RSS Mesoscale Discussions from Storm Prediction Center
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Thu Apr 16 2026
Valid 162000Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NEW YORK
INTO SOUTHERN VERMONT...AND THE OZARKS INTO THE MID-SOUTH...
...SUMMARY...
Scattered severe thunderstorms are possible this afternoon over New
York into southern Vermont with damaging gusts and perhaps a tornado
or two the primary threats. Very large hail and severe gusts are
possible with the stronger storms over the Ozarks into the
Mid-South.
...20Z Update...
The SLGT in the Ozarks/Mid-South was expanded northward into central
MO, where an isolated supercell with a risk of very large hail and
damaging gusts has emerged along the northern periphery of a remnant
cold pool. Farther south within Severe Thunderstorm Watch 127,
several discrete/splitting supercells continue to pose a risk of
very large hail (recent report of 2.75 inches) and locally damaging
wind gusts. With time, this activity may congeal into a loosely
organized cluster, with an increasing risk of damaging wind gusts.
The MRGL risk was also expanded slightly westward into southwest OK,
where boundary-layer cumulus is gradually deepening. Any isolated
storms that can form here will pose a risk of large to very large
hail and severe downbursts. Finally, the MRGL was expanded slightly
westward in southwest TX toward Fort Stockton. While convective
initiation is still in question here, deepening boundary-layer
cumulus along the higher terrain could result in an isolated storm
or two, with a risk of very large hail.
..Weinman.. 04/16/2026
.PREV DISCUSSION... /ISSUED 1124 AM CDT Thu Apr 16 2026/
...Ozark Plateau into the Mid-South...
Recent visible satellite imagery shows some ACCAS across
south-central MO, indicative of low/mid-level warm advection amid
the steep lapse rate environment in place. These steep lapse rates
are forecast to continue spread eastward, while low-level moisture
advection brings low 60s dewpoints northeastward into the region as
well. This will result in a moderate to strongly buoyant airmass
(i.e. MLCAPE from 1500 to 2000 J/kg) by the early afternoon.
Additionally, moderate mid to high level flow will remain in place,
resulting in long hodographs and overall environmental conditions
that are very favorable for supercells capable of large to very
large hail. Latest guidance continues the earlier trends of
developing storms in this area, which match observational
expectations as well. Large to very large hail (1 to 3 inches in
diameter) is possible with any updrafts that mature into supercells.
Low-level flow is weak, keeping tornado probability low but none
zero. Given the modest pocket of mid-level dry air present,
supercells will likely become outflow dominant with time,
supporting the potential for damaging gusts across the region
(particular eastern areas) as well.
...NY/VT/NH southeastward into the central Appalachians...
Recent surface analysis places a low over the eastern
Ontario/southern Quebec border vicinity, with modest surface
troughing extending southeastward from this low across central Lower
MI. Airmass across much of NY is characterized by dewpoints in the
low 60s. Dewpoints should stay in the low 60s throughout the day
despite modest mixing amid diurnal heating. This should result in
airmass destabilization ahead of the modest surface trough, with a
general increase in large-scale ascent beginning during the
afternoon as well. Little to no convective inhibition is
anticipated, supporting the potential for more cellular development
over the warm sector initially, before a more expansive convective
line develops along the eastward-progressing surface trough. Ample
mid to high-level flow will favor storm organization, including a
risk for large hail and a tornado with the more intense discrete
cells. The wind risk will tend to focus with linear structures that
evolve over time. An isolated threat for wind damage and perhaps
hail will extend southward into PA/WV and the Cumberland Plateau,
where a few stronger storms may yield those hazards.
...Edwards Plateau into the TX Big Country and western north TX...
A strongly buoyant and weakly capped airmass is expected to develop
along the dryline extending southwestward from western OK through
the Edwards Plateau. Although neutral to weak shortwave ridging is
expected throughout much of the morning into the late afternoon,
some limited ascent (associated with a weak shortwave trough moving
out of northern Mexico) may begin to spread across the dryline by
early evening. This combined with dryline circulations may be enough
to initiate isolated to widely scattered thunderstorms. Low-level
flow will be weak, but moderate to strong westerly flow aloft will
result in wind profiles very favorable for supercells capable of
large to very large hail. Any storms that develop should weaken
quickly with the onset of nocturnal cooling.
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1241 PM CDT Thu Apr 16 2026
Valid 171200Z - 181200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS EXTENDING FROM
WISCONSIN SOUTHWESTWARD INTO OKLAHOMA...
...SUMMARY...
Widespread severe thunderstorms are expected from parts of the
southern Plains to the Middle and Upper Mississippi Valley vicinity
Friday into Friday night. Tornadoes, possibly strong, very large
hail, and swaths of damaging winds will be possible.
...Synopsis...
An upper trough will move into the central and northern Plains
during the day, strengthening through Friday night as it moves into
upper MS Valley. Continuous height falls will occur across the
entire central to northern Plains region, where mid and upper level
temperatures will already be relatively cool.
During the afternoon, low pressure will develop across IA and WI,
with a cold front extending southwestward into southern KS and
northwest OK. A warm front will also lift across IA and into WI
during the day, with an influx of mid 60s F dewpoints. Given the
cool temperatures aloft, this will create a highly unstable air mass
ahead of the cold front. This front will accelerate during the
evening as storms become numerous, and should extend roughly from
Lower MI into central TX by 12Z Saturday.
The combination of steep lapse rates aloft, ample shear, and ample
moisture will support corridors of significant severe storms,
including all modes of severe.
...From IA into WI and northwest IL...
Strong tornado potential is evident Friday afternoon into early
evening, especially from IA into southern WI and northwest IL. While
convective evolution is a bit uncertain, there is good agreement in
a very unstable environment with midlevel lapse rates to 8.5 C/km,
along with 200-300 m2/s2 effective SRH ahead of the surface low and
near the warm front. While an eventual squall line may take shape
late in the day, scattered supercells appear likely after about 19Z
ahead of the developing low and as dewpoints rise rapidly. As such,
conditional tornado probabilities have been increased further to
indicate stronger tornado potential.
Cells should eventually consolidate as the front pushed east, with
damaging bowing structures expected, possibly as far east as Lake
MI. The severe risk is expected to persist as far east as IN and
lower MI late evening/overnight as the southerly low-level jet
brings moisture northward. Damaging winds appear possible.
...OK/KS/MO...
A volatile environment will develop near and ahead of the cold front
Friday afternoon, with significant severe hail, wind, and several
tornadoes expected. An impressive combination of deep-layer
shear/wind fields and steep lapse rates aloft will exist, and while
the forcing mechanism will be linear, shear vector orientation and
likely rightward-propagation of the stronger supercells will support
tornadoes and very large damaging hail initially. All this activity
is expected to merge into a linear MCS, with corridors of
destructive winds and continued large hail risk expected over much
of MO and into northern OK through the evening.
..Jewell.. 04/16/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0226 PM CDT Thu Apr 16 2026
Valid 181200Z - 191200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE
UPPER OHIO VALLEY...
...SUMMARY...
Scattered strong to severe thunderstorms capable of damaging winds
and hail will be possible on Saturday from the upper Ohio Valley.
...Synopsis...
An upper trough will move toward the upper Great Lakes and OH Valley
on Saturday, with a cold front moving quickly east and extending
from western NY/PA into KY/TN by 00Z. A narrow plume of upper 50s F
to near 60 F dewpoints will exist and contribute to up to 1000 J/kg
MUCAPE.
Storms will likely be ongoing early in the day along the front as it
moves out of IN and into western OH/KY, and 40-50 kt southwest winds
at 850 mb may support damaging gusts potential. Heating ahead of the
front from OH/PA southward into WV/KY/TN may support new
development, although lapse rates aloft over southern areas will be
poor. Still, favorable deep-layer mean wind speeds and sufficient
shear may support isolated severe gusts or marginal hail, especially
into OH/western PA. Further, low-level shear will be strongest over
northern areas, with some supercell potential.
..Jewell.. 04/16/2026
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