613
FXUS63 KGLD 162255
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
455 PM MDT Tue Jul 16 2024

.KEY MESSAGES...

- Severe chances during the late afternoon to overnight hours
  with wind the primary hazard, but also a few instances of
  marginally severe hail and flash flooding possible.

- Strong to severe storms are possible Wednesday into Friday as
  well.

- Temperatures closer to normal beginning tomorrow and
  continuing through the weekend.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 219 PM MDT Tue Jul 16 2024

Across the region this afternoon, skies are a mostly sunny to sunny
mix, with a light/variable wind regime due to high pressure still
influencing the area. Temperatures are ranging mainly in the lower
to mid 90s.

The main wx concerns for the short term period will focus on storm
chances later this afternoon into this evening. And again Wednesday
through Friday.

With an elevated ridge over the western portion of the country,
several shortwaves are set to move along the eastern periphery of
the ridge and into the CWA. Today`s round of potential storms will
be aided by a stalled boundary that is currently draped along the
Oklahoma panhandle into eastern Colorado.  The latest HRRR and
NamNest are showing storms cropping up by 22z-00z. Model track
focuses on the area south of I-70. The NamNest does continue to lean
on some areas north of I-70 still seeing 20-40% chances for rw/trw.

SPC currently has a Marginal Risk for severe over a good portion of
the CWA, with a Slight Risk still south of Highway 40 into Greeley
and Wichita counties. Inverted-v soundings still show wind as main
threat, but initial storms could give a brief hail threat as well.
WPC has an Excessive Rainfall outlook for locales along/south of I-
70. Slow movement of some of these cells, combined with PW values of
1.1 to 1.4 inches could give some locally heavy rainfall. Some areas
south of I-70 into Logan county did receive around 2.00" with storms
last night, so can`t rule out some isolated flooding issues if
training occurs as with last night. The bulk of storms should stay
south of the Interstate, but can`t rule out lingering precip
overnight north into Wednesday morning over the eastern CWA.

Going into Wednesday, surface ridge north shifts east of the CWA,
with a lee-side trough setting up over the eastern Rockies. Aloft,
the upper ridge remains in place with yet another shortwave working
off the Rockies into the CWA. Latest guidance starts things west
around 18z and pushes a bit eastward to at least Highway 25 at best
as blocking effects prevent any further eastward push into the
afternoon and evening. Late evening though, the ridge gives way east
allowing for any remaining rw/trw to drift east towards 12z
Thursday. SPC does show a Marginal Risk for severe wx for locales
along/west of Highway 25. Instability warrants mention of high wind
threat once again, although hail could be initially as storms form
in Colorado. WPC has a Marginal Risk for excessive rainfall in
Colorado as here lies the best chance for persistent heavy rainfall
due to the slow moving storms expected.

On Thursday, chances for storms through the first half of the day
with the western CWA seeing best chances(20-30%) for storms. The
shortwave expected for Thursday is a bit weaker than Wednesday and
coming from the north due to amplification of the ridge into the
Rockies. Guidance carries 20 pops going into the evening hours
before things taper by 06z Friday. There is a Marginal Risk for
severe for Thursday afternoon and evening in the northwest, but
storms set to weaken as the evening progresses with a wind threat
once again.

Going into Friday, a brief reprieve over the area as high pressure
sets up east of the CWA, with a strong lee-side trough over the
eastern slopes of the Rockies. Another shortwave(500-700mb) dives
southeast Friday afternoon into the evening for another round of
storms, with better areal coverage due to ample low level moisture
inflow/instability. 40-60% chance for storms is in place Friday
evening as the system pushes through. Looking for wind/hail threats
as well as potential for heavy rainfall again due to high PW values
around 1.2" to 1.6".

For temps, highs in the short term period will see an increasing
trend with midweek numbers ranging in the lower to mid 80s. On
Thursday, warmer with mid to upper 80s expected, and for Friday,
lower to mid 90s. Overnight lows will range widely from the upper
50s into the mid 60s. Warmest night will occur Thursday night where
all areas will be in the 60s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Issued at 135 PM MDT Tue Jul 16 2024

Looking at the latest runs of the GFS and ECMWF, both models do
carry an amplified 500 mb ridge over the western portion of the
country. A trough swings through the northern/central Plains during
this time. Models do differ as to the system forming a meandering
cutoff low or staying as a trough. From previous runs it does look
like consensus for a cutoff low forming in the 500/700 mb range,
meandering slowly over the central Plains.

At the surface, a front will settle south of the CWA going into
Saturday, as a strong ridge works into the northern Plains. The
placement of the ridge will play a key role in amount/chances(20-
40%) for rw/trw potential each day. Areal coverage spans the CWA but
does trend westward due to the surface ridge building south into the
CWA by the beginning of next week.

The result of this will have storms chances peaking late in the
weekend into next Monday, before shifting towards the west. The
caveat for the extended forecast will be the potential for heavy
rainfall. PW values will range from 1-1.5" w/ best numbers in the
east as surface winds shift easterly late in the period.

For temps, looking for highs to start off the upcoming weekend to
range in the mid to upper 80s on Saturday, giving way to slightly
cooler numbers on Sunday with upper 70s to mid 80s expected. Going
into next week, conditions begin an upward trend with mainly lower
80s Monday, mid to upper 80s for Tuesday.

Overnight lows will range mainly in the mid to upper 50s this
weekend. A few spots east of Highway 83 will reach the 60F mark.
Next week, a similar setup to this weekend with mid and upper 50s
Monday night, then a range from west to east Tuesday night from the
upper 50s to lower 60s. Warmest along/east of Highway 25.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 455 PM MDT Tue Jul 16 2024

KGLD...VFR conditions are expected through the period. A
northeasterly wind around 10kts at taf issuance will veer to the
southeast then south at similar speeds overnight. On Wednesday,
light and variable winds in the morning become easterly at
speeds up to 10kts or so with perhaps a few higher gusts.
Presently, convection well west of the area is forecast to move
to the southeast and should remain out of the area. There could
be outflow wind gusts to 30kts or so in the 02z timeframe.

KMCK...VFR conditions are expected through the period. Winds
will generally be from the east around 10kts through the period.
Will keep shower/thunderstorm mention out of the forecast at
this time. Will be watching for the potential for storms to
impact the terminal from the northwest in the 02z-06z timeframe.

&&

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

&&

$$

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