About the Interactive Map Viewer

About the Interactive Map Viewer

Glossary of Terms in the Tables

From 15 December 2010, the Interactive Map Viewer will be with improved features for selecting numerical prediction maps.

How do I use the Interactive Map Viewer?

The Interactive Weather and Wave Forecast Map Viewer is used to display images of computer-generated forecast data for up to the next 7 days.

The maps are produced from computer models. As they contain no input from weather forecasters, they do not include any symbols, such as cold fronts. For weather maps generated by Forecasters, view the Bureau of Meteorology official weather maps for the next 4 days.

Selecting and Displaying Maps

The Map Viewer allows you to select the map you are interested in seeing by choosing from several lists of:

  • the weather or ocean element to show,
  • preferred Time Zone,
  • your geographic area of interest, and
  • the Time Period you are interested in, out to 7 days.
  • Additionally, some atmospheric data types require a choice of Level (vertical level in the atmosphere).
Show:

The first list, entitled "Show:" allows you to choose the type of map you wish to view. There are 7 different types of atmospheric prediction maps (Surface pressure and Precipitation, Surface Pressure & Thickness, Wind Speed and Direction, Geopotential Height, Temperature, Relative Humidity, Dew Point) and 5 different types of ocean-wave prediction maps (Combined Sea and Swell, Primary Swell Wave Component, Secondary Swell Wave Component, Wind Wave Height, Swell Period).

Level:

Upper air charts are available for several weather elements. The levels available in the maps are predefined based on atmospheric Pressure at several standard heights.

Timezone:

Select the preferred time zone for the viewer. This selection will be retained for future use.

Times listed under each day will reflect the chosen time zone, e.g. Australian Eastern Standard Time (AEST), however the times shown on the maps in the heading will always be time-stamped in Coordinated Universal Time (UTC), which is equivalent to Greenwich Mean Time (GMT).

Area:

The map domains (coloured squares) and grid spacing or resolution (in kms) available from the models are defined below.

ACCESS-Global:
covers the entire globe. Latitude/Longitude extents (90°S,0°E) to (90°N,0°W)
ACCESS-Regional:
covers the wider Australian region and neighbouring countries. Latitude/Longitude extents (55°S,90°E) to (0°,180°E)
ACCESS-Tropical:
covers the tropics from India in the west to Hawaii in the east. Latitude/Longitude extents (45°S,60°E) to (55°N,140°W)
ACCESS-Australia:
covers the Australian mainland, Tasmania, and parts of neighbouring countries. Latitude/Longitude extents (50°S,100°E) to (0°,165°E)
City areas:
Additionally, there are five smaller areas defined around major Australian cities: PE (Perth), AD (Adelaide), VT (Victoria and Tasmania), SY (Sydney), and BR (Brisbane).
Tropical Cyclone extents:
The boundaries of the TC region, which is used to model tropical cyclone activity, varies, depending upon tropical cyclone activity.

Multiple viewing areas are available for each model. For instance, for the ACCESS-Australia model, one can view the full Australian region, or smaller regions that zoom in on the states.

For data relating to the oceans, models known as AUSWAVE-Global, AUSWAVE-Regional and AUSWAVE-Australia are used to generate the maps. The model used in a map depends upon the number of days and time interval (in hours) selected from the Period list. The extents of the models match the respective ACCESS model extents, i.e. AUSWAVE-Regional covers the same extents as ACCESS-Regional, however the only view available shows Australia.

Period:

The list of periods available varies depending on the Area selected, but will generally be a combination of a maximum period of 2, 3 or 7 days and interval of either 3 or 6 hours.

The maps are displayed in time order, with the first map being for the model's "base" or "analysis" time (the time of the weather observations which form the starting point for the model's predictions), followed by maps at 3, 6 or 12 hour intervals, depending on the particular model and area chosen. Some views start with small time intervals for the first few days and with larger time intervals for the remaining days.

Numerical model prognosis maps may be labelled with the time at which the forecast is valid or with a +012 hr, +024 hr, +036 hr, +048 hr, +072 hr etc from the base observation time (represented by the letter “t”) for that run of the model. Generally the models are run twice daily, with their initial analyses being at 00UTC and 12UTC.

The time steps of the map being displayed is shown in the date/time bar just under the animation controls. You can also jump to a map for any time step by selecting a different time in the time bar.

Generate:

By pressing the “Generate” button, the viewer then generates maps based on the selections. Those maps are then available for viewing in chronological order.

The generated map settings can be "bookmarked" (saved as a favourite) in your web browser, so that you can display your preferred maps quickly next time you return to the viewer.

Note: The maps are updated regularly during the day. As a result, a given time step (for instance, the fourth time step in the series), could fall at a different time of day depending on the base time for the most recent model run.

Displaying the maps as an Animation

Once the first map is displayed, it is possible to use the animation controls above the maps to move forwards and backwards in time through the maps.

Step back: Go back to the previous map in the time sequence
Step forward: Go forward to the next map in the time sequence
Stop: Stop the animated display of the maps
Play: Start the animated display of the maps

Note that Javascript must be enabled in your web browser for the animation to function. If you do not see the Stop and Play controls in your browser, confirm that JavaScript is enabled in your browser.

About the Maps

These maps are up to date images of Numerical Weather Prediction maps.

Analysis maps are a snapshot of the weather situation at the base observation time (current or recent time), while prognosis maps are a forecast for another specified time, up to 7 days ahead.

Who uses the maps?

The maps are used as guidance for the Bureau's official forecasts. The Bureau's forecasters all around Australia use these maps every day in conjunction with other data sources to prepare and issue the official regular weather and ocean forecasts and warnings for every Australian state and territory.

These maps are useful for those interested in a detailed view of the forecast conditions across the Australian region or globally for the atmosphere and ocean.

For information about interpreting Wind Barbs see the Bureau Glossary under Wind Barbs: How to interpret wind speed and direction?

What is the data source for the maps?

A new suite of numerical weather and wave prediction models came into operation in August 2010 when the Bureau introduced its ACCESS and AUSWAVE models. The Bureau's National Meteorological and Oceanographic Centre (NMOC) runs numerical models over several geographic areas (domains) to provide automated analyses and predictions of atmosphere and ocean characteristics on a range of time-scales. The maps generated from the ACCESS and AUSWAVE models represent a variety of atmosphere and ocean characteristics at a number of elevations. The maps showing the state of the atmosphere use the Bureau's ACCESS atmospheric modelling system while those showing the state of ocean waves use the Bureau's AUSWAVE ocean modelling system.

The ACCESS suite of models has shown a significant improvement in accuracy over the Bureau's old weather model suite (GASP, LAPS and MesoLAPS).

For more detailed information about the ACCESS or AUSWAVE models, please refer to About the ACCESS model or About the AUSWAVE model.