RSS Mesoscale Discussions from Storm Prediction Center
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0252 PM CDT Sat Jun 06 2026
Valid 062000Z - 071200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE MID ATLANTIC AND NORTHERN HIGH PLAINS...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO
VALLEY INTO THE NORTHEAST...
...SUMMARY...
Thunderstorms with severe wind swaths (some gusts possibly exceeding
75 mph) and isolated large hail are expected this afternoon/evening
from the Ohio Valley to the northern Mid-Atlantic and southern New
England. Large hail and severe wind gusts (including gusts exceeding
75 mph) are also expected in the northern High Plains late this
afternoon/evening.
...20Z Update...
The primary changes to the outlook were to upgrade to Enhanced Risk
across portions of the Mid Atlantic and the northern High Plains for
the potential of severe wind swaths.
Across the Mid Atlantic, a cold-pool-driven bow echo MCS continues
to rapidly track eastward with a history of both wind damage and
measured severe gusts well exceeding 50 knots. To the north of this
bow echo, more multicellular convection has oscillated in intensity,
also with a history of occasional damaging gusts. The latest
mesoanalysis depicts increasing buoyancy and eroding MLCINH ahead of
the aforementioned ongoing storms, with surface temperatures
exceeding 90 F, yielding over 1000 J/kg MLCAPE. The strongly heated
boundary layer will encourage efficient evaporative cooling and
downward momentum transport to support damaging to severe gusts.
Furthermore, appreciable westerly flow above 500 mb is encouraging
35+ kts of effective bulk shear oriented normal to the bow echo and
surrounding storms. This shear may aid in continued or further
development of organized storm modes capable of producing damaging
wind swaths, perhaps with a few gusts exceeding 75 mph.
Across the northern High Plains, guidance consensus continues to
depict multicellular modes of convection developing atop a
well-mixed boundary layer, where 90+ F surface temperatures and
2500+ J/kg MLCAPE are already in place. The current thinking is that
40+ kts of effective bulk shear will be in place to support
organized multicells and perhaps an MCS later this evening. As such,
a damaging wind swath may occur, with a few 75+ mph gusts possible.
Across the remainder of the CONUS, the previous forecast remains on
track.
..Squitieri.. 06/06/2026
.PREV DISCUSSION... /ISSUED 1129 AM CDT Sat Jun 06 2026/
...OH Valley into New England through late evening...
A surface cyclone will move eastward across southern QC this
afternoon and into northern New England tonight, in advance of a
midlevel shortwave trough over the Great Lakes. An associated
surface cold front will progress southward into the OH Valley and
southeastward to near the southern New England and northern
Mid-Atlantic coasts by early Sunday. A convective cluster is
ongoing as of midday in OH to the south of the cold front, and it
appears likely that these storms will be maintained through the
afternoon as surface temperatures continue to warm and MLCAPE
increases into the 1000-1500 J/kg range. Sufficient buoyancy, along
with steepening low-level lapse rates and gradually strengthening
midlevel flow, will result in the potential for downward momentum
transfer and wind damage from eastern OH across PA through the
afternoon (potentially reaching Philadelphia-New York City by this
evening). Otherwise, additional storm development will be possible
later this afternoon along the cold front from the OH Valley into
NY, where a mix of supercells and multicell clusters will be capable
of producing damaging winds, isolated large hail, and a tornado or
two.
...Northern High Plains late this afternoon through late evening...
A midlevel trough will continue eastward from WA/OR to the northern
Rockies, with downstream lee cyclogenesis expected across southeast
MT. Forecast soundings suggest surface temperatures will need to
reach ~90 F to weaken convective inhibition and support thunderstorm
development along the stalled front across northeast MT/northwest ND
late this afternoon/evening. Forecast wind profiles support both
multicell clusters and supercells, and steep lapse rates through
most of the column will favor both severe outflow gusts (up to 75
mph) and large hail (up to 2 inches in diameter) with a mix of
high-based supercells and multicell clusters.
...TX/OK this afternoon...
Pockets of surface heating from central/northwest TX into southern
OK, near and south of a weak surface low and MCV, will support
additional thunderstorm development through the afternoon. Isolated
wind damage and marginally severe hail will be the main concerns
this afternoon.
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1234 PM CDT Sat Jun 06 2026
Valid 071200Z - 081200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE
NORTHERN HIGH PLAINS...
...SUMMARY...
Scattered severe storms capable of damaging hail and wind (some
significant), and perhaps a tornado or two are forecast across the
northern High Plains. More isolated storms may produce locally
damaging wind gusts centered over southeast Virginia, with a
brief/weak tornado possible from eastern Oklahoma into western
Arkansas.
...Northern Plains...
A strong shortwave trough will move out of the Pacific Northwest and
across MT Sunday, continuing northeastward into SK overnight. The
southern periphery of the stronger midlevel flow will extend across
WY and into the western Dakotas, aiding deep-layer shear. At the
surface, low pressure will deepen across the northern High Plains,
ahead of a cold front which will surge into eastern MT and northern
WY late in the day.
Storms are likely to form over southeast MT and northern WY during
the late afternoon near the higher terrain, and within the surface
trough from western ND to the Black Hills.
Supercells appear likely initially as deep-layer shear and lapse
rates will be favorable. A tornado or two may occur with these
initial supercells over MT/WY/Black Hills area, and, over northern
ND where low-level SRH will be strongest. Locally significant hail
may occur as well.
With time, one or more corridors of severe and possibly significant
wind damage is expected, as storms produce outflow and propagate
northeastward into the Dakotas. Several models indicate a strong
rear-inflow signal with over 50 kt westerlies just off the surface
behind the activity.
...Eastern OK into AR and southwest MO...
A weak midlevel wave will move northeastward across OK and toward
MO, while southerly surface winds generally increase across the
Plains. A broad area of upper 60s F to 70s F dewpoints will develop
northward over the entire region, with areas of moderate instability
and high PWAT developing. Some increase in diurnal convection is
anticipated, related to the midlevel wave, which may enhance wind
profiles somewhat. Forecast soundings indicate veering winds with
height, and 200-300 m2/s2 SRH may develop late in the day and into
the evening. In addition to heavy rain, any stronger cells that
develop may acquire rotation, with a brief tornado or two possible.
...Southeast VA into far northeast NC...
A shortwave trough will exist over the Mid Atlantic and Northeast,
with 30-40 kt midlevel northwesterlies into eastern VA. A surface
trough will extend southwestward from the parent low over the
Maritimes, into the DelMarVa, southeast VA and northeast NC during
the afternoon. Strong heating will result in steep boundary layer
lapse rates, while sufficient low-level moisture supports marginal
instability. Given the favorable time of day and convergence near
the trough, isolated cells are expected which may produce locally
damaging gusts.
..Jewell.. 06/06/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0229 PM CDT Sat Jun 06 2026
Valid 081200Z - 091200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER THE CENTRAL
HIGH PLAINS...AND OVER THE FAR NORTHERN PLAINS LATE...
...SUMMARY...
Isolated severe storms capable of large hail and severe wind gusts
appear possible across the central High Plains Monday afternoon and
evening. Isolated hail cannot be ruled out over the far northern
Plains near the Canadian border into Tuesday morning.
...Synopsis...
On Monday, a shortwave trough will continue moving north across
central Canada, with height rises across the Plains during the day.
Scattered early day thunderstorms are expected to diminish across
the northern Plains and upper MS Valley as subsidence occurs aloft.
During the afternoon, a lee trough is forecast to redevelop from
eastern WY into CO and toward the OK/TX Panhandles, where strong
heating will lead to steep low-level lapse rates and a deeply mixed
boundary layer. Moisture will be more limited, but late-developing
southeast surface winds will eventually bring higher dewpoints
westward toward the surface trough.
...Central Plains...
Storms are expected to develop during the late afternoon and early
evening over eastern CO, with more isolated activity along the
dryline into the TX Panhandle. Deep-layer shear near 35 kt as well
as increasing 850 mb winds may support a few clusters of storms
persisting into western NE and KS through the evening as well.
Locally damaging wind gusts appear most probable.
...Far northeast MT...Northern ND...Northwest MN...
A warm front will develop and surge northward late Monday night into
Tuesday morning, close to the Canadian border by 12Z. This will
occur ahead of a developing shortwave trough moving into the
northern Rockies. Forecast soundings indicate substantial elevated
CAPE will be possible, as a 40 kt southerly low-level jet brings
moisture northward. Lapse rates aloft will be steep, and may favor
isolated hail.
...Mid MS/OH Valleys...
A slow-moving midlevel wave is likely to be located over the Mid MS
to OH Valley, where a very moist air mass will exist. Scattered
thunderstorms are likely with this feature, which may also be
accompanied by stronger low-level shear on the mesoscale. However,
predictability for this feature is low this far out in time.
..Jewell.. 06/06/2026
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