Current Weather & Forecast
Current and forecast weather and sky conditions: Cloud cover predictions will animate by pressing the play button; using the slider will show the three-day period of the graphical predictions. The chart reads from left to right and shows predictions for cloud cover, transparency (haze, smoke, water vapor), and the quality of atmospheric steadiness ("seeing"), sunrise/set, moonrise/set, wind direction, temperature, and dewpoint for the next three days.
A more detailed chart can be opened by clicking Astrospheric.com logo in the upper right corner on the chart.
The most important items to consider are the first two bars Cloud Cover & Transparency. The colors indicate what color the sky quality is likely to be, with dark blue being clear/best, and grey to white representing overcast/worst. Clicking on the International Space Station symbol near the Sun and Moon rise/set curves will bring up an all sky view and times for passage of the bright and fast-moving ISS in the sky.
The most important items to consider are the first two bars Cloud Cover & Transparency. The colors indicate what color the sky quality is likely to be, with dark blue being clear/best, and grey to white representing overcast/worst. Clicking on the International Space Station symbol near the Sun and Moon rise/set curves will bring up an all sky view and times for passage of the bright and fast-moving ISS in the sky.
Atmospheric Steadiness
An application from MeteoBlue details forecasts astronomical seeing conditions. The screen shot below on the right shows predicted seeing resolution in arc-seconds and the general 1 (poor) to 5 (excellent) seeing scales. This can be especially useful for observing lunar, solar, and planetary detail.
Jet streams are narrow bands of very strong winds that meander across the globe like rivers, sometimes reaching speeds in excess of 400km/h although they have an average speed of about 180km/h. The movement of air currents between the telescope observer and the vacuum of space causes ripples in the atmosphere – rather like the disturbance of air above a heat source – making the air appear to shimmer. If the jet stream happens to be placed where you’re observing, the atmospheric disturbance may rob your view of fine detail on planets and the Moon – perhaps even making meaningful observations difficult if not impossible. Click on the image below to see the locations of the global jet streams.
Netweather
Predicting good or bad seeing is not an exact science, just like predicting the weather generally. Its important to remember that it is not just the jet stream that affects astronomical seeing directly, local topography and micro climates can have significant effects as well.
Day & Night
Day & Night
The graphic below shows the duration of daytime, twilight, and nighttime hours for Goldendale. Click on image for current times.
Moon Phase
Even though the full moon is a beautiful sight to behold, it is very bright. While the brighter stars and planets are unaffected, the Milky Way and faint "deep sky" objects such as galaxies and nebulae can be overpowered by bright moonlight. The periods around the new moon and crescent phases are the best times for observation of these fainter objects:
If your primary interests lie in viewing "deep sky" objects, please consult the Moon Phases Calendar for new and waxing/waning crescent moon phases when planning for future observing.
