Western Australia Information

Albany

  • Location: Albany Meteorological Office, adjacent to Albany Airport (lat 34.94° S, long 117.80° E)
  • Type: DWSR 2502 C
  • Availability (Typical): 2100 — 0700, 0900 — 1300, 1430 — 1900. * All times WST*

Interpretation Notes

The Albany radar is rarely affected by false echoes or anomalous propagation and there are no permanent echoes. During the winter months rain bands may be observed moving in from the north-west ahead of strong cold fronts. Heavy showers occur with the passage of these fronts with further lines of showers embedded in the strong west to southwest winds that follow. Large thunderstorm cells can also be seen moving along just off the south coast prior to the arrival of these strong fronts.

"Cut-off" lows, with their own individual circulation, can occasionally develop off the south coast in the wake of cold fronts. Such circulations, when established, are generally slow moving and can produce large areas of rain and drizzle for days. South to southeast winds accompany such systems.

During the summer months convective thunderstorms occasionally develop to the northeast of Albany near the Stirling Ranges and move to the southeast during the evening. Lightning from these storms creates a great night display but is a very real fire hazard.

Heavy rain directly over the radar site can cause attenuation of all signals. Path attenuation can also occur when the radar beam passes through intense rainfall, with the returned signals from cells further along that path reduced.

Broome

  • Location: Broome Meteorological Office (lat 17.95° S, long 122.23° E)
  • Type: DWSR 2502 C
  • Availability (Typical): 21:00 — 00:01, 01:30 — 07:00, 09:00 — 13:00, 14:30 — 19:00. * All times WST*

Interpretation Notes

Geographical Situation

Broome Weather Watch Radar is situated so that it overlooks Roebuck Bay to the south-east and the wider Indian Ocean (north to south-west). The radar has an 360 degree unrestricted view.

Meteorological Aspects

On the 27th of October the Bureau installed a new C-Band radar at Broome airport, replacing the existing WF 44 radar. The introduction of this new more sensitive radar has led to a number of occasions where "false" or anomalous echoes have been displayed.

This is not caused by a malfunction in the radar, but rather is a result in the increased sensitivity of the radar.

Radar works by sending pulses of electromagnetic energy (in the form of waves), which are then reflected back to the radar by objects in the path of the wave. The radar beam follows a slightly curved path and goes progressively higher the further away from the radar it travels, until it hits an object in its path usually rain droplets.

In the Broome area it is quite common for strong temperature inversions to occur, which means the temperature actually increases with height over a small distance in the atmosphere instead of steadily decreasing with height. There are a number of reasons why inversions can happen, and in the Broome area, one of the most common examples is when hot air from the inland moves out over the cooler ocean. This leads to marked temperature inversions close to the surface, and the effect of this inversion is to "trap" the radar beam in the layer of air between the cool ocean and the hot air a couple of hundred metres above it. Because of the change in the refractive index between hot and cool air, the radar beam is "bent" back towards the waters surface. When the beam strikes the water it reflects its energy back to the radar and it is that image which is displayed on the radar picture.

In certain circumstances the inversion can be strong enough such that displays similar to the one below occur.

Example image of Broome Radar display.

This phenomenon is the price to be paid for increased sensitivity which means that rainfall and thunderstorms are much better depicted by the radar. With practice it is quite easy to recognise the difference between real and anomalous echoes.

Carnarvon

  • Location: Carnarvon Airport (lat 24.88° S, long 113.67° E)
  • Type: DWSR 2502 C
  • Availability (Typical): 24 hours per day

Interpretation Notes

On the 26th of June 2009 the Bureau installed a new C-Band radar at Carnarvon, replacing the existing WF100 radar.

The Carnarvon radar has an unrestricted 360 degree view with no permanent echoes. Some anomalous propagation may occur, usually manifested as false echoes along the Shark Bay coastline and extending north to include the islands off Carnarvon. This phenomenon usually occurs due to an inversion layer or when strong winds whip up spray from large swells just offshore.

During the summer months cyclonic formations may occasionally be observed out to sea but it is more common to observe cyclones that have crossed the coast in the north Gascoyne or Pilbara regions, weaken into rain bearing depressions as they pass through the Gascoyne region tracking south-east.

Heavy rain directly over the radar site can cause attenuation of all signals. Path attenuation can also occur when the radar beam passes through intense rainfall, with the returned signals from cells further along that path reduced.

Dampier

  • Location: Queens Lookout, East Intercourse Island (lat 20.65° S, long 116.69° E)
  • Type: WF 100 (C-Band, 5 centimetre wavelength)
  • Availability (Typical): 24 hours per day

Interpretation Notes

Dampier Radar has an unrestricted 360 degree view from its site 50 metres above sea level, and though no major permanent echoes appear, a small amount of low intensity clutter may be visible around parts of the coast and the islands surrounding Dampier and offshore to the west.

Dampier Radar is susceptible to a small amount of false echoes on land during the dry months. These echoes are characterised by erratic movement and very low intensities. During the wet season between December and March anomalous propagation may cause significant false echoes to appear for distances up to 60 kilometres along the coastline and seaward of it.

During the wet season (primarily January to March), thunderstorm clouds and cyclonic formations are generally well defined for distances up to approx 250 kilometres. Beyond that distance signal attenuation gives the appearance of less intensity than possibly exists. These formations are easily identified from false echoes by their regular rates in movement and direction. Thunderstorm activity can be viewed generally on a daily basis during the wet season, general preferred locations are in a trough line from the southwest to the southeast of Dampier/Karratha in and about the ranges. Heavy rain directly over the radar site can cause attenuation of all signals. Path attenuation can also occur when the radar beam passes through intense rainfall, with the returned signals from cells further along that path reduced.

Esperance

  • Location: Esperance Meteorological Office (lat 33.83° S, long 121.89° E)
  • Type: WF 100 (C-Band, 5 centimetre wavelength)
  • Availability (Typical): 2100 — 0001, 0130 — 0700, 0900 — 1300, 1430 — 1900. * All times WST*

Interpretation Notes

The Esperance Radar, which has its antenna mounted on 10 metre tower, thus providing coverage from 40 metres above sea level (M.O. at 30 metres ASL), has an unrestricted 360 degree view with no permanent echoes. Some anomalous propagation (AP) may occur within 20 kilometres of the radar site and provides a radar image of echoes appearing to dance around the station. When very hot conditions combined with northerly winds exist, speckled AP may be observed.

During early mornings, in conditions of very low temperature, areas of AP may also appear, mainly to the east of station.

The radar has an effective range beyond 250 kilometres and therefore thunderstorms can be seen further out than Norseman and Balladonia and approaching cold fronts from the south-west may be observed as they pass through Bremer Bay.

Heavy rain directly over the radar site can cause attenuation of all signals. Path attenuation can also occur when the radar beam passes through intense rainfall, with the returned signals from cells further along that path reduced.

Geraldton

  • Location: Geraldton Meteorological Office (lat 28.80° S, long 114.70° E)
  • Type: WF 100 (C-Band, 5 centimetre wavelength)
  • Availability (Typical): 2100 — 0001, 0130 — 0700, 0900 — 1300, 1430 — 1900

Interpretation Notes

Geraldton Weather Watch radar has good coverage in all directions.

Intense thunderstorm or cold fronts can be seen up to 250 kilometres away, however at this distance the radar is sensing the upper structure of the system and may give an incorrect approximation of the actual surface rainfall intensity of the system. The radar is susceptible to anomalous propagation (AP) for distances up to 80 kilometres along the coastline and seaward of it. The AP appears as an area of low intensity echoes usually around the Abrolhos Islands (the Abrolhos Islands group stretches from a position approximately 80 kilometres west of Geraldton running north-west, roughly parallel to the coast, for approximately 80 kilometres). Heavy rain directly over the radar site can cause attenuation of all signals. Path attenuation can also occur when the radar beam passes through intense rainfall, with the returned signals from cells further along that path reduced.

Giles

  • Location: Giles Meteorological Office (lat 25.03° S, long 128.30° E)
  • Type: WF 100 (C-Band, 5 centimetre wavelength)
  • Availability (Typical): 2100 — 0001, 0130 — 0700, 0900 — 1300, 1430 — 1900. * All times WST*

Interpretation Notes

NOT YET AVAILABLE

Halls Creek

  • Location: Halls Creek Meteorological Office (lat 18.23° S, long 127.66° E)
  • Type: WF 100 (C-Band, 5 centimetre wavelength)
  • Availability (Typical): 2100 — 0001, 0130 — 0700, 0900 — 1300, 1430 — 1900

Interpretation Notes

NOT YET AVAILABLE

Kalgoorlie-Boulder

Kalgoorlie Radar Replacement

The aging Kalgoorlie weather radar is being replaced as part of the Bureau's ongoing program to replace old equipment as it reaches the end of its effective operating life. The new radar is being constructed immediately adjacent to the existing radar location. This will require the old radar to be decommissioned before construction and testing of the new radar can be completed.

The old radar will cease operation on Saturday 8th March. There will also be some interruptions to service in the four days prior to this date to protect workers working on the new installation.

The new radar will be constructed during March and go through a series of tests and adjustments to ensure that it is operating correctly prior to launch. The new radar data should become available to the public in the latter part of April.

Learmonth

  • Location: Cape Range National Park (lat 22.10° S long 114.00° E)
  • Type: TVDR 2500 (C-Band, 5 centimetre wavelength)
  • Availability (Typical): 24 hours per day

Interpretation Notes

The Learmonth radar has 360 degree unimpeded view of the area and is approximately 330 metres above sea level. Radar images can be subject to anomalous propagation of the radar signal which results in false echoes along Ningaloo Reef. Ningaloo Reef is in close proximity to the shore and follows the western coastline of North West Cape. False echoes caused by reflections off the hills in the inland Pilbara can also be observed from time to time in the south-east quadrant of the radar image out to a range of 250 km. This anomalous propagation is easily identified and is displayed as a mass of low intensity echoes constantly changing shape with no apparent direction of movement. True rain echoes normally have a consistent direction of movement from one scan to the next. Echoes within approximately five kilometres of the radar and overhead can be poorly resolved as the scanning elevation is too low.

Perth (Serpentine)

  • Location: Serpentine Airfield (Yangedi Rd North, Hopelands) (lat 32.39° S, long 115.87° E)
  • Type: EEC TVDR2500C (C-Band, 5 centimetre wavelength)
  • Availability (Typical): 24 hours per day.

Interpretation Notes

Perth (Serpentine) Weather Watch radar has good coverage in all directions. Intense thunderstorm or cold fronts can be seen up to 250 kilometres away, however at this distance the radar is sensing the structure of the system well above the ground and may give a misleading view of the actual surface rainfall intensity of the system. The radar is susceptible to anomalous propagation (AP) for distances up to 60 kilometres along the coastline and seaward of it. The AP appears as an area of low intensity echoes. A local phenomenon which has been observed occasionally is that of false mirror echoes approaching the radar from the southeast as an intense cold front approaches from the south west.Heavy rain directly over the radar site can cause attenuation of all signals. Path attenuation can also occur when the radar beam passes through intense rainfall, with the returned signals from cells further along that path reduced.

Port Hedland

  • Location: Port Hedland Airport (lat 20.37° S, long 118.63° E)
  • Type: TVDR-2500 (C-Band, 5 centimetre wavelength)
  • Availability (Typical): 24 hours per day

Interpretation Notes

The Radar is located at the airport approximately 7km from the coast on flat open country with few trees. The coastline runs broadly from the northeast to the southwest. The terrain within 100km is generally lower than 200m above mean sea level (amsl). Between 100 and 200km the land rises to around 450m amsl. Ground above 500m amsl occurs to the south west at around 300km. These features are mostly beyond the geographical horizon, thus ensuring that the radar's horizon is unobstructed and that there are no significant restrictions to radar coverage. The radar is well located to detect tropical cyclones and storms as they approach or develop over the ocean. During the wet season, tropical cyclones and thunderstorm clouds are generally clearly visible on the radar for distances of up to approximately 250 km. It is common in the wet season (primarily January to March) for thunderstorm cells to form to the South of Port Hedland, with individual cells sometimes merging to form a line of storms running in a NE/SW direction, anywhere from 60 km to 200 km South of Port Hedland. Favourable locations for thunderstorm activity, as seen on the radar in these events, are generally over the ranges to the South of Port Hedland. In strong wind conditions the radar may detect the rough sea surface and show "sea clutter" over the ocean. It can often be difficult to differentiate between sea clutter and light precipitation. During the dry season, the radar may experience effects of "anomalous propagation". At these times the radar beam is more strongly curved towards the earth and features normally beyond the radar's horizon may become visible on the display. These anomalous features may appear like discrete patches of light rainfall.

Wyndham

  • Location: Five Rivers Bastion, overlooking the town of Wyndham (lat 15.45° S, long 128.12° E)
  • Type: WF 100 (C-Band, 5 centimetre wavelength)
  • Availability (Typical): 24 hours per day

Interpretation Notes

Wyndham Radar has an unrestricted 360 degree view from a commanding site 350 metres above sea level. Though no major permanent echoes appear, a small amount of low intensity clutter may be visible around parts of the coast and the surrounding islands. Wyndham Radar is occasionally susceptible to varying amounts of false echoes over the land, particularly during the dry months. Such echoes are generally characterised by erratic movement and on occasion may show significant intensity. During the wet season between December and March, anomalous propagation may cause false echoes to appear for distances of some tens of kilometres along the coastline and seawards. The installation dates from mid-2001 and it may take some time to gain particular experience with these anomalous effects which vary both seasonally and with time of day. Comparison with satellite images is often helpful in identifying spurious radar echoes. During the wet season (primarily January to March), thunderstorm clouds and cyclonic formations are generally well defined for distances up to 250 kilometres and occasionally further for structures which extend to high altitudes.

Beyond that distance attenuation effects may give the appearance of less intensity than possibly exists. These formations are easily distinguished from false echoes by their general appearance and behaviour, e.g. regular rates of movement in distance and direction.

Thunderstorm activity can often be seen on a daily basis during the wet season. Heavy rain directly over the radar site can cause attenuation of all echoes. Path attenuation can also occur when the radar beam passes through intense rainfall, with the returned signals from cells further along that path reduced. Extreme effects of this kind are generally fairly short lived as the rain bearing systems tend to move relative to the radar and to each other.