An approaching cold front and strong moisture advection along with a shortwave tracking north of Lake Ontario helped to generate scattered thunderstorms over southern Ontario to east of Lake Huron in the evening of August 24. Thunderstorms increased in intensity and coverage as they crossed the Niagara Peninsula early in the morning on August 25.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BUF wrote it up.
An approaching cold front and strong moisture advection along with a shortwave tracking north of Lake Ontario helped to generate scattered thunderstorms over southern Ontario to east of Lake Huron in the evening of August 24. Thunderstorms increased in intensity and coverage as they crossed the Niagara Peninsula early in the morning on August 25. This line of storms swept across the Niagara Frontier, including metro Buffalo with wind damage noted south of Lake Ontario. They were out of the area by 6 AM.
The local office's own words before the first event, 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 the first event at Aug 24, 9:40 PM EST, 3 hours 10 minutes earlier.
Area Forecast Discussion National Weather Service Buffalo NY 1040 PM EDT Mon Aug 24 2020 .SYNOPSIS... Warm and humid conditions will last into early Tuesday with chances of showers and thunderstorms. A brief cool down is likely on Wednesday before summer's warmth returns to end the week along with renewed chances for showers and thunderstorms. A sharp cooldown is then expected for the weekend. && .NEAR TERM /THROUGH TUESDAY NIGHT/... Mainly dry weather early, then approaching shortwave and attendant cold front to support scattered to likely pops for showers and storms as we push deeper into the overnight. Fropa Tuesday morning with showers and storms becoming focused well south of Buffalo and Rochester. Noticeably less humid by late afternoon. Much drier and cooler airmass overspread the Lower Great Lakes Tuesday night ahead of next surface high. Minimal lake response not out of the question south of Lk Ontario. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... Dry and cooler conditions will be short-lived on Wednesday as cold advection and northwesterly flow quickly turn neutral and then warm Wednesday night into Thursday as a warm front surges back northeastward through the area. This will allow for PWATs to surge upward significantly while 850 hPa temperatures run up toward +18C again. The net result will be a near tropical feel to the environment over the area by that juncture. A wave along the front that lifts north of the area will allow the boundary to sag back southward on Thursday night and Friday. With a near W-E orientation of this front across the area, this seems likely to yield a very unsettled and wet interlude for the CWA. Model guidance suggests continuous instability along this boundary, low level convergence, and ample moisture feed. Thus, this could finally be an extended period of rainfall potential for the area. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... The end of the week looks to be a continuation of tropical rainfall across the area. Moisture associated with the remnants of Laura may be drawn up into the frontal boundary that will still be laid out across the area. This would yield a near unabated continuation of solid rainfall across the bulk of the area that looks to extend at least into Saturday. Beyond Saturday, the long wave pattern looks to start to change across the eastern CONUS. What has been a very warm period will gradually be replaced by troughing in the upper levels. This will result in cooler and drier Canadian air slipping into the northeastern US for a few days. As a result, the forecast trends decidedly drier and below normal in the temperature department. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... VFR conditions will persist tonight ahead of approaching shortwave and attendant cold front. Becoming more unsettled after 05z though with some showers and storms, possibly reducing conditions to MVFR levels for a short period late. Scattered showers and thunderstorms early Tuesday, becoming more common over the Southern Tier by midday, will move out of the region during the afternoon. Otherwise, mainly VFR weather will be in place. Outlook... Wednesday...VFR. Showers and thunderstorms possible late day western NY, then all areas overnight. Thursday and Friday...VFR. Chance of showers and thunderstorms. && .MARINE... Southwest to west winds will continue into Tuesday ahead of a cold front. Winds shift to the north and northeast Tuesday night into Wednesday behind the front. Conditions will become choppy on the eastern ends of Lake Erie and Lake Ontario later today into Tuesday then along the south shore of Lake Ontario Tuesday night into Wednesday, but winds and waves look to stay below small craft advisory criteria. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && SYNOPSIS...HSK/RSH NEAR TERM...RSH SHORT TERM...Fries LONG TERM...Thomas AVIATION...RSH MARINE...HSK/JLA
Hazardous Weather Outlook National Weather Service Buffalo NY 603 PM EDT Mon Aug 24 2020 NYZ001>006-010>014-019>021-085-252100- Niagara-Orleans-Monroe-Wayne-Northern Cayuga-Oswego-Northern Erie- Genesee-Wyoming-Livingston-Ontario-Chautauqua-Cattaraugus-Allegany- Southern Erie- 603 PM EDT Mon Aug 24 2020 This Hazardous Weather Outlook is for portions of western and north central New York. .DAY ONE...Tonight. A complex of thunderstorms may track across the region late tonight. Gusty winds and heavy rain will be the primary hazards. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. On Tuesday, scattered severe thunderstorms are possible early, especially south of the New York State Thruway. The main hazards will be damaging winds and hail. On Wednesday, additional strong to severe thunderstorms are possible late in the day and overnight. The main hazards will be damaging winds and hail. .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 NYZ007-008-252100- Jefferson-Lewis- 603 PM EDT Mon Aug 24 2020 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...Tuesday through Sunday. On Tuesday, a few strong to severe thunderstorms are possible early. The main hazards will be damaging winds and hail. .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 SLZ022-024-252100- Saint Lawrence River from Cape Vincent to Ogdensburg- Saint Lawrence River from Ogdensburg to Saint Regis- 603 PM EDT Mon Aug 24 2020 This Hazardous Weather Outlook is for the New York waters of the Saint Lawrence River. .DAY ONE...Tonight. Strong to severe thunderstorms are possible into this evening. Damaging winds are the main hazard. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. On Tuesday, a few strong to severe thunderstorms are possible early. The main hazards will be damaging winds and hail. .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>045-062>065-252100- 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 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 the Niagara River to Hamlin Beach- 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- 603 PM EDT Mon Aug 24 2020 This Hazardous Weather Outlook is for portions of Lake Erie and Lake Ontario. .DAY ONE...Tonight. A complex of thunderstorms late tonight may produce strong gusty winds. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. On Tuesday, scattered severe thunderstorms will be possible on Lake Erie. The main hazards will be damaging winds and hail. On Wednesday, additional strong to severe thunderstorms are possible late in the day and into the overnight hours. The main hazards will be damaging winds and hail. .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
The Buffalo radar (KBUF), 53 km away, was scanning. The volume nearest the first event began at 05:49 UTC.
5 thunderstorm wind. Local standard time, as filed.
Trees were reported down on Richardson Road in Gowanda.
Trees were reported down onto Gowanda Zoar Road.
Several trees were down onto Smith Road in Hamburg.
A tree was reported down and blocking Ridge Road.
A tree was down and blocking a road in Lakewood.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2020Every state in 2020This day in weather historyWarnings in New York, August 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 918988, 918989, 918991, 918992, 918995.