Automated Snow Sensor Experiment

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Automated Snow Sensor Experiment
NATIONAL WEATHER SERVICE WFO GRAND RAPIDS MI

• Overview
• In 2003, Nolan Doesken (Colorado State
  Climatologist) was granted funding from
  Headquarters, to perform testing of snow sensors.
• Also in 2003, the Grand Rapids Weather Forecast
  Office and a few other NWS field offices
  purchased automated snow sensors, due to the need
  for improvement of snowfall readings.
• In 2004, a partnership developed between NWS
  field offices and Colorado State University, with
  respect to an increase in the number of offices
  performing testing.

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National Test Sites
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Automated Snow Sensor Experiment
NATIONAL WEATHER SERVICE WFO GRAND RAPIDS MI

• Two snow fences surround the sensor
• -first fence is 10' radius from sensor
• -second fence is 20' radius from sensor
• 2) Digital sensor output brought into a Linux
  Box
• Depth and Temperature readings are parsed and
  stored in a MYSQL database every 5-minutes using
  an algorithm to minimize outliers
• 4) HTML PHP pages have been written to query
  database and allow visual access to data or
  graphical output

Inner Ring 10' from sensor
Outer Ring 20' from sensor
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Ultrasonic Depth Sensor with temperature probe
The Judd Communications ultrasonic depth sensor
is an inexpensive solution for remotely measuring
snow depth. The sensor works by measuring the
time required for an ultrasonic pulse to travel
to and from a target surface.
 
An integrated temperature probe with solar radiation shield, provides an air temperature measurement for properly compensating the distance measured. An embedded microcontroller calculates a temperature compensated distance and performs an error checking routine.
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Side View of Sensor
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Benefits of automated Snow Sensor...

• - Use in storm verification
• - Provides snowfall data in remote locations
• - Provides snowfall data around the clock
  (24-hrs)
• - Allows for the analysis of melting and
  compaction rates
• Provides snowfall rates for Short Term
  Forecasting (NOWs)
• Provides enhanced service to customers

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Example of a 7-day graphical output
Freezing Line
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January 7, 2004 event...
Looking north from east side...
Looking north from west side...
Snow Sensor
Frost depth gauge
Soil temperature sensor
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Automated Snow Sensor Data...
January 7, 2004
Time (UTC) Date Temp (C)
Temp (F) Depth (Inch)
1245 - 01/07/2004 -11.5 11.3 7.8
1240 - 01/07/2004 -11.5 11.3 7.9
1235 - 01/07/2004 -11.5 11.3 7.8
1230 - 01/07/2004 -11.5 11.3 7.8
1225 - 01/07/2004 -11.0 12.2 7.1
1220 - 01/07/2004 -11.5 11.3 6.5
1215 - 01/07/2004 -11.5 11.3 7.3
1210 - 01/07/2004 -11.5 11.3 7.6
1205 - 01/07/2004 -11.5 11.3 7.8

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False Reports
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January 28, 2004 Blizzard Event
Looking north from east side...
Looking north from west side...
Uniform distribution of snow inside inner
circle...
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Automated Snow Sensor Data...
January 26 - 28, 2004
Time (UTC) Date Temp (C)
Temp (F) Depth (Inch)
2350 - 01/27/2004 -7.0 19.4 10.2
2345 - 01/27/2004 -7.0 19.4 10.1
2340 - 01/27/2004 -6.5 20.3 9.9
2335 - 01/27/2004 -6.5 20.3 9.8
2330 - 01/27/2004 -6.5 20.3 9.7
2325 - 01/27/2004 -7.0 19.4 9.7
2320 - 01/27/2004 -6.5 20.3 9.4
2315 - 01/27/2004 -6.9 19.6 9.6





Light snow collapsing...
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Internal Software Capabilities
Forecaster User Interface
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Internal Software Capabilities
Manual snow observation entry
This manual snowfall report form is merged with
the snow sensor database to allow direct
comparison between manual and automated sensor
readings.
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Internal Software Capabilities
Archive Retrieval GUI
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Internal Software CapabilitiesArchived Database
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Future Enhancements...
1) Improve algorithms to handle false reports and
snow collapses during events 2) Introduce
additional snow sensors to enhance sensitivity
-Lake Effect Snow -Low Water Equivalent
Snow 3) Increase outer fence for drifting
pattern -this would decrease likelihood of
turbulent eddies in atmosphere over snow
sensor 4) Introduce Wind Sensors to study eddy
patterns over wind fence
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Automated Snow Sensor Experiment
For additional information check out our website
at http//www.crh.noaa.gov/grr/snowsensor or
contact David Beachler MIT WFO GRR
david.beachler_at_noaa.gov