Sydenham House

Owen Sound, ON 

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5/20/12  

Live Weather

 

Conditions at 2:20pm  

Click on the image above for a time-lapse movie of the past 24 hours.

 

Temperature

30.5°C

Beaufort Scale

Light Breeze

Comfort Level

Warm

Barometer

Steady

Cloud Base

4631

Today's Highs and Lows

High
Temperature

30.7°C 
at 1:57pm

Low
Temperature

11.5°C 
at 5:57am

Peak 
Wind Gust

24km/hr 
at 2:13pm

Astronomical Data

Sunrise

4:50am

Sunset

7:50pm

Moonrise

4:31am

Moonset

7:49pm

Weather Radar

Latest XSM radar from Environment Canada

Summaries

             

 

Highs and Lows

     

Three-day Forecast

     
Mon Tue Wed
Clear Clear Clear
T-storms Chance Rain Sunny
28° 16° 21°
13°

 

Links & Tools

Official Seven-Day Forecast

Camera Calendar View

 

Celsius ( o C ):     Fahrenheit (o F)=    

 

 


Weather Data Acquisition:  Data is collected by an Oregon Scientific WMR968 weather station with an anemometer (wind), and rain gauge, and indoor and outdoor barothermohygrometers (pressure, temperature, humidity). The desktop console receives data from each field device wirelessly every 15 seconds and transmits the readings to a dedicated PC via an RS-232 serial connection. Virtual Weather Station software graphs the data, extrapolates weather conditions, and uploads tagged html files and jpegs to the server via ftp. Five-day forecasts are updated hourly from the Environment Canada weather station in Wiarton. Sky conditions are as reported hourly from Wiarton, except if rain is detected at the local sensor, when an overriding algorithm is applied. Page data is updated every 20 minutes. Live weather is updated every seven seconds. The weathercam image is updated every minute.

Snow Gauge (beta)

Snow Data Acquisition:  This is, perhaps, the only autonomous real-time snow gauge currently operating on the internet. It employs a Linksys WVC200 network camera pointed at a length of 2½-inch PVC pipe painted fluorescent orange. The pipe is held upright by an outdoor umbrella stand with its sleeve painted orange to match the PVC pipe.

To facilitate the recording of data at night, a length of LED rope lights runs down the side of the pole. It is held about four inches out from it by a combination of plumbing fixtures and improvised standoffs. The lights are secured to an aluminum yardstick by wire ties. This maintains the lights in a straight line, blocks the glare of the lights from the camera, and acts as a means of visually verifying snow depth.

An image of the pipe is recorded every ten minutes and processed by RoboRealm software, which is designed to provide vision capabilities for robots. Each image is filtered in the software so that only the florescent orange part of the image is visible (see bottom images at right). The software then draws a line from the top of the fluorescent area to its bottom, and measures the length. This value is processed by an algorithm written in VBScript that translates image pixel data to real-world snow depth in centimeters. The data is written to a CSV file and used by Image Salsa weather image processing software, and another VBScript program, to import and compose the overlays on the weather image at the top of this page. Data is accurate to within 2.5 cm (one inch).

The time-stamped image above represents the latest good data recorded by the snow gauge. To be considered good data, the same value must result from two consecutive image reads ten minutes apart. The numbers in the top-right of the image represent (in pixels) 1) the length of the visible pole; 2) the distance from the bottom of the image to the bottom of the visible pole (also shown as the green dot); and, 3) the distance from the bottom of the image to the top of the visible pole.

 

  

 

Snow Gauge 2.0 December 12, 2009: This year a number of improvements, most notably the relocation of the gauge to the deck, which accomplished several things. First, it provided a less protected, and therefore more representative exposure to snowfall. In addition, it was found that the patio stones absorbed heat and snowcover would not be sustained like it is on the deck. Just as significantly, the move permitted the relocation of the camera to the south of the pole, which reduces glare from the sun and provides a more reliable image on sunny days.

But because we have no North-facing windows, it was necessary to build weatherproof enclosure and keep the camera temperature above rated operating specifications. This enclosure comprises a Coleman cooler to keep the snow off the device. I opted not to enclose it hermetically because of problems with condensation. Instead, I wound an electric water pipe antifreezing device around the bottom of the box. This should come on and warm the box sufficiently in cold weather – if it doesn’t melt the plastic sheath and catch fire first.

Protection from the wind and the heat from the camera transformer inside the box keeps the temperature in it about five degrees above ambient. The camera operating temperature is rated at zero degrees Celsius. Thanks to the moderating effect of Lake Huron , temperatures here sit at around five degrees below most of the time. It will be interesting to see how the camera fares this winter.

Among other refinements this year: Roborealm tweaking to include temporal modules that even out rapid changes in pixel intensity and several other minor adjustments. As a result, the image is more stable and there is less flickering of the readings.

The downfall this year, if there is one, will be the fluorescent paint used on the pole. This colour is good because it doesn’t occur in nature and is unlikely to crop up on the image during weird lighting conditions to cause interference. Last year there was significant fading – to the point that Roborealm had difficulty at the end isolating the ends of the pole. I have since read that ultraviolet light degrades fluorescent paint. I changed the paint manufacturer this year with the hope that it will mitigate the problem, but I can already see some signs of fading. Next year there will have to be significant experimentation with paint colours and brands – not a task I look forward to.

I will be enjoying my Snow Gauge from sunny Florida again this year, where I will be spending January and February sipping Mohitos on the beach. Have a good winter.

 

 

The pole stands about 10 feet from the camera unit. 

Sun is the camera's enemy. It produces glare and destabilizes the image on sunny days. To prevent this, the camera needs to face north, which makes the sun travel behind it and shine directly on the pole.


Season Summary April 12, 2012: The winter that never was… record-setting high temperatures, negligible amounts of snow, and patchy gauge operation all conspired to yield relatively few readings this year. Maybe next winter we’ll have better luck. Snowfall, 2012
Season Summary March 27, 2011: More snow than the previous year; larger, more pronounced snowfalls. 33,000 data points with an 82% good read rate. Snowfall, 2011

Season Summary March 14, 2010: Not much snow this winter, but the gauge performed flawlessly, producing nearly 30,000 data points with an 86 percent good-read-rate.

Snowfall, 2010

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