TheDecisiontoSortieorRemaininPort

TheDecisiontoSortieorRemaininPort


THE DECISION TO SORTIE OR REMAIN IN PORT

General

Under normal circumstances, the decision on whether to sortie or remain in port is largely based on the answer to a single question: Would the vessel in question be better off attempting an evasion at sea or remaining in port?

Evasion rationale should include consideration of the following general factors:

  1. Vessel characteristics
  2. Berth and anchorage conditions
  3. Most recent tropical cyclone warning advisory
  4. Tropical cyclone climatology

Individual vessel characteristics and berth/anchorage conditions are best determined by those responsible for each vessel and local port authorities. Tropical cyclone warnings are issued by the Naval Pacific Meteorology and Oceanography Center/Joint Typhoon Warning Center Pearl Harbor for Department of Defense assets. Tropical cyclone and storm warnings for the waters around Fiji originated by the Fiji Meteorological Service are normally broadcast in English at Suva on 100.4 MHz. During a tropical cyclone alert for the Fiji Group, continuous broadcasts are made from all stations (Radio Fiji 1-107.6 MHz, Radio Fiji 2-105.2 MHz, Bula 98 FM-98.0 MHz, Bula 102 FM-102.0 MHz, and Bula 100 FM-100.4 MHz) in English until the alert pass. The Fiji Meteorological Service, RSMC - Nadi Tropical Cyclone Center, can be reached for general inquires at (679) 672-4888 or email at FMS@met.gov.fj. Other important phone numbers are (679) 672-4888/673-6005 for tropical cyclone inquires or 672-4888/673-6007 for general forecast inquires. Specific information on Special Weather Bulletins issued by the National Weather Forecasting and Tropical Warning Center is included in the following paragraphs.

Whenever there is a cyclone threat to Fiji, The Tropical Cyclone Warning Center (TCWC) at Nadi will be activated. It will start issuing Special Weather Bulletins giving Tropical Cyclone Alerts or Tropical Cyclone Warnings as appropriate. Special Weather Bulletins containing tropical cyclone "Alerts" or "Warnings" shall be headed "TROPICAL CYCLONE ALERT" OR "TROPICAL CYCLONE WARNING" as appropriate. Where a bulletin contains warnings for some areas and an alert still for other areas, the warning header shall take precedence. A TROPICAL CYCLONE ALERT bulletin will give progress information on the development of an incipient cyclone or the progress of a cyclone still some distance away, if there is a significant probability that winds over one or more parts of Fiji may reach gale force or stronger. Alerts will be started, where possible, about 48 hours before the likely onset of gales or stronger winds and will be maintained until such time as specific warnings may become necessary, or the threat to Fiji recedes. Bulletins containing TROPICAL CYCLONE ALERTS will normally be issued every six hours, preferably at regular bulletin times.

Wind speeds in Fiji are reported as 10-minute averages, i.e. the average wind speed observed over a 10-minute period of time. Wind speeds in the United States are reported as 1-minute averages, i.e. the average wind speed observed over a 1-minute period of time. The difference resulting from these two measurement periods is that the United States' wind speeds will be greater by a factor of 1.1 or 1.2. Consequently, a 10 kt wind as used in Fiji observations, forecasts, and warnings would convert to a speed of 11 or 12 kt in United States' observations, forecasts, and warnings.

A TROPICAL CYCLONE WARNING bulletin will contain Gale, Storm, or Hurricane Warning for specified areas according to the maximum average wind force expected and will be issued when there is an expected occurrence of gales or stronger winds within 24 hours. Apart from average wind speeds, expected winds in momentary gusts will also be given. Full Special Weather Bulletins designated as warnings will normally be issued every three hours.

If information becomes available which points to a substantial change in the situation, thus invalidating the current warning, a Special Weather Bulletin will be issued as soon as possible to inform users of the sudden change in the situation. Such an intermediate Special Weather Bulletin will be brief and contain essential information including, for example, new areas threatened or changed movement of the cyclone. The numbering sequence for Special Weather Bulletins will be retained. All intermediate bulletins will be identified for emphasis by the prefix "FLASH".

There will be circumstances when gales or stronger winds from a tropical cyclone are already affecting or are expected to affect part(s) of the Fiji waters only, and not any land area. Under these circumstances a Special Marine Bulletin will be issued giving specific warning to the marine community. Routine weather bulletins for the general public will be continued. Special Marine Bulletins will be issued at least every six hours, preferably at regular marine bulletin times.

SUVA Radio 3DP will broadcast all marine bulletins including marine warnings contained in Special Marine Bulletins. It will also broadcast all Special Weather Bulletins containing Gale, Storm, or Hurricane Warnings on receipt as well as at scheduled weather broadcast times. The frequencies used by SUVA Radio 3DP for broadcast of Marine Bulletins and Tropical Cyclone Alerts and Warnings are 2182 and 6215 kHz for the initial announcements followed by broadcasts on the working frequencies of 4372 and 8746 kHz.

The interpretation of tropical cyclone climatology is addressed in the following sections.

Evasion at Sea

Evasion at sea is the recommended course of action for Navy ships at anchorages or berths in Suva. As reported in the List of Tropical Cyclones affecting Fiji from 1830 to 2000 Seasons, a severe hurricane on the 20th of February 1941 put "ocean-going vessels ashore in Suva Harbor with a recorded maximum wind of 100 mph." Additionally, at least 11 vessels were lost, damaged, sunk, or ran aground in southern and southeastern Viti Levu during Hurricane Meli in March 1979.

According to an article in the Fiji Times dated March 12, 1997, Tropical Cyclone Gavin caused four ships to go aground on the Suva Harbor reefs. Captain Malcolm Peckham stated that beacons and navigational aids were also impacted. An article dated March 3, 1983 on Tropical Cyclone Oscar reconfirmed the hazards of remaining in Suva by stating "two cargo ships which had been anchored in Suva Port for nine months were washed by strong winds to the reef entrance."

Commanding officers and ship masters with access to tropical cyclone warnings and advisories coupled with OTSR services are most capable of making the safest and most prudent decision for successful storm evasion and avoidance. In all sortie situations, OTSR services from Naval Pacific Meteorology and Oceanography Center (NPMOC), Yokosuka should be requested and utilized. The best sortie route in a specific tropical cyclone scenario is largely dependent on the location of the tropical cyclone and the forecast track. During any tropical cyclone threat there is normally one to three options available to the commanding officer and ship master. Selection of the best option is the objective of all concerned!

Keeping in mind that tropical cyclones normally approach the Port of Suva from the northwest, the following guideline is offered: An evasion route to the south-southwest through Kandavu Passage would provide following wind and sea for almost all approaching tropical cyclone situations once the T is crossed.

In all cases, the timing of the evasion is affected by:

  1. The time required to make preparations to get underway
  2. The time required to reach open water and gain sea room
  3. The forward speed of the tropical cyclone
  4. The radius of hazardous winds and seas that can adversely impact a vessel's
  5. ability to reach open water.

Remaining in Port

Remaining in port is not the recommended course of action for all Navy ships at the wharves or at anchorage in the Port of Suva.

There are some haven qualities for small boats at the mooring buoys or steaming to an anchor in the Port. Specifically, three mooring buoys in Draunibata Bay are considered a hurricane haven for small boats. The mooring buoys can be used by fishing boats and other small vessels (up to 50 m in length) but are not considered strong enough for Navy ships during strong winds or hurricanes.

Source: http://www.nrlmry.navy.mil/port_studies/thh-nc/fiji/suva/text/sect8.htm


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