3D Radar
MetCentre 3D radar provides a unique perspective of thunderstorms and provides a vertical, 3D view of the storm.
On desktop, move your mouse over the 2D view and this will provide a vertical slice through the atmosphere displayed on the 3D view section. Click on the 2D view to lock or unlock the vertical slice.
On a mobile device, clicking on the 2D view will provide a 3D slice view with an example below:
The 3D radar scans show you rain and hail before it falls to the ground. Strong echoes high in the storm that sit above weak, or no radar echoes is a very good indication of strong or severe storm activity.
Understanding Radar Reflectivity
Radar is measured in dBZ (decibels) and is a logarithmic scale. Radar works by sending a beam into the atmosphere and measures how much of the beam is reflected back to it. The more that is reflected back to the radar dish, generally the more intense the precipitation in the clouds.
As the scale is logarithmic, this means that 50dbz is 10x stronger than 40dbz, and 100x stronger than 30dbz. This also means that for higher reflectivies (above 50-60dbz), that a small incremental increase in reflectivity values provides a significant difference for ground level impacts. This is important to note if using the Storm Path function.
3D Radar - Basic Functions
Archive - Access the 3D radar archive. A selection of weather events have been downloaded and analysed. These are for fixed locations and times only. More can be accessed on request.
Go to 2D Radar - To view a loop of the current selected radar, select the 2D radar which will open the same image in the 2D format, allowing you to run a loop.
Auto Update - Select this to ensure the 3D radar always displays the most up to date image
Lightning - Toggle lightning overlay on or off
Show Storm Info (Hail Tracker & StormPredict) - Toggle the HailTracker and StormPredict overlays. For more information see here.
Save Image - Save current image view
3D Radar - Advanced Functions
Additional functions and tools are available for further analysis. These include:
Refl/Vel - For Doppler enabled radars, toggle between precipitation (refl) and wind (vel) mode.
Change Radar Colours - Change radar colour schemes
Step Up/Down - The default 2D view is the 0.5 degree (lowest) scan and is typically the most useful view. You can change the view to look at additional elevation scans so the 2D view is showing alternative heights.
Show Storm Paths - Display accumulative storm paths (in live view you have the option to display since 9am or the previous 24 hours to 9am paths. Archive view provides time options). For more information click here.
Show DBZ Highlights - Overlays reflectivity in the upper parts of the storm onto the surface, 2D view. This provides guidance on where to scan through storms to identify stronger storms. This is customisable so you can choose your own height and reflectivity cutoff.
StormPlotter View
To display storm paths in live view:
1) Select the preferred time period (since 9am shows the most recent storm tracks and this resets at 9am each day. 9am to 9am shows the previous day's storm tracks over a 24 hour period)
2) Choose the dbz cutoff - the default is 35dbz. Choosing a higher dbz cutoff will remove more echoes and make it easier to see where the most intense area of the storm has moved.
In archive view, you can choose a custom start and end time.
Live StormPlotter only available to Corporate Users.
Adjusting Storm paths
Zooming in and gradually increasing the dbz cutoff provides a better indication of the where the strongest thunderstorms have tracked across. This example shows the difference between 35dbz, 45dbz, 55dbz and 65dbz, with the storm path becoming progressively smaller to highlight where the most damage is likely to have occurred.
As the radar scale is logarithmic, a even a 5dbz increase above 50-60dbz can provide very significant differences in ground impacts and storm severity.
HailTracker & StormPredict
MetCentre radar detects hail in thunderstorms. Each storm is provided a marker that corresponds to the size of hail in centimetres (if any) detected in the storm.
Important Note: The largest hail is not necessarily where the hail marker is placed - rather this is the largest hail occurring within the storm at the time. Using the Storm Paths feature or the 3D radar scans are useful tools to determine where the largest hail is falling.
A square marker indicates a storm that is unlikely to contain any hail. Triangles are used to display hail - with the scale listed in the image below.
Beside each storm marker is a small number (ie 14km). This is the height in kilometres of the storm. Typically higher storms are more intense than lower storms in the same environment and provides an additional guide to the intensity of storms.
MetCentre also provides the StormPredict function which plots the storm's movement in the next 15, 30, 45 and 60 minutes. This provides a guide of timing and positioning of the storm in the short term.
Storms may change direction when they cross a boundary (example, southeast change or seabreeze). As MetCentre radar does not remove the cutter, it can be easier to identify boundaries on radar that may cause a rapid change in storm intensity and movement. Using the 3D radar scan function can also help identify new updrafts that may also signify a change in storm movement.
