Weather Flashcards
⟡How can you obtain weather forecasts 24 hours a day?
・Inmarsat C Weather Bulletin.
・Internet.
・Radio.
・NOAA Wx Broadcasts:
-Los Angeles, CA - KWO 37 - 162.550 mHz.
-Santa Ana, CA - WWG 21 - 162.450 mHz.
⟡The standards of care for reduced visibility state, whenever visibility inside the federal breakwater is less than 0.5nm, the Los Angeles/Long Beach traffic center will impose _________ where appropriate.
one-way traffic
⟡NOAA Weather Radio Broadcast Channels:
・Los Angeles, CA - KWO 37 - 162.550 mHz.
・Santa Ana, CA - WWG 21 - 162.450 mHz.
⟡What time of day is the calmest?
Early morning hours.
⟡Which months have the most wind and which months have the least wind in the ports of Los Angeles and Long Beach?
April - Highest mean wind speed of 7.4 kts.
December - Lowest mean wind speed of 5.7 kts.
⟡Frequency for Oxnard NOAA WX station (PROTEST QUESTION):
There is no Oxnard Wx Station. Use the Los Angeles WX Station.
・Los Angeles, CA - KWO 37 - 162.550 mHz.
⟡What is P.O.R.T.S.?
PHYSICAL OCEANOGRAPHIC REAL TIME SYSTEM (PORTS): PORTS is a system of environmental sensors and supporting telemetry equipment that gathers and disseminates accurate “real time” information on tides, visibility, winds, currents and sea swell to maritime users, to assist in the safe and efficient transit of vessels in a port area. The PORTS system in the Ports of Los Angeles and Long Beach consists of 12 stations.
Fog
Fog is most likely from October through February. Out over the bay, it drops visibilities below 0.5 mile (0.9 km) on about 11 days per month during this period. It is mostly a land (radiation) fog that drifts out and is worst in the late night and early morning.
Definition of Inclement Weather
- High Winds: Whenever the National Weather Service issues a “small craft advisory” for sustained winds of 21 to 33 knots potentially in combination with wave heights exceeding 10 feet (or wave steepness values exceeding local thresholds).
- Restricted Visibility: Whenever conditions of visibility fall below the following:
a. For tankers 150,000 DWT or greater: 1 nautical mile.
b. For tankers greater than 60,000 DWT, but less than 150,000 DWT: 0.75 nautical mile.
c. For all other vessels 45’ draft or more: 0.75 nautical mile.
d. For all other tankers and petroleum barges: 0.5 nautical mile.
e. For all other vessels: Three (3) times vessel’s LOA.
Guidelines for Commencing a Transit During Inclement Weather (Piloted Vessel Guidelines):
a. General: When inclement weather exists along a vessel’s intended route:
i. The respective pilot station management will be notified, and
ii. Prior to commencing a transit, the operating pilot will conduct a risk analysis that includes consultation with a second pilot. This expanded participation is a key risk reduction measure.
b. Reduced Visibility:
i. When visibility inside the federal breakwater is less than 0.5 mile, the respective vessel traffic center (VTC) will impose one-way traffic restrictions when and where appropriate.
ii. When commencing a vessel movement in reduced visibility, as defined in Section 2.b. above, shoreside radar assistance and carry-on enhanced navigational tools such as a Portable Pilot Unit (PPU) shall be readily available for use.
iii. When reduced visibility is encountered after commencing a transit, the operating pilot should take appropriate precautions to minimize the risk of collision. Precautions may include but are not limited to continuing the transit or anchoring, reducing speed, enlisting shore-based radar support and securing additional tug assistance.
c. High Winds: Vessel movements will proceed on a case by case basis. Depending on direction and force of wind, type and characteristics of the vessel, movements requiring more than 50 tons of force to hold the vessel against a wind on the beam shall be carefully considered. Below are examples of wind velocities acting on corresponding sail areas that would require 50 tons of counter force exerted by tugs and/or thrusters.
[formula: (total area/1000) x (V 2 /18) = wind effect in tons where “V’ is the wind speed in meters/second]:
i. 1,000 square meters – 60 knots
ii. 5,000 square meters – 28 knots, and
iii. 10,000 square meters – 18 knots
Application of Equivalent Safety Levels
When a vessel master intends to commence a
transit during inclement weather, at a minimum, the following equivalent safety levels should
be adhered to:
1. Vessels 1600 GT or greater:
a. When operating inside the federal breakwater be under the control of a USCG licensed pilot with the appropriate endorsement for the vessel and area of operation, and
b. Have shore-based radar immediately available to assist the vessel.
2. All vessel masters and pilots (if employed) should make a positive evaluation of the following:
a. The number of vessels transiting within the harbor and expected traffic concentrations,
b. Planned transit speeds appropriate for the prevailing conditions,
c. The maneuvering characteristics of the vessel,
d. Maneuvering room at various stages of the transit,
e. Wind direction in relation to planned maneuvers,
f. The vessel’s size and draft in relation to the area to be transited,
g. Number, type and power of assist tugs,
h. Number and power of bow/stern thrusters available,
i. The quality of the vessel’s radar and navigation systems,
j. Quality of the vessel’s bridge team
k. Special circumstances to be encountered (e.g. dredging projects, obstructions).
COTP Notification of intention to move in inclement weather without applying equivalent safety levels:
Vessels 1600 GT or greater that intend to commence a vessel transit during inclement weather without complying with item 4 (including shore-based radar support) shall make the following broadcast to the VTS on VHF Channel 14 at least 15 minutes
prior to getting underway:
1. Vessel name/call sign, making our inclement weather COTP notification, as per guidance within the Harbor Safety Plan, that we intend to transit from vessel location to intended destination.
2. In addition, a safety broadcast will be made on Channel 13 and the vessel will coordinate its movement with the appropriate pilot station and the VTS.
What winds pose dangers to vessels anchored inside the federal breakwater?
Only the Santa Ana winds pose a danger to vessels anchored inside the federal breakwater.
USCP 7, Ch. 4, ¶ 279
During what season does the Santa Ana wind blow?
The Santa Ana is an offshore dessert wind occurring near San Pedro during fall and winter whenever a strong high-pressure system lies over the Socal plateau region and generates a NE to E’ly flow. The wind flows through the Cajon Pass into the Great Valley and turns SW through the Santa Ana River Valley following a well-defined path over the plains of Orange County to reach the ocean near Newport. It diminishes little in intensity immediately after passing over the bay and it is reported to blow far out to sea; however, the winds rarely extend beyond 50 miles offshore. Wind speeds of 50 knots or more have been experienced.
USCP 7, Ch. 4, ¶ 294
What are the warning indications of an impending Santa Ana wind?
Aside from weather forecasts, there is little warning of the onset of a Santa Ana. For some hours preceding its arrival, good visibility and unusually low humidity often prevail. Shortly before its arrival on the coast, the Santa Ana may be observed as an approaching dark-brown dust cloud. This will often give from 10 to 30 minutes warning, and is a positive indication. The Santa Ana can come at any time off the day. It can be reinforced by a land breeze in the early morning or weakened by a sea breeze in the afternoon.
USCP 7, Ch. 4, ¶ 295
