RSS Mesoscale Discussions from Storm Prediction Center
WW 322 SEVERE TSTM CT MA NJ NY PA CW 121905Z - 130100Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 322
NWS Storm Prediction Center Norman OK
305 PM EDT Fri Jun 12 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southwest Connecticut
Extreme western Massachusetts
Northern New Jersey
Southeast New York
Northeast Pennsylvania
Coastal Waters
* Effective this Friday afternoon and evening from 305 PM until
900 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Thunderstorms will increase in coverage this
afternoon/evening while spreading east-southeastward across
northeast Pennsylvania, southeast New York and northern New Jersey,
including New York City and vicinity. The primary threat will be
wind damage with thunderstorm gusts up to 60-70 mph, though the
strongest storms may also produce isolated large hail close to 1
inch in diameter.
The severe thunderstorm watch area is approximately along and 65
statute miles east and west of a line from 50 miles north northeast
of Monticello NY to 20 miles south southwest of Newark NJ. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU2).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 321...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 550. Mean storm motion vector
29025.
...Thompson
Read more
WW 321 SEVERE TSTM DC MD VA WV CW 121845Z - 130100Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 321
NWS Storm Prediction Center Norman OK
245 PM EDT Fri Jun 12 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
District Of Columbia
Maryland
Virginia
Eastern West Virginia
Coastal Waters
* Effective this Friday afternoon and evening from 245 PM until
900 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Clusters of storms will form in Virginia and Maryland this
afternoon, and will spread eastward from West Virginia. The storm
environment will favor damaging downbursts with winds up to 60-70
mph, while the strongest storms could produce isolated large hail
near 1 inch in diameter.
The severe thunderstorm watch area is approximately along and 85
statute miles east and west of a line from 45 miles northwest of
Washington DC to 30 miles south southeast of Dublin VA. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU1).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
29020.
...Thompson
Read more
WW 0322 Status Updates
STATUS REPORT ON WW 322
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 W ABE TO
30 NNE ABE TO 20 SSE MSV TO 25 NE MSV TO 10 NW PSF.
..CHALMERS..06/12/26
ATTN...WFO...OKX...ALY...PHI...BGM...
STATUS REPORT FOR WS 322
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
CTC001-005-009-122240-
CT
. CONNECTICUT COUNTIES INCLUDED ARE
FAIRFIELD LITCHFIELD NEW HAVEN
MAC003-122240-
MA
. MASSACHUSETTS COUNTIES INCLUDED ARE
BERKSHIRE
NJC003-013-017-019-021-023-025-027-031-035-037-039-041-122240-
NJ
. NEW JERSEY COUNTIES INCLUDED ARE
BERGEN ESSEX HUDSON
HUNTERDON MERCER MIDDLESEX
MONMOUTH MORRIS PASSAIC
SOMERSET SUSSEX UNION
Read more
WW 0321 Status Updates
STATUS REPORT ON WW 321
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..CHALMERS..06/12/26
ATTN...WFO...LWX...RNK...AKQ...RLX...
STATUS REPORT FOR WS 321
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
DCC001-122240-
DC
. DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE
DISTRICT OF COLUMBIA
MDC003-005-009-017-025-027-031-033-037-510-122240-
MD
. MARYLAND COUNTIES INCLUDED ARE
ANNE ARUNDEL BALTIMORE CALVERT
CHARLES HARFORD HOWARD
MONTGOMERY PRINCE GEORGES ST. MARYS
MARYLAND INDEPENDENT CITIES INCLUDED ARE
BALTIMORE CITY
VAC003-005-007-009-011-013-015-017-019-021-023-029-031-033-035-
Read more
MD 1109 CONCERNING SEVERE THUNDERSTORM WATCH 321... FOR WEST VIRGINIA...VIRGINIA...MARYLAND
Mesoscale Discussion 1109
NWS Storm Prediction Center Norman OK
0348 PM CDT Fri Jun 12 2026
Areas affected...West Virginia...Virginia...Maryland
Concerning...Severe Thunderstorm Watch 321...
Valid 122048Z - 122245Z
The severe weather threat for Severe Thunderstorm Watch 321
continues.
SUMMARY...Storms producing locally damaging gusts may increase in
coverage over the next several hours with continued wind potential
over much of Virginia and parts of Maryland.
DISCUSSION...Two primary areas of thunderstorms have developed this
afternoon. One is over northern VA within the surface trough, and
another extends from southeast WV into northeast TN related to the
residual pre-frontal outflow boundary.
Substantial moisture and instability have developed into the region
with daytime heating. Not only are low-level lapse rates steep, but
GPS PWAT sensors over northern VA have shown a gradual increase in
moisture as well. The RLX 18Z sounding as well as LWX and RLX VWPs
show mean midlevel westerlies of 20-30 kt, which supports
southeastward-moving clusters of storms. The warm and uncapped air
mass along with ample PWAT and favorable surface lapse rates will
support corridors of strong to severe gusts through early evening.
..Jewell.. 06/12/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...AKQ...LWX...RNK...PBZ...RLX...
LAT...LON 37587626 37267708 36587816 36758066 36838152 37138169
37308142 37828085 38428019 39297928 39387884 39237785
39037703 38817668 38337603 37587626
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
Read more
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0256 PM CDT Fri Jun 12 2026
Valid 122000Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHEAST...MID-ATLANTIC...AND SOUTHERN APPALACHIANS AS WELL AS
PARTS OF THE SOUTHERN HIGH PLAINS...
...SUMMARY...
Strong to severe storms capable of damaging winds are expected
across parts of the Appalachians, Mid-Atlantic, and Northeast,
mainly this afternoon and evening. Severe storms with a threat of
large hail and severe wind gusts will also be possible across parts
of the south-central High Plains.
...20z Update...
The previous forecast remains on track with minimal changes required
to the existing probability lines based on ongoing convective trends
and recent model guidance. The primary outlook amendment was the
introduction of 5% hail probabilities across portions of eastern
Nebraska.
...Nebraska...
12z ensemble guidance hinted at thunderstorm development across
eastern NE during the 09-12 UTC period as a weak low-level cold
front impinges on a plume of northward returning moisture. More
recent runs of the RAP/RRFS/HRRR continue to show this potential and
depict a fairly robust thermodynamic environment featuring MUCAPE
values upwards of 4000 J/kg. 18 UTC RAOBS from the southern High
Plains and Rockies sampled steep mid-level lapse rates that will
advect eastward over the next 18 hours, and recent model solutions
appear to be capturing surface moisture return well. These trends
lend sufficient confidence to introduce a targeted hail risk area.
...Mississippi/Alabama...
5% wind probabilities were removed across northern MS/AL based on
recent radar trends, which depict the outflow boundary of a decaying
MCS rapidly progressing south and undercutting developing
convection. Strong buoyancy immediately downstream may support some
localized damaging wind threat through the afternoon, but latest
model guidance largely shows diminishing convective activity as the
outflow surges south.
..Moore.. 06/12/2026
.PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jun 12 2026/
...Mid-Atlantic into New England this afternoon/evening...
Within the northern stream, a shortwave trough will progress
east-northeastward over the lower Great Lakes this
afternoon/evening, while an associated surface cold front moves
eastward into New England and southeastward into the Mid-Atlantic.
Forcing for ascent will not be particularly strong and the stronger
midlevel flow/deep-layer vertical shear will remain displaced to the
cool side of the front. Still, 25-30 kt midlevel flow will overlap
the warm sector this afternoon from northern Chesapeake Bay
northward into eastern NY. Strong surface heating is ongoing from
the Piedmont into VA/southern PA, with a few more cloud patches from
northeast PA into central NY. The net result will be moderate
buoyancy (MLCAPE of 1000-2000 J/kg) in an environment with steep
low-level lapse rates and weak upper flow, favoring multicell
clusters with occasional wind damage. The weak forcing for ascent
suggests that widely scattered, loosely organized clusters will be
possible this afternoon, with some gaps in the wind threat.
...Southern High Plains late this afternoon into early tonight...
Lee cyclogenesis across southeast CO will draw low-level moisture
northwestward into the southern High Plains as a stalled front
begins to lift northward across the TX Panhandle. Thunderstorm
development is expected this afternoon/evening with upslope flow
into the higher terrain of NM, and along the Raton Mesa. Deep-layer
vertical shear/hodograph length will be sufficient for supercells
initially off Raton Mesa, with large hail the primary threat. Some
upscale growth and an increase in the potential for severe outflow
gusts is expected late this evening as storms spread eastward toward
southwest KS and the northern Panhandles in association with a
nocturnal low-level jet and strengthened warm advection/moisture
transport.
...Eastern KS/western MO early Saturday...
In response to low-level warm advection and returning moisture,
elevated convection is probable late in the period across eastern
KS/western MO. This area will be near the east edge of the steep
midlevel lapse rates, where isolated large hail will be possible.
There will also be some potential for evolution into a cluster or
two with isolated damaging gusts. Farther north into eastern NE
(very near the end of the period) there will be a chance for
elevated storms with some hail. This area will be re-evaluated this
afternoon in the 20z update.
Read more
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1228 PM CDT Fri Jun 12 2026
Valid 131200Z - 141200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SATURDAY
AFTERNOON INTO SATURDAY NIGHT ACROSS EASTERN KANSAS...ADJACENT
PORTIONS OF SOUTHEASTERN NEBRASKA AND NORTHEASTERN OKLAHOMA...AND
MUCH OF WESTERN THROUGH CENTRAL MISSOURI...
...SUMMARY...
One or two evolving thunderstorm clusters appear possible across
parts of the central Great Plains and lower Missouri Valley vicinity
Saturday afternoon through Saturday night. Some of this activity
will pose a risk for producing large hail and swaths of strong,
potentially damaging wind gusts.
...Discussion...
Downstream of amplified mid-level ridging, offshore of the U.S.
Pacific coast through British Columbia, it appears that flow will
begin to veer to an increasing northwesterly component across and
east of the Rockies through this period. Within this regime,
substantive mid-level troughing is forecast to dig across the Upper
Midwest, to the southwest of a lingering mid-level low centered
across northwestern Ontario. Spread within model output remains
larger concerning short wave perturbations digging through initially
weaker flow across the Missouri through lower Ohio Valleys, and the
extent to which they may begin to suppress the northern periphery of
subtropical ridging centered over the northern Gulf Basin.
In lower levels, an initial, convective outflow enhanced, surface
front overspreading much of the Mid Atlantic through Mid South
vicinity will likely already be in the process of weakening at the
outset of the period. However, surges of cooler/drier air will
continue to develop southward into and through the interior of the
U.S., with the general leading edge reaching the lower Great Lakes
through Ohio Valley, Ozarks Plateau and Texas South Plains by 12Z
Sunday. This may be preceded across the Ohio Valley through western
slopes of the Appalachians by outflow from extensive prior
convective development.
...Central Great Plains into Missouri Valley...
The potential for increasing thunderstorm development at the outset
of the period across eastern Nebraska into western Iowa (near the
nose of an east-northeastward advecting plume of elevated
mixed-layer air) coupled with potential for substantive, but
weakening, remnant convection from overnight overspreading the Ozark
Plateau, contribute to continuing uncertainty concerning subsequent
convective development Saturday through Saturday night.
The evolution of convective outflows, and their impact on
boundary-layer destabilization, coupled with uncertain short wave
developments, will substantially impact the timing, location and
potential upscale growth of potentially stronger thunderstorm
development.
However, beneath the plume of elevated mixed-layer air, a corridor
of stronger boundary-layer heating and deeper mixing across Kansas
during the day seems to provide the highest certainty for moderate
to strong destabilization. Near the nose of this regime, somewhere
across eastern Kansas into western Missouri, based on a consensus of
model output, low-level warm advection in the presence of weaker
inhibition may provide the focus for intensifying thunderstorm
development by late afternoon. And there appears a general signal
in the model output that a modifying outflow boundary/zone of
differential heating may provide a focus for the southeastward
development of upscale growing convection toward the Mid South
through Saturday night. As this occurs, increasing thunderstorm
development also appears probable ahead of the southward advancing
cold front across Kansas through Oklahoma and the Texas Panhandle
vicinity.
Although deep-layer shear may be initially modest, it may still be
sufficient to support the evolution of a few supercells capable of
producing large hail and potential for a couple tornadoes, before
evolving swaths of strong to severe wind gusts become the more
prominent threat with organizing clusters into late Saturday
evening.
..Kerr.. 06/12/2026
Read more
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0227 PM CDT Fri Jun 12 2026
Valid 141200Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SUNDAY ACROSS MUCH
OF THE NORTHERN MID ATLANTIC COAST STATES...
...SUMMARY...
Severe thunderstorms are possible across the lower Great Lakes and
upper Ohio Valley vicinity through much of the northern Mid Atlantic
Sunday.
...Discussion...
Downstream of initially amplified mid-level ridging offshore of the
Pacific coast, models indicate that flow will continue to trend
cyclonic east of the Rockies through the Atlantic Seaboard, to the
south of a broadening vortex centered near southern Hudson Bay.
Within this regime, it appears that notable short wave troughing
will pivot east of the Upper Midwest through the southeastern
Canadian provinces and Northeast by late Sunday night, accompanied
by cyclogenesis across the lower Great Lakes through St. Lawrence
Valley vicinity. It appears that this may be preceded by the
remnants of an initially fairly notable mesoscale convective vortex,
within strengthening westerly flow across the Allegheny/Cumberland
Plateau through the northern Mid Atlantic by early Sunday evening.
...Northeast...
There remains considerable spread within the latest model output
concerning the extent of convective potential for this period.
Mostly this appears related pre-frontal low-level moisture return
and destabilization across the upper Ohio Valley into the lee of the
lower Great Lakes, which could be slowed or impeded by the influence
of preceding convective outflow. However, guidance generally
suggests that destabilization prior to the arrival of the MCV and
belt of enhanced lower/mid-tropospheric wind fields (30-40+ kt) will
be sufficient to support potential for organized severe convection
east of the Allegheny Mountains through the northern Mid Atlantic by
late Sunday afternoon. More substantive strengthening of mid-level
wind fields and forcing for ascent appear likely to overspread the
pre-frontal environment across parts of the upper Ohio Valley into
the lee of the lower Great Lakes region, where it appears increasing
model output is now suggesting that the evolving warm sector may
become sufficiently unstable to support a risk for organized severe
storm development.
Damaging wind gusts accompanying organizing lines and/or clusters
appear the primary severe hazard, but there also appears at least
some potential for a few tornadoes. It is still possible that
severe weather probabilities will need to be increased further in
later outlook updates for this period.
..Kerr.. 06/12/2026
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0232 PM CDT Fri Jun 12 2026
Valid 131200Z - 141200Z
...Afternoon Update...
The Isolated Dry Thunderstorm risk area was expanded southeastward
to include more of the Colorado Plateau within northwestern NM and
northeastern AZ. Southwest to westerly flow aloft will aid in
ushering mid-level moisture into portions of the Desert Southwest
and CO Plateau on Saturday afternoon. With deeper moisture and
higher PWATs (0.8-1.5") across southern AZ and NM, chances for more
appreciable rainfall with any thunderstorms will exist over these
areas. Forecast soundings across the CO Plateau depict much lower
PWATs (0.5-0.8") and a deep, dry boundary layer amid sufficient
daytime instability and fast storm motions, promoting isolated dry
thunderstorm development. Lightning ignitions will be a concern
given very dry fuels, and gusty/erratic outflow winds may exacerbate
any new and ongoing fires across the region.
Over the CO Rockies, westerly flow aloft will allow dry and breezy
conditions to persist over the higher terrain. Locally elevated fire
concerns will emerge where RH of 15-20% and 10-20 mph winds overlap
dry fuels, especially within gap-flow and terrain favored areas.
..Elizalde-Garcia.. 06/12/2026
.PREV DISCUSSION... /ISSUED 0155 AM CDT Fri Jun 12 2026/
...Synopsis...
Along the northern periphery of an upper ridge extending from Mexico
into the Southwest, a subtle midlevel impulse will advance eastward
across the southern Great Basin and central Rockies during the day.
As this feature and related ascent glance the northern periphery of
a midlevel moisture plume, isolated to widely scattered high-based
thunderstorms will form across the southern/eastern Great Basin into
the central Rockies during the afternoon -- with a focus over the
higher terrain features. Deep boundary-layer mixing beneath the
midlevel moisture will yield inverted-V soundings, favorable for
mostly dry thunderstorms capable of strong/erratic wind gusts. Given
critically dry fuels across the region (90th-95th percentile ERCs),
lighting-induced ignitions will be a concern.
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0449 PM CDT Fri Jun 12 2026
Valid 141200Z - 201200Z
...Synopsis...
Broad upper-level troughing will remain anchored over the southern
Ontario/Quebec regions on Day 3/Sunday as an upper-level ridge
continues to build over the West Coast. Simultaneously, a shortwave
trough is forecast to dig southward around the base of the
persistent Canadian trough, tracking across the northern Rockies.
The upper ridge is expected to break down mid-week as an upper jet
max strengthens and progresses ahead of an incoming northern Pacific
trough. This secondary trough is projected to move onshore into the
Pacific Northwest by Day 7-8/Thursday-Friday, subsequently shifting
the axis of the ridge eastward over the Great Plains.
...Day 3/Sunday - Portions of the Southwest...
An upper-level ridge will remain across the western CONUS as a
shortwave trough traverses the High Plains on Day 3/Sunday. A plume
of mid-level moisture advecting northward from the Baja Peninsula on
Day 2/Saturday will persist across the Southwest, promoting
continued convective potential. Given dry antecedent fuel conditions
resulting from consecutive days of hot, dry, and breezy weather, dry
thunderstorms will pose an ignition concern across southeastern NV
into the Colorado Plateau where a 10% probability of dry
thunderstorms has been introduced. Further spatial modifications to
this risk area remain likely in upcoming outlook cycles as
additional forecast guidance becomes available.
...Day 5-6/Tuesday-Wednesday - Parts of the Intermountain West...
The eventual breakdown of the western ridge is expected to escalate
fire weather concerns across the Intermountain West as the jet
strengthens and gives way to another trough later next week. At
least 2-3 days of well above normal surface temperatures will occur
under the established ridge early next week, with record high
temperatures forecast to be met or exceeded in portions of the
Pacific Northwest. This anomalous, but short-lived, heat wave is
expected to further dry dead fuels over much of the western CONUS -
significantly so over the Pacific Northwest. As the ridge dampens
and begins to slide eastward, robust northwesterly flow aloft should
foster breezy surface winds amid pre-existing very warm and dry
conditions. Thus, 40% Critical probabilities have been expanded from
the Great Basin to portions of the Central Rockies on Day 5/Tuesday
and Day 6/Wednesday.
..Elizalde-Garcia.. 06/12/2026
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
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