Thursday, April 7, 2016
(Unanticipated) Damaging Convective Wind Event

A zone of significant straight line wind damage produced by 50-60 mph winds, with very localized pockets of 80-90 mph winds, occurred between 4 and 5pm across portions of northern Albany, central and eastern Schenectady, central Saratoga, southern Warren and western Washington counties as a result of a passing intense convective line segment tied to an advancing cold front which was moving across the region. We measured a 55 mph wind gust at the CBS6 studios in Niskayuna at 4:03pm with the passage of the line and observed a period of blinding rainfall. A National Weather Service storm damage assessment team determined an 80-90 mph microburst occurred in Rotterdam Junction which was responsible for blowing down several hundred trees. Small hail and a few lightning strikes were reported in a few other locations as well with the fast hitting zone of severe weather.

Photograph contributed via Facebook by Meteorologist Jeremy Davis: Large tree down onto a parked car from the grounds of the Crandall Library, Glens Falls, late afternoon April 7, 2016

Large tree blown down on the Crandall Library grounds, Glens Falls, April 7, 2016

Probable Cause
Although a period of moderate to heavy rainfall was anticipated with a passing frontal system, severe weather was not thought to be likely in the region due to what was expected to be a lack of instability which would have effectively limited the vertical development of any convection along the front and therefore precluded any of the strong wind which was blowing aloft from mixing down to the surface. This, however, was clearly not what happened.

Two factors may have contributed to boosting the instability in the Capital Region just enough to allow for the pocket of severe weather to occur.

1) A period of partial sunshine developed in primarily the Capital Region to Saratoga and Glens Falls for a couple of hours during the morning, which was not forecast. The sun resulted in a temperature boost into the low 60s, vs the mid to upper 50s which was forecast. The couple of degrees of warming, although small, may very well have been enough to create a very small bubble of instability, aided by dewpoints in the upper 40s to around 50°, which would not have been present across the remainder of the region where sunshine did not occur and temperatures did not climb as much and also where severe weather did not occur.

2) A small, but potent, upper level disturbance (cold pocket aloft) may also have tracked up along the front which would have enhanced the instability pocket in the region where surface temperatures climbed into the 60s to allow tall enough storm towers to develop to mix strong wind from aloft down to the ground. The occurrence of a few flashes of lightning indicated storm towers up to 20,000', which in the world of thunderstorms is considered quite shallow, but in this case was sufficiently tall to support severe weather due to an existing belt of 50-60 mph winds as low as 5000'. With winds so strong so low in the atmosphere, the updraft and downdraft couplet, even in a shallow thunderstorm, would be sufficient to tap into that layer of strong wind and mix that momentum down to the ground in the form of damaging straight line surface wind gusts. And this is what was observed to have happened within the small segment over Schenectady County within the broader convective line shown on the Doppler radar image below.

Albany Doppler Radar Image only minutes after the 80-90 mph microburst in Rotterdam Junction (3:58pm) and the 55 mph wind gusts was measured at WRGB in Niskayuna (4:03pm). A 47 mph wind gusts was reported at 4:08pm at the Albany International Airport.

Albany Doppler Radar Base Reflectivity 4:10pm April 7, 2016 

Albany Doppler radar image at 4:29pm as damaging wind was beginning to impact the Glens Falls area. A severe thunderstorm warning had been issued across a broad zone along and east of the line at this time. Lightning, overall, however, was limited due to the shallow nature of the convective line. The line weakened considerably after 5pm as it moved into Rutland and Bennington counties in Vermont where the air was more stable due to lower surface temperatures.

Albany Doppler Base Reflectivity 4:29pm April 7, 2016 

The zone where most of the wind damage occurred between 4 and 5pm on April 7, 2016

The general zone where most of the wind damage occurred between 4 and 5pm April 7, 2016 


NWS Storm Reports for Thursday April 7, 2016. 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 during the event.

Town County Storm Report Time
Altamont Albany Wind damage: Trees uprooted and snapped 3:50pm
Rotterdam Junction Schenectady 80-90 mph microburst, hundreds of trees blown down along a 700 yard long and 70 yard wide path 3:58pm
Guilderland Albany Trees and wires blown down (WxNet 6 spotter report) Approx. 4:00pm
Schenectady Schenectady Large trees blown down in Central Park Approx. 4:00pm
Niskayuna Schenectady Measured 55 mph wind gust at WRGB 4:03pm
Schenectady Schenectady Wind damage, large trees blown down on Elbert and Division Streets 4:00pm-4:10pm
Schenectady Schenectady Large tree blown down on Randall Road 4:04pm
Niskayuna Schenectady 55 mph wind gusts measured at WRGB, Balltown Road 4:03pm
Niskayuna Schenectady Trees and wires blown down on Consaul Road 4:05pm
Rexford Saratoga Multiple large limbs and trees down near Nott and Riverview Roads 4:05pm
Scotia/Glenville Schenectady Numerous trees blown down throughout Scotia/Glenville 4:05pm
Hampton Manor Rensselaer One tree blown down on Ontario Avenue 4:10pm
1 Mile SSW Saratoga Saratoga Trees and power line blown down on Route 9P near Lake Road 4:15pm
Malta/Milton Saratoga Numerous trees blown down 4:15pm
Glens Falls Warren Damage to a garage and roof on Flandreaux Avenue 4:43pm
Glens Falls Warren Large tree down on a car from the Crandall Library property 4:40pm
Queensbury Warren Several trees down on houses on Meadowbook Road 4:40pm
2 Miles NNE Milton Saratoga Many uprooted trees on Duchess Court 4:21pm
1 Mile North of Glens Falls Warren Garage destroyed and roof damage to homes on Fowler St. 4:40pm
1 Mile S. Pattens Mills Washington Measured 59 mph wind gust (Kingsbury) 4:55pm


Significant Wind Damage in Glens Falls, photographs contributed via email from Joshua S., April 7, 2016

Wind Damage, Glens Falls, April 7, 2016

Glens Falls Area April 7, 2016

Wind Damage, Glens Falls, April 7, 2016


Wind Damage, Glens Falls, April 7, 2016

 

Wind Damage, Glens Falls, April 7, 2016 

Rainfall was locally torrential with the passing convective line with 1/2" to 3/4" in under a half an hour recorded at some locations and near zero visibility for up to five minutes in the regions that experienced high wind as it went through. The rainfall reports are storm totals for the day with some of the reports including a bit of additional rain which fell between midnight and 8am on the 8th as a result of a passing upper level disturbance.

WeatherNet 6 Rainfall Reports for Thursday April 7 through 8am Friday April 8, 2016

Town County Rainfall Report Town County Rainfall Report
New Marlborough, MA Berkshire 0.62" (8am/8th) Lanesborough, MA Berkshire 0.80" (6pm/7th)
Pittsfield, MA Berkshire 0.91" (6am/8th) Clarksburg, MA Berkshire 0.68" (5am/8th)
           
Glenmont Albany 0.59" (6am/8th) Westmere Albany 0.41" (11pm/7th)
Feura Bush Albany 0.50" (11pm/7th) Latham Albany 0.55" (5pm/7th)
           
Livingston Columbia 0.41" (8am/8th) Ancramdale Columbia 0.38" (6am/8th)
Germantown Columbia 0.45" (5pm/7th) Taghkanic Columbia 0.42" (7am/8th)
           
Arkville Delaware 1.00" (11pm/7th) Roxbury Delaware 0.25" (4pm/7th)
           
Perth Fulton 0.84" (10pm/7th) Fish House Fulton 0.90" (6pm/7th)
Broadalbin Fulton 0.90" (7am/8th)      
           
Round Top Greene 0.66" (11pm/7th) Halcott Center Greene 1.15" (8am/8th)
Cairo Greene 0.70" (5pm/7th) West Kill Greene 1.02" (5pm/7th)
           
Wells Hamilton 1.53" (5pm/7th) Piseco Hamilton 0.90" (5pm/7th)
           
Florida Montgomery 0.70" (11pm/7th) Amsterdam Montgomery 0.51" to 0.60" (7th)
Glen Montgomery 0.75" (11pm/7th) Fonda Montgomery 0.76" (11pm/7th)
Hessville Montgomery 0.96" (6pm/7th)      
           
Oneonta Otsego 0.90" to 1.00" (7th) Worcester Otsego 1.17" (5pm/7th)
           
Center Brunswick Rensselaer 0.32" (11pm/7th) Lansingburgh Rensselaer 0.50" (5pm/7th)
Speigletown Rensselaer 0.40" (5pm/7th)      
           
Malta Saratoga 0.27" (11pm/7th) Milton Saratoga 0.30" (9pm/7th)
Wilton Saratoga 0.47" (5pm/7th) Corinth Saratoga 0.40" (5pm/7th)
Ballston Lake Saratoga 0.35" (5pm/7th)      
           
Jefferson Schoharie 0.85" (10pm/7th) Charlotteville Schoharie 0.75" (6pm/7th)
Huntersland Schoharie 0.68" (5pm/7th)    
Gilboa Schoharie 1.00" (5pm/7th) Richmondville Schoharie 0.82" (5pm/7th)
           
Saugerties Ulster 0.71" (6pm/7th) Phoenicia Ulster 1.23" (6pm/7th)
Whiteport Ulster 0.40" (5pm/7th) Esopus Ulster 0.28" (4pm/7th
           
Warrensburg Warren 0.50" (5pm/7th) Brant Lake Warren 0.46" (5pm/7th)
           
Landgrove, VT Bennington 0.64" (11pm/7th) Woodford, VT Bennington 0.69" (6pm/7th)
Manchester, VT Bennington 0.58" to 0.69" (7th) Pownal, VT Bennington 0.33" (5pm/7th)
West Rutland, VT Rutland 0.40" (8am/8th) Pawlet, VT Rutland 0.54" (8am/8th)

Additional Storm Photographs

WeatherNet 6 weather spotter Michael Cournoyer Sr. - This is Michael's house and car in Malta, Saratoga County, after the storms moved through, April 7, 2016
Wind damage in Malta, Saratoga County, April 7, 2016

Tree damage in the Stockade District in Schenectady, Schenectady County, April 7, 2016 - Photograph contributed via email by Stephen Reichert
Wind damage in the Stockade District in Schenectady, April 7, 2016 
Tree damage on Maple Avenue in Glenville, April 7, 2016 - Photograph contributed via Facebook by Sandra Ann Bourgeault Pudim

Glenville Storm Damage, Schenectady County, April 7, 2016

 Tree damage into a home in Glenville - Photograph contributed via email by Neil James

Glenville, Schenectady County Storm Damage, April 7, 2016

Double rainbow in Granville, Washington County after the storm - Photograph contributed via Facebook by Mary Barker
Double rainbow in Granville, Washington County, after the storm