Showers and thunderstorms developed along a frontal boundary during the afternoon hours on July 29th across eastern New York. One lone thunderstorm tracked across the Mohawk Valley resulting in numerous reports of downed trees and powerlines as well as a couple of flood reports.
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 ALY wrote it up.
Showers and thunderstorms developed along a frontal boundary during the afternoon hours on July 29th across eastern New York. One lone thunderstorm tracked across the Mohawk Valley resulting in numerous reports of downed trees and powerlines as well as a couple of flood reports. Prior to the arrival of these thunderstorms, the combination of hot and humid conditions resulted in heat index values between 95 and 100 degrees across all of Dutchess and eastern Ulster counties.
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 29, 8:58 AM EST, 1 hour 52 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Albany NY 958 AM EDT Sat Jul 29 2023 .SYNOPSIS... An approaching cold front will bring showers and thunderstorms today. Some storms may be severe along with locally heavy rainfall. The cold front will pass through late today, with much cooler and less humid conditions arriving for Sunday through early next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... * Heat Advisory in effect through 6 pm today for eastern Ulster, Dutchess and Litchfield Counties. .UPDATE...Radar indicating a cluster of scattered showers with downpours developed across parts of Ulster, Dutchess and Litchfield County, possibly resulting from an outflow boundary due to prior upstream convection. Also, starting to see widespread showers with embedded T-storms with downpours moving east from the Tug Hill area. This activity will track into the western Adirondacks late this morning associated with a cold front and wave of low pressure gradually pushing southeast across upstate NY. Otherwise, not much instability yet in our area, but should occur by this afternoon due to significant breaks in the clouds this morning. An active afternoon still expected to occur with both severe storms and localized flooding. .PREV DISCUSSION[0658]...Considerable mid and high clouds across the region and some morning sun should shine through the mid and high clouds to help with some daytime heating, especially south and east of the western Mohawk Valley and southern Adirondacks to Lake George Region. There is a wind shift boundary in northern NY that is drifting south. There is a decent signal that the boundary in northern NY will continue to drift south and convection will develop along this boundary through this morning, limiting the heating along and north of the boundary. Current convection in the OH Valley is expected to dissipate later this morning as the convection proximate to the wind shift boundary in NY is expected to become the main band of showers and storms, then tracks east and south through our region. A surface trough/low will form in southern NY and southern New England where the greatest instability and moisture exists and the strongest convection will expand into that area where the greatest threat for severe weather and potential nuisance flooding is. Before the showers and storms develop and track east and south, temperatures are expected to reach the upper 70s to mid 80s and cooler in higher elevations. CAPEs will increase to over 1000 j/kg ahead of the convection. South of the wind shift boundary, CAPEs could increase to around 2000 j/kg, mainly in the mid Hudson Valley to southern Berkshires and NW CT, where there is a slight risk for severe thunderstorms. Shear is not very high but there will be some enhanced low level forcing with a distinct low level wind shift and advancing low level thermal gradient on the leading edge of the cold advection. Damaging winds are the primary risk. Localized heavy rain and brief training of thunderstorms could produce urban, small stream flooding and standing water in low lying areas. Isolated flash flooding cannot be ruled out. A few showers and isolated thunderstorms approaching the mid Hudson Valley and NW CT. Outside of the isolated activity, increasing sun through the morning into early afternoon will help those areas to have the most heating. Temperatures will reach around 90 with heat indices around or above 95 and the Heat Advisory continues there. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... Lingering showers Saturday evening will exit and by Sunday morning, some clearing, cooling and drying. Sunday should be partly to mostly sunny and an isolated shower cannot be ruled out as upper trough axis overhead and cooling aloft. Highs Sunday in the 70s to near 80. Upper trough axis still in our region and another weak upper impulse tracks through the upper trough as continued cooling aloft occurs. Morning sun will become partly sunny in the afternoon with isolated showers and storms, mainly along and north of I-90. Still, there should be enough sun for temperatures to reach the mid 70s to near 80 and around 70 higher elevations. Clearing Sunday night with lows by Tuesday morning in the 50s with a few upper 40s southern Adirondacks and Lake George Region. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Long term period begins 12z Tuesday with upper trough axis overhead associated with an upper low in southeast Canada. With the cold pool aloft, diurnally-driven cumulus clouds and a few isolated showers could develop during the afternoon, so slight chance PoPs were added for most of the area. With NW winds advecting cooler and drier air into the region, highs will only be in the 60s for the terrain and mid to upper 70s for the valleys, which is a couple degrees below average. Any showers diminish quickly with the loss of daytime heating. Lows drop into the 40s (terrain) and 50s under partly to mostly clear skies Tuesday night as high pressure builds in from the west, allowing for favorable radiational cooling conditions. Wednesday through Thursday...Heights rise aloft and we get into some flat upper ridging with upper-level W/NW flow. The surface high remains overhead Wednesday, then begins to shift off to the east Thursday. The result will be dry conditions both days. Highs Wednesday will be a degree or two warmer than Tuesday with the coldest air aloft having moved off to our east. Highs Thursday will be in the 70s for the terrain and low to mid 80s for valley areas as we see warm advection with low-level southwest flow on the backside of the departing surface high. Lows Wednesday night will be in the 40s and 50s again. Thursday night through Saturday... Upper troughing approaches from the west, and a shortwave trough or closed upper low tracks to our north. The upper forcing will allow for the formation of a surface low that will track through southeastern Canada, and the trailing cold front will track through our region, bringing chances for showers and possibly some thunderstorms. As expected, there is some uncertainty in the timing of the front this far out, but overall the trend in the latest guidance has been for a slower frontal passage with the best chance for any showers/storms on Friday. This would allow for the front to clear our region to the east by Saturday, but due to the uncertain timing have maintained slight chance PoPs for Saturday, which could work out even with the front to our east as that would place the upper trough axis overhead. Thursday night and Friday night will be warmer, with lows in the 50s and 60s. Highs Friday and Saturday in the 70s and 80s. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... Through 06Z Sunday...Any fog/mist at PSF/GFL should lift by 12z, with VFR conditions expected this morning with increasing mid and high clouds. A few showers are possible near POU this morning, and have included VCSH to reflect this. Chances for showers increase towards the mid to late morning, at which point VCSH groups were introduced at the other TAF sites. The main batch of showers and storms moves in mid-afternoon which is an hour or so later than indicated with the previous TAF issuance. Once the steadier showers move in, conditions trend down to MVFR vsbys and MVFR to low-end VFR cigs. There is also a chance for thunderstorms at all of the TAF sites this afternoon, and prob30s were converted to tempo groups highlighting this potential with little change in the timing. In heavier showers and thunderstorms, MVFR to IFR vsbys and MVFR cigs are expected. Showers and storms come to an end around sunset this evening from northwest to southeast, with just some lingering SCT to BKN mid-level clouds and VFR conditions expected through the end of the TAF period, although borderline MVFR cigs are possible at PSF through most of tonight. Winds will be light and variable this morning, then pick up from the west at ALB and PSF to around 5-10 kt by mid to late morning. GFL will be north of a wind shift boundary, and winds here will be from the NE at 5-10 kt. POU, which remains south of the boundary through the morning, will see winds at 5-10 kt from the southwest. Winds increase to around 10 kt through the afternoon, then abruptly shift to the north at around 10 kt behind a cold frontal passage this evening. Winds remain northwesterly at 5-10 kt through 12z Sunday. Outlook... Sunday Night: No Operational Impact. NO SIG WX. Monday: Low Operational Impact. Isolated SHRA...TSRA. Monday Night: No Operational Impact. NO SIG WX. Tuesday: Low Operational Impact. Slight Chance of SHRA. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: Moderate Operational Impact. Chance of SHRA. && .HYDROLOGY... Showers and thunderstorms with locally heavy rain will be possible today, especially for areas from around I-90 south. The Weather Prediction Center has included this area in a Slight Risk of excessive rainfall due to the potential for west- east oriented bands of locally heavy rainfall developing associated with thunderstorms. Rainfall of 1-2" in an hour may occur leading to possible isolated flash flooding. A Marginal Risk remains for areas north of I-90. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...Heat Advisory until 6 PM EDT this evening for CTZ001-013. NY...Heat Advisory until 6 PM EDT this evening for NYZ064>066. MA...None. VT...None. && SYNOPSIS...NAS NEAR TERM...NAS/JPV SHORT TERM...NAS LONG TERM...Main AVIATION...Main HYDROLOGY...
Hazardous Weather Outlook National Weather Service Albany NY 417 AM EDT Sat Jul 29 2023 CTZ001-013-NYZ064>066-301100- Northern Litchfield-Southern Litchfield-Eastern Ulster- Western Dutchess-Eastern Dutchess- 417 AM EDT Sat Jul 29 2023 ...HEAT ADVISORY IN EFFECT FROM NOON TODAY TO 6 PM EDT THIS EVENING... This Hazardous Weather Outlook is for northwestern Connecticut and east central New York. .DAY ONE...Today and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. There is Marginal to Slight Risk of severe thunderstorms today as a cold front moves across the region. The main threat is damaging wind gusts. Localized flash flooding is also possible, especially where storms repeatedly move across the same areas. A Slight Risk for excessive rainfall is also in effect for the area. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. MAZ001-025-NYZ032-033-038>043-047>054-058>061-063-082>084-VTZ013>015- 301100- 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-Northern Fulton- Southeast Warren-Southern Washington-Bennington-Western Windham- Eastern Windham- 417 AM EDT Sat Jul 29 2023 This Hazardous Weather Outlook is for western Massachusetts, east central New York, eastern New York and southern Vermont. .DAY ONE...Today and tonight. There is Marginal Risk of severe thunderstorms today as a cold front moves across the region. The main threat is damaging wind gusts. Localized flash flooding is also possible, especially where storms repeatedly move across the same areas. A Marginal to Slight Risk for excessive rainfall is also in effect for the area. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed.
Special Weather Statement
National Weather Service Albany NY
1120 AM EDT Sat Jul 29 2023
NYZ032-033-291600-
Northern Herkimer NY-Hamilton NY-
1120 AM EDT Sat Jul 29 2023
...A strong thunderstorm will impact portions of northwestern
Hamilton and northern Herkimer Counties through NOON EDT...
At 1119 AM EDT, Doppler radar was tracking a strong thunderstorm near
Big Moose, or near Old Forge, moving east at 25 mph.
HAZARD...Winds in excess of 30 mph and heavy rain.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Heavy rains could cause ponding of water.
Locations impacted include...
Old Forge, Inlet, Brown Tract Pond Campground, Limekiln Lake
Campground, Big Moose, Eighth Lake Campground, Eagle Bay, Raquette
Lake, Golden Beach Campground, Alger Island Public Campground, Little
Rapids, Beaver River, Carter Station, Quaker Beach, Partlow,
Sagamore, Brandreth, Woods Lake, Hasbroucks and Russian Lake.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4402 7462 4373 7455 4368 7512 4392 7515
TIME...MOT...LOC 1519Z 258DEG 23KT 4380 7502
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH
JPVThe Ft Drum radar (KTYX), 93 km away, was scanning. The volume nearest the first event began at 15:50 UTC.
16 thunderstorm wind, 3 heat, 2 flood. Local standard time, as filed.
A tree was down blocking both lanes of Bouck Road just south of Widrick Road in the town of Frankfort.
Herkimer County officials reported trees down in Mohawk due to strong thunderstorm winds.
Herkimer County officials reported trees down in Ilion due to strong thunderstorm winds.
Herkimer County officials reported trees in the town of Herkimer due to strong thunderstorm winds.
A tree was reported down.
A large tree was down across Stone Arabia Road.
Large trees were downed from strong thunderstorm winds.
Wires were down at 2536 Route 30A with lawn on fire.
A tree was down at Route 334 near Common Road.
A tree was reported down on Keller Drive.
A tree was down on Lower Prospect Street that hit two houses.
A tree was down on Route 67 between Sacandaga Road and McDonald Drive.
Trees were reported down.
Trees were reported down.
A tree was down on Clizbe Avenue.
Trees were reported down.
Minor Street Flooding was reported near Henrietta Heights in the city of Amsterdam.
There were multiple reports of water over roads and parking lots in East Glenville near Glenridge Road and Saratoga Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2023Every state in 2023This day in weather historyWarnings in New York, July 2023
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: 1107141, 1140619, 1140620, 1140621, 1107142, 1107143, 1107144, 1107145, 1107146, 1107148, 1107157, 1107159, 1107160, 1107161, 1107149, 1107150, 1107163, 1107151, 1107152, 1107154, 1107155.