Monday, April 24th, 2006
The Picton Castle‘s crew makes observations about the weather, wind, and swell, and records this information in an hourly weather log; this job is assigned to each off-going helmsman. In addition to the ship’s weather log, there is a special weather log that requires a bit more detail. The latter weather observations are voluntarily collected and forwarded several times a day from the Picton Castle to a group of scientists (meteorologists) at the department of National Oceanographic and Atmospheric Administration (NOAA). This information is specific to the location that we are currently sailing in and is used to help meteorologists make better marine weather forecasts, and the information is also made available to all crafts bound for this vicinity.
Weather warning systems and the associated technology have advanced by leaps and bounds since the age of sail (when present weather observations were all a Captain and crew had to go by), and it is information distributed by these systems that enables Captain Moreland and his Mates to review weather faxes and forecasts and avoid any weather systems that might not be so great to be caught in (ships in the age of sail often found themselves in the middle of gales and sometimes severe storms because there was no weather warning technology in existence). Aside from enabling us to prepare for or entirely avoid weather systems, another bonus of detailed marine forecasting is that it makes it possible for the Captain and Mates to be aware of any probable shifts in wind trends that might affect our ability to sail or to continue on our present course. This technology has become an essential tool for sea-going vessels, because weather avoidance is the best way to prevent ships and their crew from being vulnerable to storms and from being at risk of damage or loss due to heavy weather.
The weather observations requested by NOAA are quite specific and one or two people from each Watch are assigned to collect and record the observations properly. How our crew goes about observing the weather around us is outlined below. Perhaps you can keep a weather log at home, and make similar observations from your own backyard!
- Ship’s Course
- This is the ordered (compass) course that the helmsman has been instructed to steer.
- Average 24 hour Speed
- This information is recorded every day at noon and appears in the ship’s logbook in what is known as the “noon log.” This particular log also indicates our day’s run, that is, the distance covered; the distance to our next port of call; how many hours the main engine and generator have been running; and how many nautical miles the Picton Castle has logged on her fourth world voyage.
- Latitude and Longitude
- The ship’s position is logged on the hour, every hour, and we get this information from the Global Positioning System mounted on the wall in the chart house.
- Date / Time
- This is obvious, but just in case, there is a calendar and a clock in the Chart House
- Barometric Pressure
- There is a barometer mounted on the wall in the Chart House and in the Captain’s office. The barometer indicates whether atmospheric pressure is going up or down; a change in atmospheric pressure is an indication that there is going to be a change in weather. We record the barometric pressure every hour
- We have a thermometer that hangs from a hook in the Chart House that gives measurements in both Celsius and Fahrenheit
- Wind Direction and Speed
- We record wind speed and direction each hour in our weather log. We determine the wind speed based on the Beaufort Wind/ Wave Scale and it is an approximation of wind speed based on the conditions of the surface of the water. We have two tattle-tale pennants that we can use to help us determine wind direction, but typically we just need to feel the wind on our faces from the Port or Starboard quarter and can then consult the compass to get the direction (it is important to take into account that there is apparent wind caused by the ship herself, and that the apparent wind is not the same direction as the actual wind)
- Wind Wave Height
- There are ripples, scales or waves that appear on the top of the ocean’s swell, depending on the force of the wind. The wind wave height is measured in feet and is the estimated average distance between the highest point of the wave’s crest and the surface of the swell it appears on.
- Sea Water Temperature
- There are two ways that we can determine the salt water temperature; we can fetch a pail of water from over the rail and submerge the chart house thermometer in it, or we can turn on the Picton Castle‘s depth sounder, which is a piece of equipment that includes a feature that measures the temperature of the water that the ship is in.
- Cloud Cover
- The cloud cover is observed in eighths, as if the sky were divided up into eight parts. We indicate the type cloud and how much of the sky is covered by cloud. This observation is more specific than saying “partly cloudy,” and the scientists have their reasons for requesting that we use eighths.
- Present Weather
- We take a good look at what is happening around us, consult a large chart that has specifically worded options, and select the best fit for what we are experiencing presently.
- Past Weather
- We can consult past weather logs in the ship’s log book, or if we’ve been on deck for a while, we have an indication of what the weather has been doing since the last NOAA observation has been taken. As with the present weather, the past weather observation selected is a “best fit” from the options provided by NOAA. These generalizations provide only the key information that the NOAA scientists are looking for.
- This is an approximation of how many miles away the horizon appears to be; whether visibility is limited by fog, squalls, or is improved by clear skies and sunshine. On an average day, the horizon appears to be anywhere from 11 to 27 nautical miles away.
- Ice or Icing
- This does not apply to the Picton Castle as she voyages in tropical waters
- Humidity and Dew Point
- These measurements are obtained using a sling psychrometer. Obtaining this measurement can be fun because the crew gets to wet the tip of a cloth in what looks like a giant thermometer, and then gets to sling it around in rapid circles for the count of one minute. There are mathematical charts provided to determine the humidity and dew point based on the reading from the instrument.
- General Observations and Assessments of Weather, Conditions, and Trends
- This request allows for you to add any information that you would have liked to have made available under the Present or Past Weather headings, but the conditions are specific to the ship’s exact location, and experiences and are not included in the list of options provided by NOAA (such as rain clouds forming to the lee side or winds gusting and shifting at times)
When you are outside next, take a good look at the weather around you. Has there been a warming trend and has the snow melted away for good? Has it rained in the past few hours? Are the skies clear or partly cloudy? Can you look at a cloud and tell whether it is a rain cloud or just a regular cloud? Is it calm or windy today? From what direction is the wind coming? Keep these questions in mind and you will be doing one of the most important duties that we tend to on the Picton Castle.