WW 634 SEVERE TSTM MT 272255Z - 280400Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 634
NWS Storm Prediction Center Norman OK
455 PM MDT Thu Aug 27 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western and Central Montana
* Effective this Thursday afternoon and evening from 455 PM until
1000 PM MDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
SUMMARY...High-based storms will continue to increase and intensify,
at least on a widely scattered basis. Some of these storms may
produce severe-caliber wind gusts through the evening.
The severe thunderstorm watch area is approximately along and 80
statute miles east and west of a line from 60 miles east northeast
of Cut Bank MT to 45 miles south of Livingston MT. 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 630...WW 631...WW
632...WW 633...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
25025.
...Guyer
WW 633 SEVERE TSTM NE SD 272010Z - 280300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 633
NWS Storm Prediction Center Norman OK
210 PM MDT Thu Aug 27 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northwest into Central Nebraska
Southwest South Dakota
* Effective this Thursday afternoon and evening from 210 PM until
900 PM MDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph possible
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
SUMMARY...Thunderstorm development is ongoing from southwest South
Dakota into north-central Nebraska. This region is characterized by
very strong buoyancy and strong vertical shear, with the overall
environmental conditions supportive of supercells. Large to very
large hail (up to 2.5" in diameter) is the primary threat initially,
with the primary threat transitioning to damaging gusts as storms
cluster with time. Some gusts up to 75 mph are possible.
The severe thunderstorm watch area is approximately along and 75
statute miles east and west of a line from 90 miles north northeast
of Chadron NE to 20 miles south of Mullen NE. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).
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 630...WW 631...WW 632...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
30020.
...Mosier
WW 632 SEVERE TSTM DC MD PA VA WV CW 271915Z - 280200Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 632
NWS Storm Prediction Center Norman OK
315 PM EDT Thu Aug 27 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
District Of Columbia
Central Maryland
Central Pennsylvania
Northern Virginia
Eastern Panhandle of West Virginia
Coastal Waters
* Effective this Thursday afternoon and evening from 315 PM until
1000 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Scattered large hail events to 1.5 inches in diameter possible
A tornado or two possible
SUMMARY...Thunderstorm coverage and intensity is expected to
increase across the region this afternoon as a shortwave trough and
attendant cold front approach from the west. Warm and moist
conditions have fostered strong buoyancy across the region while
increasing mid-level flow contributes to strengthening deep-layer
vertical shear. These environmental conditions support the potential
for strong to severe thunderstorms, with damaging wind gusts and
isolated large hail as the primary risks. A low-probability risk for
a brief tornado or two exists as well.
The severe thunderstorm watch area is approximately along and 60
statute miles east and west of a line from 20 miles north northeast
of Williamsport PA to 55 miles southwest of Washington DC. 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 630...WW 631...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
27020.
...Mosier
WW 631 SEVERE TSTM CT MA NY PA VT 271750Z - 280100Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 631
NWS Storm Prediction Center Norman OK
150 PM EDT Thu Aug 27 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Far Western Connecticut
Far Western Massachusetts
New York
Northeast Pennsylvania
Far Southern Vermont
* Effective this Thursday afternoon and evening from 150 PM until
900 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Scattered large hail events to 1.5 inches in diameter possible
A tornado or two possible
SUMMARY...Thunderstorm intensity and coverage is expected to
increase this afternoon as shortwave trough and associated cold
front approach the region from the west. Environmental conditions
support the potential for strong to severe storms, with damaging
wind gusts and isolated large hail as the primary hazards. A
low-probability risk for a brief tornado exists as well.
The severe thunderstorm watch area is approximately along and 85
statute miles east and west of a line from 45 miles northwest of
Glens Falls NY to 20 miles west of Monticello NY. 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 630...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
27025.
...Mosier
WW 630 SEVERE TSTM CT DE NJ NY PA CW 271645Z - 280000Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 630
NWS Storm Prediction Center Norman OK
1245 PM EDT Thu Aug 27 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southwest Connecticut
Northern Delaware
New Jersey
Southeast New York
Far Southeast Pennsylvania
Coastal Waters
* Effective this Thursday afternoon and evening from 1245 PM
until 800 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Scattered large hail events to 1.5 inches in diameter possible
A tornado or two possible
SUMMARY...Thunderstorms intensity and coverage is expected to
increase across the region this afternoon. Environmental conditions
support the potential for strong to severe storms capable of
damaging wind gusts and isolated large hail. A low-probability
tornado risk exists with any more discrete storms as well.
The severe thunderstorm watch area is approximately along and 35
statute miles east and west of a line from 25 miles north northwest
of Newark NJ to 35 miles west southwest of Atlantic City NJ. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU0).
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
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
26020.
...Mosier
WW 0634 Status Updates
STATUS REPORT ON WW 634
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..LYONS..08/27/26
ATTN...WFO...TFX...BYZ...
STATUS REPORT FOR WS 634
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MTC001-005-007-013-015-027-031-037-041-043-045-049-051-057-059-
065-067-073-095-097-099-101-107-280040-
MT
. MONTANA COUNTIES INCLUDED ARE
BEAVERHEAD BLAINE BROADWATER
CASCADE CHOUTEAU FERGUS
GALLATIN GOLDEN VALLEY HILL
JEFFERSON JUDITH BASIN LEWIS AND CLARK
LIBERTY MADISON MEAGHER
MUSSELSHELL PARK PONDERA
STILLWATER SWEET GRASS TETON
TOOLE WHEATLAND
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
WW 0633 Status Updates
STATUS REPORT ON WW 633
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM AIA TO 35 NE
CDR TO 30 SW PIR.
..LYONS..08/28/26
ATTN...WFO...LBF...CYS...UNR...
STATUS REPORT FOR WS 633
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NEC005-009-017-031-075-091-101-111-113-117-135-161-171-280140-
NE
. NEBRASKA COUNTIES INCLUDED ARE
ARTHUR BLAINE BROWN
CHERRY GRANT HOOKER
KEITH LINCOLN LOGAN
MCPHERSON PERKINS SHERIDAN
THOMAS
SDC007-071-095-121-280140-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
BENNETT JACKSON MELLETTE
TODD
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
WW 0632 Status Updates
STATUS REPORT ON WW 632
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 E CHO TO
40 WSW DCA TO 10 SE HGR TO 10 NE HGR TO 30 ESE AOO TO 35 SSE UNV
TO 30 E UNV TO 30 NE IPT.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2157
..WENDT..08/27/26
ATTN...WFO...LWX...CTP...
STATUS REPORT FOR WS 632
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
DCC001-280040-
DC
. DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE
DISTRICT OF COLUMBIA
MDC003-005-009-013-015-017-021-025-027-031-033-037-510-280040-
MD
. MARYLAND COUNTIES INCLUDED ARE
ANNE ARUNDEL BALTIMORE CALVERT
CARROLL CECIL CHARLES
FREDERICK HARFORD HOWARD
MONTGOMERY PRINCE GEORGES ST. MARYS
MARYLAND INDEPENDENT CITIES INCLUDED ARE
WW 0631 Status Updates
STATUS REPORT ON WW 631
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 W MSV TO
55 N MSV TO 30 WNW EEN.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2156
..WENDT..08/27/26
ATTN...WFO...ALY...BGM...BUF...
STATUS REPORT FOR WS 631
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
CTC005-280040-
CT
. CONNECTICUT COUNTIES INCLUDED ARE
LITCHFIELD
MAC003-280040-
MA
. MASSACHUSETTS COUNTIES INCLUDED ARE
BERKSHIRE
NYC001-021-025-027-039-083-095-105-111-280040-
NY
. NEW YORK COUNTIES INCLUDED ARE
ALBANY COLUMBIA DELAWARE
DUTCHESS GREENE RENSSELAER
WW 0630 Status Updates
STATUS REPORT ON WW 630
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SSW BDL
TO POU TO 30 SE MSV TO 35 NNW EWR TO 20 NNW EWR TO 10 WSW EWR TO
20 WSW NEL TO 25 NE DOV TO 15 S DOV.
..WENDT..08/27/26
ATTN...WFO...OKX...PHI...
STATUS REPORT FOR WS 630
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
DEC001-272340-
DE
. DELAWARE COUNTIES INCLUDED ARE
KENT
NJC007-011-015-019-021-027-033-035-037-041-272340-
NJ
. NEW JERSEY COUNTIES INCLUDED ARE
CAMDEN CUMBERLAND GLOUCESTER
HUNTERDON MERCER MORRIS
SALEM SOMERSET SUSSEX
WARREN
PAC011-017-025-029-045-077-089-091-095-101-272340-
PA
. PENNSYLVANIA COUNTIES INCLUDED ARE
MD 2159 CONCERNING SEVERE THUNDERSTORM WATCH 633... FOR PORTIONS OF CENTRAL NEBRASKA
Mesoscale Discussion 2159
NWS Storm Prediction Center Norman OK
0747 PM CDT Thu Aug 27 2026
Areas affected...portions of central Nebraska
Concerning...Severe Thunderstorm Watch 633...
Valid 280047Z - 280145Z
The severe weather threat for Severe Thunderstorm Watch 633
continues.
SUMMARY...An organizing bowing cluster may produce significant
severe gusts (75-90 mph) as it moves toward the I-80 corridor over
the next 1-2 hours.
DISCUSSION...A cluster of formerly HP supercells over central NE has
merged and started to organize into a linear complex over the last
30 min. Recent KLNX radar data shows a developing weak reflectively
notch concurrent with increasing outbound velocities of 70+ kt at
1-2 kft AGL. This is suggestive of a rapidly organizing cold pool
and rear inflow jet. Given the favorable environment with MLCAPE in
excess of 3000 J/kg and T/TD spreads of 20+ degrees F, significant
damaging wind potential is likely increasing. Severe gusts of 75-90+
mph will be possible near the apex of the bowing cluster as it moves
toward the I-80 corridor over the next hour. If the cluster is able
to persist, a small downstream watch could be needed south of WW633
..Lyons.. 08/28/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GID...LBF...GLD...
LAT...LON 41770147 42080082 41980032 41750020 41200001 40379981
40049983 39900043 39910084 40030107 40920145 41150142
41770147
MOST PROBABLE PEAK WIND GUST...75-90 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
MD 2158 CONCERNING SEVERE THUNDERSTORM WATCH 634... FOR CENTRAL MONTANA
Mesoscale Discussion 2158
NWS Storm Prediction Center Norman OK
0703 PM CDT Thu Aug 27 2026
Areas affected...central Montana
Concerning...Severe Thunderstorm Watch 634...
Valid 280003Z - 280100Z
The severe weather threat for Severe Thunderstorm Watch 634
continues.
SUMMARY...High-based shower and thunderstorm activity will remain
capable of strong to severe gusts this evening.
DISCUSSION...Across WW634, widely scattered showers and
thunderstorms were ongoing this evening over much of central MT. The
more robust of these clusters (near the Great Falls vicinity) have
produced occasional measured severe gusts over the last 90 min. The
overall environment remains very supportive of strong downdrafts
across much of central MT owing to steep low-level lapse rates (8-9
C/km) and high cloud bases above 3 km. While instability remains
modest (500-1000 J/kg of MLCAPE) surface temperatures in the upper
80s and low 90s should be sufficient to maintain the ongoing storms
as they move east/northeast this evening. Severe gust potential
appears maximized near the aforementioned established clusters of
storms, but any coherent downdraft will likely be capable of strong
to severe gusts this evening.
..Lyons.. 08/28/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BYZ...GGW...RIW...TFX...PIH...MSO...
LAT...LON 47200842 45990743 45640755 45220816 45060874 44731037
44751222 45221288 48941221 48970929 47200842
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MD 2157 CONCERNING SEVERE THUNDERSTORM WATCH 630...632... FOR CENTRAL PENNSYLVANIA INTO CENTRAL MARYLAND
Mesoscale Discussion 2157
NWS Storm Prediction Center Norman OK
0626 PM CDT Thu Aug 27 2026
Areas affected...Central Pennsylvania into central Maryland
Concerning...Severe Thunderstorm Watch 630...632...
Valid 272326Z - 280100Z
The severe weather threat for Severe Thunderstorm Watch 630, 632
continues.
SUMMARY...Strong to severe storms from near DC/Baltimore into
central/eastern Pennsylvania will pose a risk of wind damage into
early evening.
DISCUSSION...The strongest storm activity in the Mid-Atlantic region
resides within an axis of greater buoyancy in parts of central
Pennsylvania/Maryland. To the east of these storms, convectively
modified outflow is present across much of New Jersey with similarly
poor thermodynamics in the DelMarVa owing to persistent stratus
today. The strongest activity will remain capable of isolated wind
damage. A small linear segment--with a history of wind damage
reports--moving towards the I-95 corridor in the DC/Baltimore
vicinity will pose the greatest risk for wind damage over the next
hour or so. With time, storms will eventually interact with more
stable air to the east and a gradual weakening trend will likely
occur at that time.
..Wendt.. 08/27/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PHI...BGM...CTP...LWX...
LAT...LON 39567616 39337637 39267642 38847690 38867714 39037769
40047764 41157706 41417658 41357622 40977581 40087597
39567616
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0437 PM CDT Thu Aug 27 2026
Valid 291200Z - 041200Z
...Synopsis...
Expect a series of mid-level troughs to continue impacting the
Pacific Northwest and neighboring areas of the western CONUS
throughout the Extended Outlook time frame. This will leave the west
CONUS coast and the northwestern quadrant of the CONUS under
periodically strong southwest-westerly flow into early next week.
Embedded disturbances will continue to move through the persistent
troughing and along the northern periphery of the flattening ridge.
The current consensus of long term guidance suggests these
shortwaves will contribute to the breakdown/eastward translation of
the ridge, shunting monsoonal moisture to the south and east. As a
result of the synoptic pattern, fire weather concerns will likely
continue through the forecast period across the portions of the
Northwest and nearby regions. However, low predictability and poor
agreement among ensemble members precludes additional probabilities
beyond Day 6/Tuesday.
...Northwest, Northern Great Basin, and Northern California...
Drier southwest flow aloft associated with perpetual troughing over
the northwest CONUS will promote continued fire weather concerns
into early next week. 40% Critical probabilities have been
maintained with minor adjustments for Day 3/Saturday and Day
5/Monday, and introduced across northeastern California,
northwestern Nevada, and southeastern Oregon on Day 6/Tuesday. West
to southwest winds of 15-20 mph and afternoon relative humidity of
15-20 percent will bring near-daily elevated fire weather concerns
over this region. Well below normal temperatures will moderate the
threat slightly, but conditions will remain conducive to wildfire
spread in the absence of a significant precipitation event.
Increasing potential for accumulating rainfall is introduced
mid-next-week over western WA, but forecast uncertainty remains
high.
..Stearns.. 08/27/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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