The Canadian Airport Nowcasting Project CANNow: Vision for future and preliminary results

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The Canadian Airport Nowcasting Project
(CAN-Now) Vision for future and preliminary
results

• George A. Isaac1 and Faisal S. Boudala1
• Monika Bailey1, Brian Clark1, Stewart Cober1,,
  Norman Donaldson1,
• Norbert Driedger1, Sylvie Gravel1, Ismail
  Gultepe1,
• David Hudak1, Paul Joe1, Stephen Kerr2, Alister
  Ling3, Janti Reid1,
• Gilles Simard2and Zlatko Vukovic1
• 1Science and Technology Branch, Environment
  Canada,
  Toronto, Ontario, M3H 5T4, Canada
• 2 Canadian Meteorological Aviation Centre East,
  Montreal, Quebec, Canada
• 3 Canadian Meteorological Aviation Centre West,
  Edmonton, Alberta, Canada

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Acknowledgements

• Funds from
• Transport Canada
• Search and Rescue New Initiatives Fund
• NAV CANADA
• Environment Canada
• Also operations and research colleagues in
  Montreal

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The main idea behind Nowcasting is that
extrapolation of observations, by simple or
sophisticated means, shows better skill than
numerical forecast models in the short term. For
precipitation, Nowcasting techniques are usually
better for 6 hours or more.
Nowcasting
NWP Models
Theoretical Limit
From Golding (1998) Meteorol. Appl., 5, 1-16
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Nowcasting/Forecasting High Impact Weather at a
HUB Airport Canadian Airport Nowcasting (CAN-Now)

• To improve short term forecasts (0-6 hour) or
  Nowcasts of airport severe weather.
• Develop a forecast system which will include
  routinely gathered information (radar, satellite,
  surface based data, pilot reports), numerical
  weather prediction model outputs, and a limited
  suite of specialized sensors placed at the
  airport.
• Forecast/Nowcast products will be issued with
  1-15 min resolution for most variables.
• Test this system, and its associated information
  delivery system, within an operational airport
  environment (e.g. Toronto International Airport -
  Pearson).

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Variables for Airport System

• Snow and rain events
• Freezing precipitation and ice pellets
• Frost
• Blowing snow
• Icing aloft
• High winds/gusts
• Wind shifts/shear
• Turbulence
• Lightning
• Low ceilings
• Low visibility and fog
• Convective cells

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Main equipment at Pearson at the old Test and
Evaluation site near the existing Met compound
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Main Site Instruments

• 21 instrument bases with power and data feeds.
• 10m apart rows 15m apart

• FD12P Viz meter
• Stevenson screen (humidity, dew point,
  temperature)
• Old Viz meter
• Power distribution box
• Old Viz meter
• Spinning arm, liquid/total water content probe
• Radiometer
• POSS
• Rosemount icing detector
• Belfort precip gauge, ultrasonic snow depth
• Hotplate (Yankee)
• 11-13 Empty
• 14. Tower, 2D wind sensor
• Ceilometer
• Empty
• Hotplate (Yankee)
• Geonor precip gauge
• 19, 20 Empty
• Tower, wind speed/

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Web Site

• A Web site has been created at
  http//www.canadian-airport-nowcasting.org/
• The data on this site is accessible only with a
  user name and password. The site is currently
  active.

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Click on airport to get products, including TAFS
and current weather, as well as specialized
products.
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Interaction with Users

• Terminal Weather Forecast Working Group (includes
  NAV CANADA, EC, airline dispatch, GTAA, etc)
• GTAA, Vancouver Airport Authority
• CMAC Workshops
• NAV CANADA
• Transport Canada

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Prototype Display for CAN-Now
Click for larger map
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Prototype Display Contains

• Bar chart at 15 min resolution for first two
  hours, then one hour resolution for next 4-5 h.
• Bar changes colour to attention (yellow) to red
  (alert) status. Remains green if everything OK.
  Bars main contain some text (e.g. T, RH,
  Visibility, Ceiling, Precipitation Type, etc).
• If chart changes colour, you can click and obtain
  more information as to why. Either graphs or
  text from forecaster.
• Display will have configurable radar, satellite
  or map type display depending on weather
  situation.
• It will contain recent METARS and TAFS.
• A text message from the forecaster outlining
  significant features will be included and updated
  as required.
• Besides significant weather variables, the
  ability to include AAR, Runway Friction, etc,
  will be considered.
• An area chart showing all the YYZ alternates will
  be prepared. The airports will be colour coded
  to indicate all OK (green), possible problems
  (yellow) and red (below limits).

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Algorithm Development

• Visibility/Fog (Gultepe and others)
• Ceiling
• Blowing Snow (PIEKTUKD, Li Pomeroy 1997)
• Turbulence (TKE, EDR, momentum flux, CAT)
• Winds/Gusts/Shear (Goyette et al. and Brassur )
• Icing
• Precipitation Type (BOURGOUIN (1992) )
• Precipitation Intensity
• Lightning/Convective Storm
• Real Time Verification

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YYZ Feb 6, 2008 VISIBILITY and CEILING
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YYZ Oct 07-2007 FOG and RAIN
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Questions?
YVR Fog Event Nov. 18-24, 2005