October 25th, 2012

Hurricane Sandy

Posted at 8:50 AM ET

sandysmallHurricane Sandy has the potential to interact with a frontal system leaving the U.S. coast, causing the development of a “nor-easter” type of post-tropical cyclone. The feature could then drift westward into the northeastern United States this weekend into next week. Interests along the U.S. East Coast should monitor this system closely. A more imminent threat is already underway for Jamaica, Cuba, Florida and the Bahamas.

Hurricane Sandy continued to intensify last night, and now carries maximum sustained winds of 80 mph, and a northward motion of 14 mph. Tropical-storm force conditions have been observed in Kingston Jamaica. Hurricane and tropical storm force winds extend outward from the center up to 30 and 140 miles (45 and 220 km), respectively.sandybig

Hazard data illustrated in the CAT-i map was taken from i-aXs®, Guy Carpenter’s web-based risk management platform. i-aXs users can view impacted areas on any map as well as see how their portfolios were affected. Please contact your broker or GC Analytics®   representative for assistance or go to www.i-axs.info for further information.

Watches and Warnings

  • Hurricane Warnings for Jamaica, Eastern Cuba, and the Bahamas.
  • Hurricane Watches for portions of the Bahamas.
  • Tropical Storm Warnings for the Florida Atlantic Coast from Sebastian Inlet to Ocean Reef, and Haiti.
  • Tropical Storm Watches for portions of the Bahamas, and in Florida from Sebastian Inlet to Flagler Beach, Florida Bay, and the Florida Keys from Craig Key to Ocean Reef.

Hazards

  • Southeast Florida Atlantic Coast, Florida Keys, Florida Bay

                  Tropical storm conditions as early as Thursday night and continuing into Friday

                  Rain 1-3 inches, and possible flooding

                  Storm surge 1-2 feet.

  • Jamaica

                  Hurricane conditions through this evening

                  Rain 6-12 inches, with isolated amounts to 20 inches

                  Flooding and mudslides

                  Storm surge 1-3 feet

  • Haiti/Dominican Republic

                 Tropical storm conditions this evening

                 Rain 6-12 inches, with isolated amounts to 20 inches

                 Flooding and mudslides

  • Eastern Cuba

                 Tropical storm conditions imminent

                 Hurricane conditions as early as this evening

                 Rain 6-12 inches, with isolated amounts to 20 inches

                 Flooding and mudslides

                 Storm surge 3-5 feet

  • Bahamas

                 Tropical storm conditions early Thursday.

                 Hurricane conditions Thursday night into Friday

                 Rain 3-5 inches, with isolated amounts to 12 inches

                 Some inland flooding

                 Storm surge 4-7 feet

Impacts

The eye of Sandy has moved very near or over Kingston. Reports from the area indicate flooded roadways and airport closures. Mudslides have also been reported in areas near Kingston.

Forecast

Short Term

Sandy is expected to cross Jamaica this evening on a northerly track, and approach Eastern Cuba overnight, approaching the Bahamas into Thursday. While some intensification is possible before moving over Cuba, interaction with land and increasing wind shear will likely cause weakening to Tropical Storm status sometime Thursday. Sandy is then expected to slow and turn more to the north-northwest into Friday, affecting the Florida Atlantic Coast and the Bahamas.

Long Term

As Sandy leaves the Bahamas, a highly uncertain scenario evolves for both track and intensity, with one set of scenarios affecting Bermuda and the Central Atlantic, and another affecting the Atlantic U.S. coast.

Scenario 1 - Eastward Track

Sandy moves into the North Atlantic, on a more eastward track. Sandy then makes a gradual turn to the east with the westerlies, and no other forecast complications. Such a track would impose at least storm conditions for Bermuda, and minimal impacts for the North American mainland (with the exception of Florida). Such a scenario is becoming less probable with time.

Scenario 2 - Westward Track

Sandy moves into the North Atlantic on a track further to the west, allowing interaction with a frontal system leaving the mainland. The sharp contrast between polar and tropical air causes rapid development of a large “nor-easter” type cyclone, with a possible northwest drift of the cyclone into the northeastern U.S. for early next week. This scenario would bring at least storm and potentially hurricane conditions to the northeast U.S. coast, including storm surge, storm to hurricane force winds, and excessive precipitation. Such a combination of meteorological factors is very rare, but the odds against such a scenario are diminishing. The most recent historical event comparable to this potential scenario is the “perfect storm” of October 1991.

The interaction of a tropical system, a polar frontal system, and the subtropical ridge in the Atlantic is highly complex, extremely difficult to forecast and captured with difficulty by forecast models. It is far too early to determine the exact timing and placement of this scenario.

Interests along the U.S. east coast should closely monitor the progress of this feature in the coming days, and prepare to implement response plans should it become necessary.

Interests in Florida, Jamaica, Cuba, and the Bahamas are of course facing a far more imminent threat.

Sources: National Hurricane Center (NOAA), Storm Prediction Center (NOAA), National Weather Service (NOAA), Hydrometeorological Prediction Center (HPC/NCEP/NOAA), Associated Press, Reuters.

Click here to register for e-mail updates from GC Capital Ideas >>

Guy Carpenter publishes CAT-i reports for major natural catastrophes worldwide. These reports cover catastrophes including worldwide tropical cyclones, earthquakes, major UK and European floods and any other natural event that is likely to incur a significant loss to the (re)insurance industry. Please email CAT.i@guycarp.com if you wish to be added to the free email distribution list.

Guy Carpenter compiles RISK-i reports for major technological or man-made events worldwide. These reports cover risks to property, transport and life including explosions, fires, crashes, engineering disasters and terrorist attacks that are likely to incur a significant loss to the (re)insurance industry. Please email RISK.i@guycarp.com if you wish to be added to the free email distribution list.

AddThis Feed Button
Bookmark and Share


Related Posts