Hurricane

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The State of Hawaii closes all schools when a Hurricane Watch is posted. Plan ahead and have a Family Care Plan ready to care for school age children.

Hurricane is a term utilized to describe a severe tropical cyclone occurring within the Atlantic Ocean.  A hurricane is a tropical storm with winds that have reached a constant speed of 74 miles per hour or more.  Hurricanes also produce other destructive weather including tornadoes, which add to the hurricane's destructive power.  Hurricane winds blow in a large spiral around a relative calm center known as the "eye".  The "eye" is generally 20 to 30 miles wide, and the storm may extend outward 400 miles.  As hurricane approaches, the skies will begin to darken and winds will grow in strength.  As a hurricane nears land, it can bring torrential rains, high winds, and storm surges.  A single hurricane can last for  more than 2 weeks over open waters and can run a path across the entire length of the eastern seaboard.  August and September are the peak months during the hurricane season that lasts from June 1 through November 30.

The stages of development of a hurricane are classified as follows:

  1. Tropical disturbance - A weather disturbance with maximum sustained winds of <20knots.
  2. Tropical Depression - An organized system of clouds and thunderstorms with a defined circulation and maximum sustained winds of 38 mph (33 knots) or less.
  3. Tropical Storm - An organized system of strong thunderstorms with a defied circulation and maximum sustained winds of 39 of 73 mph(34-63 knots).

 

Categories Winds (kts) Surge (feet) Damage
1 64 - 82 4 - 5 Minimal
2 83 - 95 6 - 8 Moderate
3 96 - 113 9 - 12 Extensive
4 113 - 135 13 - 18 Extreme
5 >135 >18 Catastrophic

 

Storm surge is an abnormal increase in the ocean's level, sometimes in excess of several meters.  high and miles wide.  Storm surges can come ashore up to five hours before the storm and destroy low elevation coastal areas.  it is especially damaging when the storm surge occurs during high tide and consequently is often responsible for most hurricane-related deaths.  Storm surge is a large dome of water often 50 to 100 miles wide that sweeps across the coastline near where a hurricane make landfall. Storm surge can range from 4 to 6 feet for minimal hurricane to greater than 20 feet for the stronger ones.  The surge of high water topped by waves is devastating.  The stronger the hurricane and the shallower the offshore water, the higher the surge will be.  Along the immediate coast, storm surge is the greatest threat to life and property, even more so than the high winds.

Within the Commander, fleet Forces Command (CFFC) area of responsibility along the Eastern seaboard and the Gulf of Mexico, designated Regions and Installations must set and maintain specified Tropical Cyclone Conditions of Readiness (COR) as shown in Table H-2.(below)

Table H-2: Tropical Cyclone Conditions of Readiness (CFFC AOR)

Tropical Cyclone conditions of Readiness
Indicates time until onset of winds>=50 knots
COR 5 1 Jun - 30 Nov every year
COR 4 72 hours
COR 3 48 hours
COR 2 24 hours
COR 1 12 hours

Notes:

 

  • "Tropical Wind Advisory" issues for expected tropical winds from 34-49 knots.
  • In accordance with CNRHINST 3440.17 APPENDIX 1. All tenant activities will report COR attainment to NAVSTA PH EOC. All tenant activities with subordinate command (subordinate UIC) responsibility will roll up their COR attainment and report as a consolidated listing to the installation EOC.

 

Guidance for hurricanes is also applicable to other large, organized weather-related hazards known by other names with other geographic boundaries.  Ex./ include:

  • North Pacific = Typhoon
  • Indian Ocean = Cyclone
  • Australia = Willy Willy
  • Phillippines = Baguio

 

(Last Updated: 9/4/14)

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