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John Homenuk

You just lived through one of the snowiest periods in NYC’s history

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Sounds dramatic. The response to the title of this article, from some, will likely be: “Well,  obviously.” But when you take a second to consider that we actually did live through one of the snowiest periods in the history of observed weather at New York City, it becomes fairly remarkable. The past 30 days or so have been nothing short of anomalous, with colder than normal temperatures (including a visit from an unusually impressive Polar Vortex) and well above normal snowfall throughout a vast majority of the forecast area.

The statistics don’t only confirm what we’ve known all along, they bring to the surface the reality of just how impressive the past month or so has actually been. The entire winter, in a certain sense, has been a giant anomaly — and it has been relentless. Things came to a bit of a head over the last 30 days, however, and our stats will focus on just how impressive the past month or so has actually been.

Snowfall by season in NYC, including 2013-2014 to date. Image courtesy Yehuda Hyman.

Snowfall by season in NYC, including 2013-2014 to date. Image courtesy Yehuda Hyman.

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Tom Stavola

Winter Outlook 2013-14

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Disclaimer: Long range outlooks continue to be a work in progress, and although our understanding of meteorological processes has grown, the nonlinear, chaotic nature of weather makes this task a very difficult one. With that being said, We will provide meteorological reasoning for what we believe the upcoming winter’s patterns will be!

Primary variables of examination:

  1. El Nino Southern Oscillation (ENSO),
  2. North Atlantic Oscillation (NAO),
  3. Arctic Oscillation (AO),
  4. East Pacific Oscillation (EPO),
  5. Pacific North American index (PNA),
  6.  Sea surface temperature anomalies (SSTA) in the Pacific and Atlantic

Other factors examined but may or may not be mentioned: Pacific Decadal Oscillation (PDO), Atlantic Multi-decadal Oscillation (AMO), Quasi-Biennial Oscillation (QBO), Stratospheric trends and temperature anomalies, Solar trends, specifically geomagnetic activity, solar flux, and sunspots, Pattern persistence, Analog years (years with similar patterns to the current year)

Short Description of Variables:

We will be utilizing the above abbreviations of teleconnection indices throughout the outlook. These variables reflect the atmospheric circulation patterns for certain geographical areas. The AO refers to patterns within the Arctic circle, the NAO in the north Atlantic, the PNA in the western part of North America, and the EPO in the northern/eastern Pacific, Alaska and western Canada. If you are a cold / snow lover in the Eastern US, you generally want to see the above indices in their negative phase, except for the PNA, which is more favorable in its positive phase for Eastern cold. Negative AO, NAO, and EPO generally correlate to enhanced blocking and high pressure to our north, and to balance it out, low pressure and troughs usually form underneath in the middle latitudes (our area). In contrast, positive AO, NAO, and EPO generally yield low pressure and less blocking to our north, and as a balance, we experience high pressure and more ridging. There are exceptions to the rules, but most of the time, if you like cold / snow, the preferred index phases are negative AO, NAO, EPO, and positive PNA.

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