961
FXUS63 KGLD 211952
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
152 PM MDT Tue May 21 2024

.KEY MESSAGES...

- Temperatures in northeast Colorado will fall into the upper
  30s Wednesday night and Thursday morning, where some patchy
  frost is possible.

- Scattered thunderstorms will develop Thursday afternoon and
  evening east of Highway 25 along a dry line. While severe
  storms are not currently expected, stronger storms may produce
  small hail.

- A cold front Thursday night will be accompanied by northwest
  winds gusting up to 55 mph.

- For the holiday weekend, expecting a chance for storms both
  Saturday and Sunday, with severe storms possible.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 130 AM MDT Tue May 21 2024

Another shortwave trough will move through this morning on the
heels of the exiting system. It will bring another round of
light precipitation as it moves from northeast Colorado to
southwest Nebraska between 12z and 18z. Additional rainfall
amounts this morning will generally be between a tenth and a
quarter of an inch, highest amounts in southwest Nebraska.
Expect a break in precipitation this afternoon as well as some
sun with highs in the 60s to lower 70s far south. Another
shortwave will move out of Colorado late this afternoon and
tonight. Showers and isolated thunderstorms will develop first
along the Palmer Divide late this afternoon, spreading into the
remainder of the area this evening, then ending late.
Instability will be very limited and no severe storms are
expected. Another tenth to a quarter of an inch of QPF can be
expected, this time highest amounts in Colorado. As skies clear
overnight, low temperatures will range from the upper 30s in
Colorado to the upper 40s in Hill City.

Wednesday will see zonal flow aloft and dry conditions during
the day. High temperatures will be in the low to mid 70s with
light winds. A weak wave comes out of Colorado Wednesday night
with scattered showers and isolated thunderstorms. Instability
remains extremely limited and no severe storms are expected.
Precipitation amounts will be less than a tenth of an inch. Low
temperatures will ranged from the lower 40s in northeast
Colorado the lower 50s in Hill City.

Thursday will transition to southwest flow aloft with the next
shortwave trough arriving in the afternoon. Temperatures will
warm well into the 80s. Surface pattern shows a dry line
developing and will be the focus for convective initiation
Thursday afternoon in eastern portions of the area. East of the
dry line there will be moderate instability with SBCAPE between
1000-2000 j/kg. However, deep layer shear is fairly low at only
15-20 kts. While showers and thunderstorms appear likely, the
lack of shear will likely result in pulse storms with only a
marginal risk of small hail. Showers and thunderstorms continue
in the east Thursday night, with a cold front surging south
Thursday evening. Models show breezy to windy northwest winds
with the front: the ECMWF is gusting 50-55 mph while the GFS is
gusting 40-45 mph. Given the recent precipitation, don`t expect
blowing dust to be an issue. Models show between a quarter and
a half inch of QPF in eastern areas Thursday night. Winds and
precipitation gradually diminish overnight with low temperatures
ranging from the lower 40s to the lower 50s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Issued at 152 PM MDT Tue May 21 2024

From the latest runs of the GFS/ECMWF, there will be a couple
easterly moving shortwaves this weekend which will bring chances for
precip. Both of these will affect the CWA mainly during the
afternoon hours into the evening. Going into the beginning of next
week, amplified 500mb ridging will push east off the Rockies.

At the surface, low pressure will develop over Colorado and move
east-southeast during the afternoon and evening hours through
southern kansas this weekend. The system for Sunday does drop a bit
further south than Saturday`s feature. Both days will see about 20-
40% chances for rw/trw, but Sunday will have better areal coverage
of the CWA. GFS soundings do show better instability on Saturday for
the eastern portion of the CWA, suggest some strong to severe storm
potential. On Sunday around 00z Monday, weaker instability but
inverted-V soundings are present w/ DCape around 900-1000j/kg
suggesting winds could be main factor if storms develop.

High pressure does nose south into the region behind the Sunday
system for Monday, sliding east on Tuesday allowing for a couple
warm and dry days.

For temps, daytime highs this weekend will range from the mid 70s
into the lower and some isolated mid 80s. Warmest areas will be
south of the Interstate. Going into the beginning of next week,
highs on Monday will range in the lower to mid 70s north of the
Interstate, with mid 70s to around 80F south. On Tuesday, a tighter
range is expected with a mix of upper 70s to lower 80s. Overnight
lows will range from the mid 40s west into the lower to mid 50s east
for each night.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1050 AM MDT Tue May 21 2024

For KGLD, a mix of VFR/MVFR ceilings through much of the
forecast period, before going all VFR by 06z Wednesday. VCSH is
possible from 01z-06z, but thunder could also occur, but low
confidence at this time so have left out of forecast. Winds,
north around 15-30kts through 01z Wednesday, then dropping to
10kts. By 06z, west-southwest around 10kts.

For KMCK, mainly VFR skies through the forecast period. Some
MVFR ceilings possible through 21z. Low confidence on rw/trw
potential, so have left off forecast, but could be included in
next issuance. Potential for 00z-06z timeframe if any occurs.
Winds, northwest around 15-25kts through 00z Wednesday, then
west-northwest 5-10kts.

&&

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

&&

$$

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