136
FXUS63 KGLD 180801
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
201 AM MDT Wed Sep 18 2024

.KEY MESSAGES...

- There will be an elevated fire weather risk in parts of
  northeast Colorado Friday afternoon.

- Precipitation chances return for Friday and through the
  weekend. Best chances will be Saturday and into early Sunday
  with the main upper low moving across the area. Locally heavy
  rainfall and flash flooding may be a concern during that time.

&&

.UPDATE...
Issued at 835 PM MDT Tue Sep 17 2024

A line of thunderstorms will gradually exit our area after midnight
towards the early morning hours. Westerly wind gusts upwards of
50 mph will be possible behind the line along with additional
threats of blowing dust and reduced visibilities followed by
heavy downpours. Clearing conditions behind the line of storms
will allow for temperatures to drop into the lower 60s east to
the upper 40s west into eastern CO as winds diminish returning
southerly.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 140 PM MDT Tue Sep 17 2024

Upper low in the Great Basin will lift northeast into Wyoming
tonight, with a negatively tilted trough axis moving through the
local area. A fairly solid line of thunderstorms has been
consistently forecast by the models the last few runs,
developing along the southern Colorado Front Range and quickly
moving northeast with the upper dynamics, reaching the
Colorado-Kansas border area by around 01z, Highway 83 by around
03z, and continuing east but weakening afterwards. Main hazards
with this line of storms will be wind gusts potentially between
60-80 mph and blowing dust, especially along the Kansas and
Colorado border area. The line of storms may tend to weaken
some as it moves east, but there will still be some potential
for wind gusts of up to 60 mph. There is a low end risk for
hail with the initial storms, perhaps a few instances up to
quarter sized, but wind will be the main risk. Mean
precipitation amounts are around a half inch in the
Colorado/Kansas border area, and generally between a quarter and
a half inch elsewhere, so flooding is not expected to be a
concern as the line will be moving at a good clip. Precipitation
should exit the area to the east by 06-07z with diminishing
winds. Low temperatures will be in the 50s and 60s.

The next system will dig along the Pacific west coast Wednesday
and Thursday. Southwest flow ahead of it will result in warm and
dry conditions both days. Highs on Wednesday will be in the
upper 80s to lower 90s. A weak front will move through late
Wednesday night and Thursday morning, shifting winds around to
the northwest. Temperatures will only be slightly cooler on
Thursday behind the front with highs in the low to mid 80s.
Afternoon humidity does fall below 20 percent both Wednesday and
Thursday afternoons, but winds will be light and not expecting
fire weather concerns at this time. Low temperatures will be
in the 50s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Issued at 201 AM MDT Wed Sep 18 2024

The long-term looks to start off active and become more docile
through early next week.

Saturday morning, a well organized low pressure system will be near
the Four Corners Region and rapidly moving northeast into the High
Plains. Throughout Friday night, a moderately strong 850 mb LLJ will
set up and move additional moisture into the region. The additional
moisture will keep temperatures from cooling off too much Saturday
morning, but will limit day time heating. High temperatures are
expected to be in the upper 70s to low 80s across the region, but if
the clouds break, expect warmer temperatures. The combination of
warm, moist air with the low pressure system (and associated fronts)
will fire off storms, likely in the afternoon and evening hours.
Models are fairly consistent will widespread precipitation being
expected. Deep layer shear during this event looks to increase the
potential for severe weather (~5-10%), but instability is marginal.
There is also a small (<10%) chance winds ahead of the storms could
gust around 30-35 kts in eastern Colorado producing blowing dust. If
there is a clearing of the clouds and the winds are able to pick up,
localized blowing dust could occur, otherwise blowing dust is not
expected to be a major hazard.

As the low moves farther into the CWA, winds will become
northwesterly and start cooling off the area. High temperatures on
Sunday look to remain largely in the upper 60s, and potentially
cooler depending on the efficiency of the CAA. The low pressure
system will take until Sunday night to move out of the area, giving
the area increased PoPs through Sunday evening.

Once the low moves out, northwesterly flow is expected to dominate
the High Plains through the remainder of the period. This will keep
high temperatures in the mid 70s and lows in the 40s to low 50s for
the rest of the period. As is typical in northwesterly flow on the
High Plains, shortwaves are bound to occur and could bring isolated
to scattered showers and storms into the area. Monday through
Wednesday, no organized systems seem likely, just the potential
shortwave showers.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 1049 PM MDT Tue Sep 17 2024

KGLD...VFR conditions are expected through the period. Southerly
winds gusting up to 40-45kts are forecast through ~09Z. After
09Z, south to southwest winds up to 15kts are forecast through
15Z, decreasing to around 10kts with some gusts afterwards. LLWS
up to 50kts are expected through ~10Z this morning.

KMCK...VFR conditions are forecast through the period. A
line of thunderstorms is exiting Red Willow County with wind
gusts up to 30kts. LLWS up to 40kts is expected to impact the
terminal through ~15Z. After 16z, south to southeast winds up
to 10kts are forecast.

&&

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

&&

$$

UPDATE...Sipprell
SHORT TERM...024
LONG TERM...CA
AVIATION...KMK