A March-like Chill in May for NYC

The calendar says mid-May, but it felt more like March in New York City this weekend.

After a warm spring day on Saturday with readings in the 70s, a cold front swept through the region ushering in significantly cooler conditions. The high on Sunday only reached 57°F, which is 13°F below average. This dramatic cool down was also accompanied by strong winds with gusts in excess of 40-mph.

Moving from Sunday into Monday, the over-night low in Central Park fell to a chilly 43°F. That is the coolest May temperature the city has seen in three years. It was also just one degree shy of tying the record low of 42°F set in 1878. Our normal low temperature for this time of year is 54°F.

With Memorial Day – the un-official start of summer – just two weeks away, many New Yorkers will be happy to hear that temperatures are expected to rebound to more seasonable levels later this week.

NYC Monthly Summary: April 2016

April 2016 was a weather rollercoaster in New York City. We had highs that ranged from a balmy 82°F to a chilly 43°F.  But, in the end, the cold and warmth averaged each other out. The city’s mean temperature for the month was 53.3°F, which is only 0.3°F above normal.

In terms of precipitation, April’s famous showers were few and far between this year. The city received a mere 1.60 inches of rain in Central Park. On average, NYC typically gets 4.5 inches of rain for the month. With these parched condtions coming on the heels of scant rainfall in March, the city was listed as “abnormally dry” on the latest report (4/28) from the US Drought Monitor.

Credit: The Weather Gamut

Credit: The Weather Gamut

Revised Numbers Show January 2016 Blizzard was a Record Breaker in NYC

After further review, it turns out that the Blizzard of January 2016 – also known as Winter Storm Jonas – was a record breaker for New York City.

According to the NWS, the storm dumped 27.5 inches of snow in Central Park and not the previously reported 26.8 inches. That makes it the city’s biggest snowstorm on record. The previous reading was a tenth of an inch shy of the now old record that was set in February 2006.

The error was found during an investigation launched in the wake of the historic storm. Snow measurement techniques at eight different sights along the east coast were questioned, as storm totals seemed too high in some places and too low in others. In a statement, NWS Director, Louis Uccellini, said, “Snow measurements are extremely difficult to take because precipitation is inherently variable, a problem compounded by strong winds and compaction during a long duration event.”

In NYC, the mistake stemmed from a communication issue rather than a problem with measurement technique. The Central Park Conservancy, the group responsible for measuring snowfall in Central Park, called their numbers into the NWS office by phone and one of the measurements was written down incorrectly.

In the grand scheme of this massive storm, an extra 0.7 inches of snow may not sound like a lot, but every fraction counts when it comes to records.

Blizzard 2016, NYC. Credit: Melissa Fleming

New Yorkers enjoy the record 27.5 inches of snow dumped on the city by the Blizzard of 2016. Sheep’s Meadow in Central Park, NYC. Credit: Melissa Fleming

First 80° Day of the Year for NYC

It is only April, but it felt more like mid-June in New York City today.

The temperature in Central Park soared to 82°F, which is a whopping 20°F above average. This was the first 80° reading the city has seen since the end of September last year.

The primary driver of this unseasonable warmth is the omega-blocking pattern centered over the eastern US. A persistent ridge of high pressure over the region is allowing warm air from the south to flow further north than it normally would at this time of year.

While it was unusually warm today, it was not a record for the city. That honor belongs to April 18, 1976 when the mercury hit 96°F.  Nonetheless, after a brisk start to April this year, many New Yorkers were out enjoying the summer-like weather.

Speaking Event: The Art and Science of Climate Change

Climate change is a complex scientific subject with a plethora of data-rich reports that detail its causation and diverse impacts. But, not everyone responds to facts and figures or charts and graphs. That is why art can help broaden the public conversation and help create new pathways to understanding this critical issue.

On Friday, April 15th, I will be giving a presentation that I developed called The Art and Science of Climate Change at NYU. Blending my two passions, it introduces the basic science of climate change and explores how artists from around the globe are reacting to its various impacts and possible solutions.

Please contact me to arrange a presentation for your school or organization.

When to Expect the Final Freeze of Spring

Most people often associate spring with flowers and mild weather. But as a transitional season, it can also produce some serious cold spells. Wearing shorts one day and a parka the next, you start to wonder when the cold will finally fade away.

The answer to that question largely depends on where you live. Below is a map from NOAA that shows the typical final freeze dates across the continental US. While actual weather conditions vary from year to year, the dates shown are based on climatology – a thirty-year average of temperature data.

Here in New York City, our last spring freeze usually comes in mid-April.

Credit: NOAA

Credit: NOAA

Dramatic Temperature Swing brings NYC Another Bout of Winter

With unseasonably warm temperatures causing trees and flowers to bloom early across New York City, it has felt like spring here for more than a few weeks. But now, as April begins, winter has come fighting back for an encore performance.

The high temperature in Central Park on Friday was a balmy 79°F.  Today, it was only 45°F and even colder conditions are expected as the week goes on. So, what’s causing this dramatic cool down? The answer lies in the changeable pattern of the jet stream.

A persistent area of high pressure had been sitting off the eastern seaboard recently, creating a ridge in the jet stream and blocking any cold air from moving southward. Now, the pattern has shifted and a trough in the jet stream is allowing cold air to spill out of Canada and across the northeast.

The first wave of chilly air moved through on Sunday and caused powerful winds to whip through the area. The NWS reported winds gusts of 45 mph in Central Park and 64 mph at JFK airport.

Another wave of arctic air is expected tonight. With the temperature projected to plummet into the 20’s, the NWS has issued a freeze warning for the city and surrounding area – bad news for all the early blooming plants and trees. The forecast high for Tuesday is only 39°F. The city’s normal high for this time of year is 57°F and the normal low is 41°F.

As spring is a transitional season, temperature swings between warm and cold are not uncommon. But, after the city’s second warmest winter and fourth warmest March on record, many folks are finding this spring cold snap more than bit jarring.

NYC Monthly Summary: March 2016

March 2016 was more like a lamb than a lion in New York City this year. With an average temperature of 48.9°F in Central Park, which is a staggering 6.4°F above average, it was the city’s 4th warmest March on record.

Overall, we had 23 out of 31 days with above average temperatures. Five of those days posted readings in the 70s and two set new daily high temperature records. Historically, our average temperature for the month is 42.5°F.

While a few warm days in March is not that uncommon, this extended pattern of sustained warmth was unusual. Driven primarily by El Niño, a persistent ridge in the jet stream over the eastern US allowed warm southern air to flow further north than it normally would at this time of year.

Given this unseasonable warmth, it is not surprising that only 0.9 inches of snow was measured in Central Park this March. On average, NYC usually receives 3.90 inches of snow for the month.  Rainfall was also scarce.  In all, the city received a mere 1.17 inches of rain. That is 3.19 inches below normal.

March_Temps

23 out of 31 days posted above average temperatures this March in NYC. Credit: The Weather Gamut

High Winds Whip through NYC

March, a month where the seasons transition from winter to spring, can produce some fickle weather. But, it is probably most famous for strong winds, and they were on full display in New York City yesterday.

According to the NWS, sustained winds of 25mph were measured in Central Park and gusts reached as high as 45mph. A wind advisory was issued in the afternoon and remains in effect until later this evening.

Below is a short video of strong winds whipping a tree in a NYC backyard.  Even though it is largely protected by buildings, it still moves quite a bit.

Video Credit: The Weather Gamut.

After Record Warmth, Spring Started on a Wintry Note in NYC

The first day of spring brought a mix of flowers and snowflakes to New York City this year.

After the Big Apple’s second warmest winter in history and a recent stretch of record warm days, many trees and flowers have already started to bloom – early by local standards. But, for the official start of the spring season, temperatures fell and snowflakes filled the sky. While only a trace of accumulation was measured in Central Park, the frosty conditions were a jarring reminder to many New Yorkers, who had acclimated to the warm temperatures, that March is a transitional month known for changeable weather in the northeast.

The high temperature on the Equinox was 43°F, which is 8°F below average and about 20°F below readings from just a few days ago. It is also interesting to note that the first day of spring was colder than this past Christmas. But, that tells you what type of winter it has been this year.

Looking ahead, temperatures are expected to rebound to above average levels over the next few days.

Christmas was warmer than than the first day spring in NYC. Credit: WG

Christmas was warmer than the first day spring in NYC. Credit: WG

Sheep's Meadow in Central Park is dusted with snow on the first full day of spring. Credit: Central Park Conservancy.

Sheep’s Meadow in Central Park is dusted with  snow on the morning of the first full day of spring.  Image Credit: Central Park Conservancy.