There is no better way to obtain concise and current local weather than by tuning a VHF radio to one of the National Weather Services marine broadcast frequencies. Here in Maine there are three stations covering the 200 mile coast line; designated as KEC-93 (located in Ellsworth and broadcasting on a frequency of 162.40 Mhz), WXM-60 (located in Dreseden and broadcasting on a frequency of 162.475 Mhz), and KDO-95 (located in Falmouth and broadcasting on a frequency of 162.55 Mhz).
These stations use a prescribed, but flexible, format to present a review of recent weather conditions, usually the most recent 12 to 24 hours, a synopsis of current conditions, and an outlook for the next 24 hours. These recorded messages are updated every one to three hours, or more frequently if weather is rapidly changing.
National Weather Service stations, such as the three in Maine, have an advertised broadcast range of 40 miles, but the Maine stations are routinely heard past this distance since antennaes for all three are located on hills with elevations over 500 feet. Additionally, broadcast range between adjacent stations overlap so a mariner is always within reception of at least one station, if not two.
As a mariner listens to a weather broadcast it sounds to be one recording, but is actually several separate recordings which are broadcast in sequence. Each broadcast is divided onto several tape decks that can be updated separately when necessary without having to re-record an entire message. As an aside, until recently these decks were actual eight track cartridges, but are now digital units, which provide a high quality recording.
A broadcast follows this sequence; deck one contains the marine forecast, deck two is an hourly round up of local conditions, deck three is a state weather summary, deck four contains zone forecasts and decks five, six, and seven contain special weather bulletins, and other information such as forest fire warnings, UV index, red tide and finally station identification before the sequence starts over.
Each deck can be updated as frequently as needed so portions of a broadcast might change while other sections remain unchanged during a listening period. Additionally, broadcasts during Maines cold season- October through April-do not include UV warnings, red tide, fire, or other recreational type information that does appear during warm season-May through September-broadcasts. Though you might wonder why a mariner would be interested in forest fire warnings, they do occasionally effect coastal navigation. A few years ago smoke from a large and serious forest fire in Canada drifted down on the Maine coast producing a significant reduction in visibility, and these fires and smoke were noted on the VHF marine forecasts.
Contained within the Marine forecast portion of each broadcast is both coastal (out to 25 miles), and offshore (25 miles out to the Hague Line, with the Hague Line being the boundary between US and Canadian waters) information. Included are high and low tide information for Portland and Bar Harbor as well as small craft, gale and other warnings and advisories.
Following the Marine forecast is the Hourly Round-up that is designed to provide summaries of weather from specific locations following a north-south, inland-coast sequence. Generally the temperature, dewpoint, relative humidity, winds and barometric pressure is given for each location, along with a general weather description.
Next comes the State Weather summary that provides a look at the weather during the past 6 to 12 hours and then leads into a discussion of weather features to be expected in the next 12 to 24 hours. In preparing the State Weather Summary National Weather Service meteorologists look at information from a number of sources. These include computer models, reporting stations-both land and buoys, aviation reports, radar, satellite and individual observations. A resident of Monhegan Island, for example, calls in observations to the NWS office in Gray Maine three times each day.
Zone forecasts are aired by county, with zones having like or nearly like conditions being consolidated for listening ease. There are nineteen Maine counties included in each forecast, with coastal York, Cumberland, Sagadahoc, Lincoln, Knox, Waldo, Hancock and Washington (listed from West to East) being of most interest to mariners.
However, though prepared using the best information available, NWS forecasts do not take into account local conditions that may modify overall weather patterns, such as channeling of winds through restricted headlands, convergence and divergence of sea breezes, and choppy seas where winds oppose a tide. An excellent guide for understanding how topography and local conditions modify weather is a book titled Where the Wind Blows, published by Environment Canada and available through Breakwater Books, St Johns Newfoundland Canada, phone 709-722-6680, fax 709 753 0708. This book is oriented towards the Canadian Maritimes, but is applicable to the Maine coast.
Listening, then, to a full cycle VHF weather broadcast gives a mariner the quickest and easiest method of becoming educated on local conditions and short range outlook. A mariner would do well to sit with a cup of coffee before setting out for the day and absorb the days weather, and upon departure not be reluctant to tune in again if conditions appear to be changing.