Wednesday February 14, Valentine's Day Mega Nor'easter
It had been a little over five years since the region was last hit with a storm of comparable intensity with the last major Nor'easter of this type occurring on Christmas day, 2002 when 21" of snow was dumped on Albany in a little over ten hours setting records across the region. This storm, although similar in many ways to the Christmas 2002 storm, dumped less snow on Albany than the 2002 event. Officially, the measurement at the Albany National Weather service office at the CESTM building on Fuller road in Albany was 16.8", good enough to rank the event as the 5th all time greatest February snowstorm since records have been kept dating back to the mid 1800's. Ironically the greatest February snowstorm, 23.5", occurred on February 14, 1914, 93 years earlier to the day. Despite the comparably relatively low snowfall measurement at downtown Albany this storm will be remembered and ranked as one of the all time greats for the region because of the enormity of the zone of 30"-36" snows that occurred just west of the Hudson valley through the Catskills, north through the Mohawk valley, and Adirondacks with an equally large area surrounding that of 20"-30" snows. Schools remained closed through Friday (three consecutive days) in many of the districts hit with the heaviest snow as the magnitude of the storm overwhelmed the abilities of many cities and towns to quickly and adequately clear and remove snow.
Observed Snowfall Distribution Map for the February 14, 2007 Event
(This distribution map was created using snowfall reports from WRGB's exclusive WeatherNet 6 spotter group as well as observations taken from National Weather Service spotters.)
A primary low pressure system developed from a southern branch jet stream disturbance over the Plains states Monday morning, February 12. The storm, as it ramped up through late Monday afternoon and evening, helped to cause severe weather along the gulf coast resulting in a major tornado touchdown in New Orleans that destroyed a number of homes and caused one fatality. On Tuesday, February 13, the storm tracked through the Midwest putting down a combination of heavy snow, sleet and freezing rain. Six inches of wind driven snow fell at Chicago, with 10-15" of snow and blizzard conditions at Indianapolis, IN, Columbus, and Cleveland, OH, by Tuesday evening. By 10pm Tuesday the primary low center had moved to northeast Kentucky and began gradually weakening as a new storm began forming quickly along the South Carolina coast.
The presence of three key players in the atmosphere at this stage of development on Tuesday evening February 13 stacked the deck in favor of major east coast cyclogenesis (storm formation).
The strength and favorable interaction of the features at the jet stream level as well as the low level temperature contrast zone along the coast were the key elements into driving the strong east coast cyclogenesis (storm formation) Tuesday night through Wednesday morning. But it was the combination of a favorable storm track, to the northeast up along the coast and then over or just south of Boston by the evening, the very cold air over the region which caused the snow to be very light and fluffy (a water to snow ratio on average of 12:1 to 15:1, meaning an inch of liquid would produce 12" to 15" of snow, (a more typical ratio is 10:1) and the unusually rich plume of moisture that was available for the storm to tap, were the key reasons why the storm became such an efficient and monumental snow producer for the local area. In fact, it was the deep subtropical moisture plume, a feature not always present in big east coast storm events, that was the main reason why so much snow fell within the small scale intense snow bands that developed as a result of the explosive intensification of the system.
Snow broke out across the region shortly after 9pm during the evening of Tuesday the 13th, mainly the result of the overrunning of the warmer moist air being forced northward over the cold air in place over the Northeast (air temperatures in the single digits with dewpoints near -5°), by the weakening primary low pressure system located over Kentucky. Snow picked up quickly in fits and bursts through midnight with up to an inch and a half of accumulation in parts of the Catskills as well as the mid Hudson valley. A fine powdery light to moderate snow filled in across the region through the pre-dawn hours of the 14th with average accumulations by 8am Wednesday ranging from 3 "-7". As the coastal storm quickly took over early Wednesday morning and began a process of rapid intensification, small scale bands of exceptionally heavy snow developed and were spiraled to the northwest of the low center up through eastern New York. Snowfall rates within these bands ranged from 4"-6" per hour at times over the Catskills, Mohawk valley, and Adirondacks where banding became semi-stationary through the evening. Between 11:40am and 12:40pm in the town of Worcester, NY in Otsego County, at an elevation of approximately 2000', a total of 6" of snow fell during a zero visibility burst in that hour.
The colossal snowfall rates along with the light fluffy nature to the snow caused blinding white out conditions in increasing NNE winds to 25 and 30 mph in gusts. (A Blizzard warning was issued from the Capital Region on north and west and across Vermont to account for the increasing wind and visibility frequently dropping below 1/4 mile, although true Blizzard conditions did not occur in the Capital Region, but likely did in the higher elevations. A blizzard is defined a severe winter storm producing sustained winds or gusts to 35 mph or greater and a visibility of 1/4 mile or less occurring for three hours or more.)
From the greater Capital Region on east the scene was a bit different than it was in areas immediately to the west due to the storm tracking just close enough to allow a brief period of mid level warming to race in from the east around the circulation causing snow to mix with or change over completely to sleet during the mid morning into the afternoon before changing back to snow later in the day. The sleet was most efficient at cutting down snow accumulations in Berkshire County, and the mid Hudson valley where storm total snowfall amounts ranged from 8"-15" on average . Further south and east of the region, and much closer to the storm track, sleet was the predominant precipitation type with Hartford, CT reporting a storm total accumulation of 3" of sleet and no snow. Rain fell for a period southeast of Hartford, CT up to Boston as the storm circulated warmer ocean air into southeast New England. The easterly wind flow, (cold conveyor belt) around the intensifying storm increased to between 80 an 90 knots in the layer between 5000 and 15000 feet above ground level. The very strong flow effectively transported rich ocean moisture from the subtropical plume back over the cold air over New York and western New England feeding the small scale banding features that produced the extreme snowfall rates and epic accumulations. The easterly flow, however, also downsloped off of the higher terrain in western New England, drying slightly, accounting for the very narrow zone of slightly reduced snowfall accumulations up into Bennington and southeast Washington counties depicted on the snowfall distribution map.
Snow fell heavily through the evening but began quickly breaking up after 8pm with the last narrow band of moderate snow exiting New York by midnight and moving out of western New England by 2am on Thursday the 15th, marking an end to the storm. Strong gusty winds to 45 mph continued through Friday, February 16 along with very cold air creating blowing and drifting snow issues and very low wind chills at times.
The table lists the reported storm total snowfall amounts for the Wednesday, February 14 storm. Reports were compiled from both WRGB's exclusive WeatherNet 6 spotter network as well as from Albany National Weather Service Cooperative observers. (Note: Storm totals with an asterisk next to the town name are National Weather Service reports. All other reports are from WRGB's WeatherNet 6.)