Excessive Heat - Severe Weather
Wednesday September 11, 2013

An unusually hot and humid air mass moved into the Northeast on this day resulting in a afternoon of excessive heat and oppressively humid conditions with surface temperatures climbing into the lower 90s and very high dewpoint values ranging through the mid 70s. Peak heat indices in the Capital Region hit 105° making it the hottest feeling day of the entire summer season. The following is the heat trace for Albany from the late morning through the early evening.

Albany, NY Heat Trace

Heat Index

The combination of the high heat and moisture content of the atmosphere and the presence of an elevated mixed layer of air, characterized by warm, moist, and potentially unstable air over a more stable boundary layer, resulted in extremely high atmospheric instability across eastern New York and western New England through the afternoon with surface based convective available potential energy values in the 4000 j/kg to 5000 j/kg range. High instability is favorable for explosive thunderstorm development and severe weather if that energy can be tapped and released. In this case, the elevated mixed layer effectively capped the atmosphere for much of the day preventing thunderstorm development. Further, there were no discernable triggering mechanisms to initiate thunderstorms, like a cold front or trough. And thirdly, winds aloft were not particularly strong meaning overall shear was fairly weak. All these factors contributed to limiting the overall severe thunderstorm potential.

Ultimately, however, thunderstorms developed over northern Pennsylvania and New York's southern tier due in large part to the capping inversion (warm layer of air aloft) being weaker in this region which allowed for updrafts to initiate and rapidly ascend. Once thunderstorms initiated, they had huge amounts of potential energy to work with and thus were able to easily expand to the northeast arriving in the local area through the late afternoon (approximately 4:30pm in the western Catskills) and evening and generally ending in the area by or just before midnight. Overall, severe weather was fairly limited to a few powerful multicell storms which upon updraft collapse produced damaging downburst winds with a measured gust to 70 mph at Saratoga Lake, for example, during the early evening. Very large hail also occurred with one multicell over the Caroga Lake area in Fulton County. Because of the lack of appreciable wind shear in the atmosphere, these storms were not able to organize into a complex and produce widespread severe weather. However, a short line did organize in Washington County (further north in the region where mid level winds were a tad stronger) during the evening which ended up being the cluster that produced the majority of the scattered wind damage reports in the local area as it moved east into Rutland and Bennington counties in Vermont.

Instant Doppler 6 Image: 7:43pm September 11, 2013 showing the organized t'storm line segment moving through Rutland, Bennington and northern Berkshire Counties with widespread general rain and thunder across the remainder of the region.

Instant Doppler 6 Image at around 743pm Sept 11, 2013

STORM REPORTS September 11, 2013

Town County Storm Report Time
Sharon Springs Schoharie Wind Damage: Trees blown down 5:25pm
Carlisle Schoharie Wind Damage: Trees blown down 5:35pm
4 Miles So. Caroga Lake Fulton Large Hail: Estimated 1.25" Diameter 5:52pm
Caroga Lake Fulton Large Hail: Measured 1" Diameter 6:00pm
Peck Lake Fulton 1" hail or larger covering the ground 6:00pm
Peck Lake Fulton Wind Damage: Numerous trees and power poles down 6:00pm
Poland Herkimer Wind Damage: Trees and wires blown down at the intersection of Routes 28 and 8 at Poland-Cold Brook line 6:00pm
Prattsville Greene Wind Damage: Multiple trees blown down 6:10pm
Delmar Albany Lightning strike taking down a tree on Kenwood Avenue 6:22pm
Saratoga Lake Saratoga Wind Damage: Trees down near Route 9P 6:35pm
Saratoga Springs Saratoga Wind Damage: Trees blown down on Union Avenue 6:35pm
1 Mile NE of Saratoga Lake Saratoga Measured 70 mph wind gust, many trees down, power poles snapped 6:35pm
Queensbury Warren Estimated 60 mph wind gust at Potter and West Mountain Rd 6:55pm
Argyle Washington Widespread trees and wires down in and around Argyle and across southern Washington County 7:00pm
Fort Ann Washington Wind Damage: Trees blown down 7:05pm
Queensbury Warren Wind Damage: Trees and branches down across Hidden Hills Drive near Dixon Road 7:06pm
Hartford Washington Wind Damage: Trees blown down 7:10pm
Queensbury Warren Wind Damage: Trees blown down 7:13pm
Arlington, VT Bennington Wind Damage: Large tree uprooted 7:14pm
Granville Washington Wind Damage: Trees blown down, roads closed 7:15pm

This is the Storm Prediction Center (SPC) national severe reports map for September 11, 2013 illustrating the regions where severe weather occurred.

SPC National Severe Reports Map for September 11, 2013 

Storm Photographs

Left: Large Hail from Caroga Lake, photograph posted to Facebook by Robert Witzke - Right: Cloud to ground lightning strike in Catskill, NY from WeatherNet 6 weather watcher Steve Meicht
Large hail in Caroga Lake, Fulton County September 11, 2013
Cloud to ground lightning strike in Catskill, NY September 11, 2013
Left: Storm damage near Saratoga Lake while the storm was still in progress, this is a video frame grab posted to Facebook by Evan Hatch- Right: In cloud lightning over Red Hook Dutchess County, September 11, 2013. This picture posted to Facebook by Elisa Johnson Shaw
Wind damage in Saratoga Lake with the storm still in progress, September 11, 2013
In cloud lightning over Red Hook, Dutchess County September 11, 2013

WeatherNet 6 Rainfall Reports for September 11, 2013

Town County Rainfall Report Town County Rainfall Report
Savoy, MA Berkshire 0.55" Pittsfield, MA Berkshire 0.17"
Clarksburg, MA Berkshire 0.51"      
Newtonville Albany 0.21" Latham Albany 0.41"
Westmere Albany 0.09" Preston Hollow Albany 0.31"
Germantown Columbia 0.52" Livingston Columbia 0.21"
North Chatham Columbia 0.28" Hudson Columbia 0.40"
Arkville Delaware 1.60"      
Catskill Greene 0.21" Round Top Greene 0.21"
Halcott Greene 1.70"      
Fonda Montgomery 0.22" Amsterdam Montgomery 0.15"
Hessville Montgomery 0.19"      
East Worcester Otsego 0.42" Cooperstown Otsego 0.50"
Oneonta Otsego 0.34" to 0.40"      
Center Brunswick Rensselaer 0.60" Berlin Rensselaer 0.40"
Saratoga Springs Saratoga 0.25" Edinburg Saratoga 0.40"
Charlton Saratoga 0.15" Clifton Park (Oaks) Saratoga 0.28"
Jefferson Schoharie 0.80" Richmondville Schoharie 0.36"
Ulster Park Ulster 0.05" Kingston Ulster 0.04"
Claryville Ulster 1.50" Phoenicia Ulster 0.90"
West Shokan Ulster 0.16"      
Warrensburg Warren 0.14" Brant Lake Warren 0.19"
Hudson Falls Washington 0.12"      
West Arlington, VT Bennington 0.62" Landgrove, VT Bennington 1.07"
Woodford, VT Bennington 0.51" West Rutland, VT Rutland 0.10"