Meteorology Flashcards
Global Seasons
The sailing season dates for popular destinations:
The Caribbean: midwinter and early summer (December - January or March - June)
The Mediterranean: April - October, although the winter is fine as well
Australia: May - October
UK: throughout the year
South Pacific: mostly May - October
The Mediterranean - The Mediterranean doesn’t really have a storm season, although the weather is most unsettled in late summer when the water and land temperature is highest and the air temperatures drop. This causes unsettled weather. I’ll go into more detail on the conditions in the Meds below.
Croatia - Croatia’s sailing season can be limited by the Bora, a North Eastern wind gust coming in from Russia, which can reach hurricane strength. It is strongest in winter. The Bora is a katabatic wind, which means it’s a high-pressure wind that comes crashing into the Adriatic Sea through the force of gravity.
United Kingdom - The UK doesn’t really have a sailing season, but the racing season runs from Spring - Autumn. But you can sail the coast throughout the year.
Baltic Sea - The Baltic has a short sailing season of 3 months, with extra long days and smooth water. The water, however, is very cold, especially in the first month (June) of the season.
North Atlantic Ocean - The North Atlantic has an active hurricane season running from June to December, with its peak around September. Around January, trade winds are at their best. If you want to know more about the Atlantic crossing, you should definitely read my previous article here. It explains the routes and distance, and the best time to go.
Caribbean - The Caribbean is said to have two seasons: April and November. These are the dryest and hottest months. The peak season is however around Christmas. I’ll go into more detail on the conditions in the Caribbean below.
British Virgin Islands (BVI) - The calmest period weather-wise is around the winter. The temperatures are moderate, and the winds are moderate. But it will probably rain a little every day - although it’s rare to get a full day of rain. This is also peak time, so it’s the most crowded and expensive period. Early summer is also a great period since it’s a little less crowded and expensive. Temperatures are hot, with light air (less wind than in winter).
Florida - Thunderstorms with heavy winds in the hurricane season. In the summer, nice, moderate winds (5 - 10 knots) with hot and humid weather. A lot of (very big) mosquitoes on the eastern shore locations.
Sea of Cortez - The Sea of Cortez sailing season is roughly from November till April, but the peak season is from January to March. Summer, from July - September, is very warm in this area, resulting in storm season at the end of summer.
San Francisco Bay - The sailing weather for the San Francisco Bay area is best around autumn. The weather is clean, with light, predictable winds. Spring is also nice, with good temperatures and visibility. The summer can provide choppy waters, with bad visibility. Fog clouds spread over the bay area, and the winds get unpredictable. There isn’t a real storm season here, but there can be an occasional thunderstorm.
Northeast Pacific - The Northeast Pacific is the stretch of ocean between Mexico and Hawaii. One of the most active areas in the hurricane season worldwide. Avoid between June - October.
Northwest Pacific - The waters surrounding Guam are more likely to be hit by storms from July - December. The Northwest Pacific has a lot of tropical storms, so I recommend to avoid these waters in the hurricane season.
South Pacific - Best time to sail in the South Pacific is from May - October when there are little storms and the weather is settled.
French Polynesia - Full cyclones rarely hit the islands of French Polynesia. The South Pacific doesn’t have many strong cyclones.
Australia - The waters North of Australia are prone to cyclones in the season (November - March), from 12 - 25 degrees. There aren’t many cyclones outside this area, and if there are, they are almost always well predicted. The waters South of Australia are almost entirely cyclone-free.
New Zealand - Practically hurricane-free.
North Indian Ocean - This ocean doesn’t have an official cyclone season, but most storms do form between May and November. 2018 was the most active season since 1992, with 7 cyclonic storms. The best sailing time is during the North East monsoon when the weather is cooler and settled, and the winds are lighter and more predictable.
South Indian Ocean - The most cyclones in the South Indian Ocean usually occur between December - March, but this region is notorious for cyclones outside the season.
Thailand - Thailand has two seasons and no real hurricane season: the dry season (North East monsoon), which runs from May - September, and the wet season (South West monsoon), which runs from October - April. In the dry season, winds are usually stable, come from the Northeast and blow at force 2 - 4. The weather is dry and hot, with an average temperature of 30° C or 85° F. During the South West monsoon, the winds are a bit stronger (roughly 7-8 knots), making for more challenging sailing. Although Thailand doesn’t have an official hurricane season, the change of storms increases in the monsoon season (South West monsoon).
What’s the different between ocean currents and tides?
Ocean currents are formed from the wind blowing over it for long periods of time and cr
What is a whirling hygrometer or sling psychrometer, what does it measure and how is it used?
It is used to record air temp, relative humidity and dew point. Comprised of two thermometers, one wet and one dry! Check wet bulb sensor is covered by the wick, fill the reservoir and saturate the wick of the wet bulb! Avoid touching the wick. Keep dry bucks dry Do not whirl in direct sunlight. Correct technique is face the wind and whirl the hygrometer rapidly for 30 seconds, then read wet bulb temp! 2 more whirls @ 10secs each and log the temps or until you get 3 successive readings are the same or until wet bulb temp becomes stable. Then read and record dry bulb temp while performing the same process. Calculate the depression, which is the difference between dry bulb and wet bulb. Use the psychrometric table or dew point table in NP100 to cross reference your dry bulb with the wet bulb and you can read off your relative humidity and the dew point temp.
