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Usage Notes
General
All times are recorded in Universal Time Coordinates (UTC) and converted to your device local time for display.
All Wind directions are relative to True North.
The wind, temperature, pressure and humidity charts were developed using
the Highcharts Library. Features of Highcharts include the ability to display conditions at any given time by hovering your cursor over a chart, and the ability to highlight or de-select certain properties by clicking on that property a the chart's legend. Highcharts is a commercially-available charting library available at no charge 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 weather station unimpeded, providing reliable wind direction and strength readings. However, winds from the northeast to the northwest (a 270° sector in a clockwise direction) are obstructed by land, trees and buildings, and thus both the wind strength and direction are more variable than on the lake, and the wind strength will generally under-report the winds on the lake. The weather station does accurately report the winds at the station, but that may not be a reliable indication of the winds on Lac Deschênes.
Note: When no new data is available, either because the Weather Station is down, the communication link is inoperative or the WeatherLink Cloud storage is offline, the last available values are used, resulting in constant-value (straight-line) plots.
Weather Station Data
The NSC's weather station uploads its sensors' data every 5 minutes to the Davis Weatherlink Cloud Storage (named WLL) through a small device connected to the internet via the office router.
Every 5 minutes starting on the hour, the NSC web server downloads the "last" 5-minutes data set from the WLL, and stores the time, wind, temperature, humidity and pressure values in a running 6-hour file in 5 minute increments. It takes about 15 seconds for the new data to be processed and displayed in the plots.
When you open or reload this page, the 6-hour file is downloaded by your web client and processed to generate the charts below. To update the charts, reload the page.
The WLL data is also available to other weather websites, including Sailflow, Weatherlink, Weather Underground and
CWOP. The NSC Weather WLL graphic immediately below is from the Davis WLL site. The seasonal rainfall will reset on May 1 each year. Unlike the other plots, this information is automatically refreshed every minute.
Wind Direction Polar PLot
The wind direction polar plot is also known as a Radar Plot; it shows the most recent wind direction at the outside of the polar plot, similar to the depiction of the original NSC "Windicator". When the wind speed is 0, the wind direction is "frozen" to the last non-zero value until the wind speed increases again.
Wind Frequency Polar Plot
The wind frequency polar plot is also known as a Wind Rose. The average wind data values are grouped by speed and direction according to one of 7 speed ranges and 16 compass (cardinal) points. Groups are plotted as color-coded sectors.
Prevailing Winds & Peak Gusts
This chart presents prevailing wind strength and direction. The "Wind Speed" and "Wind Direction", plotted in 5-minute increments, are the last 5-minute average values obtained from the latest data download. The "Peak Gust" is the maximum wind speed over the same period.
When the wind speed drops below 1 knot, the wind arrow is replaced by a small dot.
When the wind speed is 0, the wind direction is "frozen" to the last non-zero value until the wind speed increases again - except if the wind speed is 0 at midnight, in which case the "frozen" wind direction is reset to 0 (N).
Note that the 5-minute averages use in this plot are different from the 10-minute averages used in the 24-hr and 7-day plots, and therefore the wind speeds, directions and gusts may differ.
Temperature, Pressure & Humidity
Self-explanatory, similar to the chart, "Prevailing Wind & Peak Gust".
Water Level
The water level chart uses data from the Environment Canada Water Office's Hydrometric data for station 02KF005 (Britannia). The data file is refreshed at minute 1 of every hour from April 1st to October 31st, and every 4 hrs (at 00:01, 04:01, ...) from November 1st to March 31st.
Be advised that there are occasional data gaps, characterized by constant water levels spanning several time intervals, as well as occasional data lags when no new data is reported.
When the water level data is not available (depths being logged as 99999 in the data file), a "no data" message is displayed instead of the graph. When data collection resumes, the graph shows whatever data is available over the past 12 hours.
Disclaimer
NSC does not warrant the quality, accuracy, or completeness of any data presented in this page. The following weather information is provided on an "AS IS" basis without warranty or condition of any nature.
Suggestions? Errors?
Please
contact the Weather Station Team.
Usage Notes updated on 2024-12-08.
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