Post Tropical Cyclone Sandy

Pre-Landfall 1 | Summary
Posting Date: October 24, 2012, 10:00:00 AM

Current Conditions With maximum sustained winds currently 70 mph (110 km/h) and a minimum central pressure of 983 millibars, Tropical Storm Sandy is located 95 miles south of Kingston, Jamaica, moving north with a forward speed of 14 mph. The center of the storm should reach Jamaica in the early afternoon, local time. As of 8 am Wednesday morning (EDT), only intermittent rain squalls with rainfall totaling less than one inch (0.82 inch) are affecting Jamaica. However, as Sandy draws closer, it is anticipated to strengthen, giving rise to hurricane conditions over the island by Wednesday afternoon. Exposure at Risk In Jamaica, most buildings in the major urban areas such as Kingston are constructed of brick or reinforced concrete with tiled or cement roofs. If these buildings are well-constructed, they should not suffer much damage at the level of wind speeds being produced by Sandy. These winds could, however, test vulnerable roof materials such as light metal. Poorly constructed shanty-type homes may see more significant damage but would likely be uninsured. While Sandy’s projected wind speeds do not represent a significant threat to most Jamaican construction, damage due to flooding is an additional hazard. If severe localized flooding does occur, weaker construction types such as timber or unreinforced masonry will be the most vulnerable. In addition, contents damage could occur if walls made from these materials are compromised by flooding. Auto exposure is also particularly vulnerable to flooding. Forecast Track and Intensity With Tropical Storm Sandy currently located over very warm waters of 29.5°C, with a relative humidity of over 80%, and light wind shear of 5-10 knots, conditions are very favorable for intensification. Tropical Storm Sandy is thus predicted to gradually intensify over the next several hours, reaching hurricane strength by the time it makes landfall in Jamaica on Wednesday afternoon. A hurricane warning is thus in effect for Jamaica. It is interesting to note that Tropical Storm Sandy is taking a relatively unusual track as it heads nearly due north into Jamaica; most storms that impact Jamaica travel from east to west. It is likely that Sandy will remain a hurricane when it makes a second landfall on eastern Cuba early Thursday morning; however, Sandy is expected to weaken somewhat before affecting the Bahamas as a tropical storm later that day. Hurricane warnings have been issued for the Cuban provinces of Camaguey, Las Tunas, Granma, Santiago de Cuba, Holguin, and Guantanamo. Tropical storm conditions are also anticipated on Haiti. In all, Sandy is forecast to produce 6-12 inches of rain (with isolated maximum rainfall of 20 inches also possible in some locations) across Jamaica, Haiti, the Dominican Republic, and Eastern Cuba. The National Oceanographic and Atmospheric Administration (NOAA) cautions that this large amount of rain may cause life-threatening flash floods and mudslides, particularly in regions with mountainous terrain (such as southeast Cuba). Smaller amounts of rain – between 3 and 5 inches – are predicted to fall over parts of the Bahamas, though up to 12 inches of rain may occur in some isolated parts of these islands. By Friday morning, NOAA reports that tropical storm conditions are possible along the southeast Florida coast, the upper Florida Keys, and Florida Bay. Although all the computer models agree that Sandy will move northward over Cuba and into the Bahamas through Friday, they diverge in the long-term. Some models forecast that Sandy will move out into the ocean and away from the U.S. coastline, while others predict that the storm will curve more to the west and possibly impact the Northeastern U.S. as a post-tropical cyclone early next week. As such, AIR’s Tropical Cyclone team will continue to monitor Sandy closely during the next few days and will post additional information on the development and impacts of this storm. Elsewhere, the season's 19th named storm, (tying 2010 and 2011 for the 3rd most storms in recorded history), Tropical Storm Tony, formed Tuesday night. Currently, Tony is not a threat to impact land.

Pre-Landfall 1 | Downloads
Posting Date: October 24, 2012, 10:00:00 AM