Winter Storm Riley Underwent Bombogenesis, Battered the East With Strong Winds, Coastal Flooding and Heavy, Wet Snow (RECAP)

Winter Storm Riley became an intense nor'easter after undergoing bombogenesis off the New England coast March 2-3, producing damaging winds and coastal flooding from New York and New England to North Carolina, following a quick burst of snow in the upper Midwest and Great Lakes Feb. 28-March 1.

(NEWS: At Least 9 Dead, 1.9 Million Without Power)

Riley developed in the Midwest on the last day of February, but it really took shape off the coast of New England March 2-3. The winter storm bombed out off the coast of Massachusetts, bringing near-record high tides to the state and feet of snow across the interior Northeast. This second monster winter storm of the season for the Northeast damaged seawalls and caused extreme beach erosion.

More than 1.9 million were reportedly without power from the mid-Atlantic to the Northeast by the morning of March 3.

High Winds

Low pressure just off the southern New England coast underwent explosive development known as bombogenesis, defined by a rapid drop in atmospheric pressure of at least 24 millibars in a period of 24 hours or less. From 7 p.m. EST March 1 to 4 p.m. EST March 2, the pressure dropped from 1000 millibars to 974 millibars, or a 26-millibar drop in only 21 hours.

Four different locations in Massachusetts reported winds gusts of 90 mph or more, including Barnstable (93 mph), East Falmouth (92 mph), Wellfleet (91 mph) and Nantucket (90 mph).

Wind gusts of 80 mph or greater were clocked in Scituate, Massachusetts, and at Little Compton, Rhode Island (83 mph).

Six states recorded wind gusts of at least 70 mph. Among those locations reporting 70-mph gusts or higher were Boston's Logan Airport (70 mph), Bayville, New York (78 mph), Cape May, New Jersey (71 mph), and Washington's Dulles Airport (71 mph).

Dulles Airport reported gusts over 50 mph for more than 12 hours straight, a rare occurrence, according to the National Weather Service.

In addition to all the wind damage and power outages, these high winds wreaked havoc for some flights into Washington D.C., including extreme turbulence on one flight to Dulles Airport and one aborted landing attempt at Reagan National Airport.

A section of the American Airlines hangar's roof at New York's LaGuardia Airport appeared to have been torn off by high winds, though the initial assessment showed the building was still structurally sound.

As of early March 3, 751 reports of wind damage had been received by local National Weather Service offices in 36 hours covering the duration of the storm. 

The most numerous wind damage reports came in from Virginia (185 reports), Massachusetts (133 reports), then Maryland (108 reports), though wind damage was reported from Maine to North Carolina.

Avery County, North Carolina, 911 reported numerous trees downed across the county on the evening of March 1. A peak gust over 100 mph was clocked atop Grandfather Mountain, North Carolina, early March 2.

Winds were still gusting over 40 mph – mainly in southeastern New England, but also in a few other spots along the East Coast – by the morning of March 3.

Unfortunately, those gusts were still strong enough to trigger yet more wind damage in parts of southeastern Massachusetts.

Water inundated parts of the Massachusetts coastline during the first high-tide cycle late-morning on March 2, and a second period of higher tide occurred late that night with moderate flooding observed.

Moderate flooding was observed at tide gauges in Scituate, Massachusetts, and Boston Harbor on the morning of March 2. The storm tide at Boston Harbor peaked at its third-highest level on record, only topped by Winter Storm Grayson in January and the Blizzard of '78.

The storm caused considerable damage in the coastal town of Scituate: 

A car floating in floodwaters in Braintree, Massachusetts, prompted a water rescue.

These long-lived winds blowing over a long stretch of the ocean, piling onshore, led to additional minor coastal flooding along parts of the Northeast Seaboard through March 4 in some areas. Flood waters were very slow to recede between high-tide cycles.

Flooding at high tides through the morning of March 4 approached levels that typically produce widespread flooding of roads in Atlantic and Ocean counties, Ocean City and Somers Point, Wildwood Crest, Cape May and West Cape May, New Jersey, and Kent and Sussex counties, Delaware, according to the National Weather Service.

In the Outer Banks of North Carolina, oceanside and soundside flooding March 3-4 inundated stretches of Highway 12 near times of high tide.

Snow

Winter Storm Riley developed into a low-pressure system in the eastern Great Lakes on the morning on March 1, initially bringing snow to parts of Wisconsin, Michigan and Ohio. The storm began to push into the interior Northeast late that day with heavy rain and moderate snow.

Snowfall rates of 1 to 2 inches per hour were observed across eastern Michigan on the afternoon of March 1. Ann Arbor, Michigan, picked up 3.1 inches of snow in only 2.5 hours early- to mid-afternoon March 1.

Riley's snow then kicked into high gear on the night of March 1 into March 2.

The town of Wyoming, New York, east of Buffalo, picked up a whopping 24 inches of snow in the 24 hours ending the morning of March 2. Thundersnow was observed in parts of western New York and northwestern Pennsylvania overnight March 1 into early March 2.

Richmondville, New York – in Schoharie County, west of Albany – led the pack with 40 inches of total snowfall. Sixteen other locations in New York state picked up at least two feet of snow, according to NOAA's storm summary. 

Here are the peak snowfall totals by state and other notable accumulations:

• Connecticut: 8 inches in Kent; 6 inches in Sharon
• Delaware: 1.3 inches in Talley Brook
• Maryland: 2 inches in Oakland and at Mountain Lake Park
• Massachusetts: 12 inches in Plainfield; 1.2 inches in Worcester
• Michigan: 8.5 inches near Wixom; 7.9 inches in Ann Arbor; 5 inches at Detroit Metro Airport
• New Hampshire: 4 inches near Alstead
• New Jersey: 16.5 inches in Branchville; 0.8 inches in Atlantic City
• New York: 40 inches in Richmondville; 16.1 inches in Syracuse; 12.7 inches in Rochester; 12.4 inches in Binghamton; 12.1 inches in Buffalo; 11.9 inches in Albany
• Ohio: 12.4 inches in Monroe Township; 2.7 inches at Cleveland-Hopkins Airport
• Pennsylvania: 23.6 inches in Coolbaugh Township; 11.2 inches in Erie; 3 inches in Philadelphia
• Vermont: 18 inches in Weston; 14 inches in Woodford
• West Virginia: 5 inches in Canaan Valley
• Wisconsin: 4 inches near Lake Tomahawk

PHOTOS: Winter Storm Riley Hammers the Northeast