McCook, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

084
FXUS63 KGLD 160520
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1120 PM MDT Fri May 15 2026

.KEY MESSAGES...

- There is a 20% chance for storms to form that may produce
  large hail tonight.

- Saturday-Monday, more severe weather is expected during the
  afternoon and evening hours. All hazards are possible, and
  will generally favor northern portions of the area.

- Critical fire weather conditions are possible Sunday and
  Monday.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 222 PM MDT Fri May 15 2026

Current observations have the area underneath zonal flow aloft with
a surface low closer to the Panhandles region. This has led to winds
being from the north at 15 mph, gusting 25 mph. While relative
humidity has dropped into the single digits and teens, critical fire
weather conditions have been brief and sporadic so far. With this
expected to continue, no Red Flag Warning has been issued. Winds
should also lower as we get later into the afternoon with the
pressure gradient weakening as the low broadens. Temperatures should
remain in the 90s. We have had a few showers develop along the wrap
around side of the low in Greeley and Wichita counties with mid-
level lapse rates around 9 C/km. However, with moisture and
instability on the lower side, they have not really been able to
sustain or have precipitation reach the ground. This could move
through Northwest Kansas during the remainder of the afternoon, but
no hazards are expected with these.

This evening and into tonight, showers and storms may fire up over
the higher terrain in the Palmer Divide. Either these storms may
make it to the area or send outflow that could produce additional
storms in Eastern Colorado. If there are storms, they should make
their way east across the area. As they do so, they would move into
an environment with better instability closer to 1000-2000 J/kg of
MUCAPE instead of less than 500 J/kg. With this, a few instances of
hail nearing an inch in diameter would be possible. The saving grace
is that the dry air and overall lack of instability may prevent
storms from forming at all. There is about an 80% chance these
storms don`t develop and we maybe just have a few high showers pass
through. If storms did form, the severe weather would favor
generally east of Highway 25. Winds should shift to out of the east
around 10 mph.

Saturday continues to look like the more impactful day of the
forecast. The next upper trough is forecast to push into the
Northern Rockies and help develop another surface low along the
Front Range. With it, an area of surface convergence is forecast to
form near the Palmer Divide while southeasterly low level flow
brings in moisture. With this, storms should develop during the
afternoon hours and push east into and through the area during the
afternoon and evening hours. Meanwhile, additional storms may
develop along Highway 40 during the early afternoon as well if there
are any outflow boundaries lingering from convection during the
prior night. While less likely to form, these storms would push
east/northeast if they did form. Initiation looks to be between 12-
2pm MT, peak around 3-7pm MT / 4-8pm CT, and end around 9-11pm CT.

As for the hazards, all hazards are possible with 0-6km shear around
30-45 kts allowing for both cluster/linear and supercell modes.
Available instability is the questions with the RRFS and HRRR
favoring around 1500 J/kg of MUCAPE while the NAM 3k has closer to
3000-3500 J/kg. Either would allow for large hail, but the lower
values would favor a max closer to 2.0-2.5 inches while the higher
values would favor 3+ inches with supercells. In either case, linear
or cluster storms would favor hail around 0.5-2.0 inches. For
tornadoes, guidance generally suggests that the environment would
morph to support some tornadoes later in the afternoon as low level
shear increases. Still, the LCL`s of the storms are forecast to be
rather high around 6000-10000ft which will hamper development a
little. QLCS tornadoes are more likely, with one to two quick spin
ups forecast. If we can get a supercell ahead of the line, it
wouldn`t be unreasonable for a tornado to form then as well.
Otherwise, this event would be more of a hail and wind event.
Speaking of wind, guidance has been a bit aggressive with outputs
suggesting max wind gusts of 70-90 mph. With winds around 700-500mb
reaching 55-60 kts and corfidi downshear vectors of 50-70kts, it
wouldn`t be unreasonable for a few gusts to 80-85 mph. Most of the
winds should fall in the 50-70 mph range, even with the line of
storms. It is just if the line surges or we get a well developed
supercell, the stronger winds may come into play. The wind is more
likely after 4-5 pm MT. In regards to areas, counties along the
Nebraska border have the best chance of seeing severe weather and
the highest magnitude of severe weather. The rest of the area may
see severe weather if the secondary line forms or if an outflow
surges south. Otherwise, the severe event may be confined to the
northern portions of the area. One thing to keep in mind with all of
this is that this event can be weakened if there is too much
lingering cloud cover from the night prior or if the low center
shifts further north. We may be missed entirely if things shift to
far north.

Otherwise, Saturday should remain warm with temperatures reaching
the mid to upper 80s and southeast winds at 15-25 mph. While the
winds may be a bit breezy, the influx of lower moisture should
prevent critical fire weather conditions. Saturday night should see
skies clear for most of the area as the low begins to shift east and
bring in a dry slot. That being said, low clouds or fog may be
possible for locales in and near Southwest Nebraska if they get
either good rainfall that saturates the lower levels, or moisture
wraps around the low and back into these areas.

Sunday, the upper trough is forecast to dig down south into more of
the Rockies. With little easterly movement, the surface low is
forecast to move minimally to the east. That being said, ensemble
guidance does suggest that the low could shift a fair amount. This
is a problem for forecasting the storm positioning and evolution as
the dryslot will determine who see storms and who doesn`t. The
dryslot will also lead to critical fire weather condition concerns
for those who the dry air moves over. For now, the forecast position
of the low is to be more over the southern and eastern portions of
the area, which would be the areas that relative humidity could drop
into the teens. Winds are the limiting factor for critical
conditions as the dry air will generally be where the low center is,
which is where the weaker winds should be. Still, gusts around 25-30
mph are possible. Temperatures should be a bit cooler for those
north of a line from Cheyenne Wells, CO to Trenton, NE with
northerly winds on the backside of the low. Highs are forecast to be
in the 80s while those further east and south should reach the 90s.

As for the severe weather, there is the possibility for it ahead and
north of the low. In these areas, there should be enough instability
and shear for clusters of storms to develop and make their way east.
There is the chance though that they are over sheared with the upper
trough deepening and increasing the flow through much of the air
column. This also has upped the wind threat with winds around 500mb
potential reaching 60 kts and downshear vectors of 70-80 kts. Large
hail and tornadoes are also possible given the aforementioned shear
and instability, though over shearing would weaken both of their
chances. Storms should likely fire up around 1-3pm MT and then end
by 10-11pm MT. There doesn`t seem to be a likely secondary scenario
with ensembles split on the low placement, so just be watching for
updates as the threats and their placement may change as we get
closer.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 247 PM MDT Fri May 15 2026

Severe weather chances continue for Monday as the eastern county
warning area (CWA) is outlooked by the Storm Prediction Center (SPC)
for a Day 4 15% chance of severe weather. Our region is forecast to
be under a negatively tilted upper-level trough. There is also a
surface low in place with a north-south oriented dryline extending
from the low to the Texas-Mexico border. GFS, ECMWF and Canadian
ensembles all still disagree on where this low will set up. Some
ensembles have the low in southwestern Kansas while others have it
in central Kansas. Where the low ultimately sets up will determine
our weather for Monday. A southwest Kansas low will favor more
widespread severe weather coverage across the CWA while a more
central Kansas low will push the dryline further east increasing
fire weather potential.

Currently, the NBM is leaning more towards a southwest Kansas low
with chances of showers and thunderstorms for the northwest CWA. A
cold front is forecast to pass through the region Monday morning.
Blowing dust will be a concern ahead of the cold front with
gusts around 50 mph possible. Storms will likely develop ahead
of the boundary as they enter an environment with ample
moisture, strong instability and shear. Thunderstorms and
supercells capable of producing large hail, damaging winds and
tornadoes are possible. Probability of Precipitation (PoPs) are
40-90% for the northwest CWA.

Critical fire weather conditions will also be a concern Monday
afternoon. Relative humidity (RH) values are forecast in the high
teens for the southern CWA with gusts up to 60 mph possible. With
the region outlooked for severe weather, there is concern for
lightning ahead of storms as an ignition source. Grassland Fire
Danger Index (GFDI) values are forecast in the 80-100s for the
southern CWA. If any fires start, they will likely grow and spread
out of control rapidly. If the surface low ends up setting up in
central Kansas, fire weather conditions could end up more widespread
across the CWA.

Tuesday is cooler in the wake of a cold frontal passage. High
temperatures are forecast in the 60s to 70s. Main highlight for
Tuesday is a 10-20% chance for showers and thunderstorms for the
western CWA. The remainder of the long term is fairly consistent as
we enter more of a upper-level ridge patter. For Wednesday through
Friday, expect high temperatures in the 70s to low 80s with gusty
winds up to 30 mph for our Colorado counties in the afternoon.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1116 PM MDT Fri May 15 2026

VFR conditions will prevail for KGLD and KMCK through the
period, as long as there is not nearby convection. Tonight, we
are seeing weak signs that convection may briefly impact the
airports, but the bigger threat is Saturday afternoon. All
hazards from these storms are possible, including blowing dust.
These storms will be clear of KGLD by the end of the period and
exiting / weakening at KMCK by the same time.

&&

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

&&

$$

SHORT TERM...KAK
LONG TERM...Rhoades
AVIATION...CA