From the ABC 7 Weather team

Hurricane Sandy anniversary marked a year after massive storm

October 29, 2013 - 04:06 AM
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A year ago Tuesday marks the one year anniversary of a storm that ravaged the northern Mid-Atlantic coast.

It was a storm of epic proportions that nobody will ever forget. Sandy made landfall on this day one year ago, five miles southwest of Atlantic City, N.J., as a post-tropical cyclone.

Its impacts were far-reaching, including flooding rain, damaging winds and heavy snow from the D.C. area to the far western Appalachian slopes.

The spiral rain bands around Sandy quickly chopped down the rainfall deficit down for the year in Washington. Initially, Reagan National Airport was almost 9 inches behind par for precipitation. Sandy sliced that deficit in half, after the storm produced 4.84 inches of rain in Washington.

Baltimore had its fifth highest rainfall for any day of the year, getting 6.67 inches. Totals were highest east of the Chesapeake Bay where 8 to 10 inches was reported and less along the Interstate 81 corridor with 5 to 7 inches from Hagerstown to Winchester.

Sandy rain

Peak wind gusts ranged from about 35 to 55 mph across the entire metro area. A few of the highest gusts around 60 mph were clocked in northern Fairfax County with widespread 50-55 mph gusts along the Blue Ridge spine.

Sandy wind

Storm surge wasn’t as bad as it could have been had Sandy’s center passed by to the south of Washington. Instead of a strong south or southeast wind producing a long fetch up the Chesapeake Bay or Potomac River, northwest winds coming off the Blue Ridge slopes kept surge to 3 to 3.69 feet above normal tide along the Potomac and Chesapeake.

Sandy surge

Sandy was a unique storm in that it combined with a dip in the jet stream across the Mid-Atlantic, allowing colder air to filter from Canada into the Appalachians.

As Sandy approached this dip or trough, it combined the cold air with the moisture to produce crippling heavy snow in the Blue Ridge and Allegheny Highlands. Locally, Skyline Drive at Big Meadows was socked with a foot of snow.

Farther west along the Allegheny mountains, Bayard, W.Va., got slammed with 2 feet of snow. The highest total in Maryland was Redhouse in Garrett County with 28 inches of snow. Strong wind gusts of 60 to 80 mph toppled trees along large stretches of the Alleghenies and Blue Ridge where the snow occurred.

Sandy snow

The combined impact of the rain and wind resulted in nearly 400,000 power outages in Washington. There were 300,000 power outages in Maryland and 100,000 in northern Virginia.

Due to Sandy’s epic nature, its name was retired from the recycled list of hurricane names used in the Atlantic Basin.

Instead, “Sara” will replace “Sandy” in 2018. Storm names are reused every 6 years. The World Meteorological hurricane committee, which includes personnel from NOAA’s National Hurricane Center, can decide to retire a name if it is so deadly or costly that using the same name 6 years later would cause confusion and/or sensitivity to its former impact.

One month remains in the 2013 Atlantic Hurricane Season and so far, activity has actually been above average. Tropical Storm Lorenzo was the last storm to roam the Atlantic, making 12 named storms so far this season. In an average season, 11 named storms form by Nov. 23. Six hurricanes typically form in a season but so far only two have made it there; Humberto and Ingrid.

Tropical cyclones are most likely to form in the Caribbean and central and western Atlantic going through November. Here, the water is warmer and wind shear, or strength of upper-level winds, is minimized to allow formation.

 

November tropical formation

 

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