Alert archive / New York / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 56, NWS Buffalo, NY
NWS Buffalo, NY issued this severe thunderstorm warning at Jun 30, 2026, 10:42 PM EDT for Jefferson County, Lewis County, New York. It was in force for 48 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jun 30, 2026, 10:42 PM EDT (02:42 UTC)
- Expired
- Jun 30, 2026, 11:30 PM EDT
- In force
- 48 min
- Issued by
- NWS Buffalo, NY
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Jefferson County, NY, Lewis County, NY
The radar
The Ft Drum radar (KTYX), 61 km from the middle of the area, began a volume at 02:46 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The nearest sounding before it
Albany, NY (KALY), launched 00:00Z, 2.7 hours before the alert went out and 240 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 229 J/kg
- Mixed-layer CIN
- -142 J/kg
- Mixed-layer LCL
- 974 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 104 m²/s²
- 0-3 km storm-relative helicity
- 248 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.1
The text
As transmitted.
405
WUUS51 KBUF 010242
SVRBUF
NYC045-049-010330-
/O.NEW.KBUF.SV.W.0056.260701T0242Z-260701T0330Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Buffalo NY
1042 PM EDT Tue Jun 30 2026
The National Weather Service in Buffalo has issued a
* Severe Thunderstorm Warning for...
Northeastern Jefferson County in central New York...
North central Lewis County in central New York...
* Until 1130 PM EDT.
* At 1040 PM EDT, severe thunderstorms were located along a line
extending from 9 miles northwest of Ogdensburg to 13 miles north of
Kring Point State Park to 16 miles northwest of Cedar Point State
Park, moving southeast at 45 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Fort Drum, Carthage, West Carthage, Clayton, Herrings, Redwood,
Kring Point State Park, Wellesley Island State Park, Philadelphia,
and Alexandria Bay.
This includes Interstate 81 between exits 49 and 52.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Large hail, damaging wind, and frequent cloud to ground lightning
are occurring with these storms. Move indoors immediately. Lightning
is one of nature's leading killers. Remember, if you can hear
thunder, you are close enough to be struck by lightning.
&&
LAT...LON 4440 7583 4439 7584 4415 7530 4392 7560
4428 7616 4435 7601 4435 7595 4440 7586
TIME...MOT...LOC 0240Z 328DEG 38KT 4476 7564 4456 7596 4443 7634
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
WelchWhat forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Buffalo, NY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 30, 7:23 PM EDT, 3 hours 19 minutes earlier. Its key messages:
- 1) Dangerous heat and humidity through Friday, then slowly lessening heat/humidity for the holiday weekend. 2) Scattered strong to severe thunderstorms are possible today and Wednesday.
Area forecast discussion, Jun 30, 7:23 PM EDT, 3 hours 19 minutes before
Area Forecast Discussion
National Weather Service Buffalo NY
723 PM EDT Tue Jun 30 2026
.WHAT HAS CHANGED...
Have adjusted PoPs and weather to include the threat of
thunderstorms, similar to this afternoon's set up for Wednesday
night.
&&
.KEY MESSAGES...
1) Dangerous heat and humidity through Friday, then slowly lessening
heat/humidity for the holiday weekend.
2) Scattered strong to severe thunderstorms are possible today and
Wednesday.
&&
.DISCUSSION...
KEY MESSAGE 1...Dangerous heat and humidity through Friday, then
slowly lessening heat/humidity for the holiday weekend.
Building upper level ridging across, with a core of the ridge
strengthening to around 600 dm across the eastern CONUS will
continue through Thursday with the core of the ridge drifting
further east for the weekend. In its wake, a series of shortwave
troughs will dig southeastward across eastern Canada and help
flatten the ridge Friday through the holiday weekend. This being
said, 850 mb temperatures will topple out at +20C this afternoon,
and remain slightly above +20C through Thursday and possibly into
Friday. Then temperatures at 850mb will pull back into the mid to
upper teens this weekend.
In the wake of the warm frontal passage of the warm front,
temperatures this morning and early this afternoon, have warmed up
into the upper 80s and low 90s, except for the North Country where a
current bowing thunderstorm segment if passing across keeping
temperatures at bay and in the upper 70s. These temperatures coupled
with the dewpoints surging into the lower 70s, heat indices will
surge well into the mid 90s and even towards the low 100s range this
afternoon. As such, Heat Advisories remain in effect areawide this
afternoon.
Heat and humidity will continue Wednesday before reaching its peak
on Thursday, supporting daytime highs away from any lake influences
and higher terrain to surge into the lower to mid 90s for many
areas, while the climatologically warmer spots will warm up into the
upper 90s. Meanwhile, dewpoint temperatures will also climb up into
the lower to mid 70s Wednesday and linger through Thursday,
supporting dangerous and oppressive heat indices in the low to mid
100s across Niagara, Orleans, Monroe, Livingston, Ontario, Wayne,
Northern Cayuga, and Oswego counties, supporting Extreme Heat
Warnings, and upper 90s to low 100s elsewhere, continuing the Heat
Advisories elsewhere.
Gradually relief to the heat and humidity will begin Friday and
continue through the holiday weekend as the strong upper level ridge
slowly flattens and retreats southeastward. This will not only
allow for multiple shortwave troughs to ripple along the northern
periphery of the ridge, but also bring corresponding cooler
temperatures aloft. While there will be some relief to heat indices
on Friday, the 4 days of consistent heat will support Extreme Heat
Warnings to continue into Friday. While cooler temperatures will
grace the area this weekend, should note that the humidity will also
linger.
KEY MESSAGE 2...Scattered strong to severe thunderstorms are
possible today and Wednesday.
An MCS is in the midst of crossing southeast across the North
Country this afternoon bringing widespread damaging winds, large
hail and possibly a tornado. This bowing line segment will soon
exit the area within the next hour.
Similar to this afternoon, another cluster of storms may develop
over Canada and dive southeastward across areas southeastward of
Lake Ontario (from Niagara County to the Genesee Valley through the
North Country) Wednesday afternoon and evening. Strong instability
will again support a risk for strong to severe thunderstorms capable
of producing damaging winds and hail. This being a said, a Slight
Risk for Severe Thunderstorms exists across much of the Niagara
Frontier and east and southeastward across the Genesee Valley and
into the North Country.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Mainly dry weather and VFR flight conditions should tend to prevail
tonight, though some additional showers/storms and associated
restrictions cannot be completely ruled out across the North
Country. Late tonight, some patchy MVFR stratus could form across
the interior of the Southern Tier and North Country.
Outlook...
Wednesday...Possible MVFR ceilings across the Southern Tier and
North Country early...otherwise mainly VFR with a chance of showers
and thunderstorms east of Lake Ontario.
Thursday...Mainly VFR.
Friday and Sunday...Mainly VFR with a chance of showers and
thunderstorms.
&&
.MARINE...
In the wake of a warm frontal passage today, modest to moderate
southwesterlies will linger through the remainder of the week.
Scattered showers and thunderstorms Wednesday afternoon and evening
may produce locally higher winds and waves. The risk will be
greatest across Lake Ontario.
&&
.CLIMATE...
Dangerous heat and humidity are expected across western and
north central NY this week. Here are the record maximum and high
minimum temperatures for Buffalo, Rochester, and Watertown.
6/30 7/1 7/2 7/3
Buffalo, NY
High Max 94(1963) 93(1963) 94(1966) 94(1949)
High Low 73(1941) 75(1901) 75(1931) 74(1911*)
Rochester, NY
High Max 96(1964) 96(1901) 99(1931) 100(1911)
High Low 72(2014) 76(1931) 76(1931*) 75(1911)
Watertown, NY
High Max 89(1977) 92(1967) 92(1966) 91(1966)
High Low 73(2014*) 74(2014) 73(2002) 74(1973)
Average Temperatures for June 30-July 3
Buffalo
Max 79
Min 62
Rochester
Max 82
Min 62
Watertown
Max 78
Min 57
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Heat Advisory until 8 PM EDT this evening for NYZ001>008-
010>014-019>021-085.
Extreme Heat Warning from noon Wednesday to 8 PM EDT Friday
for NYZ001>006-013-014.
Heat Advisory from noon Wednesday to 8 PM EDT Friday for
NYZ007-008-010>012-019>021-085.
MARINE...None.
&&
DISCUSSION...EAJ
AVIATION...TMA
MARINE...EAJ
CLIMATE...Hazardous weather outlook, Jun 30, 8:15 PM EDT, 2 hours 27 minutes before
Hazardous Weather Outlook National Weather Service Buffalo NY 815 PM EDT Tue Jun 30 2026 NYZ012-019>021-085-020015- Wyoming-Chautauqua-Cattaraugus-Allegany-Southern Erie- 815 PM EDT Tue Jun 30 2026 ...HEAT ADVISORY REMAINS IN EFFECT FROM NOON WEDNESDAY TO 8 PM EDT FRIDAY... This Hazardous Weather Outlook is for portions of western New York. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. Marginal to Slight Risk of severe thunderstorms Wednesday afternoon and evening with damaging winds the primary hazard. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. This product, along with other watches, warnings, advisories, and statements issued by the National Weather Service office in Buffalo can be found on the internet at http://www.weather.gov/buf NYZ001-002-020015- Niagara-Orleans- 815 PM EDT Tue Jun 30 2026 ...EXTREME HEAT WARNING IN EFFECT FROM NOON WEDNESDAY TO 8 PM EDT FRIDAY... This Hazardous Weather Outlook is for portions of western New York. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Extreme Heat Warning. Marginal to Slight Risk of severe thunderstorms Wednesday afternoon and evening with damaging winds the primary hazard. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. This product, along with other watches, warnings, advisories, and statements issued by the National Weather Service office in Buffalo can be found on the internet at http://www.weather.gov/buf NYZ010-011-020015- Northern Erie-Genesee- 815 PM EDT Tue Jun 30 2026 ...HEAT ADVISORY REMAINS IN EFFECT FROM NOON WEDNESDAY TO 8 PM EDT FRIDAY... This Hazardous Weather Outlook is for portions of western New York. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. Marginal to Slight Risk of severe thunderstorms Wednesday afternoon and evening with damaging winds the primary hazard. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. This product, along with other watches, warnings, advisories, and statements issued by the National Weather Service office in Buffalo can be found on the internet at http://www.weather.gov/buf NYZ003>005-013-014-020015- Monroe-Wayne-Northern Cayuga-Livingston-Ontario- 815 PM EDT Tue Jun 30 2026 ...EXTREME HEAT WARNING IN EFFECT FROM NOON WEDNESDAY TO 8 PM EDT FRIDAY... This Hazardous Weather Outlook is for portions of western and north central New York. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Extreme Heat Warning. Marginal to Slight Risk of severe thunderstorms Wednesday afternoon and evening with damaging winds the primary hazard. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. This product, along with other watches, warnings, advisories, and statements issued by the National Weather Service office in Buffalo can be found on the internet at http://www.weather.gov/buf NYZ006-020015- Oswego- 815 PM EDT Tue Jun 30 2026 ...EXTREME HEAT WARNING IN EFFECT FROM NOON WEDNESDAY TO 8 PM EDT FRIDAY... This Hazardous Weather Outlook is for portions of central New York. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Extreme Heat Warning. Marginal to Slight Risk of severe thunderstorms Wednesday afternoon and evening with damaging winds the primary hazard. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. This product, along with other watches, warnings, advisories, and statements issued by the National Weather Service office in Buffalo can be found on the internet at http://www.weather.gov/buf NYZ007-008-020015- Jefferson-Lewis- 815 PM EDT Tue Jun 30 2026 ...HEAT ADVISORY REMAINS IN EFFECT FROM NOON WEDNESDAY TO 8 PM EDT FRIDAY... This Hazardous Weather Outlook is for portions of central New York. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. Marginal to Slight Risk of severe thunderstorms Wednesday afternoon and evening with damaging winds the primary hazard. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. This product, along with other watches, warnings, advisories, and statements issued by the National Weather Service office in Buffalo can be found on the internet at http://www.weather.gov/buf LEZ020-040-041-LOZ030-042-062-020015- Upper Niagara River and Buffalo Harbor- Lake Erie nearshore waters from Ripley to Dunkirk- Lake Erie nearshore waters from Dunkirk to Buffalo- Lower Niagara River- Lake Ontario nearshore waters from the Niagara River to Hamlin Beach- Lake Ontario open waters from the Niagara River to Hamlin Beach- 815 PM EDT Tue Jun 30 2026 This Hazardous Weather Outlook is for portions of Lake Erie and Lake Ontario. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Marginal to Slight Risk of severe thunderstorms Wednesday afternoon and evening with damaging winds the primary hazard. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. This product, along with other watches, warnings, advisories, and statements issued by the National Weather Service office in Buffalo can be found on the internet at http://www.weather.gov/buf LOZ043>045-063>065-020015- Lake Ontario nearshore waters from Hamlin Beach to Sodus Bay- Lake Ontario nearshore waters from Sodus Bay to Mexico Bay- Lake Ontario nearshore waters from Mexico Bay to the Saint Lawrence River-Lake Ontario open waters from Hamlin Beach to Sodus Bay- Lake Ontario open waters from Sodus Bay to Mexico Bay- Lake Ontario open waters from Mexico Bay to the Saint Lawrence River- 815 PM EDT Tue Jun 30 2026 This Hazardous Weather Outlook is for portions of Lake Ontario. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Marginal to Slight Risk of severe thunderstorms Wednesday afternoon and evening with damaging winds the primary hazard. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. This product, along with other watches, warnings, advisories, and statements issued by the National Weather Service office in Buffalo can be found on the internet at http://www.weather.gov/buf SLZ022-024-020015- Saint Lawrence River from Cape Vincent to Ogdensburg- Saint Lawrence River from Ogdensburg to Saint Regis- 815 PM EDT Tue Jun 30 2026 This Hazardous Weather Outlook is for the New York waters of the Saint Lawrence River. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Marginal to Slight Risk of severe thunderstorms Wednesday afternoon and evening with damaging winds the primary hazard. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. This product, along with other watches, warnings, advisories, and statements issued by the National Weather Service office in Buffalo can be found on the internet at http://www.weather.gov/buf
In the hours before
Local storm report, Jun 30, 6:17 PM EDT, 4 hours 25 minutes before
Preliminary Local Storm Report
National Weather Service Buffalo NY
617 PM EDT Tue Jun 30 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0153 PM Tstm Wnd Dmg Castorland 43.88N 75.52W
06/30/2026 Lewis NY Emergency Mngr
Delayed report. Report from Emergency
Manager of numerous trees downed across
Castorland. Time estimated by radar.
&&The office that day
Everything else NWS Buffalo, NY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 30, 10:10 PM EDT | Special Marine Warning | BUF | 65 min | |
| Jun 30, 11:30 PM EDT | Severe Thunderstorm Warning | BUF | Jefferson, Lewis | 60 min |
| Jul 1, 12:42 AM EDT | Special Marine Warning | BUF | 93 min | |
| Jul 1, 4:51 PM EDT | Special Marine Warning | BUF | 54 min | |
| Jul 1, 5:48 PM EDT | Severe Thunderstorm Warning | BUF | Lewis, Oswego | 42 min |
| Jul 1, 6:09 PM EDT | Special Marine Warning | BUF | 55 min | |
| Jul 1, 6:23 PM EDT | Severe Thunderstorm Warning | BUF | Erie, Niagara | 40 min |
| Jul 1, 6:40 PM EDT | Special Marine Warning | BUF | 65 min | |
| Jul 1, 6:44 PM EDT | Severe Thunderstorm Warning | BUF | Erie, Niagara | 32 min |
| Jul 1, 7:13 PM EDT | Special Marine Warning | BUF | 62 min | |
| Jul 1, 7:34 PM EDT | Special Marine Warning | BUF | 73 min | |
| Jul 1, 7:53 PM EDT | Severe Thunderstorm Warning | BUF | Monroe, Ontario, Wayne | 67 min |
| Jul 1, 7:55 PM EDT | Special Marine Warning | BUF | 65 min |
Nearby
Severe Thunderstorm Warnings in New York, 2026Every severe thunderstorm warning in 2026
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.