Pavement Precipitation Accumulation

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Pavement Precipitation Accumulation
Presenter Mark Askelson University of North
Dakota Department of Atmospheric
Sciences/RWIC/STWRC

• Precipitation Data Sources

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Precipitation Data Sources

• Primary sources
• Surface observations
• Radar
• Satellite
• Analyses/models

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Precipitation Data Sources

• Surface Gauges
• Strengths
• Accuracy (but wind contamination)
• Weaknesslimited capacity for indicating snowfall
  in real time
• ASOS Automated Surface Observing System
• Tipping bucket gaugesnot presently useful for
  measuring snowfall.
• Visibility ? snowfall rate (significant
  variability)
• Manual intervention stations
• ? Useful information, but not enough of them.

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Precipitation Data Sources

• ? North Dakota ASOS/AWOS stations.
• ? Manual intervention stations circled.
• ? Not shown (KRDRGF AFB, a manual intervention
  station).
• ? Only some of these provide real time snowfall
  amounts.

ND ASOS/AWOS stations (from http//www.faa.gov/aso
s/map/nd.cfm).
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Precipitation Data Sources

• ? South Dakota ASOS/AWOS stations.
• ? Manual intervention stations circled.
• ? Not shown (KRCAEllsworth AFB, a manual
  intervention station).
• ? Only some of these provide real time
  snowfall amounts.

SD ASOS/AWOS stations (from http//www.faa.gov/aso
s/map/nd.cfm).
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Precipitation Data Sources

• AWOS Automated Weather Observing System
• AWOSIII-P has a precipitation identification
  sensor, but does not record amounts.
• RWIS Road Weather Information System
• DOT
• 14 in North Dakota 35 in South Dakota
• Indicate precipitation occurrence

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Precipitation Data Sources

• RAWS Remote Automated Weather Stations
• United States Forest Service
• 9 in North Dakota 5 in South Dakota
• Uncertain regarding utility for snowfall
  estimation
• Citizen Weather Observer Program (CWOP)
• Forecast Systems Laboratory
• Private weather stations
• PRIMENet
• EPA and NPS
• 1 station in North Dakota
• Uncertain snowfall measurement potential

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Precipitation Data Sources

• High Plains Regional Climate Center Automated
  Weather Data Network (HPRCC-AWDN)
• NDAWN North Dakota Agricultural Weather Network
• ? NDSU
• ? 55 in North Dakota
• ? Tipping bucket rain gauge
• South Dakota
• ? 11 in South Dakota
• ? Tipping bucket rain gauges

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Precipitation Data Sources

• South Dakota Television Stations
• KOTA-TV WeatherNet
• KELO WeatherNet
• KMEG Weather Net
• Uncertain snowfall measurement utility

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Precipitation Data Sources

• Non real-time networks
• NWS Cooperative Observer Program
• NOAA/NWS 15 Minute Cooperative Observer Program
• ? 55 in North Dakota 40 in South Dakota
• ? Weighing rain gauges.
• North Dakota Atmospheric Resource Board
  Cooperative Observer Network
• ? Principally concerned with rainfall.
• ? Operates from April to September.

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Precipitation Data Sources

• Cost of setting up surface gauges for South
  Dakota
• 75,885 square miles
• Yankee Sensor
• Estimated 10,000 each (for sensor alone)
• Minimizes wind contamination of amounts
• Estimates
• 1 gauge/900 mi2 850,000
• 1 gauge/400 mi2 1.9 million
• 1 gauge/100 mi2 7.6 million
• Infrastructure and maintenance?

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Precipitation Data Sources

• Radar
• Strengths
• Good spatial and temporal coverage
• Park River Basin example courtesy of Scott Kroeber

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Precipitation Data Sources

• Weaknesses
• Accuracy
• 40-50 error common for storm total accumulation
• Can reach 100 for lt 1 snowfalls.
• Overshooting
• 0.5 beam reaches 5.0 km at 225 km range.

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Precipitation Data Sources

• Ground Clutter and Anomalous Propagation
• Ground Clutter Commonly observed return owing to
  radar beam bouncing off buildings, towers, etc.
• Anomalous Propagation Radar beam bends downward
  towards the Earth more than normalproduces
  anomalous returns to the radar.

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Precipitation Data Sources

• Satellite
• StrengthsExpands coverage area.
• Weaknesses
• Been applied more to rain than snow.
• Probably more effective for heavy snow (identify
  cloud patterns)
• May not resolve light snow (clouds cannot be
  discriminated from snow on the ground).