Jan 13

Scope Nights: Astronomer’s Weather Upgrade

The Astronomer’s Weather Upgrade is designed for those who want more than just a basic stargazing forecast. It allows you to customise stargazing forecasts using night-time coverage and observing thresholds for moon, wind, humidity and temperature. It also includes medium range global forecasts up to 10-nights, clear period notifications and sharing of astronomy weather reports via Twitter.

Medium Range Global Stargazing Forecasts

When you upgrade to the Astronomer’s Weather Pack your forecasts will include a medium range global forecast up to 10-nights derived from the European numerical forecast model which is renowned worldwide as providing the most accurate medium range global weather forecasts. While short range forecasts up to 3 nights are more accurate and better for the finer details, medium range forecasts from 3 to 10 nights can provide an idea of what’s in store and are ideal for planning astronomy events further ahead. As a general rule for most locations you should receive a 10-night forecast, but the data available depends on the amount of data provided by the weather service for that location.

Clear Period Notifications

Clear Sky Notification

Rather than pestering you with notifications every day, Scope Nights will only notify you when there is a clear 3-hour or 6-hour period in the forecast for your chosen location, and it will notify you well before sunset, so you have time to prepare.

Sharing Astronomy Weather Reports

Depending on whether you’re on the the summary or detail screen you can share your weekly or nightly astronomy weather reports via Twitter. This is great if you have an upcoming star party and wish to update everyone on the pending observing conditions, or just to inform other astronomers of conditions in your local area. Remember that if you heavily customise your forecasts using your own thresholds, your forecast may not always be relevant to other astronomers who require different conditions, so might be worth relaxing your thresholds to cover all types of observing before tweeting astronomy weather reports.

Night Coverage

For astronomers who don’t have time to observe through the whole night, night-time stargazing ratings can be misleading. So the Coverage setting allows you to choose which part of the night you are generally interested in, i.e. All Night (sunset to sunrise), Evening (sunset to midnight) or Morning (midnight to sunrise). Eg. If you set the coverage to evening, when you return to the Scope Nights forecast page the stargazing forecasts and ratings will automatically adjust to evening coverage, thus providing a more relevant stargazing summary rating for each night. This setting has been kept deliberately simple so you can quickly switch between three types of coverage, but also due to the length of forecast periods (3hr & 6hr) supplied by weather services.

 

Astronomy Weather Thresholds

Threshold Settings

When a threshold setting is reached, the colour of detail forecast values for those parameters will change, and the corresponding stargazing rating will also change as follows:

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  • If a forecast parameter is very close to the threshold setting, the parameter colour will change to amber. This will also change the stargazing rating to fair.
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  • If a forecast parameter has reached or exceeded the threshold setting, the parameter text colour will change to red.  This will also change the stargazing rating to poor.
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Moon Threshold

Setting a maximum threshold for moon phase allows you to customise you stargazing ratings to suit your dark sky requirements. If you observe brighter objects like the moon or planets then you will be able to tolerate a brighter moon than if you observe faint objects like galaxies or nebulae. You should set your moon phase threshold depending on the type of observing you plan to carry out. Lowering the moon phase threshold will limit the number of available nights for observing and your chances of good stargazing ratings. If you are unsure about setting this threshold then leave it at the default threshold to give you the maximum number of nights for observing. The moon brightness will then determine which objects are observable on any given night.

Scope Nights Astronomer's Weather Pack

Wind Threshold

Setting a maximum threshold for wind speed allows you to customise you stargazing ratings to suit your location. If you have a small telescope or observe from a sheltered location then you will be able to tolerate higher wind speeds than if you have a large telescope or observe from an exposed location. You might like to monitor the actual wind speed during different observing sessions and then set this to your highest workable wind speed.

Gust Sensitivity

If you have upgraded to national astronomy forecasts, the gust sensitivity switch will be activated. National forecasts provide wind gust information when gusts are significant. Normally Scope Nights will use the mean wind speed when checking the max wind threshold, but if you switch the gust sensitivity on, the gust speed will be used instead. This is useful if your telescope is particularly sensitive to wind and you don’t want to expose it to gusts over a certain speed. If gust sensitivity is switched on, it will limit the number of good stargazing ratings, especially in windy locations.

Humidity Threshold

Setting a maximum threshold for humidity allows you to set a limit for damp observing conditions so you can see when the humidity might stop your observing.  Humidity is the percentage of water vapour carried in the air, so the effect of high humidity is water vapour condensing onto optics or electronics. Relative humidity is related to dew point; a humidity above 90% indicates the dew point will be close to the air temperature and dew may start to condensate onto optics or electronics, and a 100% humidity indicates the dew point will be equal to or above the air temperature and the air is saturated. If you have a dew heater then you may be able to observe with humidity well above 90%, but if you have no heaters then a humidity above 90% will quickly cut short your telescope time. You might like to monitor the actual humidity during different observing sessions and then set this to your highest workable humidity.

Temperature Threshold

Setting a minimum threshold for temperature allows you to set a limit for cold conditions so you can see when the temperature might stop your observing. If you observe remotely or from a sheltered location then you may be able to tolerate lower temperatures than if you observe outside or from an exposed location. Set this temperature to the lowest you or your scope can tolerate. Some telescope electronics are only designed to work above -30°C. You might like to monitor the actual temperature during different observing sessions and then set this to your lowest workable temperature.

If you find Scope Nights useful and would like to see continued support and development, please leave a good rating on the app store.