Heavy Snow Storm - Strong Mohawk-Hudson Convergence Event
February 9, 2017

Not only did this storm produce the largest regional snowfall of the 2016-2017 season (to date), but it also beat all of the storms in the very quiet and historically snowless winter of 2015-2016. In fact the 11.2" of snow measured at Albany from this storm was the single greatest snowfall in a little over two years with the last snowfall of this magnitude occurring on February 2, 2015 when 11.9" fell. The snowfall amounts and distribution with this storm, however, were more variable, and generally much lighter in most areas as compared to the 2015 storm where most locations came in with a uniform 10"-14". Much lighter amounts of 1"-3" fell over the western Mohawk valley and Adirondacks with this storm, with a large area of 3"-6" snows which extended from the western Catskills through Schoharie County, the eastern Mohawk valley, Saratoga and southern Warren counties, to Washington and Rutland counties. Amounts ramped up to a range of 6"-10" across the eastern Catskills, Albany area through the mid Hudson valley into Berkshire and Litchfield counties with smaller pockets of snowfall ranging from 10"-14" within that zone. This was a fast moving and a cold storm with temperatures generally ranging through the teens through its duration which lead to a particularly dry and fluffy snow with the liquid to snow ratio running around 20:1 (meaning an inch of liquid precipitation would equate to 20" of snow.)

Photographer: WxNet 6 weather watcher Jim Meehan: Snowy scene in Chatham Center, Columbia County February 9, 2017 - 10" of Snow

Snowy scene in Chatham Center, NY February 9, 2017 - 10 inches of snow reported

Set-Up/Storm Character:
This was not a classic heavy snow storm for the region, originating as week wave of low pressure on Wednesday February 8 over the Tennessee valley. However, a strong temperature contrast zone set up for it to feed on with arctic air sitting on the Canadian border contrasting with temperatures well into the 60s and 70s along a stationary front which stretched from the mid Atlantic west through the Tennessee valley attached to the developing low. The strong temperature contrast zone (baroclinic zone) coupled with powerful dual structured jet stream segments allowing the system to effectively vent, produced a favorable environment for rapid intensification of the system as it raced to the northeast spreading snow across Pennsylvania Wednesday night then into eastern New York and western New England prior to daybreak on Thursday. The system was progressive as the parent wave aloft remained opened as it tracked through the region. It's also interesting to note that the snow came after a day in the 40s on Wednesday with some low 50s in the mid Hudson valley and record warmth around New York City and Long Island with highs in the lower 60s.

The storm ultimately passed well south of Long Island and New England through Thursday afternoon rapidly deepening as it moved along. The explosive intensification subsequently resulted in strong mesoscale bands of intense snowfall with rates briefly from 2"-3" per hour from the Capital Region on south into the eastern Catskills, mid Hudson valley, Berkshire and Litchfield counties locally with snowfall rates as high as 4" per hour at times across Connecticut, Rhode Island, and southeast Massachusetts. Approximately 130 lightning strikes were recorded from southeast New York through Connecticut, central and eastern Massachusetts and Rhode Island as the storm "Bombed out" and rapidly moved east. Three to four of those lightning flashes were reported at Poughkeepsie between 5:00am and 5:15am in one of the strong snow bands. And like most powerful low pressure systems the cut-off from very heavy snow to much lighter snow was quite sharp, with areas in the Mohawk valley, Adirondacks, Lake George-Saratoga region to Rutland County, VT picking up much lighter accumulations.

This series of radar images below illustrates the mesoscale banding associated with the storm as it rapidly moved across the region during the morning.

Albany Doppler Radar Image: 4:38am - Snow had quickly overspread most of the area by 4:30 am with a narrow axis of heavy snow at this time extending from northern Bennington, southern Washington, extreme southern Saratoga, eastern Schenectady, northern Albany, southeast Schoharie, and eastern Delaware counties. Snowfall in the narrow zone of dark green and yellow ranged up to 2" per hour.

Albany Doppler Radar Image at 4:38am, February 9, 2017 
Albany Doppler Radar Image: 6:03am - Light to locally moderate snow was falling at this time throughout the region with a mesoscale band of heavy snow (The dark green strip) which extended from southern Bennington County through northern Rensselaer, central Albany, southeast Schoharie, western Greene and eastern Delaware counties. Snowfall rates in this band briefly reached 2" per hour.

Albany Doppler Radar Image at 6:03am, February 9, 2017

Albany Doppler Radar Image: 7:01am - Strong mesoscale banding continued but had shifted into the Berkshires, southeast Albany, Greene, western Ulster and Columbia counties at this time - snowfall rates of 2" to briefly 3" per hour were occurring in zone of darker green and yellow.

Albany Doppler Radar Image at 7:01am, February 9, 2017 

Albany Doppler Radar Image: 9:01am - A strong mesoscale snow band continued over Berkshire, Columbia and extended into northern Dutchess and eastern Ulster counties at this time with brief snowfall rates of 2" to 3" per hour. Snow at this time was also rapidly becoming lighter and shutting down across the Adirondacks, western Mohawk valley and western Catskills.

Albany Doppler Radar Image at 9:01am, February 9, 2017 
Accumulating snow across the local area generally occurred from 2am through 2pm with some spotty very light snow or flurries into the late afternoon in the Hudson valley and across western New England.

Strong Mohawk-Hudson Convergence Event (MHC) - Roughly 11am to 2pm

Synoptic snow rapidly ended in areas west of the Hudson valley between 10am and noon and rapidly tapered off and ended in the Hudson valley and across western New England through the early afternoon. However, favorable conditions for a strong MHC quickly set up with the quick departure of the storm leaving a strong NNE wind flow channeling down the Hudson valley which converged with a strong WNW flow which was being channeled down the Mohawk valley to result in a narrow intense mesoscale band of snow which developed during the late morning across Schenectady, east central Albany and north central and northeast Greene counties. Ample moisture remained in place to fuel the zone of snow which put down snow briefly at rates of 2" to 3" per hour which enhanced snowfall over parts of eastern Schenectady, central and eastern Albany and northeast Greene counties by up to 3"-6". The zone of heavy snow was quite narrow though, with Knox in Albany County out of it and recording a total of 6" of snow for the storm event and Clifton Park just to the east coming in with 5.2" storm total. Snow totals, however, in nearby Guilderland and Voorheesville, within the MHC band were elevated to 12"-14"+.

The following two radar images illustrate the band of locally enhanced heavy snow over Schenectady, Albany, and northern Greene counties due to the MHC.

Albany Doppler Radar Image: 11:01am - The MHC was just starting to emerge as the remaining light synoptic snows (directly associated with the storm) were in the process of shutting down at 11:00am. The narrow, slightly darker band, in Schenectady, central Albany and northern Greene counties is the indication on radar of heavier snow developing in that zone.

Albany Doppler Radar Image at 11:01am, February 9, 2017

Albany Doppler Radar Image: 1:17 pm - Heavy MHC snows were in progress at this time with the darker bands over Schenectady and Albany counties indicating snowfall rates of 2" per hour. The convergence, however, rapidly diminished after 2pm as the wind in the Hudson valley became more northwesterly causing the event to quickly end with only some lingering very light snow in and around the Albany area and southern Rensselaer County through the late afternoon.

Albany Doppler Radar Image at 1:17pm, February 9, 2017 

As the storm departed, skies partially cleared for a view of the late afternoon sunset. But the partial clearing allowed for a further drop in temperatures into the single digits to lower teens after dark, coupled with winds gusting to 20-25 mph brought wind chills down to a range of 0° to -5° on average in the valleys to as low as -10° to -15° over higher elevation locations through midnight. The gusty wind also caused considerable blowing and drifting of the very dry snow.

Photograph shared via facebook by Mike Belli - Schenectady, Thursday February 9, 2017 during the MHC snow burst

Moderate snow in downtown Schenectady on Thursday February 9, 2017

WeatherNet 6 Observed Snowfall Distribution for the February 9, 2017 Storm
(Note: The small area shaded in red in central Albany County is a zone of 14"+ around Voorheesville and Feura Bush)

WeatherNet 6 Observed Snowfall Distribution for the February 9, 2017 Storm 

The snowfall distribution across the region with this storm was highly variable largely due to the small scale banding which occurred both early in the storm and with the MHC event during the late morning and the early afternoon which significantly elevated the totals in eastern Schenectady, central and eastern Albany and north eastern Greene counties. The lighter amounts in the western Mohawk valley and Adirondacks were due to being on the far northwest fringe of the storm.

WeatherNet Storm Total Snowfall Reports for February 9, 2017

Town County Snowfall Report Town County Snowfall Report
Pittsfield, MA Berkshire 9.5" Lanesborough, MA Berkshire 10"
New Marlborough, MA Berkshire 8" Savoy, MA Berkshire 12.2"
Hancock, MA Berkshire 13"      
Coeymans Hollow Albany 12" Colonie Albany 13.2"
Latham Albany 10" Delmar Albany 11"
Glenmont Albany 12.5" Cohoes Albany 9"
Knox Albany 6"      
Austerlitz Columbia 13" Ancramdale Columbia 11.2" to 12"
Chatham Columbia 12" Chatham Center Columbia 10"
North Chatham Columbia 11.5" Livingston Columbia 10.5" to 11.5"
Taghkanic Columbia 11.9"      
Denver Delaware 12" Roxbury Delaware 10.8"
Arkville Delaware 15" Stamford Delaware 10"
Red Hook Dutchess 9" Millbrook Dutchess 8"
Fish House Fulton 4" Perth Fulton 5"
Broadalbin Fulton 4.5"      
Halcott Greene 9" Norton Hill Greene 12"
Durham Greene 9" South Cairo Greene 11"
Athens Greene 11" Greenville Greene 12.5"
West Kill Greene 11" Catskill Greene 10" to 14.8"
Kiskatom Greene 15"      
Wells Hamilton 2.8" Piseco Hamilton 2"
Indian Lake Hamilton 2"      
Amsterdam Montgomery 4.2" to 5.8" Glen Montgomery 3.7"
Stone Ridge Montgomery 4.8" Hessville Montgomery 3.3"
Fonda Montgomery 3.4" Florida Montgomery 6"
Palatine Bridge Montgomery 5"      
Oneonta Otsego 5.1" to 6" Cherry Valley Otsego 4.5"
Worcester Otsego 6" East Worcester Otsego 6"
Center Brunswick Rensselaer 10.5" Berlin Rensselaer 10"
Speigletown Rensselaer 7.5"      
Stillwater Saratoga 4" Milton Saratoga 4.3"
Clifton Park (Oaks) Saratoga 5.2" Ballston Lake Saratoga 5.3"
Mechanicville Saratoga 6" Charlton Saratoga 6"
Lake Desolation Saratoga 3.5" Hadley Saratoga 4"
Malta Saratoga 5"      
Rotterdam Schenectady 8.2" Niskayuna (CBS6) Schenectady 8.5" to 9"
Duanesburg Schenectady 6"      
Charlotteville Schoharie 6" Esperance Schoharie 5"
Richmondville Schoharie 5" Gilboa Schoharie 12"
Schoharie Schoharie 4"      
Phoenicia Ulster 10" West Hurley Ulster 12"
Kingston Ulster 11" Whiteport Ulster 10.5"
Saugerties Ulster 8" Esopus Ulster 9"
Warrensburg Warren 4"      
Hebron Washington 5.5" Hudson Falls Washington 3.3"
Manchester, VT Bennington 7,5: to 8.3" Woodford, VT Bennington 10"
Landgrove, VT Bennington 7.5" Wilmington Windham 8"
Danby, VT Rutland 5" West Rutland, VT Rutland 4"

Photograph contributed via facebook by James Taylor - Athens, Greene County February 9, 2017 - 13.5" of snow

Snowy scene in Athens, NY Greene County February 9, 2017