455
FXUS63 KGLD 021830
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1230 PM MDT Sun Jun 2 2024

.KEY MESSAGES...

- Possible significant severe weather in the area this afternoon
  and evening. Very large hail, very strong wind gusts, and a
  couple of tornadoes are the main threats. There is a chance
  that severe weather will not form in the area or be very
  limited depending on how much dry air moves into the area.
  Best chance is along and north of Highway 36.

- A less active weather pattern develops Monday through Friday
  with above normal high temperatures in the 80s and 90s.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 319 AM MDT Sun Jun 2 2024

Today is forecast to be fairly warm and active. Current satellite
observations show a trough positioned near Southern California and
Southern Nevada. This trough is forecast to move further north and
east into the Four Corners region by the evening. As the upper
trough advances, the broad surface low over Eastern Colorado is
forecast to deepen and shift further east into the area.

For the daytime hours, the shifting of the low and forecasted south
to southwesterly flow will allow some drier air to begin working
into the area. This will help keep skies sunny to partly cloudy
through the mid-afternoon hours and help allow temperatures to warm
into the low to mid 90`s (with 850mb temps forecast to be around
30C). This would allow for critical fire weather conditions in parts
of Eastern Colorado as surface dewpoints are forecast to drop into
the 30`s or less, but overall fire weather concerns remain low with
the recent rainfall.

For the mid-afternoon and evening hours, there is the possibility of
significant severe weather for the area. The threat for today though
will hinge on how far the low center and drier air nudges into the
area. For locales that are behind the dryline, instability is
forecast to be relatively low (<2000 J/KG) and the flow nearly
unidirectional with similar speeds which would keep shear
generally below 30 kts. In short, storm development in this
region would be unlikely with short lived storms if they did
form. Still could see a severe wind gust though with the dry air
through much of the column. There`s also the possibility that
as the trough moves closer later, a cluster of storms could form
and move through much of the drier area.

For areas ahead of the dryline, it will get a bit more interesting
with all the moisture present near the surface. Loaded gun soundings
are being forecast, especially near the dryline with soundings
suggesting anywhere from 4000-6000 J/KG of MUCAPE present in the
region of higher surface moisture. With the presence of a cap, will
need either temperatures to warm generally towards the mid 90`s to
reach convective temperature, or have storms form along the surface
convergence from the low and dryline. If storms can initiate, the
environment will then be supportive of all hazards with significant
hail (effective shear near 40 kts) and wind gusts (DCAPE above 1500
J/KG & 60+kts flow in cloud layer) possible. Max hazards for the
event based on analogs and guidance are suggested to be 3.5 inches
for hail and 85 mph wind gusts. A couple of tornadoes would also be
possible with LCL`s forecast to lower to within a few thousand feet
while low level shear exceeds 10kts and SRH exceeds 100-200 m2/s2.
The overall flooding threat looks to be low with storm motions
generally forecast in the 30 to 40 kt range and limited chances for
training.

In short, today boils down to how far east the dryline and surface
low move. The further into our area these features move by this
afternoon, the lesser the severe threat. Any area that does have
storms develop with dewpoints generally above 55F, the severe threat
will be great with significant hazards possible. The favored area
will be along and north of Highway 36 where surface convergence is
forecast to occur along the low and where moisture would wrap
around. The entire area is at risk as temperatures may be able to
reach convective temperature and overcome any capping.

Tonight, skies will slowly clear as storms exit to the east. Winds
are also forecast to lower generally back below 15 mph as the
pressure gradient weakens and the surface low moves overhead. Lows
are forecast to drop into the 50`s and 60`s.

Tomorrow, the area is forecast to remain under mostly zonal flow
aloft while the broad surface low redevelops along the Front Range.
Temperatures are forecast to be a tad cooler then today, but with no
real air mass change, highs should still warm to near 90. Sunny to
partly cloudy skies are forecast to be over the area again with some
drier air in place. However, near surface moisture is forecast to
remain generally along and east of Highway 25. Storms might be able
to fire up if it get warm enough as the lack of synoptic forcing
will otherwise keep storms from firing up.

Tomorrow night, could see some storms move near the Tri-State border
if a cluster forms near the Front Range and can hold together.
Otherwise, cloud cover is forecast to increase from storms to the
west. Lows are forecast to hold in the upper 50`s and 60`s.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 1230 PM MDT Sun Jun 2 2024

Wednesday...500mb heights slowly rise as upper level ridging
strengthens over the western half of the country. There is a hint of
moisture in the 700-500mb layer moving through the area from the
north during the day along or immediately behind some cooler air and
wind shift. Not much instability to work with and old school Totals
Totals only in the lower 40s and K Index values 20-25 dont generally
support any convection. Presently, the forecast is dry and thats
seems reasonable this moment. 850mb temperatures in the 25C to 32C
range support high temperatures in the 90s. Low temperatures are
forecast to be in the 50s to lower 60s.

Thursday...not a whole lot of change in the 500mb pattern. Daytime
hours look to be precipitation free with a 20% chance for showers
and thunderstorms to develop during the night as 850-500mb moisture
increases from the southeast while weather disturbances move east
off the Palmer Divide and Cheyenne Ridges and into our area. 850mb
temperatures are a little cooler, ranging from 19C to 27C. This
would typically support high temperatures in the 80s. Low
temperatures are forecast to be in the 50s.

Friday...the tongue of better moisture in the 850-500mb layer over
much of the area in the morning slowly moves east through the
morning and out of the area by late afternoon with associated 20%
pops with it. The next weather system per 700-500mb relative
humidity forecasts emerges off the Colorado front range and
potentially into far eastern Colorado by 00z Saturday, moving
across the remainder of the area during the night with 30%-40%
chances of showers and thunderstorms with it. High temperatures
remain above normal in the 80s to around 90 with low
temperatures in the 50s.

Saturday...generally speaking, any mornings showers across the
eastern half of the area should move out as the next weather system
moves off the Colorado front range and into perhaps far eastern
Colorado by the end of the day, continuing east across the entire
area during the night in some form or fashion. Presently, 20% pops
are forecast in the morning with 40% chances across far eastern
Colorado late afternoon and 40%-50% chances for showers and
thunderstorms during the night. High temperatures are forecast to be
in the 80 to 85 degree range with low temperatures in the 50s.

Sunday...similar large scale scenario as Saturday with any morning
showers/thunderstorms exiting in by late morning/early afternoon
then waiting for next wave to move across from eastern Colorado
during the night. Presently, 20%-40% chances for thunderstorms
during the day, 30%-50% during the night. High temperatures cool a
bit into the upper 70s to lower 80s with low temperatures in the
50s.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1057 AM MDT Sun Jun 2 2024

Watching an outflow boundary move west from earlier morning
convection; have included a tempo group for GLD for a possible
wind shift associated with this. The main focus for this TAF
period will be thunderstorms late this afternoon and through
this evening. Isolated cells look to develop near KGLD around
21Z before growing upscale into a cluster or two which does look
to impact KMCK. For KMCK will need to watch for severe
potential and possible sub VFR conditions. In the wake of the
storms winds will become more variable but lighter through 18Z
Monday.

&&

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

&&

$$

SHORT TERM...KAK
LONG TERM...99
AVIATION...Trigg