425
FXUS63 KGLD 180457
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1057 PM MDT Tue Sep 17 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 WEDNESDAY 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 /THURSDAY THROUGH TUESDAY/...
Issued at 140 PM MDT Tue Sep 17 2024

Upper low slowly moves from southern California on Friday to the
Four Corners by Saturday morning, then lifts into eastern
Colorado Saturday afternoon and moves across the forecast area
Saturday night and Sunday, continuing east from there into
Missouri by Sunday night. End result will be increasing chances
for precipitation, with best chances occurring as the upper low
moves across Saturday and Sunday. Ahead of the system on Friday,
may see some elevated fire weather concerns in northeast
Colorado with hot and dry conditions and increasing southwest
winds during the afternoon. On Saturday, there may be a severe
threat with the approach of the upper low and a developing
surface cyclone, but models still not in particularly good
agreement on where that will occur. Nonetheless, with
increasing deep layer shear and at least some instability to
work with, could see a few severe storms. By Sunday, will be
cool and stable with no severe storms expected. Latest
statistics from the NBM shows mean rainfall amounts for the
48-hour period of around 1 inch and higher percentile amounts of
up to 2.50 inches. As long as it does not occur in a short
period of time, and that currently looks to be the case, this
would be beneficial rainfall for the area which has been
steadily slipping into drought the past several months. With the
clouds and rain, temperatures will be much cooler, with highs
in the upper 70s to lower 80s on Saturday and 60s on Sunday.
Lows will bottom out in the mid to upper 40s Monday morning.

Northwest flow strengthens for Monday and Tuesday with the upper
low transitioning to a trough to the east and a building ridge
to the west. Might see a few isolated showers associated with
any weak waves in the upper flow either afternoon, but most
locations will be dry. Temperatures will be near to slightly
below normal, with highs in the 70s and lows mainly in the 40s.

&&

.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...024
AVIATION...KMK