Marine Weather Forecasting - Softcover

Brumbaugh, Frank; Brumbaugh, J. Frank

Softcover

ISBN 10: 1892216221 ISBN 13: 9781892216229

Verlag: BRISTOL FASHION PUBN, 2000

Inhaltsangabe

Have you ever listened to a weather forecast stating there may be a slight chance of showers but the rain is coming down so hard you are seriously considering a lifejacket while standing on the dock? During such times, one suggestion to the forecaster runs through everyone's mind: "Look out the window!!" That is certainly one of the most accurate methods to forecast the immediate weather.

Everyone knows the look of the sky when a thunderstorm or squall is moving in, but few know how to determine what is in store more than a few hours ahead.

Frank has taken the mystery out of weather forecasting in his book Marine Weather Forecasting. He explains how to tell more about the weather, for hours and days to come, than any broadcast. But you must know what to look for when you go on deck. The wind, clouds, moon and sun all tell the story and Frank explains how to read these signs.

Anyone can understand Frank's detailed descriptions of forecasting and the illustrations add to the ease.

Caution: After reading this book you may never rely on another broadcast report.

Illustrated

Über diesen Titel

Über die Autorin bzw. den Autor

After serving in Europe as a parachutist in the 82nd Airborne Division during WWII he became interested in small boats. As an Electronics Engineer he designed many electronic accessories for small boats including radio direction finders, depth sounders, fuel vapor alarms, battery charge meters, etc. with Heath Company. He has been awarded five U. S. Patents for electronic circuit designs. Later his electronics work took him to Florida in 1959 where he sailed the Atlantic and Gulf of Mexico. During vacations he crewed on commercial fishing boats. His ability to translate "engineering speak" to simple sentences and his wish for more "down time" to go sailing convinced him to become a self-employed engineering consultant. During this period he wrote more than 50 technical books and numerous military Specifications and Standards for all branches of the military. Between contracts he took advantage of many sailing opportunities. He has researched and written several books concerning his first love, boats. Drawing not only upon his long and varied experience but also those of many sailors he has interviewed over the years. Frank has recently spent over five years living aboard and island hopping on his 25-foot Hunter, Jade Lotus. He continues to write for national magazines.

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CHAPTER 1 WEATHER OBSERVATIONS

Weather is much more important to the yachtsman than to the landlubber. The sailor must be prepared to take whatever sort of weather Nature brings and make the best of it. When the sky darkens, the wind freshens and the sea begins to build up, the sailor knows he must shorten sail, batten down and possibly heave to or lie ahull. There is no place he can go. Whatever comes must be faced as it comes. He must be ready for it and capable of riding it out until the disturbance is over. The waves may become mountainous and tower threateningly over his boat, but the experienced sailor knows that large waves present little real danger to him. Properly trimmed and handled, the average seaworthy small boat rises lightly like a gull to allow the waves to pass harmlessly beneath her. The wind, however, presents the real potential danger to the small boat at sea. Strong gales exert tremendous forces against the flat surfaces of freeboard and superstructure. A power-driven craft with her large topside and high center of gravity presents much more surface to the force of the wind than the lower, streamlined shape of the usual well-ballasted sailboat with a deep keel to give her a low center of gravity. Sailing craft are capable of weathering a blow at sea that would destroy a power cruiser and even cause difficulties for large steamships.

Since there are no weather maps at sea and few weather observations available, the yachtsman must depend upon his own abilities to make short-term forecasts for his local area. The hundred-mile circle surrounding his boat is the area of primary interest to the yachtsman. It is not difficult to make accurate forecasts over such a small area for periods of six to 48 hours ahead. Longer term forecasts can be made but are subject to considerable degradation in accuracy. ELEMENTS IN WEATHER FORECASTING

The factors which require consideration and which form the basic ingredients of weather forecasting at sea are few. Wind direction is determined from the boat's compass. Atmospheric pressure is monitored by the aneroid barometer which should be aboard every boat that ventures offshore.

A psychrometer which enables determination of dewpoint will be valuable, especially for forecasting fog and rain, but is not absolutely necessary. Fog is dangerous only in congested waters and shipping lanes or close inshore, but is merely an annoyance at sea far from land and other ships. Rain tends to calm the seas somewhat and is a valuable source of fresh water to replenish your tanks. A thermometer (which is part of the psychrometer) is handy for determining air temperature but is not used as such in forecasting weather. Pilot charts of your cruising waters are useful for the information they contain regarding the monthly averages for wind and current conditions and the incidence of storms and their previous tracks. ANEROID BAROMETER

The aneroid barometer is the basic weather forecasting instrument at sea. A typical barometer is illustrated in Figure 1. Barometers are readily available in numerous styles and sizes. One with a four-inch diameter face is sufficiently large to be as accurate as you will require.

Figure 1. Typical Aneroid Barometer

An aneroid barometer measures atmospheric (air) pressure at the point where it is located. Normal pressure at sea level is 14.7 pounds per square inch, sufficient to support a column of mercury about 30 inches high or a 33-foot column of water. The barometer is calibrated in inches (of mercury) or millibars (one millibar equals a pressure of 1000 dynes per square centimeter) or both. Many barometers have the words Rain-Change-Fair imprinted on the face. This is unfortunate because these words have no meaning when correlated with the range of pressure to which they are related. If these words appear on the face of your barometer, ignore them.

The only useful information available from a barometer is the current atmospheric pressure expressed in inches or millibars; whether the pressure is increasing or decreasing; and the approximate rapidity with which the pressure has changed since the barometer was last observed.

The barometer should be permanently mounted on the cabin bulkhead where it is protected from rain and spray. When first installed and periodically thereafter, it should be adjusted to the current pressure corrected for sea level. Correct current barometric pressure readings can be obtained at any time with a telephone call to the National Weather Service or the U.S. Coast Guard nearest your location. The closer you are to the official barometer, the better, but if you are less than 50 miles from the Coast Guard station or National Weather Service and the day is sunny and pleasant, the reading will not vary by much between your location and that of the official barometer. If you are farther than 50 miles, you can usually get a semi-official barometer reading from the weatherman at a local radio or television station.

Details zur Ausgabe

• Verlag: BRISTOL FASHION PUBN
• Erscheinungsdatum: 2000
• Sprache: Englisch
• ISBN 10: 1892216221
• ISBN 13: 9781892216229
• Einband: Taschenbuch
• Anzahl der Seiten: 92
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: preigu; mail@preigu.de; ; Lengericher Landstr. 19; Osnabrück; 49078; Deutschland