Following the passage of a warm front during the morning of the 27th, an unstable airmass was in place across Central New York. This frontal boundary then dropped back south and east as a cold front, sparking numerous severe thunderstorms during the afternoon and early evening.
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.
Following the passage of a warm front during the morning of the 27th, an unstable airmass was in place across Central New York. This frontal boundary then dropped back south and east as a cold front, sparking numerous severe thunderstorms during the afternoon and early evening.
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 Aug 27, 6:34 AM EST, 36 minutes earlier.
Area Forecast Discussion National Weather Service Binghamton NY 734 AM EDT Thu Aug 27 2020 .SYNOPSIS... A warm front will lift through the area with showers and occasional thunder this morning. Then, a severe weather outbreak is probable this afternoon to early evening as a cold front drops through the region. Additional rounds of showers and thunderstorms are expected Friday into Saturday which may bring heavy rain to parts of the region. && .NEAR TERM /THROUGH TONIGHT/... 410 AM Update... **Severe Weather Outbreak Anticipated This Afternoon-Evening** Little has changed with expectations for severe weather today. This may be a higher end event, with potential for damaging winds, large hail, and perhaps a few tornadoes. The Storm Prediction Center maintains an enhanced risk for severe thunderstorms for the vast majority of our area, though potential will a bit lower along and north of the New York Thruway since there will be less heating; the warm sector of the system will not quite reach there. The biggest uncertainties today, will be how far north the severe weather potential will actually extend because of warm frontal placement, as well as whether the severe storms will reach all the way through the Wyoming Valley in PA early this evening or become more scattered first. For most of the area, though, a severe weather outbreak indeed appears probable. The warm front of the incoming system, with strong west- northwest flow aloft, as expected is carrying showers and embedded thunder through the region. One cluster is exiting Bradford County PA en route the Wilkes-Barre/Scranton metro and then Poconos; frequent lightning with that but since it is elevated, strong winds are not expected. A larger cluster can be found crossing from Ontario into North Central NY; it will move over the greater Syracuse-Utica metros to the I-88 corridor- Western Catskills this morning, perhaps with locally heavy rainfall since portions of it are training. However, the main event will still be later today. The warm front will hang up as the primary wave of low pressure zips through the region by midday. This will then drop the boundary south as a cold front this afternoon-early evening; well-timed to harness significant energy from diurnal heating in the low levels as well as the beginning of cooling aloft. New storms are anticipated to start firing near the New York Thruway just after noon, which will then strengthen while working southward through Finger Lakes-Upper Susquehanna areas early-mid afternoon, down to the Twin Tiers-Catskills mid-late afternoon, and finally the rest of Northeast PA late afternoon- early evening though with some uncertainty for how solid the coverage will be by then. Models have not changed much in depicting a solid 45-55 knots of shear in the 2-6 km layer; and some directional shear as well in the lowest 1-2 km. This along with top-heavy Convective Available Potential Energy (CAPE) of 1500-2500 J/kg, points to supercell storms and thus all modes of potential severe weather. Some Add 0-1km helicity values reaching 150-250 m2/s2 and there is potential for a few tornadoes as well. It appears probable there will be at least some damage and/or power outages within our area; in addition to possible isolated tornadoes, bowing line segments as cells interact may yield microbursts/gusts of 60-70 mph or so. The top-heavy nature of the CAPE, in the hail growth zone, and lifted indices -3 to -7, also suggests explosive updrafts capable of large hail of 1-2 inches or higher. Finally, any supercells could contain torrential rain with quick street/urban flooding. Placement and timing of the front will allow a big temperature contrast across our area. It will be humid areawide, but highs will range from only 70s northeast to 80s for most, and even near 90 at lower elevations of Northeast Pennsylvania. Dewpoints of upper 60s-near 70 will push heat index values into the upper 80s-mid 90s for the warmer locations. Tonight, cool air advection behind the convection will dip temperatures into the upper 50s to upper 60s. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... 330 am update... Not much change this period. Friday plenty of clouds ahead of a warm front bringing the start of rain during the afternoon into the evening. Highs mostly upper 70s to lower 80s Friday. Still looking at a heavy rain event Friday night into Saturday. Remnants of Laura will move northeast into the lower Ohio Valley Friday night then track east. This system will be captured by a cold front associated with a surface low dropping southeast through the Great Lakes ahead of an upper level trough. Deep tropical moisture will be over the area with precipitable water amounts of 1.5 to 2 inches. Rain amounts range from around an inch to nearly 2 inches in Oneida county. Rivers are low being the end of summer so rain amounts would have to be higher to cause any flooding that way. Flash flooding possible mostly Saturday afternoon with any heavy rain. by that time the ground will be saturated. A cold front will be moving southeast through the area possible with some embedded thunderstorms. the rain exits Saturday evening with a few lingering late night showers in the Finger Lakes and western Mohawk Valley with the upper level trough. A cold northwest flow starts Saturday night with lows in the 50s. The severe weather threat looks reduced with the saturated airmass and low instability. CAPE peaks at 500 and deep wind shear is 35 to 40 kts. Clearing won't happen between the warm front and cold front to increase surface temperatures and instability. High temperatures 75 to 80 with dewpoints around 70. SPC put the far far southeast in a marginal chance of severe thunderstorms Saturday. This is further to the southeast than their outlook from yesterday which makes sense. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... 330 am update... No major changes to the long term period were made with this forecast update. The latest data supports the current forecast ideas. Sunday drier air moves in but a few showers are still possible in CNY under the upper level trough. Highs mostly only around 70. With less moisture Sunday night lows fall to 50. On Monday the surface high is centered over the area as the upper level pattern becomes zonal. A warming trend into Thursday with highs around 80 and lows around 60. A slow moving system with showers and thunderstorms starts to move in late Tuesday and exits Wednesday but another system with more showers possible Thursday. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Very busy TAF period. Showers-embedded thunder and associated restrictions are occurring this morning as well as a window of low level wind shear as a warm front lifts through the region with a strengthening jet not far off the surface. Then, we will likely experience a severe weather outbreak with gusty thunderstorms dropping south with a cold front across the terminals this afternoon- early evening. They are expected to form around KSYR-KRME 15Z-18Z, reaching KITH-KBGM-KELM around 20Z-23Z, and then still a decent chance of it getting to KAVP 23Z or shortly after. Hail could even occur at any terminal that receives a direct hit from a storm core. Post-frontal restrictions from low clouds or fog are anticipated to develop tonight with abundant low level moisture in the wake of the rainfall. Winds initially light and variable, will become WSW to W 10-15 knots with some higher gusts during the daytime except remaining variable at KRME; however, storms impacting any terminal could cause considerably stronger winds. Winds will then become variable tonight. Outlook... Friday morning...Lingering post-frontal ceiling restrictions likely; possible fog as well. Friday afternoon through Saturday night...Rain developing and occasional thunderstorms expected, especially Friday night into Saturday, with associated restrictions. Sunday through Monday...Mainly VFR, but valley fog likely Sunday night for at least KELM and possibly other terminals. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && SYNOPSIS...MDP NEAR TERM...MDP SHORT TERM...TAC LONG TERM...TAC AVIATION...MDP
Hazardous Weather Outlook National Weather Service Binghamton NY 420 AM EDT Thu Aug 27 2020 NYZ009-015>018-022>025-036-037-044>046-055>057-062-PAZ038>040-043- 044-047-048-072-280830- Northern Oneida-Yates-Seneca-Southern Cayuga-Onondaga-Steuben- Schuyler-Chemung-Tompkins-Madison-Southern Oneida-Cortland-Chenango- Otsego-Tioga-Broome-Delaware-Sullivan-Bradford-Susquehanna- Northern Wayne-Wyoming-Lackawanna-Luzerne-Pike-Southern Wayne- 420 AM EDT Thu Aug 27 2020 This Hazardous Weather Outlook is for central New York and northeast Pennsylvania. .DAY ONE...Today and tonight. ...POTENTIAL SEVERE WEATHER OUTBREAK TODAY... There is an enhanced risk for severe thunderstorms today. Strong to severe thunderstorms are expected to develop, near the New York Thruway in early afternoon and then pressing southward across the rest of Central New York this afternoon, and into Northeast Pennsylvania by early evening. Damaging winds and large hail are anticipated with the strongest storms, and a even few tornadoes will be possible in the region. Heavy rainfall may occur in the strongest storms as well, with localized flooding possible in streets and urban areas. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. A system late Friday through especially Saturday, will bring another round of rain and occasional thunderstorms. Heavy rainfall will be possible, which could lead to localized flooding. Monitor the forecast for updates. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures. 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
747 AM EDT Thu Aug 27 2020
NYZ009-018-036-037-271245-
Onondaga NY-Southern Oneida NY-Madison NY-Northern Oneida NY-
747 AM EDT Thu Aug 27 2020
...STRONG THUNDERSTORM WILL AFFECT...WEST CENTRAL ONEIDA...
NORTHWESTERN MADISON AND NORTHERN ONONDAGA COUNTIES UNTIL 845 AM
EDT...
At 747 AM EDT, Doppler radar was tracking a strong thunderstorm over
Lysander, or near Fulton, moving east at 40 mph.
Wind gusts up to 50 mph will be possible with this storm.
Locations impacted include...
Onondaga, Syracuse, Clay, Cicero, De Witt, Lysander, Sullivan, Van
Buren, Oneida and Lenox.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Heavy rainfall is also occurring with this storm, and may lead to
minor flooding. Do not drive your vehicle through flooded roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 4322 7609 4320 7608 4315 7589 4324 7587
4320 7568 4300 7566 4289 7579 4309 7650
4311 7647 4322 7648 4323 7630 4320 7627
4322 7626 4324 7627 4324 7626 4320 7622
4322 7620 4327 7621
TIME...MOT...LOC 1147Z 289DEG 43KT 4324 7644
MJMThe Ft Drum radar (KTYX), 94 km away, was scanning. The volume nearest the first event began at 12:06 UTC.
32 thunderstorm wind, 1 hail. Local standard time, as filed.
Strong thunderstorm winds brought down trees and blew around lawn furniture.
Strong thunderstorm winds brought down trees.
Strong thunderstorm winds brought down wires.
Strong thunderstorm winds brought down trees and wires on Chestnut Street.
Strong thunderstorm winds brought down a tree on Hickey Road and Brown Road.
Strong thunderstorm winds brought down large tree branches.
Strong thunderstorm winds brought down trees and wires on Williams Road.
Strong thunderstorm winds brought down trees and wires on Boston Avenue.
Strong thunderstorm winds brought down trees and wires on Lake Road.
Strong thunderstorm winds brought down a tree, blocking a road.
Strong thunderstorm winds brought down trees and wires.
Strong thunderstorm winds brought down several trees and wires and snapped a power pole.
Strong thunderstorm winds brought down wires.
Strong thunderstorm winds brought down a tree on a vehicle.
Strong thunderstorm winds brought down a tree.
Strong thunderstorm winds brought down trees and wires.
Strong thunderstorm winds brought down a tree across Boswell Hill Road.
Strong thunderstorm winds uprooted and snapped multiple trees along Airport Road near the intersection with Upper Stella Ireland Road.
Strong thunderstorm winds brought down a tree branch through a roof.
Strong thunderstorm winds brought down trees on Fordham Road.
Strong thunderstorm winds brought down trees.
Strong thunderstorm winds brought down trees and wires on Yorkshire Road.
Strong thunderstorm winds brought down trees on Highland Avenue.
Strong thunderstorm winds brought down trees.
Strong thunderstorm winds brought down multiple trees.
Strong thunderstorm winds brought down trees and wires.
Strong thunderstorm winds brought down trees and wires.
Strong thunderstorm winds brought down trees and wires on Horseshoe Lake Road.
Strong thunderstorm winds brought down trees and wires.
Strong thunderstorm winds brought down numerous trees on Route 209, closing the road in both directions.
Strong thunderstorm winds brought down a tree on a propane tank.
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: 916590, 916592, 916593, 916608, 916620, 916637, 916646, 916649, 916651, 916662, 916659, 916664, 916670, 916674, 916678, 916695, 916680, 916681, 916683, 916686, 916687, 916692, 916688, 916689, 916693, 916691, 916690, 916697, 916698, 916700, 916701, 916703, 916705.