Clarus Quality Checking Summary Formats Is a Task Force Needed

1
ClarusQuality Checking Summary FormatsIs a Task
Force Needed?
Clarus ICC5 Meeting Session 5

• Andy Stern
• Consulting Meteorologist (Noblis)
• FHWA Road Weather Management Team

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Quality Checking Summaries

• Topic of Quality Checking (QCh) summaries was
  brought up at the Clarus QCh Task Force meeting
  in 6/06
• The focus of this workshop was on formulating a
  next generation of QCh algorithms for Clarus
• There was a lot of interest expressed then and
  recently at a regional demonstration training
  meeting
• Question to think about Is there a need for a
  QCh Summary Format Task Force?

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QCh Flag Output in Clarus

• Here is a sample of text output from a dozen
  sensors. QCh flags are at the end

• Flag Summary
• P Pass
• N Not Pass
• Available but
• does not run
• / Test is not
• supposed to run

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Viewing QCh Flags Graphically
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MADIS QCh Output

• NOAAs MADIS (Meteorological Assimilation Data
  Ingest System) creates QCh output summaries
• Provides statistical output based upon time
  periods (Hourly, Daily, Weekly or Monthly)
• Summaries only include stations with one or more
  flagged sensors
• Errors are based on observations subtracted from
  an area analysis (Analysis-ObservationError)
• Is meteorologically cryptic

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Hourly QC Message
Key QST OBS Questionable Observations Percent
QST Percentage of Total that is Questionable
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Daily QC Message
RMS Error6F/Mean Error-5F/100 of Observations
are Questionable
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Weekly QC Message
Daily, weekly, and monthly summaries include only
those stations with observations that have failed
more than 25 of the time.
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Monthly QC Message
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QCh Summary from Canadian RWIN
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Issues from the QCh Task Force
1 of 2

• Amount of interest differed among the
  participants wrt summary formats
• Many will not see an emailed QCh summary must
  FTP or provide on web page
• Only outage notification should be sent via email
• Need additional sensor information on QCh
  summaries (e.g. subsurface temperature for weight
  restrictions/thaw cycles) and vertical thermistor
  string data
• Hourly output is critical!

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Issues from the QCh Task Force
2 of 2

• QCh information can be used to update public
  traveler information systems
• Daily summary is needed for performance measures
  (would like to see 12Z-12Z summary output)
• Some only want to see basic information easy to
  use and understand (easier to use than MADIS)
  not overwhelm the user

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Legal Issues

• Caveat Emptor which is Latin for Let the buyer
  beware. Should the onus be on the party that
  uses the data?
• Are states liable if QCh shows failed sensors?
• As long as states show a reasonable effort to
  correct failed readings, is that enough?

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Need for a Task Force?

• Is there a need to convene a task force of data
  providers, data users and service providers for
  recommendations on
• QCh formats for Clarus users
• Summary time periods (hourly, weekly, etc)
• Statistical output types (rms error, mean error)
• Method of transmission (email, FTP, web)
• Liability considerations (archiving summaries)