Weather

Answers About New York Weather

Cold, New York City, Rain, Snow, Weather, Wind

March 4, 2009 T I M E S B L O G

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Answers About the Weather

By The New York Times

Taking Questions Ask the Meterologist

I. Ross Dickman is answering City Room readers’ questions.

Following is the first set of responses from I. Ross Dickman, meteorologist in charge of the National Weather Service team serving New York City and the metropolitan region. This week, he is answering City Room readers’ questions about his experience and observations working with weather, community planners and emergency managers in the region. Post a question for Mr. Dickman in the comments box below. Please note that this Q. and A. was scheduled before Monday’s snowstorm.

Maybe you could describe the chain of events leading up to the forecasts for this particular storm. When is a decision made to put out an alert or a warning? How did it play out in this case? How precise can you be about the timing of a storm, when it will hit? What data goes into that prediction?

— Posted by Weatherman

For the March 2, 2009, snowstorm, the forecasts were right on target. The local National Weather Service forecast office here in Upton, N.Y. on eastern Long Island issued winter storm watches and warnings with more than 24 hours of lead time as well as heightened awareness of the event that occurred several days in advance. As you might imagine, timely and reliable dissemination of forecasts and warnings is critical to the protection of life and property. When forecast confidence increases to at least 50 percent based on the interpretation of forecast model output, a watch is issued. When forecast confidence increases to at least 80 percent, a warning is issued. Our goal is to issue watches with lead times of 24 to 36 hours and warnings 12 to 18 hours in advance of the storm. For this storm, we provided longer lead times than our goals.

The National Weather Service follows a specific forecast process for all weather situations before putting out a forecast or warning. The process goes something like this: Observations including satellites, upper air data and radar are collected by the local forecast office and then checked for quality, analyzed, and then infused into a suite of computer models at the National Centers for Environmental Prediction. Millions of calculations occur with these models to generate predictions of storm behavior and the general conditions of the atmosphere. The model results are then evaluated and used in the National Weather Service forecast and warning process.

Unfortunately, these models cannot account for all of the short-term changes in the atmosphere, resulting in forecast error or uncertainty. Interpretations of the model guidance are then translated into forecasts and warnings that are coordinated between the national centers and surrounding local forecast offices to ensure consistency. Once completed, the issuing office generates forecast and warning products for release to the public and emergency management groups.

Somehow it seems that New York City is becoming windier. What is causing this, and where do these strong winds we’ve been having recently come from? Thank you.

— Posted by Darinka Zaharieff

Winds in New York City are greatly affected by the buildings, which can greatly increase speeds. We do not have any indication that winds have been on the increase in recent years. Statistically, February and March are the windiest months for New York City, and August and September have the least wind. The National Oceanic and Atmospheric Administration’s National Environmental Satellite, Data and Information Service operates the National Climatic Data Center in Ashville, N.C. The Climatic Data Center is the world’s largest archive of climate data, much of which is online for researchers and the public to query.

When the water surrounding Lower Manhattan rises, what is the projected annual rate of increase? Are the rising waters expected to affect the Hudson and the East Rivers similarly, and what measure do engineers recommend to revamp the seawall?

— Posted by Rima Blair

While I can’t comment on the engineering aspects, I can affirm that rising sea levels and other phenomena like hurricanes are a real threat to the New York City region.

The Center for Climate Systems Research at Columbia University cites these threats. According to the researchers: “Regional sea level trends of the past century range between 0.08 to 0.16 inches per year (2 to 4 millimeters per year). From a suite of sea-level rise scenarios based on an extrapolation of historical trends and outputs from several global climate model simulations, the researchers projected a rise in sea level of 11.8 to 37.5 inches (30 to 95.5 centimeters) in New York City and 9.5 to 42.5 inches (24 to 108 centimeters) in the metropolitan region by the 2080s. Flooding by major storms would inundate many low-lying neighborhoods and shut down the metropolitan transportation system with much greater frequency.”

Severe hurricanes and associated storm surge have the most serious immediate threat to the coastline. The National Oceanic and Atmospheric Administration’s Sea, Lake and Overland Surges From Hurricanes model (SLOSH) shows a Category 3 hurricane on the worst-case track projection has the potential to bring nearly 25 feet of water into Lower Manhattan and surrounding areas.

Is it likely that we will have another big snow event during the rest of the season (winter-spring 2009)? Statistically speaking, where is the coolest place in Brooklyn to chill out during the dog days of summer?

— Posted by Brooklynite

While we could have another significant snowstorm (six inches or greater) this month, it is not likely. Typically, New York has one big snow a year, most commonly in February. On average, March has only a 1 in 5 chance of a significant snowstorm. Interestingly, we have to go all the way back to March 13-14, 1993, to the last time that we had a snowfall of six inches or more, though we came close on March 16, 2007, with 5.5 inches.

As for where to cool off in summer in Brooklyn — Coney Island is the place. The daily sea breeze keeps temperatures the coolest around during a hot summer afternoon.

How can I be a Weather Service storm spotter?

— Posted by David

Your National Weather Service offers the Skywarn Spotter Program to volunteers who are willing to assist Weather Service meteorologists in making warning decisions. A free three-hour spotter training class will be offered this spring, which will be posted to our Skywarn Web site by April 3. You will have to register for a class. You will be trained to recognize and report features associated with rapidly developing, mature, and dissipating thunderstorms that cause hazardous weather. For further information on our Skywarn program, please contact Brian Ciemnecki.

England Gets Slammed With Worst Snowstorm in 18 Years

Crazy Weather, England, London

Large swaths of Britain came to a standstill in the grip of the worst snowstorms for 18 years.

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By Gordon Rayner, Chief Reporter
02 Feb 2009

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Despite five days of severe weather warnings, transport bosses still appeared to have been completely caught out as up to a foot of snow fell across the country, bringing rail, air and road networks to a halt.

They faced a growing public backlash as one in five workers was left stranded at home, at an estimated cost to the economy of £1.2billion.

In London, all bus services were cancelled for the first time in living memory, as a network which had carried on running during the Blitz – and during much worse conditions in 1963 – proved unable to deal with six inches of snow. Cancelled Tube trains added to the chaos in the capital.

Heathrow, Gatwick, London City, Luton, Stansted, Southampton and Birmingham airports were closed for all or part of the day, causing knock-on delays at most regional airports. At Heathrow, a Cyprus Air passenger jet skidded off the taxiway, coming to rest with its front wheel on the grass.

Debates in the Houses of Parliament finished early while some parts of the building did not open as staff could not get in. As hundreds of train services and flights were stopped and drivers faced treacherous conditions on ungritted roads, angry commuters demanded to know why the severe weather warnings had not been properly heeded.

Nigel Humphries, of the Association of British Drivers, said there could be no excuse for the failure of transport authorities to prepare for “entirely predictable weather conditions”.

The British Chambers of Commerce said a “clear lack of preparation” had cost business dearly.

With more snow predicted today and further flurries expected later in the week, Britain’s battered economy could suffer up to £3billion in lost productivity by the end of the week.Snowstorms which swept the country overnight and during the day had first been forecast by the Met Office last Wednesday, when it issued a severe weather warning accurately predicting the blizzards.

Yet local councils and transport authorities were still accused of failing to put adequate plans in place to deal with the weather.

The nature of the response was summed up in London, where main roads had been gritted by Transport for London, keeping them clear, but suburban roads leading to bus depots had not been gritted, stranding the city’s entire bus fleet, which is used by six million people a day.Tens of thousands of commuters braved the cold to walk to work instead, with some even skiing through the capital.

The Highways Agency and local councils were also heavily criticised by motorists for failing to put down enough grit on major roads, including the M25, where a 53-mile tailback built up yesterday morning between junction 19 at Watford and junction 8 at Reigate.

At one stage, it was estimated that there were 1,000 miles of tailbacks across the country.

The Local Government Association said councils had been overwhelmed by the relentless snowfalls, which had covered roads as quickly as they could be cleared, meaning the grit had less impact.

The Highways Agency blamed lorry drivers for clogging up major routes after ignoring advice to stay off the roads.

But David Frost, the director-general of the British Chambers of Commerce, said the collapse of the transport network was unacceptable.

He said: “People of my generation saw much worse winters than this in the 1960s and 1970s, yet things kept going. Why can’t we cope now?

“This weather was forecast five days ago – it’s not as if we suddenly woke up to find six inches of snow outside, and it’s clear that not enough preparation has been done.”

Susie Squire, of the TaxPayers’ Alliance pressure group, said the excuses simply wouldn’t wash with the public.

“Recent conditions do not merit total shutdown, and rail companies, councils and other authorities should have been able to cope,” she said.

“Many other first-world countries keep going in much worse conditions. People see their fares go up and up, and yet services seem to remain at the same sub-standard level.”

Boris Johnson, the Mayor of London, blamed “some of the most challenging weather conditions” for two decades for the disruption.

He said: “The difficulty really has been that the volume of snow has been so huge that you can put down the grit but then it simply snows over it again and you run the risk of unleashing a 12-ton bus on to heavily packed snow or ice and turning it into a lethal weapon.”

But his predecessor, Ken Livingstone, said Londoners had a right to ask why buses had stopped running and 10 of the 11 Tube lines had been crippled. “Boris should have been on the phone from Thursday, when the warnings first started, making sure everyone was prepared for the snowfall,” he said.

“Every few years in the early 1980s we had chaos with the weather but the buses always came out. It’s quite clear the borough councils, either because they wouldn’t pay overtime on a Sunday or because they have cut everything back to the bone, didn’t grit properly, even though there was plenty of advance warning.”

Two brothers died on Snowdon in North Wales after becoming stranded on the mountain as the weather closed in on Sunday night. They are thought to have fallen 700ft. Motoring organisations, meanwhile, said accidents on the roads were “too numerous” to catalogue.

Emergency services were so stretched by the number of road accidents and weather-related emergencies that London Ambulance service said it could only deal with life-threatening incidents.

More than 2,000 schools closed nationwide, operations had to be cancelled at hospitals and many courts and other public buildings shut down. The Federation of Small Businesses estimated that six million people – a fifth of the workforce – had stayed home, costing the economy £1.2 billion in wages and lost sales.

Conditions are unlikely to improve before the weekend, as temperatures are expected to remain below freezing in most parts of the country, turning snow and slush to ice, with yet more snow expected during the rest of the week.

The AA is telling drivers to keep warm clothes in their cars in case of breakdowns. A spokesman said attendants had seen stranded motorists “flirting with hypothermia” by going out unprepared.