On Thu, 6 May 2004, steve_koehler wrote:

> Allan and Attilla,
>
> I'm curious if either of you have things in the works that will show
> up in the CMC forecasts or the Clear Sky Clocks. I think your work
> has been a fantastic service to the astronomical community. Thank
> you very much.
>
> -- Steve Koehler
>

Hi Steeve,

On my side the answer is yes and no. Yes, because there will be major
changes and no because it won't be transparent on the Clear Sky Clocks.

I am going to use a brand new weather model to creates all the
astro-weather images with nearly twice the resolution. The new in house
regional model will have an horizontal resolution of 15km instead of the
actual 24km. On the vertical, the number of calculation levels will
increase from 28 to 58.
I will also use new cloud physic schemes which improves the forecast for
low clouds and convection (thunderstorms). I did many comparison and you
should see better cloud forecast this coming summer than last year. I did
also some comparaison over the prairies where the new schemes handle
better low clouds. Of course, it is not perfect and the problem we have
over Ohio with low clouds advected from the Great Lakes is not resolved
yet and the model will still over-forecast the cloud cover during the
winter under northwesterlies.
You won't see the difference on the CSC but on the maps where there will
be a lot more resolution for cloud and seeing conditions and somewhat on
the transparency forecast which is more or less filterred. Transparency
and specially the seeing code were modified to use the new information of
the 15km model. The implementation of the new astro-weather maps will take
place May 12th or May 18th... no more sure yet... still have some work to
do and we are behind schedule.

I am also planning to change the transparency forecast in adding new code
to introduce the smog but with a brand new approach. I did it last year as
a parallele run but didn't verified well. I am going to give another try
in June (when I will have more free time). I will also take this
opportunity to add another level of transparency. In the longer
term, I wish to re-write the seeing forecast.

* *
_~~~~~~~
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