Tag Archives: snow

NYC Monthly Summary: December 2012

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December 2012 was unusually warm and wet in New York City.  With nineteen out of thirty-one days posting warmer than normal readings, the city’s average monthly temperature reached 41.5°F, which is 3.5°F above normal.

On the precipitation side of things, the city collected 4.80 inches of rain, which is 0.8 inches above average.  This is only the third time this year that NYC received normal to above normal monthly rainfall.    In terms of snow this December, we saw 0.4 inches accumulate in Central Park – all of which fell as part of a wintry mix during the nor’easter on the day after Christmas. This meager snowfall total is 4.4 inches below the city’s long-term norm for the month.

Dec2012_NYCGraph Credit: Weather Gamut

White Christmas

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The holidays are here and many people are dreaming of a white Christmas.  The likelihood of seeing those dreams come true, however, are largely dependent on where you live.

According to NOAA, a white Christmas is defined as having at least one inch of snow on the ground on December 25th. In the Unites States – aside from mountainous regions – the greatest chance of seeing snow for Christmas is in cities across the northern tier of the country.  Average temperatures in that region are usually below freezing  by December.  Moving farther south, the probability of having a white Christmas steadily decreases.

Locally, here in New York City, the odds of having snow on Christmas Day are less than twenty-five percent. This low probability is largely due to the city’s proximity to the Atlantic Ocean and its relatively mild air. This year, despite some recent chilly temperatures, NYC is not expecting a white Christmas.

Snow or no snow, the Weather Gamut wishes you a very happy holiday!

white_christmas_noaa

Probability of a white Christmas based on data from 1981-2010.

Image Credit: NOAA

NYC Monthly Summary: November 2012

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November was unusually chilly in New York City this year.  In fact, we had 24 out of 30 days with below normal temperatures.  This extended stretch of cool weather helped lower the city’s average monthly temperature to 43.9°F, which is 4.2°F below normal.  

In terms of rainfall this November, NYC collected a meager 1.81 inches. That is 2.21 inches below average.  More significant precipitation, however, came in the form of snow.  A nor’easter blustered its way through the city on November 7th and brought the Big Apple its first snowfall of the season – 4.7 inches in Central Park. This accumulation not only set a new daily snowfall record, but also made November 2012 the 6th snowiest November on record.

Graph Credit: The Weather Gamut

Post-Sandy Nor’easter

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A nor’easter blasted the eastern seaboard yesterday from the mid-Atlantic states to New England.  This type of storm is not unusual in the area, but its timing left a lot to be desired.

Arriving only nine days after Super-Storm Sandy devastated the region, this winter storm slammed the area with high winds and heavy, wet snow.  In New York City, 4.7 inches of snow was reported in Central Park – a new daily snowfall record.

The weight of the snow on the region’s already storm damaged trees caused many branches to break and fall.  This, in turn, resulted in even more power outages in communities still struggling to recover from Sandy, adding insult to injury for tens of thousands of people.

The local forecast is calling for a significant warm-up over the next few days, so the snow will not be sticking around for long.

First Snow of 2012 in NYC

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On Saturday, New York City received 4.3 inches of snow in Central Park.  This was our first significant snowfall of the season.  The city’s last measurable snowfall was back in October during a surprising pre-season snowstorm.

This winter has been relatively mild, so it was exciting to finally see some snow on the ground.  The local forecast, however, is calling for a major warm up this week.  As a result, this snow will not last long.  However, with more than two months left to the winter season, I am guessing that the snow will be back before long.

Central Park's Lake frozen and covered in snow.

The Sheep's Meadow in Central Park covered by a blanket of snow.

Photo Credit: MF at The Weather Gamut

Thundersnow

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The drama of last week’s pre-winter snowstorm was heightened by the booming sound of thunder-snow. This is the term used to describe thunder and lighting that takes place during a large winter storm, a rare meteorological event.

Thunder-snow, like any thunderstorm, is the result of convective processes. What makes it rare, is the fact that it requires very precise conditions that are unusual in winter. For example, the air near the ground needs to be warmer than the air above it, yet still cool enough to support snow. The main difference between thunder-snow and a regular thunderstorm is the form of precipitation that reaches the ground…snow instead of rain.

Growing up in the northeast, I never experienced thunder-snow until last winter here in New York City. During that busy winter season, we heard it’s startling sound a few times. Last week’s pre-season snowstorm unleashed it again. For a rare phenomenon, it seems to be happening more often. I wonder if there is a reason for this increased frequency?

October Surprise

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A pre-winter snowstorm left its mark on the northeast this weekend.  Heavy, wet snow fell from Maryland to Maine in record amounts for the month of October.

The storm was a classic nor-easter.  It moved up the east coast pulling in moisture from the Atlantic Ocean.  The area of low pressure also pulled in colder air from the NW producing snow, instead of just rain.  In addition, this storm delivered the rare sounds of thunder-snow.

In New York City, we set a new record for October snowfall with 2.9 inches in Central Park!  October snowfall here is rare, but not unprecedented.  The last time we saw the flakes fly this early was in 2002, but that event did not produce any accumulation.  For measurable snowfall (0.1 of an inch or more) in the October, we have to go back to 1952 when 0.5 of an inch fell.  The record amount, prior to this weekend, was 0.8 of an inch in 1925. Typically, we do not see measurable snow in NYC until December.

The excitement of this early snowfall did not come without a price.  Many of the trees in the area still have leaves on their branches.  The leaves provide more surface area for the snow to accumulate.  The extra weight was too much for some trees and caused many branches to break and fall.  In some cases, entire trees were split in two.  In Manhattan, Central Park is reported to have lost 1,000 trees in the storm.  That is more damage than the park endured from Hurricane Irene this past summer. Downed trees also damaged aboveground power-lines causing outages in many areas.

Depending on your point of view, the storm could be seen as Mother Nature’s trick or treat. Either way, the residents of the northeast will remember the snowstorm of Halloween weekend for years to come.

Pumpkin in the snow, October 2011

Autumn Tree in the Snow

Photo credit: MF at The Weather Gamut