Thursday, July 2, 2020
Hudson Valley Severe Multi-Cell Thunderstorm Event

An interesting and unique small complex of multi-cell severe thunderstorms impacted the Hudson valley from Lake George south through Glens Falls, Saratoga Springs, Albany, Troy, south to Kinderhook, Catskill and Kingston producing intense cloud to ground to lightning, torrential rain, and pockets of microburst wind damage with numerous reports of trees and power lines blown down along the path of the complex. According to National Grid, 41,000 customers lost electricity in the impacted zone with NYSEG reporting 5000 of their customers out due to power line damage with outages in Rensselaer and Columbia counties persisting well into Friday July 3. The image below illustrates the general path with the report markers indicating storm damage reports received and relayed by the Albany National Weather Service. The event was unique due to an unusual north to south track and long life span of the system as it pressed south through the region.

Local storm reports for the July 2, 2020 Event 

SET-UP:
There were no discernible triggers for thunderstorms across the local area where plentiful sunshine well into the afternoon aided in a sharp temperature rise into the upper 80s to low 90s. Dewpoints locally ranged through the mid 60s, which coupled with the high heat and somewhat cool air aloft allowed CAPE (convective available potential energy) to build up toward 1500 to 2000 J/kg which was a considerable amount of thunderstorm fuel, should any thunderstorm be able to form and tap into it. The atmosphere locally, however, was largely capped with weak mid level lapse rates which inhibited local development, but was primed for any thunderstorm that might move into it. Downdraft CAPE, which is a value used to estimate thunderstorm downdraft intensity, climbed to around 1200 J/kg during the afternoon, which is a high value and signified a strong potential for microbursts (strong damaging straight line gusts) from any thunderstorms migrating through the environment.

The event initiated as a small cluster of thunderstorms over Essex county, well north of Lake George early in the afternoon either as the result of some differential heating between higher and lower elevation areas causing some convergence to trigger the storms, or potentially as a result of some convergence running in advance of a slow moving cold front that was located across southern Canada, just north of the New York and Vermont border area at the time in a region of high dewpoint air.

The small thunderstorm cluster which initiated in Essex County moved south to the northern tip of Lake George around Ticonderoga by 3pm tapping into the hot and convectively unstable air mass allowing it to expand in size and intensify. A north to south flow in the atmosphere propelled the developing multi-cell complex south through eastern Warren County along the length of Lake George with development east into Washington County between 3 and 4pm where it reached Glens Falls with frequent cloud to ground lightning and strong wind gusts. Our weather station in Glens Falls, located at about 100' above ground level, so quite elevated, did record a 57 mph wind gust at 4:10pm and a quick 0.88" of rainfall with the passage of the storm.

The storm, now with multiple updraft and downdraft couplets (hence the classification as multi-cell) continued to move or propagate due south through Saratoga and southern Washington counties through 5pm where it further intensified producing a tremendous amount of cloud to ground lightning and pockets of highly localized microburst type wind damage with trees and power lines blown down in spots. The storm continued to press south through Albany and Rensselaer counties through 6pm and then Greene and Columbia counties through 7pm with areas of wind damage being produced along the path. Weakening occurred in Ulster and Dutchess counties through 8pm but there were still some strong downburst winds into Dutchess County which resulted in a few more trees and power lines being blown down before ultimately the storm ran out of gas in the lower Hudson valley prior to reaching New York City.

This is how the storm cluster appeared around 5:30pm on the CBS6 Live Instant Doppler 6 radar over eastern Schenectady, southern Saratoga and northwest Rensselaer counties.

Instant Doppler 6 around 5:30pm Thursday July 2, 2020 

The following series of Albany National Weather Service Doppler radar images chronicle the progress of the storm complex as it moved down the Hudson valley from the mid afternoon through the early evening.

Albany Doppler Radar image the developing storm over northeast Warren County around 3pm July 2, 2020

Albany Doppler Radar image the developing storm over northeast Warren County around 4:15pm July 2, 2020 
Albany Doppler Radar image the developing storm over northeast Warren County around 5:20pm July 2, 2020

Albany Doppler Radar image the developing storm over northeast Warren County around 6pm July 2, 2020

Albany Doppler Radar image the developing storm over northeast Warren County around 7pm July 2, 2020

NWS Storm Reports for Thursday, July 2, 2020. Note, these reports are used to verify the NWS warnings which were issued for this event and therefore do not necessarily represent an accounting for all of the wind damage which may have occurred.

Town County Severe Weather Report Time
3 Miles NE of Queensbury Warren Wind Damage: Tree blown down onto a vehicle on Meadowbrook Rd. 4:09pm
Glens Falls Warren 57 mph gust (100' above ground level) measured on the CBS6 weather station in Monument Square 4:10pm
Glens Falls Warren Wind Damage: Tree split on Ridge Street near the Queensbury Hotel 4:12pm
2 Miles S. of Wilton Saratoga Wind Damage: Tree uprooted by the wind 4:30pm
4 Miles N. of Schuylerville Washington Wind Damage: Tree and wires blown down at Route 4 and Fort Miller Road 4:35pm
Milton Saratoga Wind Damage: Tree blown down at Fern Drive and Hathorn Blvd. 4:40pm
Cambridge Washington Wind Damage: Trees and wires blown down 4:50pm
Cohoes Albany Wind Damage: Tree blown down 5:25pm
Sycaway Rensselaer Wind Damage: Tree snapped on Greene Street 5:28pm
2 Miles SE of Rotterdam Schenectady Wind Damage: Several trees uprooted and limbs snapped in a wooded area near Sandra Lane 5:30pm
Rotterdam Schenectady Wind Damage: A number of trees blown down, one on I-890 eastbound near the Highbridge Rd. exit 5:32pm
Poestenkill Rensselaer Wind Damage: Tree blown down on Weatherwax Rd. Near Victorian Drive 5:35pm
West Sand Lake Rensselaer Wind Damage: Tree blown down on Springer Rd. near Route 43 5:40pm
1 Mile WNW of Albany Albany Wind Damage: Large tree branch snapped leaning on a building 5:48pm
Knox Albany Wind Damage: Tree limb down on Berne-Altamont Road 5:49pm
Niverville columbia NY Route 203 closed due to a tree down on wires 5:49pm
Castleon-on-Hudson Rensselaer Wind Damage: Large tree blown down on Greene Avenue and Chestnut Street 5:51pm
Delmar Albany Wind Damage: Tree and wires blown down 5:55pm
1 Mile NW of Berne Albany Wind Damage: Tree and wires blown down on Rock Road 5:58pm
Berne Albany Wind Damage: Tree blown down blocking a road near the intersection of Pleasant Valley Road and Berne-Altamont Road 5:59pm
Delmar Albany Wind Damage: Large tree blown down 5:59pm
Kinderhook Columbia 51 mph wind gusts measured by the NYS mesonet station 6:00pm
Niverville Columbia Wind Damage: Tree and wires blown down on Little Lake Road and Route 203 6:03pm
2 Miles SE of Niverville Columbia Wind Damage: Tree down on Harris Road 6:03pm
Stottville Columbia Wind Damage: Tree down on Delaware Avenue 6:07pm
Claverack Columbia Wind Damage: Tree and wires blown down on Orchard Road 6:12pm
Ravena Albany Wind Damage: Tree and wires blown down at Fuller Road and Route 9W 6:12pm
4 Miles NNW of Clermont Columbia Wind Damage: Tree blown down onto a house on Hilltop Road 6:22pm
Pine Plaines Dutchess Wind Damage: Tree down on Route 82 north of Church Street 6:53pm
5 Miles WSW of Pine Plaines Dutchess Wind Damage: Tree blown down on Route 199 east of the Taconic Parkway 6:55pm
Fairview Dutchess Wind Damage: Tree blown down on Route 155 and Underhill Road 7:08pm

Storm Reports: Thursday July 2, 2020

Storm Prediction Center Storm Reports For July 2, 2020