339
FXUS63 KGLD 161936
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
136 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.

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

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 434 AM MDT Tue Jul 16 2024

On Tuesday an upper trough extending over the Plains from south of
the Hudson Bay in Canada and will flatten the upper ridge over the
Central Plains giving us more of a zonal flow aloft. Moisture will
continue trying to advect in from the Atlantic and NE Canada again
today while weak shortwaves move over the Rockies and Central High
Plains. This will provide another chance for showers and storms to
impact the entire area and continue through Thursday morning. SPC
has placed the entire area in a Slight Risk for today as large
clusters could develop over East-Central Colorado and Northwest
Kansas during the late afternoon/early evening to overnight hours. A
big question is whether or not the upper level divergence can help
provide some lift so that whatever develops can interact with the
500-2000 J/kg of CAPE over the area. Shear is also slightly better
today to promote more organized storms. The NAMnest seems to be more
of the high end/"worst case" as it has more isolated to scattered
convection developing out of Southern Nebraska into Northwest Kansas
during the late afternoon followed by a widespread cluster of storms
moving into the area from  East-Central Colorado and impacting those
generally south of the Nebraska border. Over the last few nights,
the 06Z run of the HRRR has seemed to handle the convection fairly
well, so we are trending more towards it today. The 06Z HRRR is also
the "best case" as we have limited convection over the area around
00Z with majority of the strong to severe storms occurring just
outside of our southern CWA border. Inverted-v soundings seen in
CAMs along and south of I-70 indicate damaging wind gusts and large
hail up to the size of quarters are the primary concerns; however,
the hail threat will decrease as we move in the evening and evolve
into more of a linear cluster. Heavy rain is also a concern with PWs
greater than 1" favorable for flash flooding should storms begin to
train over the same area or move slowly given the 15-20 kt storm
motions. Highs will be in the low to mid 90s with overnight lows in
the upper 50s to mid 60s.

On Wednesday the upper trough will push further south and amplify
the ridge over the Western CONUS placing the Tri-State area under NW
flow aloft. Some monsoonal moisture will interact with the moisture
stemming from the Atlantic to keep the rain and storm chances (up to
45%) continuing through the overnight hours where chances decrease
to around 15-20% over the central columns of counties. SPC has
placed those along and west of a Trenton to Leoti line into a
Marginal Risk for strong to damaging wind gusts associated with
isolated to scattered storms. High temperatures will be even cooler
thanks to the cloud cover with temperatures forecast to reach the
low to mid 80s. Overnight lows will be in the upper 50s to lower
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 /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 952 AM MDT Tue Jul 16 2024

For KGLD, expecting mainly VFR conditions through the forecast
period. VCTS possible from 00z-06z Wednesday. Winds will be
10kts or less through the forecast, but veering from the north
initially to the southeast by 02z Wednesday, southwest by 06z
then back to southeast from 13z onward.

For KMCK, expecting mainly VFR conditions through the forecast
period. VCTS possible from 00z-03z Wednesday. Winds, north-
northwest around 10kts through 03z Wednesday, then northeast.
By 05z, veering southwest, then becoming southeast from 09z
onward.

&&

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

&&

$$

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