An unstable environment and a passing disturbance triggered many severe storms across Central New York. Large hail and damaging winds were the hazards associated with these storms.
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 BGM wrote it up.
An unstable environment and a passing disturbance triggered many severe storms across Central New York. Large hail and damaging winds were the hazards associated with these storms. A tree fell on an occupied vehicle, but the occupant was uninjured. Lightning also struck a house, resulting in the house catching on fire.
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 Binghamton, NY wrote its last area forecast discussion before the first event at Jul 20, 4:38 PM EST, 43 minutes earlier.
Area Forecast Discussion National Weather Service Binghamton NY 538 PM EDT Tue Jul 20 2021 .SYNOPSIS... A warm mostly sunny day is in store, but a new disturbance will drop into the region late this afternoon through tonight with scattered showers and thunderstorms. The strongest cells could contain damaging winds and locally heavy rainfall. A cold front will finish sweeping through the area Wednesday, eventually taking showers and thunderstorms away with it. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... 535 pm update... Have issued a flash flood watch for Oneida County until 2 am tonight. After receiving over 4 inches across northern Oneida County yesterday and heavy rainfall expected with thunderstorms tonight, flash flooding will be possible. 330 pm update... A severe thunderstorm watch has been issued until 11 PM for central NY except for the PA border counties. The biggest threat will be damaging winds but large hail is also possible in discreet cells ahead of a line of showers and thunderstorms. Heavy rain will also be a threat for flash flooding. Storms will be moving but as the line goes through it will slow and start training this evening. Low level moisture mixed out this morning leaving mostly sunny but hazy skies. Temperatures have risen mostly into the lower 80s. So far a cap is keeping convection away. Instability is high with cape over 2k and lifted indices of -5. As the convective line and cold front drop south wind shear will increase to 35 kts in the north. Strong downdrafts will cause damaging winds. The instability will help water get above the -20c level to form hail. Precipitable water is increasing to 1.4 inches in the north. Initially the single cells should be moving and spaced apart enough to limit flash flooding. Depending on how strong the line is when it gets here this evening, that rain could be a problem. The line will slow over our area as the main forcing drops southeast into the Hudson Valley. Some of the models have rainfall amounts in excess of 2 inches. With the wet antecedent conditions 2 inches in an hour would be enough to cause flooding. In the case of Oneida County it would be less given the flooding there just yesterday. The cold front goes through late tonight and Wednesday morning. Convection tonight will be tapering off as it outruns the better wind shear and forcing. Midday tomorrow there could be a resurgence in NEPA and Sullivan County NY with weak surface heating and another short wave moves through. SPC has put the far southeast in a marginal chance of severe thunderstorms for Wednesday. Showers and thunderstorms there end in the afternoon. Temperatures will fall into the 60s tonight then rising into the 70s Wednesday. The far southeast could near 80. Low temperatures will be in the 50s Wednesday night. Wednesday into Wednesday night skies will clear front northwest to southeast behind the front as drier air comes in. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... Only minor changes with the forecast update this afternoon in the short term. Previous discussion below. High pressure will bring dry conditions to the area on Thursday along with a mix of sun and clouds. High temperatures are expected to mainly be in the mid to upper 70s. Some lower 70s are expected in the higher elevations of Central NY/Catskills. Meanwhile some lower 80s will be possible in portions of the Wyoming Valley in PA. Another shortwave will approach the area Thursday night, which may touch off a few light showers late Thursday night/early Friday morning, mainly west of I-81. That being said, the majority of the area will likely remain dry. Lows are expected to be in the mid to upper 50s. As the shortwave moves through the area on Friday, a few scattered showers will be possible and perhaps a few thunderstorms by the afternoon. However, at this time, it appears overall coverage will be rather limited and there will be plenty of dry breaks with some sunshine throughout the day. Highs are expected to be very similar to Thursday, mainly in the mid to upper 70s. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... Dry weather is expected to return for Friday night into Saturday as high pressure settles in. An isolated late afternoon shower cannot be ruled out Saturday ahead of the next system, but the majority of the area will likely remain dry through the day with mostly sunny skies. After low temperatures in 50s Friday night, highs are expected to be in the mid 70s to lower 80s on Saturday. Another shortwave/frontal system is expected to impact the region Saturday night through Sunday, bringing scattered showers and some thunderstorms. With greater instability Sunday afternoon, the chance for thunderstorms will be highest during that period. Modeling at this time is indicating the potential for 1,000-2,000 J/KG of CAPE and 20-30 knots of 0-6 KM bulk shear to promote the potential for gusty winds with the storms. Given timing uncertainty, it is a bit early to hone in on the threat for strong to severe storms at this time. Heavy rainfall will be another concern too given recent rounds of rainfall with the details ironed out as we get closer to the event. Some additional scattered showers will be possible on Monday with a northwest flow, before high pressure likely brings dry conditions by Tuesday. Temperatures Sunday/Monday are expected to be a bit warmer; mainly mid 70s to lower 80s Sunday and upper 70s to mid 80s Monday. With dewpoints back in the 60s to perhaps near 70, it will be more humid as well. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... 140 pm update... Other than some smoke dropping vsbys to 5sm conditions are VFR. We are waiting for a line of showers and thunderstorms to drop south with MVFR restrictions and brief IFR possible in NY. SYR/RME 22 to 01z then 23 to 02z for BGM/ITH/ELM. A cold front will follow the convection tonight dropping cigs and vsbys mostly to IFR in CNY. IFR will lift to MVFR around 14z. At AVP convection will die before getting there. The front will wait until after 12z but could have MVFR cigs. West winds at 5 to 10 kts this afternoon into evening. Tonight light and variable winds. Wednesday northwest winds at 5 to 10 kts. Outlook... Wednesday afternoon...In CNY improvement to VFR. For AVP lingering scattered showers and thunder with associated intermittent restrictions. Late Wednesday through Saturday...Late night-early morning fog possible, especially KELM; otherwise mainly VFR. Small chances of showers and thunder with brief restrictions Friday. Late Saturday night through Sunday...chances of showers and thunder with restrictions. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...Flash Flood Watch until 2 AM EDT Wednesday for NYZ009-037. && SYNOPSIS...TAC NEAR TERM...MPK/TAC SHORT TERM...BJG/MWG LONG TERM...BJG/MWG AVIATION...TAC
Hazardous Weather Outlook National Weather Service Binghamton NY 535 PM EDT Tue Jul 20 2021 NYZ015>018-023-025-036-044>046-212145- Yates-Seneca-Southern Cayuga-Onondaga-Schuyler-Tompkins-Madison- Cortland-Chenango-Otsego- 535 PM EDT Tue Jul 20 2021 ...SEVERE THUNDERSTORM WATCH 384 IN EFFECT UNTIL 11 PM EDT THIS EVENING... This Hazardous Weather Outlook is for central New York. .DAY ONE...Tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Severe Thunderstorm Watch. ...SCATTERED SEVERE THUNDERSTORMS AND LOCALLY HEAVY RAIN POSSIBLE... Scattered showers and thunderstorms are forecast to move into the area this evening, lasting into tonight. With soils still very wet from several bouts of rain during the past week, isolated flash flooding will also be possible. Locations that recently experienced flooding, will be more vulnerable to additional rainfall. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about severe weather to the NWS while following local, state and CDC guidelines. PAZ043-044-047-048-072-212145- Wyoming-Lackawanna-Luzerne-Pike-Southern Wayne- 535 PM EDT Tue Jul 20 2021 This Hazardous Weather Outlook is for northeast Pennsylvania. .DAY ONE...Tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. NYZ022-024-055>057-062-PAZ038>040-212145- Steuben-Chemung-Tioga-Broome-Delaware-Sullivan-Bradford-Susquehanna- Northern Wayne- 535 PM EDT Tue Jul 20 2021 This Hazardous Weather Outlook is for central New York and northeast Pennsylvania. .DAY ONE...Tonight. ...ISOLATED SEVERE THUNDERSTORMS AND LOCALLY HEAVY RAIN POSSIBLE... Scattered showers and thunderstorms are forecast to move into the area late this afternoon, lasting into tonight. A few of the strongest storms could become severe with damaging wind gusts and large hail. With soils still very wet from several bouts of rain during the past week, isolated flash flooding will also be possible. Locations that recently experienced flooding, will be more vulnerable to additional rainfall. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about severe weather to the NWS while following local, state and CDC guidelines. NYZ009-037-212145- Northern Oneida-Southern Oneida- 535 PM EDT Tue Jul 20 2021 ...SEVERE THUNDERSTORM WATCH 384 IN EFFECT UNTIL 11 PM EDT THIS EVENING... ...FLASH FLOOD WATCH IN EFFECT UNTIL 2 AM EDT WEDNESDAY... This Hazardous Weather Outlook is for central New York. .DAY ONE...Tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Severe Thunderstorm Watch. Flash Flood Watch. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about severe weather to the NWS while following local, state and CDC guidelines.
Special Weather Statement
National Weather Service Binghamton NY
534 PM EDT Tue Jul 20 2021
NYZ009-018-036-037-202215-
Onondaga-Southern Oneida-Madison-Northern Oneida-
534 PM EDT Tue Jul 20 2021
...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN ONEIDA...
NORTHWESTERN MADISON AND NORTHERN ONONDAGA COUNTIES...
At 533 PM EDT, a strong thunderstorm was located near Fulton, moving
east at 35 mph.
Winds in excess of 40 mph and pea size hail are possible with this
storm.
Locations impacted include...
Clay, Rome, Cicero, Lysander, Sullivan, Oneida, Lenox, Baldwinsville,
North Syracuse and Vienna.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
To report severe weather, contact your nearest law enforcement
agency. They can relay your report to the National Weather Service
office in Binghamton.
LAT...LON 4344 7559 4299 7562 4316 7648 4322 7648
4323 7630 4320 7627 4322 7626 4324 7627
4324 7626 4320 7622 4322 7620 4327 7621
4322 7609 4320 7608 4315 7589 4328 7587
4333 7588 4347 7582
TIME...MOT...LOC 2133Z 278DEG 32KT 4327 7646
HLCSpecial Weather Statement
National Weather Service Binghamton NY
605 PM EDT Tue Jul 20 2021
NYZ015-022-023-202230-
Steuben-Yates-Schuyler-
605 PM EDT Tue Jul 20 2021
...A STRONG THUNDERSTORM WILL AFFECT WESTERN SCHUYLER...SOUTHEASTERN
YATES AND NORTHEASTERN STEUBEN COUNTIES...
At 605 PM EDT, a strong thunderstorm was located over Urbana, or 10
miles west of Dundee, moving east at 25 mph.
Winds in excess of 40 mph and pea size hail are possible with this
storm.
Locations impacted include...
Hector, Starkey, Urbana, Watkins Glen, Dundee, Montour Falls, Tyrone,
Pulteney, Wayne and Bradford.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
To report severe weather, contact your nearest law enforcement
agency. They can relay your report to the National Weather Service
office in Binghamton.
LAT...LON 4248 7726 4255 7724 4255 7690 4254 7689
4254 7681 4230 7686 4238 7727
TIME...MOT...LOC 2205Z 275DEG 21KT 4248 7718
HLCSpecial Weather Statement
National Weather Service Binghamton NY
610 PM EDT Tue Jul 20 2021
NYZ017-018-044-202245-
Onondaga-Cortland-Southern Cayuga-
610 PM EDT Tue Jul 20 2021
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTHEASTERN CAYUGA...
NORTHWESTERN CORTLAND AND SOUTHWESTERN ONONDAGA COUNTIES...
At 610 PM EDT, radar indicated strong thunderstorms were located
along a line extending from near Owasco to near Locke. Movement was
east at 30 mph.
Winds in excess of 40 mph and pea size hail are possible with these
storms.
Locations impacted include...
Cortland, Owasco, Homer, Fleming, Otisco, Locke, Genoa, Preble,
Moravia and Niles.
These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
To report severe weather, contact your nearest law enforcement
agency. They can relay your report to the National Weather Service
office in Binghamton.
LAT...LON 4258 7597 4260 7627 4262 7627 4262 7646
4263 7646 4263 7653 4287 7660 4299 7608
TIME...MOT...LOC 2210Z 250DEG 24KT 4284 7650 4268 7646
HLCThe Ft Drum radar (KTYX), 42 km away, was scanning. The volume nearest the first event began at 22:18 UTC.
20 thunderstorm wind, 1 hail, 1 lightning. Local standard time, as filed.
Strong thunderstorm winds knocked down a tree onto wires.
Strong thunderstorm winds knocked down a tree and wires onto a roaday.
Strong thunderstorm winds knocked down a tree onto a roadway.
Strong thunderstorm winds knocked down a tree onto wires.
Strong thunderstorm winds knocked down a tree onto a roadway.
Strong thunderstorm winds knocked down a tree onto a vehicle in Delta Lake State Park. No injuries were reported as the woman in vehicle refused treatment.
Strong thunderstorm winds knocked down a tree onto wires.
Strong thunderstorm winds knocked down a tree onto a roadway.
Strong thunderstorm winds knocked down tree onto a roadway.
Strong thunderstorm winds knocked down a tree onto a roadway.
Strong thunderstorm winds knocked down a tree onto a roadway.
Strong thunderstorm winds knocked down large tree limbs.
Strong thunderstorm winds knocked down a tree onto a roadway.
A thunderstorm produced 1-inch hail.
Strong thunderstorm winds knocked down down multiple trees on a couple of roadways.
Strong thunderstorm winds knocked down a tree and wires onto a house.
Strong thunderstorm winds knocked down a tree onto a roadway.
Strong thunderstorm winds knocked down a tree onto a roadway.
Strong thunderstorm winds knocked down a tree onto a roadway.
Strong thunderstorm winds knocked down a tree onto wires.
Lightning from a passing storm struck a house, and then the house caught on fire.
Strong thunderstorm winds knocked down trees and wires.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2021Every state in 2021This day in weather historyWarnings in New York, July 2021
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: 972848, 972851, 972849, 972852, 972856, 972858, 972857, 972878, 972879, 972883, 972884, 972885, 972887, 972795, 972889, 972888, 972892, 972891, 972890, 972893, 972796, 972894.