Australian Monthly Climate Summary: February 2008
Tuesday 4th March, 2008
February was a cool month in most of Australia, especially in the eastern states, where above-normal rainfall was also widespread in the eastern halves of both NSW and Queensland. It was also a wet month in most of the northern tropics and much of the southern half of WA, but was another generally dry month in central Australia.
The cool conditions were most noticeable during the day, with Australian average maximum temperatures 1.12°C below the long-term (1961−90) average (7th lowest on record). New South Wales was especially cool, with the state anomaly of −2.67°C being the second-lowest on record, ranking behind only 1954. Overnight minimum temperatures were closer to normal, with the Australian mean 0.17°C below normal (21st lowest). NSW was again cool (anomaly −1.25°C, 7th lowest), but in contrast nights were rather warm in the NT (anomaly +0.91°C, 8th highest).
The only substantial areas where daytime maximum temperatures were above normal were firstly an area of the central and eastern NT centred on Tennant Creek and extending into far western Queensland, and secondly the south-west of WA south of a line from Geraldton to Esperance. Peak anomalies reached around +2°C near Tennant Creek, with no significant areas in the highest decile. Cool days covered the remainder of the continent, with most of the eastern states (including Tasmania) apart from the east coastal fringe at least 1°C below normal, along with the Kimberley (WA) and northwestern Top End (NT), and parts of the southern interior of WA. Much of NSW and southern inland Queensland was more than 2°C below normal, with anomalies peaking at −4 to −5°C in a region straddling the NSW/Queensland border between Bourke and Charleville. Much of this region was in the lowest decile with records set around Cobar and in the Sydney region (although not in Sydney itself). Similar anomalies occurred locally around Kalgoorlie, partly as a result of an exceptional cool spell in the aftermath of Tropical Cyclone Nicholas.
Minimum temperatures were mostly slightly above normal through the tropics, as well as on the subtropical coasts of Queensland and the western coast of Western Australia. Elsewhere they were mostly below normal. Anomalies in both directions were mostly reasonably small. Overnight minima were 1−2°C above normal in much of the central and southern NT; conversely, they were 1−2°C below normal in most of inland NSW, southern inland Queensland and northern and eastern Victoria, reaching near-record levels of 2−3°C below normal around Nyngan.
* Anomaly is the difference from the long-term average
Average rainfall across the continent was also generally above normal, with the Australian average 34% above the 1961−90 average (22nd highest on record). There were three major areas of above-normal rainfall. The east coast and adjacent inland again saw well above-normal rainfall; the rains did not generally penetrate as far inland as they did in December and January, with the western boundary of the wet area running approximately Melbourne-Albury-Bourke-Charleville-Hughenden-Normanton, but did extend to cover most of Tasmania, in contrast with January. It was also wet in the northern part of the NT, north of Elliott, and the adjacent north of WA, as well as in much of the southern half of WA except for the southwest south of a Perth-Esperance line. In the latter region most of the rain came as a result of the movement inland of the remnants of Tropical Cyclone Nicholas, which made landfall north of Carnarvon on 20 February.
The most notable rainfall occurred along the Queensland coast and adjacent inland between Townsville and Hervey Bay. Most of this area was in the highest decile, and there were several major rain events, the most exceptional being on 15 February when daily falls of up to 625 mm (most of it in five hours) occurred in the Mackay area. Monthly records were set inland from Mackay, as well as on the Atherton Tableland. Rainfall in the highest decile also occurred widely in the NT Top End and the northern Kimberley, with records set around Victoria River Downs and near Darwin, and in the mid-west of WA along the track of TC Nicholas. State averages were 35−45% above normal for Queensland (+45%), WA (+41%), Tasmania (+41%) and NSW (+37%), although none of these ranked in the top ten.
In contrast, it was rather dry in much of central Australia, extending south to cover most of SA, western Victoria and south-western NSW. A region extending from the northern Mallee in Victoria into adjacent areas of NSW and South Australia, most of which had little or no rain for the month, ranked in the lowest decile and the South Australian state average was 59% below normal.