138
FXUS63 KGLD 152015
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
215 PM MDT Tue Jul 15 2025

.KEY MESSAGES...

- Heat indices in the 100s east of Highway 83 this afternoon.
  Chance for severe storms today, favoring those who are along
  and north of I-70 this afternoon and evening.

- Chances for storms continue into Wednesday, with the chance
  for severe storms late in the day into the evening. Some
  localized flooding concerns may be possible as well.

- Daily chances for showers and storms continue through early
  next week. Strong to severe storms are possible as well.

- Increasing signal for hot temperatures next week.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 1253 PM MDT Tue Jul 15 2025

The main compact shortwave for today`s severe weather potential is
already evident on satellite and water vapor imagery as cumulus is
seen developing across the mountains in northern Colorado. With the
shortwave already breaching the mountains am leaning towards
the earlier start time for storms across the area as they may
begin as early as 1pm MT. A pronounced theta e boundary is seen
via the RAP13 which is where the potential for initiation looks
to occur at around the 19-21Z time frame across eastern portions
of Yuma towards the Cheyenne (KS), Dundy county lines. Surface
low positioning will be key if there is a severe threat or not
with this, if the low is further to the east then that will drag
drier air further east with it than if the low is further west
then moist air would support higher CAPE values and better shear
and hail up to golf ball size would be possible if a mature and
discrete storm were to form. If the dry air is further east
then any developing storms would support a dry lightning
potential as PWATS would be around 0.7; if the low is further
east then PWATS would be over 1 inch. Additional storms are also
possible further south from roughly St. Francis down to around
Cheyenne Wells along the theta e boundary but would be driven
by reaching our convective temperature which is in the mid to
upper 90s according to NAM and RAP soundings. If the boundary
were to stall a landspout or two can`t be completely ruled out.
Through the rest of the evening; the better forcing does lie
across western and central Nebraska where a cluster of storms
looks to develop with some additional southward development
towards the Kansas/Nebraska state line where damaging winds
would be the main threat through mid evening. The other
potential hazard would be dust with storms as well as we will
have very steep lapse rates in place and after the past few days
of warm temperatures and breezyish winds can`t completely rule
out some patchy instances of visibilities less than 1 mile
potentially as low as zero especially near any recent harvested
fields. In fact NASASPORT 0-10cm soil moisture does highlight a
corridor along I-70 of upper teen to upper 20 percentages which
may support this as well. Any severe threat looks to be done by
around 03Z with lingering thundershowers across Sheridan,
Graham, Decatur, and Norton counties through 06Z.

For temperatures for today, warm to hot temperatures are forecasted
with highs in the upper 90s to low 100s across the area. Heat
indices in the low 100s are forecast as well especially along
and east of Highway 25 where the more humid air characterized
by dew points in the low to mid 60s are forecast to reside.
Can`t completely rule out a rogue instance or two of heat
indices approaching 105 degrees but the coverage would be way
to spotty for any heat related products to be considered. Winds
for the day are forecast to be southerly but with a wind shift
from the north as the initial surface trough moves on through;
some gusts around 25-30 mph are possible across eastern portions
of the area and a few hours of similar gusts across western
portions of the Colorado counties just behind the surface
trough during the mid to late afternoon hours.

Tonight, as the surface low pushes to the east winds will turn to
the northeast and again begin advecting in moisture from Nebraska,
this moisture advection does look to be fairly strong as a decent
signal for low stratus looks to affect nearly the entire forecast
area. Do think there is some fog potential as well especially
east of the Highway 25 corridor where winds look to be lighter
due to being further away from the trough; also think some dense
fog may be on the table as well currently favoring eastern
Colorado. Not anticipating any fog products as of now but
trends will need to be monitored on subsequent shifts.

Wednesday, fog and stratus may continue to linger through the
majority of the morning. Have lowered high temperatures across the
area due to the concern of the fog/status lingering and the higher
moisture content guidance suggesting 850mb temperatures around 15-
16C. I didn`t want to lower high temperatures to much as I do think
breaks in the clouds will occur which wherever that does occurs
then temperatures will rise locally. The current forecast has
high temperatures in the mid 70s across the north and mid 80s
across the south and the east. Some smoke aloft from fire across
the SW CONUS may also bring in some haze to the area through
the day Wednesday but at this time not anticipating any
reductions in visibility due to the smoke; those with
respiratory issues may want to use precautions if outdoors.
Can`t rule out some localized instances of a smoke smell at the
surface however.

Continuing to monitor for potential for more shower and storms
during the afternoon and through the evening hours of Wednesday. NAM
continues to suggest a potent shortwave coming off of the Rockies
during the afternoon hours which will be the main focus for severe
weather with large hail, damaging winds the main threats. Other
guidance does have the shortwave but not as compact. Guidance
suggests that triple point driven by a potential differential
heating boundary may be in place around or east of Highway 23 where
a discrete supercell may have the potential to develop if this
does occur then large to very large hail would be the main
hazard. The big question mark for the day is how strong and the
location of the shortwave and how quickly the front will move
through. The NAM continues to indicate a potent shortwave moving
across the area however other guidance has backed off the
intensity and keeps it further north. At this time am leaning
against the NAM which will result in the event being a later
event. If this is the case then a heavy rain event similar to
last week may be on the table. The other variable as mentioned
above is the speed of the front. Typically fronts move through
the area quicker which is what the NAMNEST suggests which will
move the the heaviest of the rain to the south which is similar
to what the HREF is suggesting which is highlighting Wichita
county with a 30% chance of 3+ inches of rain which may lead to
some hydro concerns. At this time due to higher Corfidi
downshear and upshear vectors don`t think widespread flooding
will be a concern but any storm will be efficient rain produces
due to a high freezing level of 15,000-16,000 feet AGL and
PWATS of 1.6-1.8. However some other guidance is slower moving
with the front which leads to some discrete storm development
before an additional upscale growth with heavy rain potential,
if this does occur then hydro concerns would be shifted to the
north. At this time am leaning towards the HREF/NAM solutions so
have decreased rain chances a little bit further north as it
won`t be as widespread.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 213 PM MDT Tue Jul 15 2025

Thursday is forecast to be post frontal as high temperatures are
forecast to be in the mid 70s. It may be even cooler as moisture
will still remain across the area especially if cloud cover
lingers through the day. Some weak vorticity off of the Rockies
during the day may lead to some additional shower and storm
potential but at this time am not expecting any severe weather
at this time. Into the weekend a surface high develops across
the southeast portion of the CONUS as longwave trough develops
across the western portions of the CONUS. Moisture is forecast
to remain in place as well which suggests that daily chances for
showers and storms and potentially severe weather through the
weekend.

The surface high pressure across the south does appear to begin to
shift to north during the start of next week which favors hot
temperatures returning to the area. Depending on the orientation
of the high some monsoonal moisture may advect into the area as
well which would support storm development along the western
periphery of the high pressure. If the high pressure shifts to
the east then a better coverage of storms would be possible
across the area, but if it shifts to the west then rainfall
would be confined to Colorado.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1050 AM MDT Tue Jul 15 2025

Southerly winds are forecast to continue through the afternoon
with some gusts of 20-30 mph possible; highest at KMCK. Continue
to monitor for some thunderstorm development this afternoon and
through the evening. For KGLD, a slim chance of storms
developing before 00Z but think any activity should remain to
the NW of the terminal. A little better signal from 01-04Z so
have included a PROB30 as a surface trough moves through, severe
weather is not expected for the terminal. KMCK does have a
better potential after 00Z with a concern for strong to perhaps
severe winds and IFR visibilities due to heavy rains so have
included a tempo for this as the forcing is better the further
north you go. An increasing signal for stratus overnight as
moisture moves in from the north; some patchy fog is also
possible for the KGLD terminal as well.

&&

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

&&

$$

SHORT TERM...Trigg
LONG TERM...Trigg
AVIATION...Trigg