Loading ...
Sorry, an error occurred while loading the content.

Re: [AstronomyWeather] Re: any news about CMC forecasts or CSC rendition?

Expand Messages
  • Stephen C. Koehler
    Attilla, Thanks for your update. I look forward to the new features. That would be very exciting if someone can get a European model going so you can also
    Message 1 of 12 , May 7, 2004
    View Source
    • 0 Attachment
      Attilla,

      Thanks for your update. I look forward to the new features. That would be
      very exciting if someone can get a European model going so you can also
      cover Europe.

      I'm wondering if you will experience problems with the increased spatial
      resolution in the CMC images causing individual 1 hour CSC squares to be
      less representative. If the model gets to the point of producing a region
      of speckled clear sky and cloud, you will probably have to average (i.e.,
      blur) the model to get a representative forecast for the 1 hour slot.
      Has this been a problem in the past? Do you think it will be a problem
      with higher resolution maps?
      --
      Steve Koehler
      koehler@...
    • Allan Rahill
      ... Indeed, it will be a problem for a few Clear Sky Clocks. I have already did some animations to see how those little holes moves within low clouds. I have
      Message 2 of 12 , May 7, 2004
      View Source
      • 0 Attachment
        On Fri, 7 May 2004, Stephen C. Koehler wrote:

        >
        > Attilla,
        >
        > Thanks for your update. I look forward to the new features. That would be
        > very exciting if someone can get a European model going so you can also
        > cover Europe.
        >
        > I'm wondering if you will experience problems with the increased spatial
        > resolution in the CMC images causing individual 1 hour CSC squares to be
        > less representative. If the model gets to the point of producing a region
        > of speckled clear sky and cloud, you will probably have to average (i.e.,
        > blur) the model to get a representative forecast for the 1 hour slot.
        > Has this been a problem in the past? Do you think it will be a problem
        > with higher resolution maps?
        > --
        > Steve Koehler
        > koehler@...

        Indeed, it will be a problem for a few Clear Sky Clocks. I have already
        did some animations to see how those little holes moves within low clouds.
        I have seen a few point or grid points where holes doesn't move which will
        give the impression to clear sky clocks users of many clear skies hours
        when it will be cloudy all around. We found the problem which seems to be
        related to lakes being ice covered (which should not be a problem for
        southern regions). The way the low clouds are forecast, well what I can
        say... they are not advected.
        With icy lakes, well there is no moisture being evaporated and tile in the
        model is dryer than surrounding tiles with snow or vegetation. So, over
        the lake (or within 15km around the lake) the grid point is dryer and tend
        to evaporate the clouds.
        There is no easy solution for now, but we should add a patch in the model
        to solve this freaky stationnary holes which appear occasionnally.

        I have to say, I am quite happy with the general picture of the new 15km
        cloud schemes. When compared to satellite pictures, it is getting close to
        satellite picture quality... and it verifies!!!!

        Have a good weekend!

        * *
        _~~~~~~~
        Allan Rahill * * *( )
        ~~-(__ )
        Centre meteorologique Canadien * (____ CMC )
        Canadian Meteorological Center, Dorval, Canada (_______)
        ////
        ASTRO-METEO-WEATHER '''
        http://www.cmc.ec.gc.ca/cmc/htmls/mainpage.html '''
        Attilla web page
        http://www.cleardarksky.com/csk
      • Allan Rahill
        On Fri, 7 May 2004, Stephen C. Koehler wrote: Just want to let you know the implementation of the higher resolution cloud-transparency-seeing forecast based on
        Message 3 of 12 , May 7, 2004
        View Source
        • 0 Attachment
          On Fri, 7 May 2004, Stephen C. Koehler wrote:


          Just want to let you know the implementation of the higher resolution
          cloud-transparency-seeing forecast based on the 15km resolution models
          will done on May 18th for the noon integration.

          * *
          _~~~~~~~
          Allan Rahill * * *( )
          ~~-(__ )
          Centre meteorologique Canadien * (____ CMC )
          Canadian Meteorological Center, Dorval, Canada (_______)
          ////
          ASTRO-METEO-WEATHER '''
          http://www.cmc.ec.gc.ca/cmc/htmls/mainpage.html '''
          Attilla web page
          http://www.cleardarksky.com/csk
        • steve_koehler
          Allan, ... 15km ... close to ... When you have some time, I would be interested to hear more about how you verify your models. Do you continuously measure the
          Message 4 of 12 , May 7, 2004
          View Source
          • 0 Attachment
            Allan,

            > I have to say, I am quite happy with the general picture of the new
            15km
            > cloud schemes. When compared to satellite pictures, it is getting
            close to
            > satellite picture quality... and it verifies!!!!

            When you have some time, I would be interested to hear more about how
            you verify your models. Do you continuously measure the prediction
            against reality, or do you spot check? How do you quantify the
            closeness of the fit to reality?

            -- Steve Koehler
          • Attilla Danko
            ... spatial ... squares to be ... It s sometimes a problem now. A clock can display a long string of clear blocks when there is a bank of cloud very closeby
            Message 5 of 12 , May 8, 2004
            View Source
            • 0 Attachment
              --- In AstronomyWeather@yahoogroups.com, Allan Rahill <

              > > I'm wondering if you will experience problems with the increased
              spatial
              > > resolution in the CMC images causing individual 1 hour CSC
              squares to be
              > > less representative.


              > Indeed, it will be a problem for a few Clear Sky Clocks.

              It's sometimes a problem now. A clock can display a long
              string of clear blocks when there is a bank of cloud very closeby
              moving in a paralell direction. A tiny error in the forecasted
              position of the cloud bank, or the lat/long of the clock, can
              mean difference between a long string of blue or a long string
              of white block. Only one is likely to be right.

              It's a problem unique to the way clear sky clocks show
              Allan's forecasts data.

              A solution the the problem is one of the 4 features I'm working
              on.

              -ad
            Your message has been successfully submitted and would be delivered to recipients shortly.