March is a month notorious for some of our largest snow storms and most severe blizzards due in part to increased baroclinicity (tighter temperature gradients) in the atmosphere and the availability of a bit more moisture with what is often no shortage of cold air, with the blizzard that occurred on March 17, 2017 a case example. In context, true blizzards are about a once in ten year occurrence in our area as getting the wind criteria, of three consecutive hours or more of sustained or gusting winds of 35 mph or greater causing a prolonged reduction in the visibility to 1/4 mile or less, is tough to do here. But it did happen in this event with a true blockbuster that checked every box in terms of winter storm severity.
Tuesday-Wednesday March 14-15, 2017
Blizzard
Not since the Valentine's Day super nor'easter, a decade earlier, on February 14, 2007, had the region seen a storm of the magnitude of this one on Tuesday March 14, 2017. The storm spanned from roughly 3-4am on the 14th through 2"-3 am on Wednesday March 15, with the majority of the snow accumulation on the ground by 10-11pm on the 14th.
Snow came in fast and hard early in the morning, accumulating quickly on the cold previously snow free ground. Widespread accumulations of 3"-6" had occurred by 8am across the Catskills, Capital Region, mid Hudson valley and Berkshires with 1"-3" in the Mohawk valley, Adirondacks, and Vermont. Snowfall rates of 2"-3" per hour were common through the day with rates as high as an astonishing 5"-6" per hour across portions of western Hamilton, Herkimer, and western Otsego counties where epic snowfall accumulations of 30"-42" occurred within roughly a twenty two hour period. Strong north to northeast winds produced blizzard conditions across the region with frequent periods of zero visibility from the mid morning through the mid to late afternoon with snow accumulating so quickly it choked off roads making travel all but impossible at times through the day. Blizzard warnings, the first issued for the region since February 14, 2007, were in effect for the majority of the area to account for the winds, which gusted in higher elevation locations, especially across Vermont and the Berkshires, past 50 mph at times, with gusts ranging from 35-40 mph in valley locations as the storm raged.
It was a cold storm as well, with temperatures ranging through the lower to mid 20s with wind chills generally in the single digits and lower teens, dropping to near zero at times after dark. The cold storm profile in the end was beneficial, supporting a dry snow (snow to liquid ratio of about 11:1) limiting substantial accumulations on branches and trees which prevented widespread power outages from occurring, a problem that was pronounced across eastern New England where the snow was wetter in consistency.
The storm impacted the entire Northeast with a state of emergency declared across all of New York as well as specific states of emergency for individual counties. All schools, government offices, and malls shut down for the day with some schools remaining closed on the 15th long after the majority of the snow had ended. Albany International airport saw most of its flights, incoming and outbound, cancelled for the day with significant delays lasting through the 15th as planes, which ordinarily would have been located at Albany and other Northeast airports had been moved out of the storm's path, and had to be brought back in.
The official snowfall measurement at the Albany Airport (the measurement that goes into Albany's climate record) was 17", one of the lower totals from across the region, but almost identical to what had fallen with the Valentine's day storm in 2007 (16.8".) The 17" with this storm made it the 6th heaviest March snow storm on record (to date) and also broke the daily 24 hour snowfall record on the 14th which previously was 12.9"/1958. This was also the largest snowfall from a single storm at Albany since the 18" accumulation in the December 6-7, 2003.
MODIS 1km visible satellite picture taken on Thursday, March 16, 2017 showing the snow cover created by the storm
WeatherNet 6 Snowfall Amount and Distribution Analysis of the March 14-15, 2017 Blizzard
Storm Character
This was a classic Nor'easter, forming out of two distinct disturbances, one from the northern branch of the jet, the other from the south with phasing of the two along the mid Atlantic coast during the late night and pre-dawn hours of the 13th and 14th.
Explosive development and intensification occurred during the morning and afternoon of the 14th as the system tracked over the local benchmark across east central Long Island up through southeast Massachusetts into Tuesday night. (Benchmark = the track supporting optimal snowfall for eastern New York and western New England) The storm became a meteorological bomb, (bomb = a barometric pressure drop of at least 1 millibar per hour for twenty four hours) deepening at one point a remarkable 10mb in two hours as strong dynamics aloft came into play along with a strong baroclinic zone along the coast (tight gradient of warm air to cold from the ocean to inland locations.) The rapid intensification coupled with good venting aloft supported tremendous upward vertical velocities in the atmosphere which created bands of exceptionally heavy snow that pivoted quickly from SE to NW across the local area through the morning and the afternoon. The Albany Doppler base reflectivity radar image here shows a particularly intense mesoscale band of exceptionally heavy snow with zero visibility at 11:44 am extending from central and northern Berkshire County through southern Rensselaer, northern Columbia, southern Albany, northern Greene into Schoharie counties. Snowfall rates in this band were confirmed at 3" to 4" per hour with the band taking about an hour to move through any one location.
As the storm progressed into the early to mid afternoon the westward motion of the heavy snow bands stopped, with a pivot point over the Adirondacks and western Catskills, where a a zone of 2"-4" and briefly 5"-6" per hour snowfall rates sat over western Hamilton, Herkimer, and Otsego counties for several hours as the storm lifted across eastern Long Island into southeastern New England. The result was a plastering in the areas under the darker green to yellow shaded areas on the 2:10 pm Albany Doppler base reflectivity radar image below with storm total snowfall amounts amounts in excess of 3 feet occurring in many instances.
The late morning surface analysis showing the cyclone off the Delmarva on a track which would take it up over eastern Long Island and into southern New England during the evening and overnight period, Tuesday March 14, 2017
As the storm moved past our latitude through the night, the zone of steadier snow moved eastward through the region producing additional accumulations through midnight with a rapid dissipation of the snow shield through 2-3am on the 15th. Additional snow fell in more select areas through the 15th and even into the 16th as a strong west to northwest wind evolved allowing for significant lake effect snows to develop and last in the Adirondacks, Mohawk valley and Catskills as well as significant upslope snows across the northern Taconics, southern Vermont and the Berkshires. Snow totals on top of Woodford Mt., VT, Bennington County by 8 am on Thursday March 16 had reached a whopping 42" due to the combined accumulations from the synoptically generated snow (snow directly as the result of the storm) and the locally terrain driven upslope snows through the morning of the 16th.
Cars in the WRGB parking lot around 1am on Wednesday March 15, 2017 as the storm was winding down. Approximately 18" of accumulated snow with drifts to several feet in many areas - Photograph by Steve LaPointe
Both the Valentine's 2007 storm and this one were remarkably similar in scope and behavior. They both formed in about the same position due to the phasing of northern and southern jet stream branch features. Both had ample supplies of moisture and powerful jet stream winds contributing to tremendous lift in the atmosphere which resulted in rapid intensification and intense banding of heavy snowfall in both cases. Blizzard conditions occurred regionally in both storms due to the combination of heavy blowing snow with strong wind gusts frequently bringing the visibility down to zero. And both tracks were remarkably similar with the 2007 storm also tracking across the eastern Long Island benchmark while undergoing rapid intensification. And incredibly, the snow accumulations at Albany (16.8" in 2007 and 17" in 2017) were almost identical with the zones of heaviest snows in both storms locally just to the west of the Albany area, all occurring in both storms within a 24 hour period.
There were a few differences though, as no two storms are ever completely alike. The 2007 storm had a stronger warm nose in the mid levels develop which allowed for a significant period of sleet in the mid Hudson valley and Berkshires with some into the Capital Region as well, resulting in lower snow totals in those regions as compared to this storm where no sleet occurred resulting in very heavy snows in the mid Hudson valley and Berkshires as well. And on average, the zones of heaviest snow with this storm had somewhat lower snow totals than what was observed in the 2007 storm, but only by a small margin.