714
FXUS63 KGLD 172250
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
450 PM MDT Tue Sep 17 2024

.KEY MESSAGES...

- Line of thunderstorms will develop in northeast Colorado later
  this afternoon and move through northwest Kansas and southwest
  Nebraska this evening. The main hazards will be damaging winds
  gusts between 60 and 80 mph and reduced visibility in blowing
  dust.

- 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.

&&

.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 FRIDAY/...
Issued at 450 PM MDT Tue Sep 17 2024

KGLD...a line/broken line of thunderstorms are forecast to
impact the terminal in the 00z-04z timeframe with the worst
conditions (gusts to 50kts, blowing dust and sub VFR conditions)
in the 00z-02z timeframe. Outside of convection, southerly winds
gusting up to 40kts are forecast through 04z. From 05z-07z,
southerly winds gusting to 35kts are forecast with VFR
conditions anticipated. After 08z, south to southwest winds up
to 11kts are forecast through 19z, increasing to around 12kts
with some gusts after 20z.

KMCK...VFR conditions are forecast from taf issuance through
01z. From 02z-05z, a line/broken line of thunderstorms is
forecast to impact the terminal with wind gusts up to 40kts and
potentially sub VFR visibilities due to heavy rainfall. After
06z, VFR conditions are expected. South to southwest winds up to
12kts are forecast.

&&

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

&&

$$

SHORT TERM...024
LONG TERM...024
AVIATION...99