The Mean Sea Level (MSL) Charts show the latest surface analysis plus 3 prognoses (forecast) charts.  All these charts are manually drawn and show the MSL pressure pattern, using Isobars in 4 Hectopascal (hPa) graduations as well as High and Low pressure centres with the central pressures labelled in hectopascals.  Frontal postitions and troughs are also shown on the MSL Charts.

Two different options are available: 

• Tasman- The chart extends from eastern Australia to well east of New Zealand.

• South West Pacific- This chart covers a much wider area, including the south west Pacific and is therefore useful to view the location and expected paths of tropical cyclones. 

The animation controller, loop toggle, speed controller and scaler buttons are used as described below.  

This module is useful in order to ascertain the location and expected movement of frontal systems, highs (anticyclones), ridges (extending from anticyclones), lows (depressions), troughs (extending from depressions) and tropical weather systems, such as tropical cyclones.

Navigation

The navigation bar at the left of the Aggregated 3 Day Forecast shows the series of times at which forecast images are available. The forecast time for the current image is highlighted in orange. As the player buttons are used, the highlighted image time will alter accordingly. To alter the displayed image, hover the mouse on a time that is visible in the list. To quickly navigate through all the images available, hover across the orange bar available at the far left.

Player

Images can be animated using the player buttons, which operate as follows:

	Display the first image in the series
	Display the previous image in the series
	Play the images in sequence
	Stop the images playing in sequence
	Display the next image in the series
	Display the last image in the series
	When playing the images, treat the data series as a loop to jump from last to first and vice versa.
	Alter the speed at which images are played. Selecting a negative speed will play images in reverse order.