676
FXUS63 KGLD 060816
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
216 AM MDT Thu Jun 6 2024

.KEY MESSAGES...

- Dry conditions are forecast for today with only a slight
  chance of showers and storms tonight for areas south of I-70.

- Friday and Saturday bring back chances for severe weather in
  the area. Friday has the higher chance for severe weather with
  large hail, wind gusts to 70 mph, and maybe a tornado
  possible. Friday is also forecast to have highs in the 90`s.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 213 AM MDT Thu Jun 6 2024

For the short term, relatively calm conditions today will be
followed by more active weather going into the weekend.

Today, the area is forecast to remain in northwest flow aloft with a
ridge over the Western CONUS and a trough over the Great Lakes. With
some slightly cooler air moving into the area, highs today will
likely round out in the mid 80`s in spite of another day with sunny
skies. Winds will remain generally from the east, but pick up more
of a southeasterly component later in the day. For tonight, most of
the area north of I-70 is forecast to see mostly clear skies. For
locales south, the southeasterly flow in the low levels is forecast
to bring some more moisture for the southern half of the area. With
the additional moisture, a few showers and storms may be able to
form in Eastern Colorado if a shortwave moves through and/or with
some slight upslope flow. Severe weather is unlikely with CAPE
forecast to be below 2000 J/KG, little synoptic lift, and little to
no effective shear. Lows should mainly be in the 50`s, but
persistent cloud cover or effective moisture advection could have
some areas stay in the 60`s.

Tomorrow, the upper ridge over the west is forecast to deamplify
over the area and become more pronounced near the Western Coast. This
is forecast to happen as a smaller upper low/trough moves through
the Upper Plains. As this feature slides through the Plains, it is
forecast to move the lower surface pressure from off the Front Range
east into the Plains. With the moisture return from the prior night,
the advancing surface low is forecast to trigger storms during the
afternoon and evening hours (generally after 21Z). Similar to prior
events like this, storms should form over Eastern Colorado and move
east across the area. The environment in Eastern Colorado may not be
as favorable for severe weather with weaker shear and drier air due
to the surface low`s advancement. If so, storms would likely be
marginally severe at best and begin to cluster. The question then is
how much moisture and instability remains as the storms and low
pressure system move east. If prior events are a good guide, then
enough moisture and instability should be present to allow for
continued severe storms chances across the area and through the
evening. Will also have to watch for flooding. If the clusters move
through as forecast with the system, 1 to 2 inches would be
reasonable in some spots, but not enough for flooding. However, if
training occurs or a cluster forms ahead of the main convergence
zone with the low, two rounds or more could move through and pose a
flooding risk. In terms of temperatures, the southerly flow will
help temperatures warm back into the 90`s. Some locales south of I-
70 may even get close to 100.

Saturday, the area is forecast to be in zonal to northwest flow
aloft with very little discernible features near the area. The area
should also be in slightly higher pressure with post frontal air.
This is forecast to keep temperatures cooler in the upper 70`s and
80`s. With moisture still forecast to linger in the area (the drier
air looks to retreat back overnight Friday), showers and storms will
again be possible during the afternoon through early overnight
hours. Based on current guidance, instability and shear are a little
lacking with the main synoptic driver forecast to be a shortwave
that moves through the flow. But a severe storm or two could be
possible.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Issued at 122 PM MDT Wed Jun 5 2024

From the latest GFS/ECMWF, the overall upper level pattern for the
extended period from Saturday onward will consist of persistent W/NW
flow aloft due to a meandering upper ridge in the Rockies. Several
shortwaves will impact the CWA as they move off the Rockies on the
east side of the upper ridge.

At the surface:

Saturday through Saturday night, the position of the strong ridge
nosing south from the northern Plains will play a key role to the
areal coverage of expected QPF. There are differences from the GFS
versus the ECMWF with the GFS more broadly spaced as it comes into
contact with a surface low/front over southern KS/OK Panhandle. With
the inconsistency of the two models, have combined them for coverage
purposes which will initially start rw/trw chances mainly along/west
of Highway 27 during the afternoon and overspread the CWA by the
evening hours, slowly dissipating overnight.

Sunday and Sunday night, the E/SE flow on Saturday shifts to more
southerly as the ridge pushes east of the area. This will push best
chances for rw/trw into the western CWA, especially northeast
Colorado, as those locales will be closest to a lee-side
trough/upper level shortwave over the central Colorado area. The
chances for convection will persist over the 24 hour period.

Monday through Tuesday night, persistent southerly flow initially on
Monday will keep increased warmth area-wide, but storm chances will
persist as well. The aforementioned lee-side trough does push east
going into Tuesday, allowing for an increased areal coverage of
potential storms versus hwy and west for Sun-Mon.

Wednesday, warmest day of the extended period as upper/surface
ridging becoming more prominent over the area. Some instability in
far western zones may allow for rw/trw to develop, but chances are
low at this time.

Overall, PW values will reach around an inch for much of the
extended period, bringing along the chances for some locally heavy
rainfall to portions of the CWA. This will have to be monitored,
especially in the western CWA where current pops chances are
highest/persistent.

For temps, looking for daytime highs this weekend to range in the
upper 70s to the mid 80s for Saturday, and for Sunday, upper 70s to
around 80F. Going into next week, mid to upper 70s for Monday,
increasing to the lower to mid 80s for Tuesday, with mid to upper
80s for next Wednesday. Overnight lows will range in the 50s for
most nights. Some 60s are possible for areas along and east of
Highway 83 for next Tuesday/Wednesday nights.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 1018 PM MDT Wed Jun 5 2024

VFR expected to prevail at both KGLD and KMCK through the TAF
period. High pressure will build over the area behind a cold
front tonight and Thursday, resulting in light winds and mostly
clear skies.

&&

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

&&

$$

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