A wind barb is a compact means of representing both wind speed and direction graphically.
Each full-barb represents 10 knots (nautical miles per hour), a half-barb 5 knots and a flag 50 knots. Calm conditions are indicated by a dot only. 1 knot is equal to around 1.9km/h.
In the examples to the left the first indicates a 5 knot wind from the south-west, the second a 15 knot wind from the west-north-west, the third a 45 knot easterly and the fourth a 65 knot northerly.
Stormtracker allows you to view different elements of current weather on the one display.
Lightning strikes are displayed as crosses and fade from white (current) to red (30 minutes ago) to blue (60 minutes ago).
Surface observations are displayed as a 'rose' with temperature, dew point and relative humidity down the left-hand side and rainfall since 9am, pressure and location name displayed down the right-hand side.
Temperatures fade in colour from blue (cold) to red (warm) and dew points fade in colour from blue (moist) to red (dry).
You may change the display between static (latest) and animating using the 'display' option. An animating display shows the closest data available to each of the past 3 hours.
On radar and sector pages distance and latitude/longitude coordinates are displayed next to the time stamp when you mouse over the map. The origin for distance measuring is indicated by a red dot and defaults to either your location, if specified and in range, or the location of the radar (the centre of the map). The origin may be changed by clicking elsewhere on the map.
Sentinel hotspots detected within the last 24 (or 48) hours are displayed. Sentinel is a satellite-based national bushfire monitoring system operated by Geoscience Australia.
12:21 AEDT An impressive area of thunderstorms swept across the southwest of the country last night.