only a mention of 15-20% chance
for showers mainly from Highway 27 and points west into eastern
Colorado.

Dry conditions with near to above normal temperatures will ensue
from Tuesday into the end of next week, aided in part by a
persistent southerly surface flow beginning from late Tuesday
onward. Both sets of guidance do show the potential for a cutoff
upper low well east of the CWA to begin to retrograde Friday
evening. Moisture pinwheeling around the system right now does work
into eastern portions of Graham and Norton counties. Have kept in a
15% chance for a shower in those areas, but nothing major expected.

For temps, looking for a slight increasing trend for highs across
the area. Monday and Tuesday will see mainly 70s, with a few
isolated 60s possible. By Wednesday mid to upper 70s expected with
upper 70s to lower 80s for Thursday onward. Overall near to above
normal numbers for highs from Wednesday onward, with slightly below
normal for Monday and Tuesday. Overnight lows will range in the 40s
area-wide through midweek, and then from Thursday night onward a
range from the upper 40s west into the mid 50s east. Lows will range
near to above normal.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1144 AM MDT Sat Sep 21 2024

For KGLD & KMCK... VFR conditions are forecast for a majority of
the period, with MVFR and maybe some IFR ceilings near the end
of the period. The front is through the area and winds are
forecast to remain gusty until the cloud cover moves over and
limits the mixing. Winds would still likely gusts near 20-25 kts
through the evening and night. Rain is forecast to enter the
area starting this afternoon, but dry air is forecast to keep
the precipitation limited at both airports. So be alert for
showers and storms starting around 21Z, but the main timeframe
and higher chances is around 08-12Z as the upper wave moves over
the area. Once this passes, the low levels are forecast to
saturate and allow ceilings to drop to near 1000ft across most
of the area. KMCK is more likely to stay VFR depending on how
the dry air streak sets up over the area.

&&

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

&&

$$

SHORT TERM...KAK
LONG TERM...JN
AVIATION...KAK