UPDATE Oct. 29, 2012 11 a.m. EDT: Hurricane Sandy forecast to Bring Life-Threatening Storm Surge, Coastal Hurricane Winds and Heavy Appalachian Snows

Miami, Florida—(ENEWSPF)–October 29, 2012 11 a.m. EDT:

Changes in Watches and Warnings with This Advisory

The Bermuda Weather Service has discontinued the Tropical Storm Warning for Bermuda.

Summary of Watches and Warnings in Effect

A Tropical Storm Warning is in effect for:

  • North of Surf City to Duck North Carolina  
  • Pamlico and Albemarle Sounds

In addition, hurricane-force winds are expected along portions of the coast between Chincoteague Virginia and Chatham Massachusetts. This includes the tidal Potomac from Cobb Island to Smith Point, the middle and upper Chesapeake Bay, Delaware Bay and the coasts of the northern Delmarva Peninsula, New Jersey, the New York City area, Long Island, Connecticut, and Rhode Island.

Tropical-storm-force winds are expected north of Chatham to Merrimack River Massachusetts, the lower Chesapeake Bay, and south of Chincoteague to Duck North Carolina, the northern endpoint of the tropical storm warning.

Other coastal and inland watches and warnings are in effect for these areas. Please see statements from local National Weather Service Forecast Offices.

For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service Forecast Office. For storm information specific to your area outside the United States, please monitor products issued by your National Meteorological Service.

Discussion and 48-hour Outlook

At 11:00 a.m. EDT (1500 UTC), the center of Hurricane Sandy was located near latitude 37.5 north, longitude 71.5 west. Sandy is moving toward the north-northwest near 18 mph (30 km/h). A turn toward the northwest is expected soon, followed by a turn toward the west-northwest tonight. On the forecast track, the center of sandy is expected to make landfall along or just south of the southern New Jersey coast this evening or tonight.

Reports from an Air Force Hurricane Hunter Aircraft indicate that the maximum sustained winds have increased to near 90 mph (150 km/h) with higher gusts. Sandy is expected to transition into a frontal or wintertime low pressure system prior to landfall. However, this transition will not be accompanied by a weakening of the system, and, in fact, a little strengthening is possible during this process. Sandy is expected to weaken after moving inland.

Hurricane-force winds extend outward up to 175 miles (280 km), mainly southwest of the center, and tropical-storm-force winds extend outward up to 485 miles (780 km). Sustained winds to tropical storm force are occurring from long island southward along the coasts of New Jersey, Delaware, and eastern Virginia, and extend as far inland as the central and southern Chesapeake Bay and Delaware Bay. A Weatherflow Report indicates a sustained wind of 53 mph (85 km/h) with a gust to 63 mph (102 km/h) has recently occurred on Long Island at Eatons Neck New York.

The estimated minimum central pressure recently reported by Reconnaissance Aircraft was 943 mb (27.85 inches).

Hazards Affecting Land

Wind. Tropical Storm conditions, or gale-force winds, are already occurring over portions of the Mid-Atlantic States from North Carolina northward to Long Island. Gale-force winds are expected to continue to spread over other portions of the mid-Atlantic coast, New York City, and southern New England today. Hurricane-force winds could reach the Mid-Atlantic States, including New York City and Long Island, by this evening. Winds affecting the upper floors of high-rise buildings will be significantly stronger than those near ground level.

Storm Surge. The combination of an extremely dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters. The water could reach the following depths above ground if the peak surge occurs at the time of high tide:

  • North Carolina north of Surf City including Pamlico/Albemarle Sounds, 4 to 6 ft.
  • Southeast Virginia and Delmarva including lower Chesapeake Bay, 2 to 4 ft.
  • Upper and middle Chesapeake Bay, 1 to 3 ft.
  • Long Island Sound, Raritan Bay, and New York Harbor, 6 to 11 ft.
  • Elsewhere from Ocean City Maryland to the Connecticut/Rhode Island border, 4 to 8 ft.
  • Connecticut/Rhode Island border to the south shore of Cape Cod including Buzzards Bay and Narragansett Bay, 3 to 6 ft.
  • Cape Cod to the Massachusetts/New Hampshire border including Cape Cod Bay, 2 to 4 ft.
  • Massachusetts/New Hampshire border to the U.S./Canada border, 1 to 3 ft.

Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. Given the large wind field associated with Sandy, elevated water levels could span multiple tide cycles resulting in repeated and extended periods of coastal and bayside flooding.  In addition, elevated waters could occur far removed from the center of sandy. Furthermore, these conditions will occur regardless of whether sandy is a tropical or post-tropical cyclone.  For information specific to your area…please see products issued by your local National Weather Service Office.

Rainfall. Rainfall totals of 3 to 6 inches are expected over far northeastern North Carolina with isolated maximum totals of 8 inches possible. Rainfall amounts of 4 to 8 inches are expected over portions of the Mid – Atlantic States, including the Delmarva Peninsula, with isolated maximum amounts of 12 inches possible. rainfall amounts of 1 to 3 inches with isolated maximum amounts of 5 inches are possible from the southern tier of New York State northeastward through New England.

Snowfall. Snow accumulations of 2 to 3 feet are expected in the mountains of West Virginia with locally higher totals today through Wednesday. Snowfall of 1 to 2 feet is expected in the mountains of southwestern Virginia to the Kentucky border, with 12 to 18 inches of snow expected in the mountains near the North Carolina/Tennessee border and in the mountains of western Maryland.

Surf. Dangerous surf conditions will continue from Florida through New England for the next couple of days.

Source: nhc.gov

Surface Wind Field

Click image to zoom in – Download GIS data [Image of initial wind radii]
Click Here for a Printer Friendly Graphic

About this Graphic:

This graphic shows the areas potentially being affected by the sustained winds of tropical storm force (in orange) and hurricane force (in red). The display is based on the wind radii contained in the latest Forecast/Advisory (indicated at the top of the figure). Users are reminded that the Forecast/Advisory wind radii represent the maximum possible extent of a given wind speed within particular quadrants around the tropical cyclone. As a result, not all locations falling within the orange or red shaded areas will be experiencing sustained tropical storm or hurricane force winds, respectively.

In addition to the wind field, this graphic shows an approximate representation of coastal areas under a hurricane warning (red), hurricane watch (pink), tropical storm warning (blue) and tropical storm watch (yellow). The white dot indicates the current position of the center of the tropical cyclone, and the dashed line shows the history of the center of the tropical cyclone. 

Related Article:

Department of Energy Hurricane Sandy Situation Report # 2 October 29, 2012 (10:00 AM EDT)