120:, called a clear sky chart, showed all of Rahill's forecast data, but for only one location. Danko writes "It shows at a glance when, in the next 48 hours, we might expect clear and dark skies for one specific observing site". Danko accepts requests from observatories and private individuals to create new CSCs for locations not currently covered. However, since CMC's GEM model only covers North America, CSCs are limited to North America. In 2020, Danko added Norwegian/European forecast (ECMWF) information to some charts. Research continues as to which forecast is more reliable.
53:, parameters which are not forecast by civil or aviation forecasts. They forecast hourly data, but are limited to forecasting at most 48 hours into the future. Each individual chart provides data for only a 9 mile radius, and so are essentially point forecasts. There are clear sky chart forecasts for over 6100 locations, though the coverage area is limited to Canada, the USA and parts of Mexico and the Caribbean. Locations are typically cities, professional and public
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On
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89:(CMC) and amateur astronomer, created a forecast processing step that took data from CMC's Global Element Multi-scale (GEM) forecast model and created a new forecast of cloud cover. Rahill specially designed his cloud forecast to consider the formation of
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trademark, but also advised that changing the name was the "least painful" and least "expensive" solution. However, there continue to be references to the old name on web sites not controlled by the domain cleardarksky.com.
93:. The cirrus cloud modeling distinguishes Rahill's model from other cloud forecast models, as sufficient cirrus clouds to make a night unusable for astronomers is still called "clear" by civil weather forecasts.
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In later years, Rahill added a forecast of astronomical transparency, which is a measure of how much starlight traverses the Earth's atmosphere when otherwise free of clouds. Rahill also added a forecast of
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permit non-commercial web sites to display clear sky chart images, they are most commonly recognized by private and club astronomy websites in North
America.
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awarded their
Amateur Achievement Award to Allan Rahill on behalf of the Clear Sky Chart team composed of Allan Rahill and Attilla Danko.
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296:"Astronomical Society of the Pacific : GET INVOLVED : Membership : Become a Member"
241:*Ivan Semeniuk., "STARSTRUCK: Clear Sky Clock", Daily Planet, Discovery Channel. April 15, 2005
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Alternative services include 7timer (based on NOAA data) and
Astrospheric (based on CMC data).
373:"STARSTRUCK: Clear Sky Clock", Ivan Semeniuk'. Daily Planet, Discovery Channel. April 15, 2005
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Lydia
Lousteaux., "'Interview with the creators of the Clear Sky Clock'" astronomytoday.com;
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Rahill and Danko have received awards from meteorological and astronomical organizations:
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367:"Interview with the creators of the Clear Sky Clock" Lydia Lousteaux. astronomytoday.com
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364:"The Clear Sky Clock" Sky News magazine. #54 | Volume IX, Issue 6 | March/April, 2004
361:"A Weather Clock for Observers". A.Danko. Sky & Telescope Magazine; Apr 2003; 62;
261:"The Clear Sky Clock" Sky News magazine. #54 | Volume IX, Issue 6 | March/April, 2004
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271:"'Clear Sky Chart FAQ: Why the name change?'"; cleardarksky.com
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168:in recognition of Danko's and Rahill's forecasts.
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382:"How We Really Predict Clouds" Danko, A.,
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45:. They forecast the
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541:Weather forecasting
200:Other Recognition:
187:Astronomical League
99:astronomical seeing
51:astronomical seeing
49:, transparency and
418:2019-12-23 at the
413:Environment Canada
350:2006-02-07 at the
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345:TSP History
206:Allanrahill
158:Andrew Lowe
141:Recognition
124:Name change
47:cloud cover
43:astronomers
530:Categories
331:2008-01-02
218:References
107:atmosphere
103:turbulence
472:Astronomy
210:Asteroid
204:Asteroid
118:meteogram
438:Download
416:Archived
348:Archived
33:(called
458:Portals
452:iOS App
85:at the
77:History
35:clocks
484:Stars
444:myCSC
411:from
430:The
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
