168
FXUS63 KGLD 261916
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
116 PM MDT Wed Jun 26 2024

.KEY MESSAGES...

- Not as hot today; thunderstorms develop across east Colorado
  late afternoon/early evening before spreading into Nebraska
  and Kansas. Severe possible along with torrential rainfall.

- Scattered severe storms again Thursday with large hail,
  damaging winds, torrential rainfall and perhaps a window of
  opportunity around sunset for a tornado.

- Near daily chances for thunderstorms Friday into next week.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 225 AM MDT Wed Jun 26 2024

A moist airmass is starting to advect into the area from the
northeast where dew points have been increasing 5-10 degrees with
the passage of the incoming boundary. Weak isentropic lift and
interaction with the moist boundary is leading to some scattered
showers across northern Kit Carson county as of 08Z; RAP suggests
that this corridor may continue to move south through sunrise so
have introduced slight chance pops (15%) to account for this.
)Surface high continues to reside across the SW CONUS, but is
forecasted to flatten out through the day today. As a result, a
reprieve from the triple digit heat looks to be in store for the
area with highs in the low to mid 90s.

Main focus for the day will be thunderstorm development across
eastern Colorado. Discrete strong to severe storms look to develop
during the late afternoon hours and into the evening as a shortwave
emanates off of the Rockies; some supercellular characteristics may
be possible as well with shear around 40 knots and 3000 j/kg of
MUCAPE. Large hail looks to be the primary hazards initially
across Yuma, Kit Carson and Cheyenne (CO); will need to watch
for flooding potential as well especially with any right moving
storms as the motion is around 5 knots and PWATS increasing up
to around 2 inches. The storms are then forecasted to grow
upscale into a cluster with perhaps a damaging wind potential
as they move across the state line especially with cold pool
driven enhancements. Some localized flooding potential may occur
as well with the high PWATS but currently think that storms
will be moving quickly enough to avoid any further hydro issues.


The difficult portion of today`s forecast will be how much the
surface high across the south breaks down. If some amplification
remains then the rainfall will shift to the north or be delayed
until the subsidence exits the area such as the ECMWF. Other
guidance such as the RAP/NAM differ on the area with the
greatest moisture  with the RAP favoring north of I70 and the
NAM to the south. All this said, continues to keep me from
increasing pops to much and does bring some cautiousness.
Overall though this does appear to be the area`s relative best
chance at meaningful precipitation that has been seen in a few
weeks.


Thursday, will see the moist air mass continue across the area. Will
need to watch for stratus and perhaps fog across the area during the
morning; fog will be dependent on how quickly the rainfall can exit
and how much occurs. Fairly decent agreement with guidance with
850mb moisture greater than 90% hanging around the eastern
portion of the area for the good part of the day in the form of
stratus. With the stratus and dewpoints in the low 70s have
lowered high temperatures for the day into the low to mid 80s
across the east. Western portions of the area will see more
breaks in sun where highs in the low to mid 90s remain
forecasted.

Another threat for severe storms exists on Thursday, but the
coverage and hazards will be highly dependent on how the Wednesday
system plays out. Large hail and damaging winds will be the primary
threat; the large hail threat may be a bit more uncertain given
meager lapse rates of 6.5 to 7.0 C. It appears that two zones for
convective initation will be in play as a warm front and a dry line
will be present across the area; will also need to watch for any
additional lingering boundaries from the potential storm
cluster from Wednesday night. A tornado threat may also develop
along the warm front and across any additional outflow
boundaries as forecast guidance is showing 0-3 SRH around 300
m2/s2 and 0-1 SRH around 150 m2/s2. NAM hodographs show decent
low level shear as well; a dewpoint depression of around 10
degrees and 3000 j/kg of SBCAPE does indicate that any storm
should be surface based. PWATS will continue to be very high as
well around 2 inches still which will lead to continued concern
for torrential rainfall and perhaps additional flooding concerns
especially where heavy rainfall may fall Wednesday night.

Friday, will see a similar pattern as another wave moves off of the
Rockies bringing shower and storm potential to the area. Storms
again look to initiate across eastern Colorado and move into
the adjacent states; moisture and PWATS at this time don`t
appear to be as high and there may be some capping concerns as
well. A warm front does look to be draped across the area again
as well but the exact location differs between models so is
difficult to pinpoint down at this time. Highs are currently
forecasted in the 90s across the area with the potential for
upper 90s across the south.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 115 PM MDT Wed Jun 26 2024

From the latest runs of the GFS/ECMWF, a meandering 500mb ridge will
move across the southern portion of the country. The northern edge
of the ridge will see several shortwaves passing eastward through
the central Plains during this time. Current guidance brings these
systems through mainly during the evening hours.

At the surface, a low does work into the northern CWA during the
Sunday timeframe, sinking slowly south through next Wed-Thu. This
boundary will interact with the aforementioned shortwaves to trigger
several rounds of rw/trw. Overall chances during the evening will
range 30-40%, with some 20% chances during the late afternoon hours
as things begin to wind up over the area.

The area will see basically a W/NW flow aloft during the extended,
and at the surface, southerly flow initially before the front moves
south, and eventually E/SE by midweek.

Overall this will give the area a return to well above normal and
hot temperatures especially from Monday onwards. The E/SE flow by
the end of the forecast will increase low level moisture(PW values 1-
2") into the region, aiding storms chances and better areal
coverage. The persistent inflow of moisture could pose a heavy
rainfall threat where the storms set up in additions to any
wind/hail threats.

For temps, highs on Sunday will range in the mid to upper 80s. Going
into next Monday, a range from the upper 90s to the lower 100s. For
Tuesday and Wednesday, mainly lower to mid 90s are expected.

Areas along and east of Highway 83 on Monday will see heat indices
approach the lower 100s and will need to be monitored for potential
Heat Advisory issuance in the coming days.

Overnight lows for tonight will range in the upper 60s to lower 70s.
Thereafter, mainly 60s expected, warmest east. A few spots in far
eastern zones could be around the 70F mark.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1100 AM MDT Wed Jun 26 2024

KGLD...VFR conditions are expected from taf issuance through
11z. East winds gusting to 20kts at taf issuance will slowly
veer to the east-southeast through the afternoon, gusting up to
30kts. Tonight, east-southeast winds gusting up to 25kts are
forecast through 02z, decreasing without any gusts after 03z.
There is a possibility of stratus toward 12z. Showers and
thunderstorms are possible at the terminal as they move through
from the west in the 07z-11z timeframe. Thursday morning, winds
veer to the south and increase with gusts up to 30kts. Morning
potential sub VFR cigs slowly improve through the morning to VFR
category.

KMCK...VFR conditions are expected from taf issuance through
about 12z or so. An east wind around 11kts at taf issuance will
increase slightly with gusts up to 20kts through 00z. Tonight,
east to east-southeast winds up to 11kts are forecast. Showers
and thunderstorms are currently forecast to reach the terminal
from the west in the 09z-13z timeframe. Sub VFR cigs are
possible as stratus moves in. Thursday morning, winds veer to
the south and increase with gusts up to 30kts. There could be
some showers/thunderstorms in the vicinity of the terminal
through 15z-16z before they move away. Cigs look to remain sub
VFR.

&&

.HYDROLOGY...
Issued at 225 AM MDT Wed Jun 26 2024

Any storms that develop across western portions of Kit Carson,
Cheyenne (CO) and Yuma counties late this afternoon and evening
will have the potential for torrential rainfall leading to some
flooding. Precipitable water values look to increase to around 2
inches during this time frame along with right moving storm
motion of 5-10 knots storms will not move very quickly and may
produce localized areas of flooding. Due to the recent hot and
dry weather and localized and conditional potential of this
threat have opted to not issue any hydro highlights. Storms look
to grow upscale after initial discrete cells but may have to
overcome some dry lower level air across NW Kansas. Once the low
levels can saturate then the continued potential for torrential
rainfall will return along some isolated flooding potential in
low lying areas.

Scattered storms are again forecasted on Thursday with continued
very high PWATS around 2 inches. There is potential for multiple
rounds of rainfall Thursday afternoon and into the overnight
hours. Those who see heavy rainfall Wednesday night will be most
at prone for additional flooding.

&&

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

&&

$$

SHORT TERM...Trigg
LONG TERM...JN
AVIATION...99
HYDROLOGY...