Understanding the weather around us may be the most important part of being a good sailor. Most sailors know about the wind and how much wind they can tolerate in their present boat. They may not know about those little weather details that's so important for a long and healthy sailing career. The first task in understanding the weather is to identify what type of sailboat you own. Small sailboats are divided into two types. The first type is a light boat with a large sail area that is best suited for sailing on lakes. Most lakes are in areas with surrounding terrain that limits wind strength. In the United States, most small boat sailing is done on lakes and most boat builders make boats for that market. Other sailboats are built for coastal conditions where we have more wind. There are a few boats that try to do both conditions. There is no black and white in sailing, only shades of gray. Keep that in mind as we talk about the weather.
If we are going to have an accident while sailing, the weather will probalily play a roll in that accident. The purpose of understanding the weather is to reduce accidents and damage to our equipment while we are trying to enjoy our sport. Sailing is suppose to be fun.
Basic weather conditions on earth are created by the earth's rotation and it's relative position to the sun. The warm air at the equator raises and then moves to the poles in the upper atmosphere as the earth spins. As the air moves to the poles, it cools and descends to become the surface weather on it's way back to the equator to start the process over again. The weather picks up the earth's surface characteristics on it's way back to the equator. The angle of sun with respect to our position on earth determines the seasons. The fiction between the atmosphere and the earth's rotation make the weather move from west to east and north to south in the northern hemisphere.
A way to identify the weather at different places in the United States was required for safe aviation travel. If you were going to fly between Kansas City and San Francisco, a pilot needed to know the current weather at both places and at all the places in between. The system they developed was called "the sequenced report". All the airports throughout the country reported their weather at 12 minutes pass the hour every hour every day. This teletype report for most airports in the United States was available to all pilots. It was part of their preflight check list. The weather man at the local radio or television station analyzed those reports and made a weather prediction called a forecast. The sequenced reports are still in use by aviation, but satellite and computer models are what your local weather people use today. An important point to remember is that a weather forecast is only a guess based on current conditions at difference locations. A one day guess should be pretty good, but your five day forecast is a gamble.
There is a big difference between day sailing for several hours one weekend and taking an extended trip of several days on your sailboat. The big difference is the weather and the accuracy of the weather forecast. Even if the forecast is good, you as a sailor need to understand the weather conditions and your limitations.
Some of the small details that every sailor should know is that different pressure systems on earth have their own internal weather conditions and wind. If we have a high pressure system located northwest of our position in the morning, moves north of our position at noon and then continues on to the northeast in the evening, we could say that the wind at our position will clock from the north/northeast to southeast/southwest during that same period of time. Your exact wind direction will be determined by the size of the pressure system and your distance from the center. High pressure systems have cockwise weather rotation. Low pressure systems have counter cockwise rotation. Hurricanes are a good example of a low pressure system. If a hurricane passes off the coast of Jacksonville, FL going north, the winds in the city will come from the northeast/north as the hurricane moves north in the ocean. If a hurricane makes landfall south of Jacksonville, the winds in the city would be from the southeast/south as the storm moves inland.
What makes some months so turbulent is fronts moving through an area with different weather conditions on each side. If we have warm conditions on one side of a front and cold conditions on the other, the area between the two will be very windy. An example is the famous "Nor-Easters" that runs down our east coast during the winter. The "Grave Yard Of The Atlantic" earned it name from those severe storm conditions and the gulf stream meeting just off the North Carlina coast.
On most sunny days, sailors have more wind in the afternoon than they have in the morning. The reason is convection or the sun's heat being reflected back into space. Convection also cause afternoon thunderstorms that can be dangerous. A thunderstorm that has lighting in the storm means we need to take evasive action as soon as possible to avoid the storm. Sailboats are slow movers and reaching shore and a safe building or automobile is not always possible. Cruising boats with cabins should anchor and everyone on board should seek shelter in the cabin during the storm. Day sailing boats without cabins need to dock or beach their boats and seek shelter on land. Day sailing in an area where your car is parked is a good idea if you own a boat without a cabin. Long distance cruising without a cabin should be avoided.
Short days on both sides of the winter season can be a problem. Night sailing and navigation is never a good idea. You can't see your sails or most obstructions on the water and lights on the shore blend with the buoy and other boat lights on the water. Entering an inlet at night without local knowledge is an unsafe procedure. This situation can occur if you cruise a slow sailboat during the winter months. Most small sailboats can average 5 miles in 1 hour. Count your miles between stopping points and then figure the daylight hours for a safe passage. Bad weather or big wind on the nose could mean that you should stay put. All cruising sailors make a departure decision at every anchorage on their cruise. Will the weather be good enough to proceed to the next port and arrive during daylight hours?
A great way to practice your weather forecasting is to research the weather the day before your next outing. Predict the wind direction for your sailing day and how that wind will appear at your sailing area. Most sailors can forecast the general wind direction with a little practice. More practice and a good map should get the average sailor down to a wind direction accuracy of 10 to 20 degrees in the actual area.
North Carolina Weather
North Carolina has all four seasons. Most of the time we don't have snow during the winter season from Raleigh to the coast. The transition seasons, spring and fall are turbulent and day sailing with a moderate wind forecast is desirable. Overnight cruises with some distance involved is best accomplished during the summer months. May is a little cool and June for the most part is just right. July and August are super hot months unless your sailing on the coast and enjoying an ocean breeze. September is still warm, but October is similar to June and is an excellent sailing month. November through March are the transition months and we are back to day sailing.
The weather gets one of our young sailors every now and then. The water is cold in the spring and you can't sail a boat that can turn over during the transition months unless you have moderate wind conditions. A new sailor, a sunfish and going sailing in early March at some isolated location is a recipe for disaster. The same situation in late October would work because the water is still warm at that time. Going for a swim can be fun. Small boat sailing on the ocean only works on light wind days. When the wind is up, the waves are high and a small sailboat can't make enough forward progress with sails or motor. The difference between coastal chop and ocean swells is substantial. Twenty knots of wind on the ocean and the same amount of wind on a river cause different water conditions. The weather decides when and where we go sailing.
When we make plans for an extended cruise, we need to program extra time and an alternate plan for bad weather. We live in a time that most us have jobs and a bunch of responsibilities. The most important responsibility is getting back to our family and friends safe and sound. We need to have lots of respect for the weather and the marine environment that we enjoy. If your going to be a good sailor, you need to understand weather.
The Sailboat Company
Richlands, NC 910-324-4005