By Joe D'Aleo
Monday, October 27, 2008
We will start this week with the two premier storms affecting the northeast ranked number 1 and 2 on the Northeast Storm Impact list compiled by Paul Kocin and Lou Uccellini in their AMS monograph on Northeast Snowstorms.
Storm of the Century March 12-15, 1993
It was an El Nino year that had delivered lots of snow for New England but was rather mild and lackluster in many areas. Then came this mid-March blockbuster that was well predicted by the computer models days in advance and was being hyped in the media as a storm likely to be historic. Unlike many other storms, this storm lived up to the hype.
A very strong southern branch system rich with tropical moisture was shown to be picked up with a very amplifying northern branch trough. Very strong thermal contrast and plentiful moisture was correctly forecast by the models to combine produce a major storm. For a change all the models agreed on this scenario.
For the first time, National Weather Service forecasters and those in private industry were able to forecast a storm of this magnitude at least five days in advance and provide storm and blizzard warnings two days in advance. This was unprecedented.
The five-day lead time allowed the NWS and private industry to warn the 100,000,000 people in the eastern third of the United States of this impending natural disaster.
With a level of confidence they had never experienced, forecasters began using terms like “of historic proportions” to describe the impending storm. In turn, this allowed, for the first time, officials such as the governors of New York and the New England states to declare states of emergency prior to the first snow flake falling on their states and take actions to mitigate potential disaster.
The storm became one of the most intense nor'easters to ever strike the Eastern United States. Record low pressures, wind speeds, low temperatures and mountainous snowfall amounts were more than enough for this storm to gain the status of "Storm of the Century" early in its existence.
Indeed, this storm was monumental, killing over 250 people and cancelling 25% of the United States' flights for two days. On March 12, 1993, a newly formed cyclone moved into a low level baroclinic zone already in place over the Gulf of Mexico and began to rapidly intensify. The deepening cyclone turned northeastward and the storm made landfall in northwestern Florida during the early hours of March 13. An intense squall line preceding a rapidly moving cold front swept across Florida with torrential downpours, wind gusts in excess of 90 miles per hour, 9 to 13 foot storm surges and 11 confirmed tornado touchdowns.
Also by this time, widespread moderate to heavy snows extended from Alabama to New York, virtually paralyzing the eastern third of the country. 50 inches fell on Mt. Mitchell in North Carolina, 44 inches in Snowshoe, West Virginia and 43 inches in Syracuse, New York.
Surface maps from Kocin and Uccelini Northeast Snowstorms, AMS Monograph
A downed tree and snow-covered automobile attest to the magnitude of snowfall in the Asheville, North Carolina area. Photo courtesy of NOAA taken March 14, 1993.
An intense pressure gradient developed from the rapidly dropping central pressure, resulting in strong winds up and down the East Coast from 110 mph in Franklin County, Florida to 101 mph Flat Top Mountain, North Carolina and 144 on Mt. Washington in New Hampshire.
THE BLIZZARD AND WINTER OF 1995/96
The winter of 1995/96 was a record breaker for many of the big cities of the east and central United States. A very weak La Nina winter with very strong repetitive Atlantic blocking situation produced a continuous series of moderate snowstorms and one blockbuster storm called the “Blizzard of ‘96”.Normally La Ninas bring a northern storm track and snows only across the northern tier. (like 2007/08 when the storm track was steady across the north resulting in record snowfall from Oregon to Colorado, parts of Wisconsin, Michigan, Ohio and northern New England). But 1995/96 blocking events were so strong, they suppressed the storm track south. A classic “neck of the high” polar air mass covered areas north and west of the system providing the cold air, both the Gulf and Atlantic provided the moisture.
Surface maps from Kocin and Uccelini, Northeast Snowstorms, AMS monograph
The Book “Washington Weather” described its effect on the Nation’s Capitol.
“The Blizzard of 1996 was incredibly massive and truly historic in its scope. All-time snowfall records were widespread, including 24.9 inches in Roanoke, Virginia; 30.7 inches in Philadelphia, Pennsylvania; 27.8 in Newark, New Jersey; and 14.4 inches as far away as Cincinnati, Ohio. Every city along the northeast megalopolis, from Washington to Boston, received between 17 to 30 inches of snow. While other storms have been bigger in any given city, it appears that there has never been a greater snowfall event for such a large, highly populated area of the Eastern U.S.
Snow began falling in Washington during the late evening of Saturday, January 6 and continued at an amazingly steady rate until mid-afternoon Sunday, January 7. By that time, 13 to 17 inches of snow had accumulated in most areas, with up to 20 inches in the distant western suburbs. For several hours during the afternoon, sleet took over, primarily in the eastern suburbs. The precipitation stopped during late Sunday afternoon and early evening, giving the impression that the worst of the storm was over.
But this proved to be just a lull. During the overnight hours, as the storm crawled slowly north along the Delmarva Peninsula, bands of heavy snow redeveloped and swept into the area from the east. The snow bands were accompanied by lightning, thunder and whiteout conditions. Gusty north winds, which at times approached 40 mph, created a blizzard-like scene. By Monday morning, January 8, the snow squalls had tapered off, leaving the Washington Metro area buried under 15 to 25 inches of snow.
The snowfall ranged between 15 to 20 inches in the southeastern portion of the metro area and 20 to 25 inches in the northern and western suburbs. National Airport received 17.1 inches of snow, Dulles Airport received 24.6 inches of snow and BWI received 22.5 inches of snow. In nearby northern and western suburbs, Silver Spring, Maryland received 23 inches of snow and McLean, Virginia received 22 inches of snow. Totals were even heavier farther to the north and west, with Rockville, Maryland receiving 25.7 inches of snow and Damascus, Maryland receiving 30 inches of snow.”
Fairfax, Virginia after the Blizzard of 1996.
THE INFAMOUS WINTER OF 1995/96
The storms came at a steady stream from November to May. By the time, it had warmed enough to produce mainly rain, all-time seasonal snow records were set in many locations. By the end of the 1995-1996 winter season, New York City had experienced 16 snowstorms and recorded more than 75 inches of snow. In many cases, seasonal snowfall exceeded 250 or even 300% of the normal.
THE LOCATIONS WHERE 1995/96 SNOWFALL EXCEEDED ALL-TIME RECORDS
Sault Ste. Marie, MI
Blue Hill Observatory, MA
International Falls, MN
Windsor Locks, CT
N.Y.- Central Park, NY
N.Y.- JFK Airport, NY
Dulles Airport, VA
National Airport, VA
For Boston both 1992/93 and 1995/96 fell in the top 10 snowiest winters.
As you can see the top dozen years has included 5 years the last two decades.
If you have photos to share of these storms, we will post them in a future story. Send images to firstname.lastname@example.org. Your recollections and local details would be welcome and will be posted with the images. We will cover some other storms this decade in this and other regions including one or more of the big snows of last winter in the Midwest in upcoming stories.