A couple of thunderstorms progressed from west to east across eastern New York ahead of an approaching cold front from the north during the afternoon hours on Tuesday, July 27, 2021. Damaging winds associated with these storms led to downed trees and power lines across portions of the Mohawk and Schoharie valleys and into the Capital District.
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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 ALY wrote it up.
A couple of thunderstorms progressed from west to east across eastern New York ahead of an approaching cold front from the north during the afternoon hours on Tuesday, July 27, 2021. Damaging winds associated with these storms led to downed trees and power lines across portions of the Mohawk and Schoharie valleys and into the Capital District. Penny-size hail was also observed in Selkirk.
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 Albany, NY wrote its last area forecast discussion before the first event at Jul 27, 1:15 PM EST, 34 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Albany NY 215 PM EDT Tue Jul 27 2021 .SYNOPSIS... A cold front will bring showers and thunderstorms to the region this afternoon and evening. Some of the storms can become strong to severe producing damaging winds and locally heavy rain. It will turn cooler and less humid Wednesday with only isolated showers around. Another system will approach Thursday into Friday with additional showers and thunderstorms. && .NEAR TERM /THROUGH TONIGHT/... As of 1:45PM...Water vapor imagery shows a potent shortwave trough pushing through southern Canada with the high res guidance suggesting a surface low developing in its wake. Areas of convection have already developed downstream in western and central New York in the form of two distinct lines. The air mass ahead of the line is not all that impressive. Despite abundant sunshine throughout the day and sfc dew points in the low 60s, SB CAPE values only ranging 500 - 1000 J/kg which is likely due to mid-level dry air. Our 18 UTC ALY sounding is currently sampling the atmosphere and will be insightful. While thermodynamics are not all the impressive, the kinematic certainly are strong enough to support organized convection with damaging winds the main concerns. The line moving into the southern Adirondacks is already weakening and will likely cool temperatures and contaminant the environment north of I-90. Further south, abundant sun and dew points in the mid 60s will remain in place contributing to increased instability through the afternoon and promote upscale growth as the secondary line currently in the southern Tier and central NY advances eastward into the Mohawk Valley, Capital District, eastern Catskills, mid-Hudson Valley, Berkshires and NW CT. This will be the line of convection to watch as it could become a bowing segment and the strong environment shear combined with steep low level lapse rates may allow its cool pool to propagate eastward resulting in damaging winds. With strong winds aloft, the line is tracking eastward quickly at about 40-45kts so it should reach our region by 1830 - 19 UTC and continue through 00 - 03 UTC. Previous discussion...12 UTC ALY sounding shows impressive deep layer shear already in place with 0-6km shear at 44 kts which will support organized convection. We also note plenty of mid- level dry air which should enhance DCAPE values. SB CAPE values on the latest SPC mesoanalysis are still low at under 500 J/kg but the continued sunshine and favorable dew points in place should contributed to increasing SB CAPE values through the afternoon. The 12 UTC ALY soundings also shows an inverted-v signature which will support very steep low-level lapse rates likely to exceed 7C/km once the boundary layer reaches maximum mixing depth. This will enhance the damaging wind threat from any strong to severe storms. We coordinated with SPC and plan on launching a special 18 UTC sounding to sample the warm sector. With deep layer shear vectors oriented mainly from the west and the incoming boundary positioned from west-southwest to east- northeast, still expecting a mainly linear storm mode but the slight perpendicular orientation should also support storm clusters which is depicted in the latest CAMs/high resolution guidance. Additional, with broad troughing positioned over the Northeast, we note a few mid-level impulses that will be concentrated along the I-90 corridor which will likely result in storms tracking across this region. Not only will storms present a damaging wind potential (especially if the line of storms becomes a bowing segment and the segment remains balanced or shear dominant) but if storms repeatedly track along the Mohawk Valley into the Capital District and into the Berkshires, we will have to monitor the potential for urbanized/poor drainage flooding or even isolated flash flooding. Best timing for storms today looks to be from 19 UTC through 03 UTC (3pm to 11pm). Guidance has trended less with training thunderstorm concerns, so any incidents of flash flooding, if any, will be very isolated. Given the quick progression of storms, most places could end up receiving 0.25 to 0.75 of an inch of rain, which can be handled in most locations given the fairly dry weather the past couple of days. In the wake of the line, isolated to scattered rain showers will linger for at least part if not all of the night. Lows will dip into the mid-50s to mid-60s. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... The cold front will progress south of the region on Wednesday, while an area of high pressure builds to our north. A cold pocket of air aloft and an upper-level trough pushing eastward across the region may lead to at least some isolated showers throughout the day. Model profiles suggest weak instability may be present (500-1000 J/kg SBCAPE) but a capping inversion in the mid-levels suggest convection will be shallow. Therefore, thunder was not added in the forecast. Guidance continues to differ on the coverage of showers, however, so went with slight chance pops or isolated coverage for now. Activity should wane by the late afternoon and evening hours. Wednesday will be cooler and not as humid with highs in the 60s and 70s. Wednesday night should turn out mainly dry though some increased low- level moisture could produce a brief shower in some areas toward daybreak. Lows mainly in the 50s but lower 60s in the mid-Hudson Valley. Another upper-level disturbance and surface feature will push across the region Thursday and Thursday night. Showers and thunderstorms are expected to return, though coverage and timing is uncertain at this time. Highs Thursday will reach the upper 60s to upper 70s with lows Thursday night in the lower 50s to mid-60s. && .LONG TERM /THURSDAY THROUGH MONDAY/... An upper level disturbance will drop southeast out of Canada, on the southern periphery of the upper trough on Thursday. Showers and thunderstorms are expected with this feature but timing is still a bit uncertain. Both the GFS and ECMWF bring showers/storms into the forecast area during the afternoon but the main forcing may not reach the area until the evening. Showers may linger into the overnight period and even into parts of the day Friday with the upper trough persisting. Highs on Thursday should warm into the low to upper 70s. Depending on the shower activity/cloud cover on Friday, temps may range from the mid 60s in the southern Dacks up to near 80 degrees in the mid- Hudson Valley. Surface high pressure builds into the region Friday night into Saturday with dry, sunny weather and below normal temperatures. The normal high for Albany is 84 degrees with the forecast high around 75 degrees. The forecast confidence decreases as we head into Sunday as models struggle with the timing of additional upper level energy moving through the main upper trough. With the upper trough in place, additional chances for precipitation will be in play at times through Monday. Temperatures should stay below normal but comfortable for the beginning of August. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... Main concern this afternoon is the passage of a cold front and associated convection. Current radar trends show two lines of showers and storms moving through central NY. These are expected to progress through the forecast area through the afternoon hours, likely impacting KGFL/KALB/KPSF. Therefore, expect brief reduction in visibilities along with gusty winds with any thunderstorm. The convective activity should wane between 00-02Z/Wed with some lingering showers potentially into the overnight period. Fog may also be an issue, especially for KGFL/KPSF but this is also dependent on how much rain these sites receive today. Variable winds between 5 - 10 kts will weaken to less than 5 kts overnight, also aiding in the fog potential. Outlook... Wednesday Night: Low Operational Impact. NO SIG WX. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Breezy. Chance of SHRA. Friday Night: No Operational Impact. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: Low Operational Impact. Slight Chance of SHRA. Sunday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... A passing cold front will bring a round of showers and thunderstorms to the region during the afternoon and evening hours today. Some of the storms can become strong to severe with damaging winds and locally heavy rainfall. It will turn cooler and less humid Wednesday with only isolated showers around. Another system will approach Thursday into Friday with additional showers and thunderstorms. RH values will lower to 40 to 60 percent this afternoon, then rebound to 90 to 100 percent tonight. RH values lower to 50 to 60 percent tomorrow. Wind will increase to 8 to 15 mph today with a few higher gusts possible before turning light and variable tonight. Wind will be out of the north at 5-10 mph tomorrow. && .HYDROLOGY... A cold front will usher in showers and thunderstorms during the afternoon and evening hours today. Any thunderstorm can produce locally heavy rainfall, though the quick progression of storms and low signal for training storms will limit flash flood potential, but still cannot be ruled out. A general 0.25 to 0.75 of an inch of rain is expected across the area through tonight. Area rivers will have little response to this activity. Only isolated showers are expected on Wednesday followed by an increase in shower and thunderstorm coverage Thursday into Friday. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && SYNOPSIS...Rathbun/Speciale NEAR TERM...Rathbun/Speciale SHORT TERM...Rathbun LONG TERM...JLV AVIATION...JLV FIRE WEATHER...Rathbun HYDROLOGY...Rathbun
Hazardous Weather Outlook National Weather Service Albany NY 1001 AM EDT Tue Jul 27 2021 CTZ001-013-MAZ001-025-NYZ032-033-038>043-047>054-058>061-063>066- 082>084-VTZ013>015-272100- Northern Litchfield-Southern Litchfield-Northern Berkshire- Southern Berkshire-Northern Herkimer-Hamilton-Southern Herkimer- Southern Fulton-Montgomery-Northern Saratoga-Northern Warren- Northern Washington-Schoharie-Western Schenectady- Eastern Schenectady-Southern Saratoga-Western Albany-Eastern Albany- Western Rensselaer-Eastern Rensselaer-Western Greene-Eastern Greene- Western Columbia-Eastern Columbia-Western Ulster-Eastern Ulster- Western Dutchess-Eastern Dutchess-Northern Fulton-Southeast Warren- Southern Washington-Bennington-Western Windham-Eastern Windham- 1001 AM EDT Tue Jul 27 2021 This Hazardous Weather Outlook is for northwestern Connecticut, western Massachusetts, east central New York, eastern New York and southern Vermont. .DAY ONE...Today and tonight. There is a slight risk for severe weather this afternoon and evening across the Interstate 90 corridor with a marginal risk for severe weather elsewhere across eastern New York and western New England. The strongest storms will be capable of producing damaging winds and locally heavy rainfall. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. There is a chance of thunderstorms on Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed this afternoon and evening.
Special Weather Statement National Weather Service Albany NY 248 PM EDT Tue Jul 27 2021 NYZ039-040-048>050-271915- Southern Fulton-Eastern Schenectady-Western Schenectady-Montgomery-Southern Saratoga- 248 PM EDT Tue Jul 27 2021 ...A STRONG THUNDERSTORM WILL AFFECT CENTRAL SCHENECTADY... SOUTHEASTERN FULTON...SOUTHWESTERN SARATOGA AND SOUTHEASTERN MONTGOMERY COUNTIES... At 248 PM EDT, a strong thunderstorm was located over Fonda, moving east at 30 mph. Wind gusts up to 50 mph and half inch hail are possible with this storm. Locations impacted include... Rotterdam, Amsterdam, Gloversville, Johnstown, Scotia, Fonda, Glenville, Hagaman, Fort Johnson, Galway, Tribes Hill, Rotterdam Junction, Pattersonville-Rotterdam Junction, Charlton, Perth, Glen, Berkshire, Fultonville, Meco and West Perth. This includes the following highways... Interstate 90 between exits 25a and 28. Interstate 890 between exits 1a and 2b. Torrential rainfall is also occurring with this storm, and may cause localized flooding. Do not drive your vehicle through flooded roadways. 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. LAT...LON 4289 7447 4307 7442 4303 7389 4277 7397 TIME...MOT...LOC 1848Z 282DEG 26KT 4297 7435 BGM
The Albany radar (KENX), 50 km away, was scanning. The volume nearest the first event began at 18:46 UTC.
13 thunderstorm wind, 1 hail. Local standard time, as filed.
Trees and wires were downed on Route 30A between Route 5 in Fonda and Chestnut Street in Johnstown.
A tree was downed on wires at 2972 Route 30A in the Village of Fultonville.
Large tree branches were downed on many properties along Mohawk Drive in Tribes Hill.
Two trees were downed in Fort Hunter near the Intersection of Main Street and Schoharie Street.
A tree was downed on Englemore Road in the Town of Clifton Park.
Wires were downed on Riverview Road in the Hamlet of Rexford.
A tree and wires were downed across Kennedy Lane near the Town of Clifton Park.
A large tree limb was downed on Howard Street in the City of Cohoes.
A power pole was snapped on Broadway in the City of Cohoes.
A couple of trees were downed on Eminence Road near the Town of Summit.
A couple of trees were downed on Schoharie Hill Road near the Village of Schoharie.
Trees were downed in the Town of Coxsackie. This occurred along an outflow boundary ahead of thunderstorms.
Trees were downed in the Town of Athens. This occurred along an outflow boundary ahead of thunderstorms.
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: 972308, 972309, 972311, 972310, 972315, 972312, 972313, 972316, 972317, 972320, 972324, 972329, 972332, 972334.