RSS Mesoscale Discussions from Storm Prediction Center
WW 376 SEVERE TSTM MT NE SD WY 221835Z - 230200Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 376
NWS Storm Prediction Center Norman OK
1235 PM MDT Mon Jun 22 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southeast Montana
Nebraska Panhandle
Southwest South Dakota
Eastern Wyoming
* Effective this Monday afternoon and evening from 1235 PM until
800 PM MDT.
* Primary threats include...
Scattered large hail likely with isolated very large hail events
to 3 inches in diameter possible
Scattered damaging wind gusts to 70 mph possible
A tornado or two possible
SUMMARY...Scattered severe/supercell thunderstorms are expected to
develop this afternoon over parts of southeast Montana and eastern
Wyoming - spreading southeastward through the evening. Parameters
appear quite favorable for large hail in the strongest cells.
The severe thunderstorm watch area is approximately along and 60
statute miles east and west of a line from 50 miles north of Broadus
MT to 40 miles west of Sidney NE. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU6).
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 374...WW 375...
AVIATION...A few severe thunderstorms with hail surface and aloft to
3 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
29030.
...Hart
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WW 375 SEVERE TSTM DC DE MD NJ PA VA WV CW 221810Z - 230100Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 375
NWS Storm Prediction Center Norman OK
210 PM EDT Mon Jun 22 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
District Of Columbia
Delaware
Maryland
Central and Southern New Jersey
Southeast Pennsylvania
Central and Northern Virginia
Eastern West Virginia
Coastal Waters
* Effective this Monday afternoon and evening from 210 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
A tornado or two possible
SUMMARY...Thunderstorms will develop and spread across the watch
area through the afternoon, moving offshore after dark. Organized
cells and clusters of storms capable of damaging wind gusts are
expected.
The severe thunderstorm watch area is approximately along and 90
statute miles north and south of a line from 45 miles west of
Staunton VA to 30 miles southeast of Atlantic City NJ. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU5).
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 374...
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
26030.
...Hart
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WW 374 SEVERE TSTM AL MS TN 221720Z - 230000Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 374
NWS Storm Prediction Center Norman OK
1220 PM CDT Mon Jun 22 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northern and Central Alabama
Central and Northeast Mississippi
Southern Middle Tennessee
* Effective this Monday afternoon and evening from 1220 PM until
700 PM CDT.
* Primary threats include...
Scattered damaging winds likely with isolated significant gusts
to 75 mph possible
Isolated large hail events to 1 inch in diameter possible
A tornado or two possible
SUMMARY...Thunderstorms will increase in coverage and intensity
across the watch area through the afternoon, with scattered severe
storms expected. Damaging wind gusts are the primary concern, but
there is a risk of a tornado or two as well.
The severe thunderstorm watch area is approximately along and 85
statute miles east and west of a line from 65 miles west southwest
of Meridian MS to 55 miles north northeast of Huntsville AL. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU4).
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 65 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
25030.
...Hart
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WW 0376 Status Updates
STATUS FOR WATCH 0376 HAS NOT BEEN ISSUED YET
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WW 0375 Status Updates
STATUS FOR WATCH 0375 HAS NOT BEEN ISSUED YET
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WW 0374 Status Updates
STATUS FOR WATCH 0374 HAS NOT BEEN ISSUED YET
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MD 1255 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR EAST-CENTRAL TO SOUTHEAST COLORADO
Mesoscale Discussion 1255
NWS Storm Prediction Center Norman OK
0140 PM CDT Mon Jun 22 2026
Areas affected...East-central to southeast Colorado
Concerning...Severe potential...Watch likely
Valid 221840Z - 222045Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorm development appears likely along the Front
Range from central to southern Colorado in the next 1-2 hours. Watch
issuance is likely as storms develop and spread east/southeast.
DISCUSSION...Latest GOES imagery depicts growing cumulus from the
Denver area southward along the Front Range and into the Raton Mesa
within a weak upslope flow regime. This comes as temperatures begin
to warm into the low to mid 80s, which latest CAM guidance suggests
is required to erode mixed-layer inhibition and support convective
initiation. Based on these satellite and temperature trends, deep
convective initiation appears probable within the next 1-2 hours.
Initially high-based convection will quickly spread east/southeast
given the 30-40 knot west/northwest flow regime aloft. Steady
intensification with eastward extent is expected as storms migrate
into the axis of rich low-level moisture (dewpoints in the upper 50s
to low 60s) in place along the eastern Plains. Additionally,
elongated hodographs featuring 40-50 knots of effective bulk shear
analyzed in recent mesoanalyses/forecast soundings (and confirmed by
regional VWPs) will promote splitting supercells capable of large to
very large hail (possibly as high as 2-3 inches) as well as strong
outflow winds. Watch issuance will be needed this afternoon as
initiation becomes more imminent and storms begin to mature.
..Moore/Hart.. 06/22/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DDC...GLD...AMA...PUB...BOU...ABQ...
LAT...LON 36970280 37000336 37190395 37440450 37650481 37900503
38230522 38670542 39010540 39270522 39400488 39420443
39420397 39310341 39230321 38930273 38590235 38220211
37820201 37390201 37190207 37070217 36970280
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN
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MD 1254 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR SOUTHEAST WYOMING INTO ADJACENT PORTIONS OF NEBRASKA...COLORADO...SOUTH DAKOTA...AND MONTANA
Mesoscale Discussion 1254
NWS Storm Prediction Center Norman OK
1229 PM CDT Mon Jun 22 2026
Areas affected...Southeast Wyoming into adjacent portions of
Nebraska...Colorado...South Dakota...and Montana
Concerning...Severe potential...Watch likely
Valid 221729Z - 221930Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorm development appears likely in the next couple
of hours across southeast Wyoming. Storms that develop will likely
mature into supercells posing a threat for very large hail; watch
issuance will likely be needed as convection begins to develop.
DISCUSSION...Latest GOES imagery shows a small zone of deepening
cumulus within a weak upslope flow regime along the eastern slopes
of the Laramie and Big Horn Mountains in Wyoming. Latest forecast
guidance suggests that lingering mixed-layer inhibition will be
largely eroded as temperatures warm into the mid to upper 70s. With
observed temperatures in the vicinity of the deepening cumulus
currently in the upper 60s and low 70s, it appears likely that
further growth will occur with increasing probability for convective
initiation over the next couple of hours - especially as broad-scale
ascent ahead of an upstream wave continues to overspread the region.
Regional VWPs are sampling 35-45 knot mid-level flow, which should
increase through late afternoon as the mid-level disturbance
continues to the southeast. This will yield elongated hodographs
with effective shear values on the order of 40-50 knots by late
afternoon, which will promote splitting supercells capable of
producing very large hail (possibly as high as 2.5 to 3 inches based
on sounding analogs). Large hail, as well as brief tornado,
potential appears highest across southeast WY into northeast
CO/western NE where richer low-level moisture will support higher
buoyancy and more intense updrafts and some effective SRH is noted
in latest RAP mesoanalyses. Trends are being monitored for the onset
of more substantial/widespread initiation, and watch issuance will
likely be needed once this becomes apparent.
..Moore/Hart.. 06/22/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...UNR...BOU...CYS...BYZ...RIW...
LAT...LON 41040280 40490278 39840289 39590311 39480349 39450403
39500439 39730463 40170468 40510465 41030475 41240477
41800491 42580541 42900570 43580623 44400676 44930699
45230685 45270612 45120552 44710501 44140455 43370401
42610357 41460294 41040280
MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN
Read more
MD 1253 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PORTIONS OF THE CENTRAL APPALACHIANS INTO THE MID-ATLANTIC
Mesoscale Discussion 1253
NWS Storm Prediction Center Norman OK
1225 PM CDT Mon Jun 22 2026
Areas affected...portions of the central Appalachians into the
Mid-Atlantic
Concerning...Severe potential...Watch likely
Valid 221725Z - 221930Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorms will increase in coverage and intensity over
the next couple of hours. Scattered damaging wind gusts, isolated
hail and perhaps a tornado will be possible through evening. A
severe thunderstorm watch will likely be needed by 19z.
DISCUSSION...Thunderstorms over the higher terrain of WV and
vicinity are gradually increasing in intensity this afternoon as
gradual destabilization occurs. Downstream from higher terrain
across portions of VA into MD/DE, southern NJ and southeast PA,
stronger heating is occurring within areas of mostly clear skies.
Higher quality moisture across eastern VA has been streaming
northward toward southeast PA/southern NJ and ensuing stronger
destabilization is noted. Enhanced westerly flow is apparent in
early afternoon mesoanalysis and 12z regional RAOBs. This should
allow for sufficient deep layer shear for storm organization.
Thunderstorm clusters will pose mainly a risk of damaging wind gusts
given steep (greater than 7.5 C/km) 0-3 km lapse rates and PW values
around 1.75 inches.
Some forecast guidance suggests sufficient clustering/outflow
consolidation may occur in the vicinity of northern VA/MD and a
forward propagating cluster/bowing segment could develop and track
northeast with time toward southeast PA/NJ. This corridor aligns
with the corridor of stronger midlevel westerlies, and may pose a
relative greater severe risk compared to points further south into
southern VA and NC where flow is weaker. If this scenario unfolds,
damaging wind potential will increase. Given modest 0-1 km SRH
across the region, a tornado or two also could occur, though the
damaging wind risk is expected to be the primary hazard into early
evening.
..Leitman/Hart.. 06/22/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PHI...AKQ...CTP...LWX...RAH...RNK...PBZ...RLX...
GSP...MRX...JKL...
LAT...LON 40497808 40747686 40807597 40757507 40587476 40047426
39677428 38847474 38197525 37847570 37297702 36447933
36097997 35748149 35858253 36268338 36608350 36928354
37748308 38378233 39148140 40177908 40497808
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1120 AM CDT Mon Jun 22 2026
Valid 221630Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE
SOUTHEAST TO THE MID-ATLANTIC...AND ACROSS PORTIONS OF THE
NORTHERN/CENTRAL HIGH PLAINS...
...SUMMARY...
Scattered severe thunderstorms capable of producing damaging winds
and perhaps a couple of tornadoes should occur this afternoon and
evening across portions of the Mid-Atlantic into the Southeast.
Scattered severe thunderstorms are also expected across the
northern/central High Plains, with large to very large hail the main
threat.
...Mid Atlantic...
Relatively fast zonal flow is present today from the OH Valley into
the Mid-Atlantic and Northeast US, with a shortwave trough evident
over OH/MI. As this feature tracks eastward, it will push a surface
cold front southward across the central Appalachians and into the
Mid-Atlantic region. Considerable clouds are present ahead of the
front from KY/WV into VA/PA/NJ, limiting destabilization and
confidence in the details of where clusters of storms may form later
today. However, given the relatively strong winds aloft and
dewpoints in the 60s, it would seem likely that scattered strong to
severe storms will occur, capable of locally damaging winds and
perhaps a tornado.
...TN/MS/AL/GA...
The remnants of a severe overnight MCS are over AR/west TN/northern
MS. This system has considerable mesoscale organization with an MCV
noted over eastern AR. A very moist and unstable air mass is in
place ahead of this system over northern MS/AL, where heating into
the mid 80s will foster thunderstorm intensification this afternoon.
Damaging winds are the main concern with these storms, but a
low-level jet feature associated with the MCV could result in a few
supercell structures and the risk of a tornado or two. Activity
will track into north GA this evening. Refer to MD #1252 for
further details.
...Central High Plains...
Similar to yesterday, low-clouds are slowly burning off across the
High Plains of eastern CO and western SD/NE/KS, where moderate CAPE
values will develop by mid-afternoon. Easterly/upslope flow will
contribute to scattered thunderstorm development over eastern WY and
southward along the DCVZ in CO. These storms will track into the
CAPE axis, where favorable deep-layer shear will promote supercells
capable of very large hail and a few tornadoes.
..Hart/Moore.. 06/22/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1222 PM CDT Mon Jun 22 2026
Valid 231200Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
HIGH PLAINS INTO PARTS OF THE CENTRAL AND SOUTHERN PLAINS...
...SUMMARY...
Scattered severe storms capable of hail in excess of two inches and
wind gusts greater than 75 mph are expected from the central High
Plains into parts of the central and southern Plains Tuesday and
Tuesday night. Isolated severe storms capable of mainly hail are
possible across the northern Plains into the upper Mississippi
Valley. Isolated severe storms capable of damaging winds also appear
possible from the Delmarva into eastern North Carolina.
...Synopsis...
Within the base of an upper low centered over Saskatchewan and
Manitoba, a vorticity lobe will progress through the northern Plains
into the upper MS Valley. That disturbance will be attended by a
belt of 40-50 kt flow in the mid levels, which will overspread the
northern and central Plains. Elsewhere, an apparent MCV initially
over western parts of VA and NC at 12Z Tuesday will progress through
the Piedmont and Coastal Plain over the course of the day.
At the surface, an area of low pressure is expected to slowly move
east along the southern Manitoba, northeast ND, northwest MN border
region with an associated cold front trailing southwest into the
central High Plains. Along the East Coast, an area of low pressure
is forecast to track through VA into the Tidewater region with a
trailing cold front moving through the Southeast.
...Central High Plains into the Central and Southern Plains...
The 12Z parameterized and convection-allowing models offer various
scenarios in regard to the location of ongoing storms Tuesday
morning, which in turn affects the evolution of diurnally enhanced
storm development by afternoon, and the subsequent track of a severe
MCS Tuesday night. Despite these differences, an EML will remain
intact across the High Plains, which coupled with a moist, upslope
regime in the low levels, will support a moderately unstable air
mass by afternoon. Isolated to widely scattered storms appear
possible from the vicinity of the Cheyenne Ridge south along the CO
Front Range with 40-50+ kt of effective bulk shear favoring
supercells capable of large to very large hail. Additional severe
storms appear possible during the afternoon across lower elevations
of the central and southern Plains, the details of which remain
highly uncertain.
As mentioned above, the models are in generally good agreement in
depicting the upscale growth of the afternoon storms into a
southeastward-moving MCS capable of damaging wind swaths and
significant gusts in excess of 75 mph. However, uncertainty in the
specific track of the MCS precludes the introduction of higher wind
probabilities and a categorical upgrade to a level 3/Enhanced Risk.
...Northern Plains into the Upper Midwest...
Multiple clusters of mainly elevated thunderstorms are expected to
be ongoing Tuesday morning from the eastern Dakotas into northern
NE, within a zone of forcing for ascent preceding the disturbance
mentioned in the synopsis. Modest instability coupled with 40-50 kt
of effective bulk shear may support some transient supercell
structures capable of large hail.
Additional surface-based storms appear possible by afternoon in the
vicinity of the surface front over the Red River Valley. Some
uncertainty still exists in the degree of air mass destabilization
owing to the potential for lingering clouds in the wake of the
early-day storms. Where greater destabilization can occur, the
environment will support mainly a large hail threat. Should stronger
heating and resultant steep, low-level lapse rates develop in the
vicinity of the front, a brief tornado or two will be possible owing
to a local maximum in vertical vorticity. Confidence in that
scenario is currently too low to include a 2% probability in this
forecast.
...Delmarva into eastern North Carolina...
A narrow corridor of severe-weather potential may materialize
Tuesday afternoon ahead of the surface low and surface front moving
through the area. A slight enhancement of mid-level flow (and
resultant vertical shear) will coincide with a moist and moderately
unstable air mass to support some organization with the primary
hazard being locally damaging wind gusts. Some tornado threat may
materialize ahead of the surface low, where backed near-surface
winds enhance low-level shear. A 2% tornado probability may need to
be included in subsequent Day 1 outlooks should the current model
signal persist.
..Mead.. 06/22/2026
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1123 AM CDT Mon Jun 22 2026
Valid 221700Z - 231200Z
A broad area of elevated fire weather highlights remains across much
of the lower CO River Basin and adjacent Four Corners region.
Critically dry and breezy conditions will develop under a building
upper ridge, with current RH across much of the Southwestern U.S.
already in the single digits following poor overnight recoveries.
Sustained southwest winds of 10-15 mph, very low RH and dry fuels
are still expected for several hours during peak afternoon heating.
Elevated highlights were expanded northward into portions of
southeastern NV and southwestern UT where sustained south to
southwest winds of around 15 mph could prove impactful to existing
active wildfires.
..Williams.. 06/22/2026
.PREV DISCUSSION... /ISSUED 1149 PM CDT Sun Jun 21 2026/
...Synopsis...
A mid-level ridge will begin building over the Interior West as
upper troughing takes shape over the eastern U.S. today. An embedded
impulse will overspread the central Rockies, encouraging surface
trough development over the Great Basin, where dry and breezy
conditions are expected through the afternoon. Fifteen (15) mph
sustained west-southwesterly surface winds and 10-15 percent RH will
overspread dry fuels across the southern Great Basin into the Four
Corners, warranting the continuation of Elevated highlights. Dry and
breezy conditions will also occur across the Snake River Plain in
southern Idaho due to channeled flow. Fifteen to twenty (15-20) mph
west-southwesterly surface winds will overlap with 10-15 percent RH,
with Elevated highlights continued here as well.
...Please see www.spc.noaa.gov/fire for graphic product...
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