Victorian Information

Melbourne

  • Location: Approximately 19 km west-south-west of Melbourne's Central Business District. (Latitude 37.86°South, Longitude 144.76°East, 44 m above mean sea level)
  • Type: M1500-S1, 1°S-band Doppler radar.
  • Availability (Typical): 24 Hours per day

Interpretation Notes

Geographical Situation

The radar is situated on the western plains of the Melbourne basin some 19 km west-south-west of the Central Business District, about six kilometres from the western shores of Port Phillip bay and on a low rise about 20 m above mean sea level. The radar is on a tower 24 m above ground level.

The Great Dividing Range dominates the topography from the east, through the north to the west. The most significant obstructions, starting from the east, are: Mt Dandenong 644 m high, 53 km to the east; Yarra ranges 1219 m, 83 km to ENE; Mt Macedon 1013 m, 56 km to the north; Pentland Hills 763 m and the Brisbane ranges 421m, 45 km from the NNW through to the west and the You Yangs 363 m, 30 km to the SW.

Meteorological Aspects

The radar is well sited to provide very good coverage for the Greater Melbourne Metropolitan Area. The high ground from the east, through north and to the south west tends to obscure shallow rain falling further away. Summer thunderstorms that develop on the surrounding hills and mountains may be observed in detail. Similarly, cold fronts and associated rain and thunderstorms approaching from the northwest, through west and south are well detected.

The location on the floor of a wide basin is ideal for Doppler observations which provide wind speed information.

Non-meteorological aspects

In most cases the processing of the radar signal removes permanent echoes caused by obstructions such as hills, buildings and other solid objects rather than rainfall. Occasionally, some permanent echoes will not be completely removed from the display. These echoes usually occur along ridges and peaks as isolated, stationary patches, being most common near the Yarra Ranges to the ENE and Mount Macedon to the north. These usually become more noticeable on cold, clear, winter nights or early winter mornings.

Because the radar has an unobstructed view of Port Phillip Bay out to about 25km, sea-clutter may be seen over the bay during strong winds. These echoes may be distinguished from rain as they do not move with the wind and end abruptly at the shoreline of the bay.

Doppler observations are occasionally affected by multi path reflections off Melbourne City buildings and approaching rain bands. These appear as radials of incorrect Doppler velocities in the area to the northeast of the radar. Doppler observations can also reveal the presence of flocks of birds over Port Phillip Bay, which appear as thin lines, and generally have a higher velocity than the surrounding area.

Mildura

  • Location: Mildura Airport (lat 34.23° S, long 142.08° E)
  • Type: WF 100 C-Band
  • Availability (Typical): 24 hours per day

Interpretation Notes

The Mildura radar has a very good view in all directions as there are no significant geographic features in the area. Its only limitations are those common to all C-Band radar, that is that if there are large thunderstorms around, the radar will not be able to detect accurately the strength of storms located behind the closest storms. This will also lead to the underestimation of the strength, at times, of very intense isolated storms. False echoes are sometimes observed very close to the radar especially in stable conditions. Echoes within five or so kilometres of the radar and overhead are poorly resolved as the scanning elevation is too low.

Bairnsdale

  • Location: Approximately 9 km south-west of Bairnsdale (lat 37.89° S, long 147.56° E)
  • Type: DWSR 2502 C-Band
  • Availability (Typical): 24 Hours per day

Interpretation Notes

Geographical Situation

The Gippsland radar is situated on the coastal plain at the airport about nine kilometres south-west of the city of Bairnsdale. The Great Dividing Range, stretching east to west north of the radar, regularly reaches 1000 m in elevation, with many ridges exceeding 1500 m and peaking at 1986 m at Mt. Bogong approximately 130 km to the north-north-west.

Meteorological Aspects

This location provides good coverage of nearly all of the catchments of rivers flowing south from the Great Dividing Range. The radar's standard coverage, taken as the maximum range at which rainfall can be detected at 3000 m altitude, extends to the east as far as Gabo Island, south to the northern tip of Flinders Island, and west to the eastern shores of Westernport Bay. Inland from the west through north to the east, the coverage is reduced by the Great Dividing Range along an arc from Marysville, to just south of Bright and Mount Bogong, the headwaters of the Murray River and then through to Delegate and back to Gabo Island.

The radar is well situated to provide weather watch for south eastern Victoria from the crest of the Great Dividing Range along the coastal plains of east, central and west Gippsland and eastern Bass Strait. The radar's coverage overlaps the Melbourne radar by about 100 km and these two radars provide contiguous coverage from Cape Otway in the west through to Gabo Island in the east.

Summer thunderstorms that develop on the surrounding hills and mountains may be observed in detail. Cold fronts and low pressure systems with their associated rain and thunderstorms may be effectively detected as they approach from the northwest, through west and south or develop over eastern Bass Strait.

Non-meteorological aspects

In most cases the processing of the radar signal removes permanent echoes caused by obstructions such as hills, buildings and other solid objects. Occasionally, some permanent echoes will not be completely removed from the display. These echoes usually occur as isolated, stationary patches along the Great Dividing Range, the Strzeleki Ranges and the peaks on Wilson's Promontory. These usually become more noticeable on cold, clear, winter nights or early winter mornings when cold air lies near the land's surface.

Because the radar has an unobstructed view of Bass Strait and also parts of the Gippsland Lakes; 'sea-clutter', due to waves, may be seen over these waters during strong winds out to about 25km from the coast. These echoes may be distinguished from rain as they do not move with the wind and end abruptly at the shoreline. Sea clutter may become more prominent when hot northerly winds blow over these cooler waters.

Occasionally, particularly when it is cool, ships can produce radar echoes, which often appear as small areas of high intensity rainfall. Because the ships are moving, they can not be automatically removed by the permanent echo filter.

Yarrawonga

  • Location: Yarrawonga (lat 36.03° S, long 146.03° E)
  • Type: WSR 81C C-Band
  • Availability (Typical): 24 Hours per day

Interpretation Notes

The Yarrawonga radar has a very good view in all directions and is the primary weather radar for Northern Victoria, which includes the Goulbourn Valley. It should provide useful weather information as far south as Marysville, west to Bendigo and north to Griffith. The advantage of the "C-Band" radar is that it is better at detecting smaller drops so therefore performs better in light rain situations. The Yarrawonga radar has a greater ability to resolve thunderstorms in the summer months when echoes are generally larger. Being a "C-Band" radar, if there are large thunderstorms in the area, the radar may not be able to determine accurately the strength of additional storms located behind the closest storms. False echoes can be sometimes observed very close to the radar especially in stable conditions. These are normally easy to distinguish because they are usually of the lowest intensity level and are very small and randomly scattered. Echoes within approximately five kilometres of the radar and overhead can be poorly resolved as the scanning elevation is too low.