No watches are valid as of Thu Sep 3 06:09:02 UTC 2026.MD 2212 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR WESTERN/CENTRAL PA AND ADJACENT PARTS OF FAR NORTHEAST OH/WESTERN NY
Mesoscale Discussion 2212
NWS Storm Prediction Center Norman OK
0107 AM CDT Thu Sep 03 2026
Areas affected...Western/central PA and adjacent parts of far
northeast OH/western NY
Concerning...Severe potential...Watch unlikely
Valid 030607Z - 030800Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated wind damage remains possible overnight.
DISCUSSION...Vigorous convection persists early this morning from
northeast OH into parts of northwest and central PA. Much of this
activity is ongoing north of a composite outflow, which will tend to
limit severe-wind potential, though MUCAPE of greater than 1000 J/kg
and moderate deep-layer shear may continue to support occasionally
organized storm structures and isolated wind-damage potential.
A small cluster that moved off of Lake Erie and produced a 51 kt
gust near Ashtabula, OH will move through a somewhat more favorable
environment in the short term, with wind-damage potential. However,
unless this cluster begins to propagate more southeastward, any
severe threat will tend to remain isolated. Trends will continue to
be monitored for storm development or propagation into the somewhat
warmer and more unstable environment across west-central/southwest
PA through the overnight.
..Dean/Hart.. 09/03/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BUF...CTP...PBZ...CLE...
LAT...LON 42267984 41357780 40957699 40637657 40247640 40067681
39927763 40347936 40868030 41148079 41398113 41538116
41688116 42267984
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MD 2211 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EAST-CENTRAL/NORTHEAST MT INTO FAR WESTERN ND
Mesoscale Discussion 2211
NWS Storm Prediction Center Norman OK
1244 AM CDT Thu Sep 03 2026
Areas affected...Parts of east-central/northeast MT into far western
ND
Concerning...Severe potential...Watch unlikely
Valid 030544Z - 030745Z
Probability of Watch Issuance...20 percent
SUMMARY...Storms with a threat of isolated hail and severe gusts
will spread east-northeast late tonight.
DISCUSSION...Downstream of a vigorous mid/upper-level shortwave
trough moving across northwest MT and the Canadian Prairies,
vigorous storms are ongoing across parts of east-central and
northeast MT. The ongoing elevated convection is being aided by
moistening in the 850-700 mb layer, with steep lapse rates both
above and below this layer supporting vigorous updrafts and
potential for strong downdrafts. Effective shear of 30-40 kt will
continue to support some storm organization, with a continued mix of
line segments and transient elevated supercells possible.
Recent gusts of 60-65 mph have recently been reported to the
east/southeast of Glasgow, and strong to isolated severe gusts will
continue to be possible as the primary gust front continues to move
east-northeastward. The strongest semi-discrete cells will also be
capable of producing isolated hail.
The most favorable zone of low-level warm advection and ascent is
forecast to continue shifting northward into the early morning. This
will eventually result in the strongest storms being confined to
parts of southern SK, but some threat could reach parts of western
ND before this occurs.
..Dean/Hart.. 09/03/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BIS...BYZ...GGW...
LAT...LON 46810636 47490552 48200569 48540595 48890600 49080594
49080475 49040409 48920380 48510371 47760355 47250369
47110407 46990441 46810636
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1253 AM CDT Thu Sep 03 2026
Valid 031200Z - 041200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY THROUGH
TONIGHT ACROSS PARTS OF THE SOUTHERN GREAT LAKES INTO MID ATLANTIC
AND PARTS OF THE NORTHERN GREAT PLAINS...
...SUMMARY...
Scattered strong thunderstorm development is likely today through
tonight, perhaps including a few organizing clusters, posing a risk
for severe wind and hail across parts of the southern Great Lakes
into Mid Atlantic and portions of the northern Great Plains into
Upper Midwest.
...Discussion...
Large-scale mid-level troughing has overspread much of the Pacific
coast through the Rockies. However, models indicate that further
eastward progress will slow, as at least one significant embedded
short wave trough digs offshore and contributes to amplification of
the larger-scale trough near and offshore of the Pacific coast. As
this occurs, downstream ridging is forecast to build across the
northern Great Plains/middle Missouri Valley vicinity by late
tonight, in the wake of a short wave trough now emerging from the
Great Basin and forecast to progress north-northeast of the northern
Rockies through the eastern Canadian Prairies and northwestern
Ontario. Farther east, it appears that mid-level troughing and an
embedded remnant low will slowly dig southeast of western
Quebec/southern Ontario through the northern Atlantic Seaboard.
A surface cold front accompanying the eastern Canadian perturbation
is preceded by considerable ongoing thunderstorm activity
overspreading the northern Mid Atlantic through Lake Erie vicinity.
It appears that an outflow boundary associated with this convection
may become quasi-stationary across parts of southeastern
Pennsylvania/New Jersey, before the initially stalled upstream
front, across southern portions of the Great Lakes vicinity into
Upper Midwest, advances southeast of the lower Great Lakes through
much of the northern Mid Atlantic and upper Ohio Valley by late
tonight.
...Southern Great Lakes into northern Mid Atlantic...
The initially stalled composite outflow boundary and surface front
appear likely to provide the focus for renewed thunderstorm
development later today through tonight. Across the southeastern
Wisconsin through southern Lower Michigan/northern Indiana and Ohio
vicinity, it appears that the corridor of stronger destabilization
along this boundary will remain in relatively close proximity to the
southern fringe of the westerlies. East-southeastward into the
northern Mid Atlantic this remains more unclear.
Regardless, where the seasonably moist boundary layer becomes
strongly heated, thermodynamic profiles a bit further aloft into
mid-levels, aided by elevated mixed-layer air, will remain
characterized by steep lapse rates of temperature and potential
wet-bulb temperature. This will promote the risk for strong
downbursts and evolving cold pools capable of producing strong to
severe wind gusts in developing thunderstorm activity.
There appears potential for one or two organizing clusters across
and east-southeast of the southern Great Lakes region this afternoon
into tonight. It is possible that severe wind probabilities could
still be increased further, once forcing for convection and the
potential negative impacts of early day convection become clearer.
...Northern Great Plains into Upper Midwest...
Forcing for ascent, near and downstream of the short wave emerging
from the Great Basin, appears likely to overspread northern/eastern
North Dakota into northwestern Minnesota during peak boundary-layer
instability this afternoon and evening. Latest convection-allowing
guidance suggests that this will provide support for intensifying
thunderstorm development, which may include a few supercells in the
leading warm advection regime, ahead of a possible upscale growing
cluster near the crest of the building larger-scale mid-level
ridging. Aided by pronounced veering of lower through mid-level
wind fields, deep-layer shear appears conducive to the risk for
large hail, in the presence of thermodynamic profiles with steep
mid-level lapse rates and large CAPE in mid/upper levels. A few
strong downbursts also appear possible.
..Kerr/Wendt.. 09/03/2026
SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1242 AM CDT Thu Sep 03 2026
Valid 041200Z - 051200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE MID ATLANTIC...
...SUMMARY...
Widely scattered severe thunderstorms, mainly producing damaging
gusts, are expected across portions of the southern Mid-Atlantic on
Friday. More isolated severe storms capable of severe winds and
large hail may occur over parts of the Midwest Friday afternoon into
night.
...Synopsis...
Upper ridging will amplify over the Plains states, with upper
troughs meandering over the Interior West and along the East Coast.
East of the ridge crest, multiple impulses will track southeastward
across the Midwest to the Mid-Atlantic, atop a surface warm frontal
boundary, serving as the impetus for thunderstorm initiation in
these areas. Given modestly stronger flow and cooler temperatures
aloft overspreading this moisture-rich surface boundary, a few
storms may become severe.
...Portions of the Mid-Atlantic...
At least one or more subtle mid-level impulses will pivot around the
broader East Coast trough, supporting scattered thunderstorm
initiation by afternoon. By this time, surface temperatures should
reach 90 F, amid 70 F dewpoints, yielding around 2000 J/kg MLCAPE
given 6.5-7 C/km mid-level lapse rates. Deep-layer northwesterly
flow will be in place, supporting 20-40 kts of effective bulk (speed
shear), favoring multicells and perhaps a transient supercell, the
strongest of which may produce damaging gusts or an instance of
hail.
...Portions of the Midwest to Ohio Valley...
Upper support for convective initiation will be even weaker across
the Midwest/OH Valley compared to the areas closer to the East
Coast. Nonetheless, 70s F surface dewpoints beneath 7-8 C/km
mid-level lapse rates will contribute to 3000+ J/kg MLCAPE along a
surface warm front, where subtle convergence will reside.
Thunderstorm coverage should be quite isolated. However, any storms
that manage to mature may become multicellular or supercellular
given 30+ kts of effective bulk shear in place. An instance or two
of severe wind or hail are possible.
..Squitieri.. 09/03/2026
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