Questions About Our Data
Environment Canada CWYY-AUTO Data
Temperature, precipitation and wind are being obtained from Environment Canada's automated station located at Kinsmen Park in East Osoyoos. This station updates every minute throughout the day. Precipitation will give context to our station's reading when pole vibration causes the rain sensor to misbehave.
This station is located at grounf level within a short distance, 470 metres of Desert Mirage. Latitude 49.028292, Longitude -119.441041, Elevation 284.2 metres. Corner of Highway 3 and Tamarack Drive.
Count on Regular Calibrations
The SKY leaves the factory with pretty good calibration, but calibration can shift during shipping and setup, and will drift over time. Also, your particular installation can affect SKY's calibration (Levelness, stiffness of mount). Fortunately, SKY has a feature that no other weather station in the world has: It learns about your location and produces more accurate data over time. SKY is now going through a continuous learning process that automatically adjusts its calibration as necessary. You probably won't notice anything odd, but rest assured it's only temporary.
How frequently are measurements reported by the sensors?
All values are reported on a one-minute average cycle. Lightning strikes are instantaneously reported upon detection. The haptic rain sensor also reports instantaneous rain start events when more than 5 seconds of continuous rain occurs. The ultrasonic anemometer samples the wind every 3 seconds and sends an average of wind speed & direction to the Hub.
More on wind sampling...
Every 3 seconds the ultrasonic transducers sample the wind speed and direction. These values are averaged in one-minute observations. The lull is the lowest of the 3-sec readings and the gust is the highest of the 3 sec readings. The one minute averages become part of your station’s long term record. These are World Meteorological Organization (WMO) standard sampling methods.
How does the ultra-sonic anemometer work?
The ultra-sonic anemometer is comprised of 4 transducers housed in the top of the device. The Tempest measures wind speed and direction based on the time of flight of ultra-sonic pulses between pairs of transducers. This allows for a high degree of accuracy especially in variable wind conditions. For more information, check out Wikipedia on Ultra-Sonic Anemometers.
Beaufort Wind Scale
| Force | Speed Km/h | Term | Effects Observed on Land |
|---|---|---|---|
| 0 | < 1 | Calm | Smoke rises vertically. |
| 1 | 1 - 5 | Light air | Direction of wind shown by smoke drift, but not wind vanes. |
| 2 | 6 - 11 | Light breeze | Wind felt on face. Leaves rustle. Ordinary vane moved by wind. |
| 3 | 12 - 19 | Gentle breeze | Leaves and small twigs in constant motion. Wind extends light flag. |
| 4 | 20 - 28 | Moderate breeze | Raises dust and loose paper. Small branches are moved. |
| 5 | 29 - 38 | Fresh breeze | Small trees with leaves begin to sway. Crested wavelets form on inland waters. |
| 6 | 39 - 49 | Strong breeze | Large branches in motion. Whistling heard in telephone wires. Umbrellas used with difficulty. |
| 7 | 50 - 61 | Near gale | Whole trees in motion. Inconvenience felt in walking against wind. |
| 8 | 62 - 74 | Gale | Breaks twigs off trees. Generally impedes progress. Walking into wind almost impossible. |
| 9 | 75 - 88 | Strong gale | Slight structural damage occurs, e.g. roofing shingles may become loose or blow off. |
| 10 | 89 - 102 | Storm | Trees uprooted. Considerable structural damage occurs. |
| 11 | 103 - 117 | Violent storm | Widespread damage. |
| 12 | 118 - 133 | Hurricane | Rare. Severe widespread damage to vegetation and significant structural damage possible. |
How does the haptic rain sensor work?
Tempest uses a patent-pending haptic rain sensor in the top of the device. Using a combination of pressure and capacitance, Tempest measures and counts each falling raindrop. Algorithms exclude things that are not rain (like the rumblings of a passing train or Harley). This allows Tempest to report the instant rain begins falling, the current intensity, and the total rain accumulation over time. Accuracy compares to a large tipping bucket, but does not get fouled with leaves or bird poop.
The SKY unit is mounted in a manner that is suggested by the manufacturer. However, it does not remain vibration free. This may effect the precipitation measurements.
If the sensor has registered rain and there is a consistantly strong wind, the total rainfall maybe over estimated. This may indicate rainfall even though no rain is falling. Suspect any rainfall totals greater than those measured at CWYY-AUTO.
What are the rates of the rain intensity values?
VERY LIGHT: < 0.25 mm/hour
LIGHT: ≥ 0.25, < 1.0 mm/hour
MODERATE: ≥ 1.0, < 4.0 mm/hour
HEAVY: ≥ 4.0, < 16.0 mm/hour
VERY HEAVY: ≥ 16.0, < 50 mm/hour
EXTREME: > 50.0 mm/hour
Pressure trends: The following trends are determined from changes over 3 hour intervals...
Falling/Rising: if the magnitude of the pressure change is ≥ 1 hPa
Steady: if the magnitude of the pressure change is ≤ 1
