Clouds over Munlochy
Altocumulus Lenticularis (Cm4) clouds photographed over the Moray Firth on the 30 th August 2016
How does the Aurora Cloud Sensor work?
This system works by comparing the cloud base temperature with the air temperature 2m above ground.
Under clear skies the system senses the upper atmosphere temperature (which is very cold).
However if the sky is cloudy the base temperature is only slightly colder than the air temperature.
The system comprises of sensors for cloud, rain, light and sensor temperature.
The Cloud Sensor III also incorporates heaters to prevent false alerts due to dew / frost / light snow.
Live sky view (during daylight hours) over MillbankPWS. At night click the centre of the image to play a video of todays sky view.
Cloud base height shown takes account of the station elevation at 18 meters (59ft) above MSL.
Live cloud base height at MillbankPWS
Cloud Altitude Calculator
Cloud Altitude Calculator

  Select a Temperature Unit:
  Select a distance unit:
1. Enter the Air Temperature (A)
2. Enter the Dew Point (D)
3. Estimated cloud altitude
4. Estimated cloud temperature

This calculator is based on the assumption that the air temperature drops 9.84 degrees C per 1000 m of altitude and the dewpoint drops 1.82 degrees C per 1000 meters altitude. The following formulas must be solved to estimate cloud height and temperature:

cloudTemp = - 0.00984*cloudHeight + airTemp
cloudTemp = - 0.00182*cloudHeight + dewPoint

All Temps in degrees C, all distances in meters