Southeast Alaska is an area comprised of many different weather zones, although all are marine driven. The maritime climate, described in Section 3 - Region Information Weather, is highly influenced by local topography which affects precipitation, winds and sea movement. As an introduction to zone-specific information, the following links and illustrations aid in plan preparation:
General current circulation information as well as information specific to Southeast Alaska is available on the Alaska State
Geo-Spatial Data Clearinghouse (ASGDC) website. Click their logo to access. 
*note: if you are using Mozilla Fire Fox, the link will download the document to your download folder
Realistic maximum operating limitations are dependent upon many factors, although the overriding consideration in any response will always be the safety of response personnel. When temperature, visibility, sea states, wind chill, etc. are beyond what is considered safe for the responders, activities will be terminated until the situation improves. Capabilities of skimmers and boom owned by SEAPRO (and/or available to SEAPRO through Blanket Purchase Agreements (BPA) between SEAPRO and its member companies) to operate under certain conditions is listed on the equipment specifications pages and can be accessed at SEAPRO Equipment. Beyond the upper limits of these conditions, the equipment is rendered less effective. Fortunately, the weather conditions in most areas of Southeast Alaska’s inside waters are relatively mild.
Although SEAPRO’s boom and skimming equipment is effective in wind to 20 knots, there are several ways in which wind can affect a spill response. First of all, wind impacts the water surface and therefore the movement of the oil. Wind influences the direction that a slick will travel; it can trap oil against the shoreline where it can be stranded; and it affects the rate at which the volatile components of beached oil will evaporate. In addition, wind can cause boom failure by trapping oil against the boom and splashing it over the top, or by driving currents that entrain the oil under the booms. Boom mooring points may fail as a result of pressure placed on the anchor points by the wind. Onshore operations are made more difficult because of wind blown sediments and the displacement of light work equipment. Both onshore and near shore operations are also impacted by wind in that working conditions may become unsafe (for small boats or vessel deck workers), or the air temperature may be lowered and a “wind chill” factor created, reducing the body temperature of the workers and hastening fatigue.
The impacts of reduced or low visibility (from darkness, fog, snow, heavy rain or low clouds) are several. Oil slick tracking from the water or the air is hindered, equipment and personnel deployment times are increased, and spill response activities are slowed in order to assure the safety of response personnel. When the low visibility is the result of “sea smoke”, an additional issue arises: equipment icing. There are few times in Southeast Alaska, however, notably around August and during winter storms where low visibility, including sea smoke, might impact a spill response.
Temperatures in Southeast Alaska are relatively moderate as are the winds in most places. Extended cold snaps, however, can impact the ease of starting motorized equipment. If extremely low temperatures are combined with relatively high winds, an equivalent wind chill temperature well below the free air temperature results and the safety of response personnel as far as hypothermia becomes a concern. Furthermore, working in cold temperatures requires warm clothing, but the very bulk of the clothing can hamper workers’ movements. Hypothermia and frostbite can result from prolonged exposure to cold air as well as prolonged contact with cold water.
Wind, tide and current all impact the “sea state.” Tides, except in constricted areas where shoreline protection booming is required, are generally not a problem. As wind speed, duration and fetch increase, the sea state deteriorates and surface waves and swells increase. If wind and tide are sufficiently strong to create wave heights beyond 3 feet, efficiency will decrease for all but ocean boom and all but the Foilex TDS weir skimmer. Decks awash in heavy seas may make it dangerous for personnel to work and certainly make small boat operation, beach landing, and equipment launching are difficult and unsafe. Should the latter occur, the response will be suspended until there is an improvement in the situation.
Daylight hours, at their most limited in Southeast Alaska, will vary from 6.2 hours/day in Yakutat to 7.2 hours/day in Ketchikan in December. Although air support and surveillance are usually prohibited in darkness, a nearshore response can nevertheless be conducted as long as it is not a general safety threat to response personnel or the darkness does not preclude locating operating response resources. Without the necessary air support and surveillance, however, the response will be less effective. Click here to access day light and civil twilight hours for any locations in Southeast Alaska.
State of Alaska regulations regarding contents of oil discharge and contingency plans under 18 AAC 75.425 specify that the following information be included within the Realistic Maximum Response Operating Limitations Section of a plan:
"A description of the realistic maximum response operating limitations
that might be encountered at the facility or operation and, based on environmental and safety
considerations, an analysis of the frequency and duration, expressed as a percentage of time,
of limitations that would render mechanical and other response methods ineffective; the
realistic maximum operating limitations for a response must be defined, with descriptions
of any measures that will be taken to compensate for those periods when environmental
conditions exceed this maximum; environmental conditions to be considered in this analysis
must include:
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This regulation is further explained in the Approval Criteria Section:
“In designing a spill response, severe weather and environmental limitations that might be reasonably expected to occur during a discharge event must be identified. The plan must use realistic efficiency rates for the specified response methods to account for the reduction of control or removal rates under those severe weather or other environmental limitations that might reasonably be expected to occur. The department will, at its discretion, require the plan holder to take specific temporary prevention measures until environmental conditions improve to reduce the risk or magnitude of an oil discharge during periods when planned spill response methods are rendered ineffective by environmental limitations”. 18 AAC 75.445 (f)