Major Snow, Ice, and Rain Storm
March 6-7, 2011

Another major La Nina driven storm system, originating largely in the southern branch of the jet stream, crashed through the Northeast, moving slowly, while bringing an enormous amount of moisture over a prolonged period from Saturday March 5 through Monday morning March 7. The brunt of the storm, however, with the greatest impact on the region occurred during the Sunday through Monday morning period when a combination of heavy snow, heavy rain, and significant sleet and freezing rain fell. Storm total rainfall/liquid equivalent precipitation ranged from two to three inches on average. Total snowfall accumulations of 15"-20" occurred on average throughout the Adirondacks, Otsego, and much of Montgomery County, with 6"-10" surrounding that zone which included the rest of the Catskills, Mohawk valley to much of Rutland County, VT. Lesser snow totals of 3"-6" occurred in the Capital Region after rainfall of approximately 1.75" to 2.25" and up to 1/2" of ice accretion. 1"-3" of snow came on the very tail end of the storm in parts of the mid Hudson valley and northern Berkshire County after 2"-4" of rain and icing ranging from .20" to .50".

The Major Snow Zone
Adirondacks-Catskills-Schoharie County-The Mohawk Valley-northern Saratoga, northern Washington, and Rutland Counties
One to two inch per hour snowfall rates developed during the early to mid morning on Sunday in northern Herkimer and Hamilton counties with the snow line moving south into the Mohawk valley, western Catskills, and Schoharie County through the mid to late afternoon. Strong northeast-northeast wind in combination with the heavy snowfall rates produced low visibility and exceptionally hazardous travel conditions from Sunday afternoon through the mid morning on Monday. Scattered power outages were reported due to the combined effects of snow weighting and the strong wind gusts. Minor flooding was also reported in portions of the Mohawk valley as heavy rain preceded the change to snow.

Photographer: WeatherNet 6 Spotter Chris Hayes
Speculator, NY Hamilton County
Monday Afternoon March 7, 2011, 17" Storm Total Snowfall
Photographer: WeatherNet 6 Spotter Sue Buhl
Richmondville, NY Schoharie County
Monday Afternoon March 7, 2011, 21 " Storm Total Snowfall
A heavy snow accumulation of 17 inches in Speculator, Hamilton County  A Heavy Snow accumulation of 21 inches in Richmondville, Schoharie County 

The Heavy Rain to Ice Zone
Capital Region-Bennington County, VT-the Mid Hudson valley

Rain overspread this zone through Sunday morning becoming heavy at times during the afternoon. Temperatures dropped from around 50° at noon with the passage of a cold front to near 30° by the late afternoon and the evening. Mild air remained in place aloft which set the stage for the change to freezing rain, and eventually a mixture of freezing rain and sleet as colder air deepened slightly aloft along the northern edge of the mix zone through Schenectady, southern Saratoga, southern Washington and southern Bennington counties where sleet accumulations ranged from 3/4" to as much as 3" on average. More of a pure wind driven freezing rain developed from Albany on south and through the mid Hudson valley as a low level cold air drainage flow set up. Ice accumulations ranged from .10" to as much as .50" with the higher amounts more widespread from eastern Schenectady, southern Saratoga, southern Washington, southern Bennington, Albany, Rensselaer, and Columbia counties. Numerous power outages occurred in this zone from Sunday night through Monday morning as the combination of heavy ice weighting and strong gusty NNE winds brought down tree branches and trees on power lines. Approximately 10,000 National Grid and NYSEG customers in the Capital Region remained without power through Tuesday March 8.

Photographer: WeatherNet 6 Spotter Spencer Conlin
Eagle Bridge Washington County
Tuesday Afternoon March 8, 2011, Heavy Icing still on the trees
Photographer: WeatherNet 6 Spotter Spencer Conlin
Eagle Bridge Washington County
Tuesday Afternoon March 8, 2011, Heavy Icing still on the trees
A heavy ice accumulation in Eagle Bridge, southern Washington County  A heavy ice accumulation in Eagle Bridge, southern Washington County 

The Main Flood Zone:
Eastern Ulster, eastern Greene, Columbia, Dutchess, southern Berkshire and Litchfield Counties
Preceding a change to ice and a little snow at the tail end of the storm, exceptionally heavy rain fell in these counties from Sunday afternoon through Sunday night, amounting to 2"-4" on average. Widespread urban and poor drainage flooding was reported as well as basement flooding. Minor to locally moderate flooding of small streams and creeks was also reported as the combined runoff from the rainfall and melting snow was more than sufficient to produce significant rises on the waterways. Several ice jams were reported on area rivers and streams, but no significant flooding resulted from the blockages.

Set-Up-Saturday March 5
This storm largely originated from the southern branch of the jet stream, amplifying as it tracked east across the country. High pressure ridging at the jet stream level in advance of the storm over the eastern half of the country caused a lead low pressure system to initially track west of the St. Lawrence valley Saturday March 5. This track allowed a warm frontal passage Saturday morning with scattered light mixed snow, sleet, and rain showers which all but dissipated by the early to mid morning. A mild air mass flowed into eastern New York and western New England through the day with generally dry conditions and temperatures warming to 45°-50°. An advancing cold frontal zone brought the first steady rain to the Adirondacks from Saturday afternoon through Saturday night with rainfall totals ranging from 1/2" to an 1" by early Sunday morning.

Sunday-Sunday Night March 6-7:
Deep southwesterly flow at the jet stream level along the Atlantic seaboard was in place through Sunday night. The flow through this jet transported an anomalously high amount of gulf of Mexico moisture into the region while also causing the eastward progress of the entire system to slow. This resulted in a prolonged period of very heavy precipitation from central New York through western New England as moisture channeled north along the stalling frontal boundary. The precipitation was further enhanced as a strong upper air trough rotating around the base of the mean jet stream flow amplified as it tracked up the Appalachians causing surface storm to form along the front over the mid Atlantic region. This storm rapidly intensified as it tracked north Sunday night, passing east of the eastern tip of Long Island through Monday morning. The combined effects of the storm's circulation pumping the moisture rich Atlantic air over the increasingly cold dome of low level air over New York and the approaching upper air storm produced strong vertical motions in the atmosphere creating a favorable scenario for heavy precipitation. The surface storm also had the effect of slowing the eastward progress of the heavy snow zone as the circulation blocked the advance of the deep cold air. However, the low level northerly cold air drainage flow increased in response to the deepening low pressure system causing surface temperatures to drop below freezing through the night in the mid Hudson valley causing the heavy rain to change to heavy freezing rain.. A north to northeast wind increased with the approach of the storm, gusting at times from 30-40 mph which produced a dramatic weather event with a heavy wind driven snow in the snow zone to a heavy wind driven sleet and ice storm in the narrow mixed precipitation zone, to a torrential wind driven rain storm in the mid Hudson valley to southern Berkshire and Litchfield counties.

Monday March 7:
Heavy snow persisted in the Catskills, Mohawk valley, and Adirondacks through the morning with a change to snow working into the Capital Region and southern Vermont between 4am and 6am. The change to snow in the mid Hudson valley during the morning was brief as rapid drying occurred on the southwest flank of the storm. The circulation moved well northeast of the region by the early afternoon marking an end to the storm. Strong sinking air in the atmosphere behind the storm blew out the clouds allowing for a sunny and dry afternoon.

WeatherNet 6 Observed Snowfall Distribution for the March 6-7, 2011 Storm

March 6-7, 2011 Snowfall Distribution 

WeatherNet Storm Storm Total Combined Sleet and Snowfall Reports for March 6-7, 2011

Town County Snowfall Report Town County Snowfall Report
Pittsfield, MA Berkshire 1/2" Alford, MA Berkshire 1/2"
Savoy, MA Berkshire 1.1"      
Green Island Albany 6.5" Latham Albany 5"
Knox Albany 12" Colonie Albany 5"
Albany (NWS) Albany 6.1" East Berne Albany 6"
Glenmont Albany 3" Preston Hollow Albany 6.5"
Potter Hollow Albany
Voorheesville Albany 5.3"
Feura Bush Albany 3"      
Chatham Center Columbia 3" Livingston Columbia 1.5"
Taghkanic Columbia 1/2" Germantown Columbia 1.5"
Kinderhook Columbia 2"      
Arkville Delaware 10.3" Harpersfield Delaware 8.5" (4:30am) Not a Total
Caroga Lake Fulton 11.5" Gloversville Fulton 10"
Broadalbin Fulton 10.5" Johnstown Fulton 10"
Halcott Greene 6" Prattsville Greene 12"
Ashland Greene 12" Catskill Greene 2" to 3"
Freehold Greene 5.5" Greenville Greene 4"
Cairo Greene 4"      
Blue Mountain Lake Hamilton 23.3" Indian Lake Hamilton 22.5"
Wells Hamilton 19" Speculator Hamilton 17"
Dolgeville Herkimer 12"      
Fonda Montgomery 10" to 12" Glen Montgomery 15"
Hessville Mongtomery 19" Stone Ridge Mongtomery 9.3"
Amsterdam Montgomery 9" to 12.3" Palatine Bridge Mongtomery 15"
Maryland Otsego 16" East Worcester Otsego 15.5"
Cherry Valley Otsego 16" Worcester Otsego 15"
Schenevus Otsego 19" Oneonta Otsego 14.5"
Center Brunswick Rensselaer 5.8" Speigletown Rensselaer 6"
Stephentown Rensselaer 1.5" Berlin Rensselaer 0.8"
Malta Saratoga 6" Gansevoort Saratoga 14"
Clifton Park Saratoga 5.5" Milton Saratoga 8"
Corinth Saratoga 11.5" Charlton Saratoga 5.3"
Saratoga Springs Saratoga 8" to 9.1" Porter Corners Saratoga 13.5" (5am) Not a Total)
Edinburg Saratoga 8" (5am) Not a Total      
Scotia Schenectady 5" Duanesburg Schenectady 12"
Princetown Schenectady 16.5"      
Richmondville Schoharie 21" Summit Schoharie 18"
Middleburgh Schoharie 19.5" Schoharie Schoharie 13"
Esperance Schoharie 16" Huntersland Schoharie 12.5"
Jefferson Schoharie 12" Seward Schoharie 14"
Cobleskill Schoharie 13.5" Charlotteville Schoharie 13.5"
Phoenicia Ulster 1.5" Kingston Ulster 0.2"
Kerhonkson Ulster Trace Highmount Ulster 1"
Saugerties Ulster 0.2" Whiteport Ulster 1/2"
Esopus Ulster Trace      
Warrensburg Warren 15" Brant Lake Warren 17"
Queensbury Warren 15" Lake Luzerne Warren 16.5"
Granville Washington 18" Cossayuna Washington 10.5"
Fort Edward Washington 15" Kingsbury Washington 15"
West Arlington, VT Bennington 3" Landgrove, VT Bennington 1.5"
Woodford, VT Bennington 1.3" Danby, VT Rutland 9.5"
West Rutland, VT Rutland 12.5" East Wallingford, VT Rutland 10"

WeatherNet 6-NWS Rainfall/Liquid Equivalent Reports For the Event

Town County Rainfall/Liquid Equivalent Report
2 Miles NNE of Voorheesville Albany 2.83"
Albany (NWS Office) Albany 2.27"
Albany (Airport) Albany 2.05"
Voorheesville Albany 1.75"
Taghkanic Columbia 3.25"
Clarksburg, MA Berkshire 1.99" (5:30am March 7) Not a Total
Stormville Dutchess 3.78"
Poughkeepsie Dutchess 2.80"
Red Hook Dutchess 2.50"
Northville Fulton 2.26"
Near Gloversville Fulton 2.18"
Catskill Greene 2.45"
Near Indian Lake Hamilton 2.66"
Near Fort Plain Montgomery 2.26"
Averill Park Rensselaer 2.18"
Saratoga Springs Saratoga
Niskayuna Schenectady 2.02"
Kingston Ulster 2.78"
Esopus Ulster 2.00"
Phoenicia Ulster 4.81"
Whiteport Ulster 2.60"
West Shokan Ulster 3.49"

WeatherNet 6 Observed Ice Distribution for the March 6-7, 2011 Storm

March 6-7, 2011 Ice Distribution 

WeatherNet 6-NWS Ice Accumulation Observations For the Event

Town County Ice Accumulation
Boght Corners Albany 0.30"
Feura Bush Albany 0.50"
Albany (NWS) Albany 0.20"
2 Miles NNE of Voorheesville Albany 0.10"
North Adams, MA Berkshire 0.10"
La Granville Dutchess 0.20"
Salt Point Dutchess 0.10"
Taghkanic Columbia 0.40"
Chatham Center Columbia 0.50"
Buskirk Rensselaer 0.50"
Eagle Mills Rensselaer 0.20"
Saratoga Springs Saratoga 0.10"...3/4" of Sleet
Clifton Park (Oaks) Saratoga 0.25" to 0.30"
Mechanicville Saratoga 0.20" to 0.50"
1 Mile NNE Hawthorne Hill Schenectady 0.10"
North Blenheim Schoharie 0.10"
Sunderland, VT Bennington 0.50"
Landgrove, VT Bennington 0.50"
Esopus Ulster Thin Glaze
Cossayuna Washington 1/8" Ice...3" of Sleet