Archives For snow depth

Take care on journeys this morning. <1cm wet slushy snow lying in Reigate but big local variations likely; just above freezing. Light snow/sleet will die out during the morning. Dull and cold. Map shows lying snow across UK. Snow boundary in SE goes right through out area: in Reigate we were, as predicted here, “on the edge”! Snow continued throughout the day, on and off (mostly on!), confounding most forecasts.  2cm of snow total fall but melting throughout the day caused reduction in depth in many places and patchy snow cover. 

In Reigate snow started falling lightly at 8:00 am and continued throughout the morning building to a peak moderate snowfall intensity for a few hours  around midday, thereafter gradually dying out through to (approximately) 4.00 pm when the main period of snow stopped.  A total of 8 cm of snow was measured lying at our observation site at Reigate Grammar School (see post below). This is equivalent to approximately 8 mm of rainfall (i.e not much).  So, a total of 8 hours of snowfall delivered just 8 cm of snow, which fell as light or moderate falls. The maximum temperature for the day was +0.2°C at 12:15 am in the morning! The lowest temperature recorded was -2.1°C at 10:00 am.  The lowest wind chill temperature was -7.8°C recorded at 8:00 am, just as the snow started.  

It’s NOT over yet! Another significant snowfall event is possible on Sunday through to Monday with a LOW winding up over the continent and bringing our own special snow just to the South East! We will post details as they become clearer. Please measure snow depth where you are and send in the cm depth! Who has got the most?!  Follow us on twitter @RGSweather for updates and Facebook.

Photos: scenes from today around Reigate Grammar and Reigate.

SOLVED! our anemometer and wind direction transmitter on the school roof malfunctioned early Friday due to snow on rooves interrupting wireless signal from the anemometer and wind vane unit.  Wind records for Friday are therefore invalid because they got stuck! The problem has been fixed.

How do you measure snow depth properly (i.e.World Meterological Organisation approved method)?
Measuring the depth of lying snow is not quite as simple as sticking a rule (ruler) in and taking a measurement. To be really accurate and “by the book” do the following:

  1. Place a white board down before it snows, away from trees and buildings. 
  2. Find a graduated ruler or graduate your own stick in cm / mm.
  3. Find a patch of untrampled and undrifted snow which has a clear sky view, away from trees and buildings.
  4. Take 10 measurements holding the rule vertically and read the depth carefully in cm. Note down the measurements. Disregard the highest and lowest reading.
  5. Take the average of the rest as the “depth of snow” reading.
  6. Note the maximum and minimum depths within the area too.

how to measure snow fall

Note that old snow (>1day) will become compacted so increasing depth of snowfall on top of old layers becomes inaccurate.
To measure “fresh snowfall” on top of old snow place a “board” (snow board?!) over the old layer before it starts snowing again.  Remember where your board is (mark with a stick!) and measure fresh snowfall there. Repeat with further boards if you live somewhere like Alaska.

So, you don’t need any high tech equipment to measure snow, infact, technology has lagged behind in this regard. All you need is YOU, a stick, a pencil and paper and… some snow.

Now have fun and get measuring snow depth where you are and please send us some measurements from your area! 🙂