This week a large could front is inching across the eastern states with the promise of strong winds and rain along the coast. So, skippers who are trying to head south on the winter migration to warmer areas are all scratching their heads and watching the forecasts closely. Those on a fixed schedule may have to day hop their ways southward until they can get a window for an offshore run while those who can wait for a weather window to head offshore are doing just that.
Weather windows are those days between high winds that most of us like to use to make progress offshore. In temperate latitudes from the autumnal equinox right through the vernal equinox in the spring, you can expect some sort of weather disturbance every four days or so that last 24 to 36 hours. These are punctuated by days of clearing winds that most often blow from the northwest and north and then settle into the west and southwest.
Choosing your time to head offshore in the fall involves watching approaching lows and fronts, timing their arrival and then being ready to go as soon as the wind swings around from the south and southeast to the north and west. You often then will have two to four clear days before you may need to duck in somewhere for cover.
Sometimes you have to choose an alternate route to find the wind you want particularly if you are already at sea when a low approaches. If you are heading south in the fall, you may have to sail around the back side of a low, which will be moving east, to catch the favorable northerly winds on the systems back side. Sometimes you have to simply stop for a few hours to let a moving system play through.
Weather windows appear regularly between weather disturbances. To sail in tame and favorable winds, it makes sense to keep an eye on weather forecasts and to have patience. Here are two websites that offer good marine weather info: www.weather.gov/om/marine/home.htm and www.passageweather.com