763
FXUS63 KGLD 212240
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
440 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. Severe storms are
  possible.

- A cold front Thursday night could be accompanied by northwest
  winds gusting up to 40 to 50 mph.

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

&&

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

Across the region this afternoon, skies are a mix from partly sunny
to sunny with a nosing surface ridge over a good portion of the
area, with an inverted trough/front over central Colorado. This set
up is providing temperatures in the 60s as of 200 PM MDT, and winds
remain northerly with gusts over 30-35 mph at times.

For the remainder of the afternoon into this evening, the main wx
concerns are going to focus on the slackening northerly gradient
along with the chance for rw/trw. Currently, convection is already
starting to churn up over central Colorado near the vicinity of the
inverted trough and attached front. They are trying to push eastward
but are running into the blocking ridge over the CWA. Latest CAMs
does show this activity will eventually push east through the CWA,
aided by an upper trough currently in the central Rockies.
Reflectivity guidance is mixed, but overall the convection should
get a bit more organized moving east, with a first round affecting
locales along/south of I-70, quickly followed by a second round/line
that will eventually traverse northern tier zones this evening. All
of this tapers and pushes east by 06z-08z Wednesday. Weak
instability with these storms, so not ruling out some small hail
with locally heavy downpours(dewpts still in the 40s/50s w/ PW
values in the 0.60-0.80" range).

Guidance is still mixed as to the extent of clearing towards 12z
Wednesday in western portions of northeast Colorado zones. Still the
potential for some to form if clouds can clear out, but wider
coverage not expected.

Going into Wednesday, west-southwest flow aloft with surface ridge
traversing the CWA at least during the morning hours. This pushes
east late as a weak low sets up over eastern Colorado. There is a
weak 700mb shortwave moving through the flow late Wednesday and
Wednesday evening. Some weak instability so have a 20% chance in for
some rw/isolated trw.

For Thursday, surface low west intensifies with it moving east
through the day along with an associated dryline. The dryline sets
up over the central CWA by the afternoon hrs. Conditions behind this
are dry with elevated to near critical fire wx conditions setting
up. Ahead of the dryline, enough instability warrants a Marginal
Risk for strong to severe storms, mainly along/east of Highway 83.
As this exits Thursday night, strong northerly flow is possible.
right now 20-30 mph expected but some guidance is hinting at 40-50
mph possible.

On Friday, high pressure at the surface will provide dry wx for most
of the daytime hours, but going into the evening a weak shortwave
works along the W/NW periphery of the CWA with the potential for 20-
30% rw/trw.

For temps, daytime highs on Wednesday will range in the lower to mid
70s. On Thursday, 80s are expected area-wide. Going into Friday,
cooler air will bring a daytime range from the upper 60s into the
lower and mid 70s. Overnight lows tonight will range from the upper
30s to around 40F in colorado. Elsewhere 40s are expected with
warmest areas along/east of Highway 83. Wednesday and Thursday
nights will have a wide range with lower 40s west into the lower 50s
range east. By friday night, a tighter range with mid to upper 40s
expected.

&&

.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 /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 440 PM MDT Tue May 21 2024

KGLD...sub VFR conditions are expected from taf issuance through
01z as a line of showers and possible thunderstorms moves
through. Winds generally from the northwest under 12kts but
could have some gusts. After 02z, VFR conditions are expected.
Northwest winds under 12kts this evening slowly back to the
south through the rest of the period with speeds under 12kts.

KMCK...VFR conditions are expected through the period. Northwest
winds up to 12kts this evening back to the west overnight then
south during the day Wednesday with speeds under 12kts. Showers
and possible thunderstorms should impact the terminal in the
03z-08z timeframe with a potential for sub VFR visibilities in
the 03z-04z timeframe presently.

&&

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

&&

$$

SHORT TERM...JN
LONG TERM...JN
AVIATION...99