A rare East Indian Ocean autumn season tropical cut-off low: impacts and a high-resolution modelling study

被引:3
作者
Buckley, B. W.
Leslie, L. M.
Sullivan, W.
Leplastrier, M.
Qi, L.
机构
[1] Bur Meteorol, Perth, WA 6872, Australia
[2] Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA
[3] Insurance Australia Grp, Sydney, NSW, Australia
[4] Univ New S Wales, Sch Math, Kensington, NSW 2033, Australia
关键词
D O I
10.1007/s00703-006-0221-8
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
There are two aims of this study. The first is to provide a synoptic description of the lifecycle and impacts of a seasonally rare but intense cut-off low of tropical origin that developed off the northwest coast of Australia, during the Southern Hemisphere autumn months of late April/early May, 2005. The second, and more important, part of this study is an assessment of the capacity of a state-of-the-science numerical model, assimilating all available satellite-derived observational data, to predict the track, intensity, duration, and severe weather that occurred during the life cycle of the cut-off low. The system was unusual in that its initial development occurred over tropical waters and was associated with a strong and highly involuted subtropical jetstream, generating a cloud band that produced record 24 h rainfall totals in northwest Western Australia for this time of the year. The cut-off low then underwent further deepening which produced more unseasonable heavy rainfall. Confirmed tornado reports occurred over the populous southwest corner of Western Australia. The synoptic discussion focuses initially on the intensification phase of the system, next on the period of heavy rainfall and gale to storm force winds that were generated by the cut-off during its most intense phase, and finally on the severe thunderstorm outbreak over southwest Western Australia. The study reveals a possible additional reason for the intensification of the tropical low, namely, the presence of positive SST anomalies of up to 3 degrees C over which the storm track passed early in its life. The modelling study used a high-resolution version (10 km horizontal grid spacing) of a coupled atmosphere-ocean model developed at the University of Oklahoma. The 96 hour forecast covered the period 00 UTC April 28 to 00 UTC May 2, 2005. The initial and boundary conditions were obtained from the archived analyses and forecasts from the Australian Bureau of Meteorology. The numerical forecasts focussed on the salient features of the tropical cut-off low, including the development, track and the rainfall patterns and totals.
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收藏
页码:61 / 84
页数:24
相关论文
共 30 条
[1]   IMPACT OF A CUTOFF LOW DEVELOPMENT ON DOWNWARD TRANSPORT OF OZONE IN THE TROPOSPHERE [J].
ANCELLET, G ;
BEEKMANN, M ;
PAPAYANNIS, A .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 1994, 99 (D2) :3451-3468
[2]   TOTAL OZONE AND SYNOPTIC WEATHER RELATIONSHIPS OVER SOUTHERN AFRICA AND SURROUNDING OCEANS [J].
BARSBY, J ;
DIAB, RD .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 1995, 100 (D2) :3023-3032
[3]  
Buckley BW, 2000, WEATHER FORECAST, V15, P543, DOI 10.1175/1520-0434(2000)015<0543:TABDSO>2.0.CO
[4]  
2
[5]   Preliminary climatology and improved modelling of South Indian Ocean and southern ocean mid-latitude cyclones [J].
Buckley, BW ;
Leslie, LM .
INTERNATIONAL JOURNAL OF CLIMATOLOGY, 2004, 24 (10) :1211-1230
[6]   Observations of a cut-off low over southern Australia [J].
Griffiths, M ;
Reeder, MJ ;
Low, DJ ;
Vincent, RA .
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 1998, 124 (548) :1109-1132
[7]   Model study of a stratospheric intrusion event at lower midlatitudes associated with the development of a cutoff low [J].
Kentarchos, AS ;
Roelofs, GJ ;
Lelieveld, J .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 1999, 104 (D1) :1717-1727
[8]   A low latitude stratospheric intrusion associated with a cut-off low [J].
Kentarchos, AS ;
Davies, TD ;
Zerefos, CS .
GEOPHYSICAL RESEARCH LETTERS, 1998, 25 (01) :67-70
[9]  
LANGFORD A, 1997, GEOPHYS RES LETT, V24, P791
[10]  
Leslie LM, 1998, WEATHER FORECAST, V13, P822, DOI 10.1175/1520-0434(1998)013<0822:SREFOE>2.0.CO