Tuesday, November 6, 2012

The Numbers on Sandy

From a meteorological standpoint Sandy was an impressive and historic storm.  Here are some of the more interesting statistics for this historic storm.

Near-record central pressure of 940 millibars (27.76 inches) when the center of the storm was about 35 miles off the New Jersey coast. This was the lowest pressure of any storm that has made landfall north of Cape Hatteras, NC. Hurricane Gladys in 1977 holds the record the for lowest pressure of 938 millibars (27.73 inches), a category 4 hurricane which never made landfall in the U.S.  At landfall Sandy's central pressure was 946 millibars. A number of locations set reord lower pressure readings. Atlantic City, NJ dropped to 948.3 millibars, breaking the old record of 961 millibars on March 6, 1932.

Winds gusted to in excess of 50 mph from Maine south through Virginia, but the strongest winds occurred from Washington DC north through New York City. Here are some of the locations that recorded hurricane force winds:

96 mph  Eaton’s Park,NY
90 mph  Islip, NY
90 mph  Chesapeake Bay Bridge, MD
89 mph  Surf City, NJ
88 mph  Montclair, NJ
88 mph  Tuckerton, NJ
87 mph  Newport, NJ
86 mph  Westerly, RI
85 mph  Madison, CT
83 mph  Cuttyhunk, MA
81 mph  Allentown, PA
79 mph  JFK International Airport, NY
79 mph  Thomas Point, MD
79 mph  Chester Gap, VA
76 mph  Laytonsville, MD
78 mph  Newark Int’l Airport, NJ
74 mph  LaGuardia Airport, NY

The combination of the hurricane-force onshore winds, the timing of high tide near Sandy's landfall, a full moon, and coastal topography resulted in destructive storm surge from Virginia to Rhode Island. The storm surge along the Virginia coast was 4 to 6 feet. Of course, as we know the worst surge was near and just north of Sandy's center in New Jersey and New York.

 Here are the most impressive and significant storm surges, measured as feet above normal average low tide:
  • 14.38 ft at Kings Point, NY
  • 13.88 ft at The Battery, Lower Manhattan. This broke the old record of 10.02 feet reached during Hurricane Donna in 1960.
  • 13.31 ft at Sandy Hook, NJ

RAINFALL from 10/28 to 11/1

There were more than 320  daily precipitation records set October 29-31 as a result of Sandy. You can find record values at the National Climatic Data Center web site U.S. Records page.

New Jersey
An impressive 237 New Jersey CoCoRaHS observers reported rainfall during this five-day period. The highest amount report was 12.71 inches at Stone Harbor 1.6 NNW in Cape May County, with 9.73 inches of that total on October 30. Other CoCoRaHS observers in Cape May County had 11.91 inches (Wildwood Crest 0.6 NNE); 11.70 inches (Wildwood Crest 0.1 WSW); and 11.41 inches (Middle Twp 4.4 SW). Other totals from Cape May County were generally greater than 7 inches.

CoCoRaHS observers reported period totals ranging from five to ten inches in eastern Virginia. The highest amount reported was 9.83 inches at Cashville .01 S in Accomack County, VA. This total is likely higher, as there were no reports after the morning of October 30.  The heaviest amounts in Virginia were in a corridor from Newport News and Virginia Beach northward and generally ranged from six to nine inches.

Amounts reported by CoCoRaHS observers in Maryland ranged from five to almost 11 inches. Here are the amounts greater than ten inches:

10.85     Easton 2.4 SE     Talbot County
10.70     Greensboro 1.4 ENE   Caroline County
10.68     Ridgely 0.2 ESE    Caroline County
10.29     Queenstown 2.6 S    Queen Anne's County
10.22     Easton 1.2 SSW    Talbot County

District of Columbia
The CoCoRaHS observer at Washington 5.1 NW (DC) reported 6.03 inches of rain.

Rainfall in Delaware ranged from five to ten inches. The highest CoCoRaHS amount reported there was 9.88 inches at Dover 6.4 WNW (Kent County). There were a number of stations reporting over seven and eight inches.

Eastern Pennsylvania also received heavy rain from this system with amounts ranging from three to eight inches. The observer at French Creek 3.4 SE (Chester County) measured 8.19 inches of rain during the period, and the observer at Schellsburg 2.6 WNW (Bedford County) reported 7.94 inches.
The heaviest precipitation amounts in West Virginia were in the higher elevations that also received snow and ranged from four to more than six inches. The highest precipitation amount for the period was 6.84 inches, along with 9.0 inches of snow at     French Creek 3.4 SE in Upshur County.

New York, Connecticut, and north

One to four inches of rain were reported in New York, two inches in Connecticut, one to three inches in Rhode Island, one half to 4.5 inches in Massachusetts, one half to 2.5 inches in Vermont, generally one to five inches in New Hampshire, but with 8.45 inches at Gorham 3.1 S and 6.23 inches at Randolph 1.4 NE, both in Coos County. One half to 3.5 inches of rain fell across Maine.

The rain from Sandy extended as far west as Ohio and Indiana. Four to more than seven inches of rain fell in eastern Ohio, with the heaviest and lake-enhanced amounts in Lake, Cuyahoga, and  Lorain Counties which border the southern shore of Lake Erie. More than six inches of rain were measured in these counties, with 7.68 inches at Painesville 3.8 SSW in Lake County and 7.54 inches by the observer at Mayfield 0.2 NW in Cuyahoga County.

72-hour snowfall ending October 31, 2012
Snow fell in southwestern Pennsylvania, much of West Virginia, western Maryland, western and southwest Virginia, southeastern Ohio, western North Caorina, and eastern Tennessee.  The heavy, wet snow brought down trees and power lines. Some of the highest snowfall totals were:

Richwood, WV  36"
Mount LeConte, TN:  34"
Snowshoe, WV  32"
Quinwood, WV 29"
Frostburg, MD 28"

Of course, the book hasn't closed on Sandy. At its peak 8.5 million customers in the eastern U.S. were without power. As of tonight  there are still 1 million without power, and the impending storm tomorrow will likely slow the restoration of power and may cause additional outages.

Sadly, Sandy has been responsible for 170 deaths with 111 of those in the U.S., 2 in Canada, and 57 Carribean.


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  2. It seems that storms are getting harsher to the point that it's almost pointless doing preventative maintenance if you live in a strongly affected area. They say it's a once in a century storm, but are they really sure that we won't have one again next year?