NWS Goodland, KS wrote its last area forecast discussion before the first event at May 31, 11:17 PM CST, 43 minutes earlier. Its key messages:
Area forecast discussion, May 31, 11:17 PM CST, 43 minutes before
Area Forecast Discussion
National Weather Service Goodland KS
1117 PM MDT Sun May 31 2026
.KEY MESSAGES...
- Monday there is a slight risk for severe storms in the
afternoon and evening for the entire area. Supercells will be
possible, capable of producing large hail, damaging winds and
blowing dust, and perhaps a tornado.
- Storm chances continue through much of the week. Severe
weather is possible Tuesday.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 1223 PM MDT Sun May 31 2026
Current observations show a large, negatively tilted upper trough
over the Western CONUS and High Plains with slight ridging over the
south. There is also broad low pressure located along much of the
Plains. With this, skies have been clearing and mostly sunny skies
are forecast for the remainder of the day. Winds should stay
light from the north while temperatures steadily warm towards
the 80s.
This evening and into tonight, the upper trough axis is forecast to
lift north while keeping the area in the southwest flow aloft. With
this, some mid-level moisture is forecast to move over the area and
increase cloud cover. There is also the chance that some
sprinkles/showers will try and form, but dry low levels should keep
the chances for anything measurable below 10%. Otherwise,
temperatures should drop into the 50s underneath a mix of clear and
cloudy skies.
Monday, the lifting upper trough axis is forecast to spin in place
over the Northwest CONUS more as a low. This will keep the Tri-State
area under southwest flow aloft, while allowing lower surface
pressure to build just to the west of the area. Between a
combination of ridging trying to amplify in the south and low
level flow from the southeast, both warmer temperatures (highs
reach the 90s for most of the area) and increased low level
moisture is forecast.
With the warm temperatures and increased moisture availability,
storms are forecast to fire up over the area during the afternoon
and evening hours. The current forecast has a couple of zones of
interest. The first is the usual higher terrain in Eastern Colorado.
This zone looks to be more likely to produce storms and then bring
them east into and through the area. The other is convergence zones
along the leading edge of the surface low. Guidance is a bit more
split on this for two reasons. One, the low may be more broad which
would limit the strength of the convergence. Two, in spite of
increasing moisture, we still may be too dry and end up capped until
later storms move through. If the convergence on the low does set
up, then storms would likely fire in the area. The favored zone is
near I-70. The convergence zones would give the area an earlier
start time around 2-4pm MT / 3-5pm CT. Otherwise, we would have to
wait until around 5-7pm MT / 6-8pm CT just for the storms to reach
Eastern Colorado. It is worth mentioning that if storms don't form
over the area, there is another possibility of outflow from storms
closer to the Panhandle Region racing north and also providing a
spark for storms.
These storms would have a chance to be severe, especially with 0-6km
shear around 45-50 kts supporting supercells and downshear vectors
around 50-55 kts supporting wind gusts of 60-70 mph. The main
inhibitor is currently forecast to be the instability, with MUCAPE
forecast between 750-2000 J/kg. If the instability is truly on the
lower side, then storms would probably end up cycling and clustering
which would lower the potential for higher end hazards. For now,
messaging hail around 0.5-2", wind gusts 45-65 mph (maybe 75 mph), a
tornado or two, and some blowing dust. The entire area is at an
equal threat for the hazards for now. If we advect in more moisture
and raise dewpoints more into the mid to upper 50s, the hazards
would become stronger.
Getting into the late evening and overnight hours, storms may
continue through the night with little change in the upper or
surface pattern. With moisture continuing to advect in, there would
be no shortage of fuel for storms. The main question is if there
will be enough synoptic forcing or enough storm outflows to produce
the continued storms. If the storms do continue, there is a risk for
flooding and maybe even some flash flooding. The overall chance
looks to be about 20%. Otherwise, with the storms lingering and
little change in the pattern, winds should remain from the southeast
around 10-15 mph with temperatures in the 50s and 60s. The cooler
temperatures are more likely in the west where skies may clear out.
Tuesday the upper low is forecast to lift a little more to the
north, while still keeping troughing over the Western CONUS and the
Tri-State area under southwest flow aloft. The surface pattern isn't
forecast to be too different either with lower pressure still to the
west of the area and southeast flow at the surface. The main
difference for the daytime hours is that mostly cloudy skies are
forecast for most of the day Tuesday. So in spite of the ridge in
the south trying to amplify, temperatures are currently forecast to
be cooler in the 80s.
As for storms, the low being shifted back a bit further west are
increasing the chance that storms would form west of the area and
have to move into the area. This would lead to a later start time,
with storms mainly during the evening hours. There is also the
chance that the area is stable enough from the prior day's
storms and Tuesday's cloud cover to inhibit storms for most of
the area. Otherwise, marginal severe hazards are possible with
MUCAPE around 1000 J/kg and effective shear lower around 25-35
kts. There could be more flooding concerns if storms cluster
over an area that received heavy rain the prior day. The
nighttime hours could see storms continue into the night with
plenty of moisture remaining. With the storms and cloud cover,
lows should be in the 50s and 60s again.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 117 PM MDT Sun May 31 2026
For the extended period of the week, Wednesday there is a weak ridge
that is sandwiched between two lows. The low pressure system to the
northwest of the ridge, will kick out some shortwave disturbances
that will bring precipitation chances to the region. Then the upper
flow transitions to more zonal flow. As next weekend approaches, the
upper pattern begins to change. There are signs of a trough that
moves into the area from the Pacific Northwest.
Guidance has been showing the high temperatures to be in the mid 80s
to low 90s for the majority of this period. The lows are forecast to
be in the 50-60s range. Winds look to remain relatively calm and
from the south to southeast. The only outlier in this is Wednesday
where temperatures hangout in the mid to low 80s. However, the lows
remain in the 50 to 60 range.
As for precipitation chances, the CWA is in the typical afternoon
shower/storm chances in the afternoon/evening. Wednesday through
Friday PoPs are in the 20-70% range. Saturday and Sunday's
precipitation chances decrease to 10-30%. Each day is currently
forecast to have atleast 1000 J/kg of SFC CAPE which would support
storm development.
As for severe potential, there is no strong signal for anything yet.
However, different guidance outputs have suggested that the
shortwave disturbances could be stronger. Also, more moisture could
be advected in increasing more fuel for storms.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1116 PM MDT Sun May 31 2026
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1111 PM MDT Sun May 31 2026
Main aviation concern for both KGLD and KMCK for the period will
be thunderstorm chances. Overnight, scattered showers and a few
isolated thunderstorms may develop towards 12z and persist into
Monday morning. Confidence is low in both development and
coverage, so will not mention in the TAFs at this time. Later in
the afternoon, thunderstorms will redevelop across the area
with an upper level disturbance. These storms will have better
coverage and will continue into the evening hours. Potential
impacts to the terminals will be brief gusty winds and minor
visibility reductions in rain.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
SHORT TERM...KAK
LONG TERM...KAK/Holdren
AVIATION...024