RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1108 AM CDT Thu May 28 2026
Valid 281630Z - 291200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING FROM WESTERN IDAHO INTO WESTERN AND CENTRAL
WASHINGTON/OREGON....
...SUMMARY...
Scattered severe thunderstorms are possible this afternoon and
evening over western Idaho and east of the Cascades in Washington
and Oregon, capable of damaging gusts, large hail, and perhaps a
tornado.
...WA/OR/ID...
Morning water vapor imagery shows an upper low over central CA, with
a strong shortwave trough rotating around the low over central NV.
This feature is forecast to move into ID/OR later today, with an
associated 40-50 knot mid level jet affecting the area. Strong
heating, dewpoints in the upper 40s-lower 50s, and steepening
mid-level lapse rates will lead to moderate CAPE values over much of
western ID into central WA/OR, setting the stage for afternoon
thunderstorms. Activity is expected to first develop across
southwest ID/southern OR, where sufficient vertical shear would
support supercell structures capable of large hail and damaging wind
gusts. Morning CAM guidance suggests activity will organize into
multiple clusters by evening, tracking northwestward across the
Columbia Basin into western/central WA. These storms would continue
to pose a damaging wind threat.
...CO...
Strong heating and sufficient low-level moisture will likely result
in widely scattered thunderstorms in the foothills of the Front
Range this afternoon. The strongest cells could produce hail.
...KS...
A remnant weak vorticity max is tracking northward near the OK/KS
border. Southeasterly low-level winds to the north of the vort max
may result in sufficient shear for weak rotation in a few storms
later today. While a brief spin-up over north-central KS cannot be
ruled out, the overall threat appears too weak for outlook
probabilities today.
..Hart/Lyons.. 05/28/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1218 PM CDT Thu May 28 2026
Valid 291200Z - 301200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
WESTERN AND NORTHERN MONTANA...THE CENTRAL HIGH PLAINS...AND THE
SOUTHERN HIGH PLAINS INTO THE CENTRAL PLAINS...
...SUMMARY...
A few storms may produce marginal hail or strong gusts from eastern
New Mexico and western Texas across Oklahoma and toward Kansas on
Friday. A few strong to severe storms may also occur across western
Montana with gusty winds and marginal hail. Isolated severe storms
are also possible across portions of the central High Plains.
...Synopsis...
A closed low across the Great Basin will become an open wave on
Friday and start to advance northeast toward the central Rockies. As
this occurs, lee troughing will begin across the southern and
central High Plains and into eastern Montana. A strong mid-level
trough will move southward across eastern Canada into the Northeast.
...Western into north-central Montana...
Weak to moderate instability will build across western Montana on
Friday as dewpoints increase into the mid 50s and mid-level
temperatures cool. Mid-level flow is forecast to increase to 25 to
30 knots across western Montana which may provide sufficient shear
for a few more organized storms. These storms should develop by
mid-afternoon and move northward, potentially growing upscale into
one or more linear structures.
...Central High Plains...
Surface moisture is forecast to back up near the terrain across
northern Colorado and southeast Wyoming on Friday. This will lead to
weak to moderate instability across the region. In addition to
typical terrain circulations, guidance suggests a weak mid-level
shortwave trough may emerge across the region and provide additional
support for storm development. Shear is forecast to remain
relatively weak, but weak to moderate instability, and steep lapse
rates will support some threat for severe wind gusts and perhaps
isolated large hail.
...Southern High Plains into the central Plains...
A southern stream mid-level jet streak is forecast to emerge from
northern Mexico into the southern High Plains Friday
afternoon/evening. This ~40 knot jet streak will overspread portions
of the southern High Plains and the dryline. This should provide
ample shear for storm organization during the afternoon/evening.
Greater storm coverage and storm organization may exist between
Midland and Amarillo at the nose of this stronger mid-level flow.
However, it appears the greater moisture will remain farther east
and thus, storm intensity maybe somewhat mitigated. Therefore,
hail/wind probabilities remain 5% at this time.
Additional storms may develop from central Kansas to north-central
Oklahoma along a frontal boundary amid weak isentropic ascent.
Greater instability is expected within this zone, however, mid-level
flow is forecast to be weaker which may challenge storm
organization.
..Bentley.. 05/28/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0138 PM CDT Thu May 28 2026
Valid 301200Z - 311200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER WESTERN
NEBRASKA AND SOUTH DAKOTA...
...SUMMARY...
Scattered storms, some possibly severe with wind and hail potential,
are expected over parts of the Plains states on Saturday. The most
concentrated area is forecast to be over western Nebraska and South
Dakota.
...Synopsis...
As a mid-level shortwave trough rotates from the Rockies into the
central Plains a lee surface cylcone will develop across western
Kansas. A dryline will mix eastward across southwest Kansas into the
Texas Panhandle.
...Northern High Plains...
Moderate to strong instability is forecast to develop from northern
Oklahoma and central Kansas back into western Nebraska and southwest
North Dakota where low to potentially mid 70s dewpoints are expected
to develop northeast of a surface dryline. While most of this
dryline should remain capped due to minimal forcing, storm
development is expected across northeast Colorado and northwest
Kansas into western Nebraska during the afternoon as the mid-level
trough advects across the region and mid-level temperatures cool.
Mid-level flow is initially forecast to remain relatively weak, but
strengthen to ~40 knots by late afternoon to early evening when
storm organization may improve. Steep lapse rates will support large
hail and severe wind gusts with these storms which may eventually
grow upscale into a cluster during the evening.
...Kansas into northwest Texas...
Farther south along the dryline, forcing will remain somewhat
nebulous amid rising heights aloft and weak convergence. However,
forecast soundings show an uncapped airmass with strong heating (mid
to upper 90s). This may support a few severe storms and if they
develop, some storm organization is possible given 50 to 70 knots of
flow forecast around 300mb. Damaging winds and perhaps some large
hail would be the primary threats with this activity.
..Bentley.. 05/28/2026
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