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Usage Notes
General
All times are recorded in Universal Time Coordinates (UTC) and converted to your device’s local time for display.
All wind directions are relative to True North.
The wind, temperature, pressure, and humidity charts are powered by the
Highcharts Library. Features include:
- Hovering over a chart displays conditions at that specific time.
- Clicking legend items toggles the visibility of corresponding data series.
Highcharts is a commercially available charting library, free to use for not-for-profit organizations like NSC.
Wind Data Accuracy and Reliability
The weather station is mounted on the lighthouse at the harbour entrance.
Winds from the northwest to the northeast
(a 90° sector) reach the station unobstructed, providing reliable readings. In contrast, winds from the northeast to the northwest
(a 270° clockwise sector) are obstructed by land, trees, and buildings. These obstructions can cause under-reporting and variability
in wind strength and direction compared to actual lake conditions. The station reports accurate data *at its location*, but this may
not reflect conditions on Lac Deschênes.
Note: When no new data is available—due to station outage, network issues, or WeatherLink Cloud downtime—the last known
values are retained, resulting in flat (constant) chart segments.
Weather Station Data Flow
NSC's weather station uploads sensor data every 5 minutes to Davis WeatherLink Cloud Storage (WLL) via a small internet-connected device on the office router.
Hourly, the NSC server processes the latest 10-minute data file (already downloaded for the 24-hour plots), extracts time, wind, temperature, humidity, and pressure readings, and stores them in a 7-day rolling data file. This update and processing takes approximately 25 seconds.
When you load or reload this page, your browser downloads the 7-day file and generates the charts locally. To refresh the data, reload the page.
WLL data is also accessible from third-party weather services including
Sailflow,
WeatherLink,
Weather Underground, and
CWOP.
Prevailing Wind Direction - Polar Plot
Also known as a Radar Plot, this chart displays the most recent wind direction at the outer edge—similar to the original NSC "Windicator." When wind speed drops to zero, the last non-zero wind direction is retained (i.e., "frozen") until wind resumes.
Prevailing Wind Frequency - Polar Plot
Also known as a Wind Rose, this chart groups wind data by speed and direction into seven speed ranges and 16 compass directions. Each group is shown as a colored sector representing frequency.
On-the-Hour Wind & Highest Gust
This chart shows wind strength and direction at hourly intervals. The "Wind Speed" and "Wind Direction" are the final 10-minute average values from the hourly data snapshot. The "Highest Gust" shows the maximum wind speed recorded within the full hour.
When wind speed drops below 1 knot, a small dot replaces the wind arrow. If wind speed is 0, the last direction is held (frozen) until new wind data is received.
Note: This chart (and the 24-hour chart) uses 10-minute averages, while the 6-hour chart uses 5-minute averages. Differences in averaging periods may result in variation between plots.
Temperature, Pressure & Humidity
These are shown in standard line plots and follow the same timing and data update procedures as the wind charts.
Disclaimer
NSC provides this weather data "AS IS" without any warranty regarding accuracy, completeness, or fitness for a particular purpose.
Suggestions or Errors?
If you notice an issue or have a suggestion, please
contact the Weather Station Team.
Usage Notes updated on 2025-06-29.
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