What is Cloud Free Night?

Cloud Free Night is an online weather forecast information service for the benefit of the Australia astronomy and photography communities. Weather forecasts from the United States GFS global model can be compared with local (Bureau of Meteorology, WeatherWatch, OzForecast) and overseas (Meteologix, Yr, meteoblue, Clear Outside) forecasts, improving your confidence in the accuracy of these weather predictions.

Do you have a Facebook page?

The Cloud Free Night Facebook page is located at www.facebook.com/cloudfreenight.

Do you have any testimonials?

"thanks for ongoing marvellous predictions with an uncannily high rate of getting it right! For example, over the last week, I was following your predictions and those of BOM. The two differed appreciably, and I watched as BOM slowly started to shift their prediction to what you had said days before they did. And your prediction was right. I actually use the website to predict when there will be high cloud or fog, to aid my photographic work, rather than looking for clear nights!" - Les Irwig, Les Irwig Photography (13 June 2020)

"Running an observatory taking people out on a monthly basis using CFN is my goto. This weekend in Perth it was crazy weather, tornadoes, hail and rain. Using the metorogram the group threaded the needle and got perfect clear skies and 10 hours of imaging time and just as we finished packing up to go home it started raining" - Brendan Mitchell, Astronomy Academy Perth (1 September 2019)

"The usability is great on my iPhone, your invaluable site has led to many successful adventures when conventional predictions were inaccurate and pessimistic. Keep up the amazing work, your users love each and every improvement you are making!" - Kevin Lurie, Cloud Free Night Facebook post (29 July 2019)

"Thanks for including Ulladulla in the meteogram ... I'm currently imaging NGC 6744 galaxy down near Ulladulla ... Beautiful night and as usual CFN is spot on ... CFN , an important part of my Astro tool kit ... Thanks very much" - IceInSpace Member Startrek (Martin) (9 July 2019)

"A superbly practical tool with the local Access model for planning public and school events, astro field trips for observation collection, and knowing whether to get out of bed to try seeing something that's pre-dawn. Over the years since it was first developed and trialled, it's always been by far the most reliable predictor for the Mornington Peninsula region, including the Briars observatory. Three cheers for Robert, Phil et al." - Peter Skilton, Mornington Peninsula Astronomical Society (13 March 2019)

Where does the weather forecast come from?

Cloud Free Night displays the official forecasts from the Bureau of Meteorology, including district and precis forecasts out to seven days for over 680 locations around Australia.

Almost every weather website and app you have ever heard of is providing data from the United States GFS model, because it is freely available, even for commercial use, allowing anybody around the world to resell weather services using the same underlying data. However, as a global model, this is far from the best source of forecasts for Australia, particularly for short-term outlooks.

Cloud Free Night displays detailed cloud forecast information from the United States GFS model. Forecast maps and meteograms over specific Australian regions and locations summarise the model forecasts over the next seven days. The model forecasts can then be compared with local (WeatherWatch, OzForecast) and overseas (Meteologix, Yr, meteoblue, Clear Outside) weather forecasts.

Where does the weather observations come from?

Cloud Free Night displays the latest Himawari-8 satellite images from the Bureau of Meteorology. The high-definition satellite images are available over many areas covering Australia. Satellite images originally processed by the Bureau of Meteorology are from the geostationary satellite Himawari-8 operated by the Japan Meteorological Agency.

What is available in Cloud Free Night?

Bureau of Meteorology official forecasts (full, district or precis) over the next seven days for over 680 locations around Australia.

GFS global model (28 km resolution) hourly (+0 to +72 hours) and 3-hourly (+75 to +168 hours) forecasts over the next seven days updated 4 times/day (00, 06, 12 and 18 UTC).

GFS hourly (+0 to +72 hours) and 3-hourly (+75 to +168 hours) forecast maps of Total Cloud, Low Cloud, Middle Cloud, High Cloud, Wind, Jetstream, Pressure/Rainfall, Temperature, Humidity, Precipitable Water, Solar Irradiance and Total Rainfall (Accumulated Precipitation).

GFS forecast map regions of Australia, SE Australia, Victoria, New South Wales, Australian Capital Territory, SE Queensland, North Queensland, Far North Queensland, Northern Territory, Central Australia, NW Western Australia, SW Western Australia, South Australia, NE South Australia, Tasmania, Melbourne, Sydney, Canberra, Brisbane, Darwin, Perth, Adelaide and Hobart.

GFS hourly (Day 1, Day 2 and Day 3) and 3-hourly (Days 1-3, Days 3-5 and Days 5-7) forecast (Dark Sky, Cloud, Solar and All) meteograms (TBC meteogram locations).

Himawari-8 satellite images updated every 10 minutes for the Australian Region, Australia, SE Australia, Victoria, Melbourne, New South Wales, Sydney, Australian Capital Territory, Canberra, SE Queensland, Brisbane, North Queensland, Far North Queensland, Coral Sea, Northern Territory, Darwin, Central Australia, NW Western Australia, SW Western Australia, Perth, South Australia, Adelaide, NE South Australia, Tasmania, Hobart and Tasman Sea.

Cloud camera (e.g. aviation weather cameras, all sky cameras, webcams, etc.) images around Australia (over 300 locations and nearly 700 camera images), including links to the original image and source.

Synoptic chart images updated every 6 hours of the latest colour mean sea-level pressure analysis (including satellite image background) from the Bureau of Meteorology.

What is Forecast?

Bureau of Meteorology official forecasts (full, district or precis) over the next seven days for over 680 locations around Australia.

To display an official precis forecast, select the REGION (Melbourne, VIC, Sydney, Canberra, West NSW, SE NSW, NE NSW, Brisbane, SW QLD, SE QLD, North QLD, Darwin, North NT, South NT, Perth, South WA, North WA, Adelaide, SA, Hobart or TAS) and LOCATION using the buttons to the right of the image. The map and list of locations will be updated for the selected region. The location can also be selected from the displayed map. Selecting the forecast image will display the full or district forecast in a new window. Your selections for REGION and LOCATION will be remembered.

What is Map?

Map images show GFS hourly (for the first three days) and 3-hourly model forecasts over specific regions for the next seven days. The maps display forecasts of Total Cloud, Low Cloud, Middle Cloud, High Cloud, Wind, Jetstream, Pressure/Rainfall, Temperature, Humidity, Precipitable Water, Solar Irradiance and Total Rainfall (Accumulated Precipitation) for Australia, SE Australia, Victoria, New South Wales, Australian Capital Territory, SE Queensland, North Queensland, Far North Queensland, Northern Territory, Central Australia, NW Western Australia, SW Western Australia, South Australia, NE South Australia, Tasmania, Melbourne, Sydney, Canberra, Brisbane, Darwin, Perth, Adelaide and Hobart map regions.

To display a forecast map, select the MODEL, REGION and TYPE using the buttons to the right of the image. Select the Show/Hide Placenames button below the image to toggle the display of placenames and longitude/latitude grid over the forecast map. Step Forwards/Backwards through time (i.e forecast period) using the 1, 3, 6, 12 or 24 hour(s) buttons below the image. This will increment/decrement the forecast period (i.e. time). Select the Reset button below the center of the image to return to the default (+003 hr) forecast period. Your selections for MODEL, REGION, TYPE, Show/Hide Placenames and Forecast Period will be remembered.

To display the synoptic charts, select the Synoptic Chart button to the right of the image. Select the Show/Hide Satellite button below the image to toggle the display of the synoptic chart over the satellite image. Step Forwards/Backwards through time, Move to the Earliest/Latest image or Start/Stop Animation of the images using the arrow buttons below the image. The most recent 3 weeks of chart images can be displayed. Your selection for Show/Hide Satellite will be remembered.

To display local ACCESS model forecasts (no longer available in Cloud Free Night), select the WeatherWatch button to the right of the image. The WeatherWatch MetCentre website page will be displayed in a new window. A Pro subscription ($8/month) is required to display the ACCESS model forecasts.

To display overseas model (e.g. ECMWF) forecasts, select the Meteologix button to the right of the image. The Meteologix website page will be displayed in a new window.

What happened to the Chart page?

The Chart page can be displayed from the Synoptic Chart link on the Map page.

What is Synoptic Chart?

Synoptic chart images updated every 6 hours of the latest colour mean sea-level pressure analysis (including satellite image background) from the Bureau of Meteorology, freely available (in real-time) for non-commercial use from the Bureau of Meteorology FTP Server. For further information, see Interpreting the Mean Sea Level Pressure (MSLP) Analysis (Bureau of Meteorology).

Select the Show/Hide Satellite button below the image to toggle the display of the synoptic chart over the satellite image. Step Forwards/Backwards through time, Move to the Earliest/Latest image or Start/Stop Animation of the images using the arrow buttons below the image. The most recent 3 weeks of chart images can be displayed. Your selection for Show/Hide Satellite will be remembered.

What is the GFS model?

United States National Center for Environmental Prediction Global operational Forecast System (GFS) model: GFS global model (28 km resolution) with hourly (+0 to +72 hours) and 3-hourly (+75 to +168 hours) forecast parameters updated 4 times per day (00, 06, 12, 18 UTC); with data freely available (in real-time) for commercial use downloaded from the NOMADS (NOAA Operational Model Archive and Distribution System).

When is GFS model data updated?

GFS 12 UTC (03:15-05:00)
GFS 18 UTC (09:15-11:00)
GFS 00 UTC (15:15-17:00)
GFS 06 UTC (21:15-23:00)
(Melbourne/Sydney local time)

What is Meteogram?

Meteogram images show a summary of GFS model forecasts over the next seven days: Day 1 (+0 to +24 hours), Day 2 (+24 to +48 hours), Day 3 (+48 to +72 hours), Days 1-3 (+0 to +72 hours), Days 3-5 (+48 to +120 hours) or Days 5-7 (+96 to +168 hours) for particular locations (TBC meteogram locations). The (Dark Sky, Cloud, Solar and All) meteograms (time-series graphs and tables) present detailed cloud information. The graph/table displays hourly or 3-hourly values of the temperature, rainfall, wind, jetstream, pressure, humidity, precipitable water, solar irradiance and total, low, middle and high cloud cover.

The Dark Sky meteograms show GFS hourly or 3-hourly graphs of the total cloud cover, moon phase (% illumination) and moon/sun rise/set times; and tables of temperature, moon phase, wind, jetstream, precipitable water, humidity, total, low, middle and high cloud cover for particular locations out to seven days, to identify dark sky night opportunities. Dark sky night hours are defined by total cloud cover < 20% and moon illumination < 50% (or no moon), and are displayed using star icons near the top of the graph and in the table.

The Solar meteograms show GFS hourly or 3-hourly graphs of the total cloud cover, temperature and solar irradiance; and tables of temperature, solar irradiance, wind, total, low, middle and high cloud cover for particular locations out to seven days.

To display a forecast meteogram, select the MODEL (i.e. GFS) and location using the buttons to the right of the image. Select the meteogram type (Dark Sky, Cloud, Solar or All) using the buttons below the image. Select the day(s) using the D1 (+0 to +24 hours), D2 (+24 to +48 hours), D3 (+48 to +72 hours), D1-3 (+0 to +72 hours), D3-5 (+48 to +120 hours) or D5-7 (+96 to +168 hours) buttons below the image. Select a location in another state or country using the VIC, NSW, ACT, QLD, NT, WA, SA or TAS buttons below the image. Your selections for MODEL, location, type and day(s) will be remembered.

To display an alternative forecast for the selected location, select the source (OzForecast, Yr, meteoblue, Clear Outside) using the buttons below the image. The OzForecast (ADFD meteogram), Yr (Detailed hourly forecast), meteoblue (Astronomical seeing) or Clear Outside website page will display in a new window.

Where are the Victoria meteogram locations?

Where are the New South Wales meteogram locations?

Where are the Australia Capital Territory meteogram locations?

Where are the Queensland meteogram locations?

Where are the Northern Territory meteogram locations?

Where are the Western Australia meteogram locations?

Where are the South Australia meteogram locations?

Where are the Tasmania meteogram locations?

What is Satellite?

Satellite images originally processed by the Bureau of Meteorology from the geostationary satellite Himawari-8 operated by the Japan Meteorological Agency, updated every ten minutes, freely available (in real-time) for non-commercial use from the Bureau of Meteorology FTP Server. The high-definition satellite images (Day + Night, Visible Greyscale, Infrared Greyscale, Infrared + Rainbow, Infrared + Zehr and Water Vapour) are available over many areas (Australian Region, Australia, SE Australia, Victoria, Melbourne, New South Wales, Sydney, Australian Capital Territory, Canberra, SE Queensland, Brisbane, North Queensland, Far North Queensland, Coral Sea, Northern Territory, Darwin, Central Australia, NW Western Australia, SW Western Australia, Perth, South Australia, Adelaide, Tasmania, Hobart and Tasman Sea) covering the Australian region.

To display a satellite image, select the REGION and TYPE using the buttons to the right of the image. Select the Show/Hide Placenames button below the image to toggle the display of placenames and longitude/latitude grid over the satellite image. Step Forwards/Backwards through time, Move to the Earliest/Latest image or Start/Stop Animation of the images using the arrow buttons below the image. The most recent 12 hours of satellite images can be displayed. Your selections for REGION, TYPE and Show/Hide Placenames will be remembered.

Day + Night: True-colour images (1 km resolution) based on reflected visible light. These are useful, for example, for identifying fog and low cloud, which may not be visible in thermal infrared images because it has a similar temperature to the ground below. The visible light images only show parts of the Earth that are in daylight. Areas with no sunlight to reflect are replaced with greyscale thermal infrared imagery. To match the familiar colour of clouds, the infrared imagery colour table is inversed, which shows cloud as shades of white.

Visible Greyscale: Greyscale images (0.5 km resolution) based on one single visible wavelength (in comparison to the true colour image which combines three). These images will appear black in regions of no sunlight, i.e. night-time. Visible images are a record of the visible light scattered or reflected towards the satellite from the Earth and clouds. They give meteorologists extra information that may not appear on infrared images. For example, fog appears in visible images, but may not show up in infrared images as its temperature is very close to that of the land below. Visible images are only available during daytime, as at night there is no reflected sunlight.

Infrared Greyscale: Infrared (IR) images (2 km resolution) are derived from radiation emitted from the Earth and its atmosphere at thermal-infrared wavelengths (10-12 um). These images provide information on the temperature of the underlying surface or cloud. IR images are available 24 hours per day because temperatures can always be measured. This is in contrast to visible images, which are only available during daylight hours. Temperatures are represented by a greyscale, where black and white represent the hottest and coldest areas respectively. As clouds tend to be cooler than the ground or sea below (not always the case for low-lying clouds), they appear as light grey to white, making IR images simple to compare with visible images.

Infrared + Rainbow: Colour-enhanced images (2 km resolution). To assist in interpreting greyscale IR images, methods can be used to colour all pixels representing a particular temperature range. The temperature of clouds is associated with their height, so highlighting certain temperature ranges is useful for estimating the height of the observed clouds. These precision of these temperature measurements are within one or two degrees Celsius. Images coloured in this way are known as 'false colour' images.

Infrared + Zehr: Colour-enhanced images (2 km resolution). Ray Zehr from the US National Oceanic and Atmospheric Administration developed the Zehr enhancement, which applies temperature colour ranges to the cold end of the scale. This highlights deep convection that is generally associated with tropical cyclones and thunderstorms. These images can be useful in tracking the movement of tropical cyclones.

Water Vapour: Colour-enhanced images (2 km resolution) showing a measure of the amount of water vapour contained in the mid to upper levels of the troposphere. These images can be used to determine moisture advection (horizontal transport from one region to another), vertical movement of air (rising and sinking or air) and synoptic features such as short wave troughs, ridges and jet streams. Colour-enhanced imagery helps to show how saturated an area is.

What is Camera?

Cloud camera (e.g. aviation weather cameras, all sky cameras, webcams, etc.) images around Australia (over 300 locations and nearly 700 camera images), including links to the original image and source.

To display a cloud camera image, select the REGION (VIC, Melbourne, NSW, Sydney, ACT, SE QLD, Brisbane, North QLD, SW WA, Perth, SA, Adelaide, NE SA, TAS or Hobart) and LOCATION using the buttons to the right of the image. The map and list of locations will be updated for the selected region. The location can also be selected from the displayed map. Selecting the cloud camera image or image source will display the original image or image source in a new window. Your selections for REGION and LOCATION will be remembered.

How can I bookmark a specific product page?

The link to the specific product being displayed on the Map, Meteogram, Satellite or Camera pages can be seen by moving the cursor over the page header. Use this link to bookmark the specific product page or add the link to your own website.

What happened to the Radar page?

The Cloud Free Night Radar display is no longer available. Please use The Weather Chaser radar viewer for access to real-time radar and extensive archives of radar imagery. The links to the right of the Radar page will take you to the radar viewer for each location. A Personal subscription ($4/month) is required to remove the ads for better viewing.

What happened to the ACCESS model forecasts?

ACCESS model forecasts are no longer available. Unable to download any ACCESS model data from the Bureau of Meteorology since late September 2020. Please use the WeatherWatch Metcentre to display ACCESS model forecasts (at a small cost).

How does the Cloud Free Night service operate?

Cloud Free Night is operated by a small team from the Australia astronomy community. The Cloud Free Night service is hosted on a leased (Binary Lane), self-managed Linux Virtual Private Server (VPS), with IDL® (Harris Geospatial Solutions) installed and licensed (esri Australia). IDL® applications are run automatically to download (using OPeNDAP) the United States National Center for Environmental Prediction GFS model data, and Bureau of Meteorology Himawari-8 satellite images, to produce the forecast maps, meteograms and satellite images available from this VPS-hosted website. IDL® is a registered trademark of Harris Geospatial Solutions for their Interactive Data Language software, used by astronomers worldwide. Esri Australia is the official local distributor of IDL®.

How can I contact the Cloud Free Night team?

Cloud Free Night is operated by a small team from the Australia astronomy community. Please contact us at info@cloudfreenight.com if you have any questions. We would also like to hear of your experience in using, or suggestions to improve, the Cloud Free Night service.

How can I support the Cloud Free Night service?

Cloud Free Night is a completely free service, funded by past donations from the Australia astronomy and photography communities. The images below acknowledge those organisations who have supported Cloud Free Night in the past. Please consider donating to support the maintenance and further development of the Cloud Free Night service. Donations can be made using PayPal, or for other options, contact us at info@cloudfreenight.com.