Monthly Weather Review South Australia November 2009 Monthly Weather Review South Australia November 2009 The Monthly Weather Review - South Australia is produced twelve times each year by the Australian Bureau of Meteorology's South Australia Climate Services Centre. It is intended to provide a concise but informative overview of the temperatures, rainfall and significant weather events in South Australia for the month. To keep the Monthly Weather Review as timely as possible, much of the information is based on electronic reports. Although every effort is made to ensure the accuracy of these reports, the results can be considered only preliminary until complete quality control procedures have been carried out. Major discrepancies will be noted in later issues. We are keen to ensure that the Monthly Weather Review is appropriate to the needs of its readers. If you have any comments or suggestions, please do not hesitate to contact us: By mail South Australia Climate Services Centre Bureau of Meteorology PO Box 421 Kent Town SA 5071 AUSTRALIA By telephone (08) 8366 2600 By email [email protected] You may also wish to visit the Bureau's home page, http://www.bom.gov.au. Units of measurement Except where noted, temperature is given in degrees Celsius (°C), rainfall in millimetres (mm), and wind speed in kilometres per hour (km/h). Observation times and periods Each station in South Australia makes its main observation for the day at 9 am local time. At this time, the precipitation over the past 24 hours is determined, and maximum and minimum thermometers are also read and reset. In this publication, the following conventions are used for assigning dates to the observations made: Maximum temperatures are for the 24 hours from 9 am on the date mentioned. They normally occur in the afternoon of that day. Minimum temperatures are for the 24 hours to 9 am on the date mentioned. They normally occur in the early morning of that day. Daily rainfall is for the 24 hours to 9 am on the date mentioned. This means a significant fraction of the rain may have occurred on the previous calendar day. Monthly rainfall is for the period from 9 am on the last day of the previous month to 9 am on the last day of this month. Maximum daily wind gusts are in the 24 hours from midnight to midnight. Climatological values The climatological averages shown in the text and tables are generally long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 20 years of record, as they cannot then be calculated reliably. Climatological extremes are generally taken from available observations from all available years of record. The number of years can vary substantially from site to site. Copyright © Commonwealth of Australia 2010 This work is copyright. You may download, display, print and reproduce this material in unaltered form only (retaining this notice) for your personal, non-commercial use or use within your organisation. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. Requests and inquiries concerning reproduction and rights should be addressed to Commonwealth Copyright Administration, Attorney General’s Department, Robert Garran Offices, National Circuit, Barton ACT 2600 or posted at http://www.ag.gov.au/cca. Product code IDCKGC23R1. Prepared on 25 January 2010. ISSN 1836-3024 Cover photograph Wave clouds over the Adelaide Hills. Photograph by Bob Schahinger, 30 November 2002. Used with permission. If you have a photo you think would make a good cover for the Monthly Weather Review, please contact us at the address above. Monthly Weather Review South Australia November 2009 Overview • During the first 3 weeks of the month, an extended period of well above average temperatures prevailed, resulting in the hottest state-wide November on record, and almost all individual locations having record warmest Novembers by large margins. • Many locations, including Adelaide, Hawker, Ceduna, Leigh Creek, Marree, Streaky Bay, Woomera, Kimba and Eudunda, also recorded highest November daily maximum temperatures, with some overnight minimum temperature daily November records at some stations. • After a generally very dry first 3 weeks, the month as a whole saw above average rainfall across most of the state as a result of moisture infeed from the tropics and thunderstorm activity, apart from coastal areas which recorded closer to average rainfall. Extremes in November 2009 Hottest day (Highest daily maximum temperature) 47.4 °C at Marree Comparison on the 18th Warmest days on average (Highest mean daily maximum temperature) 36.3 °C at Moomba Airport Coolest days on average (Lowest mean daily maximum temperature) 22.5 °C at Neptune Island Coldest day (Lowest daily maximum temperature) 12.4 °C at Mount Lofty on the 28th Coldest night (Lowest daily minimum temperature) 1.3 °C at Keith (Munkora) on the 6th Coolest nights on average (Lowest mean daily minimum temperature) 11.2 °C at Keith (Munkora) 11.2 °C at Kingscote Aero Warmest nights on average (Highest mean daily minimum temperature) 21.7 °C at Moomba Airport Warmest night (Highest daily minimum temperature) 31.1 °C at Moomba Airport on the 20th Wettest overall (Highest total rainfall) 137.2 mm at Erudina Driest overall (Lowest total rainfall) 0 mm at Roxby Downs (Olympic Dam Aerodrome) Wettest day (Highest daily rainfall) 96.4 mm at Ki Ki (Moorilla) on the 27th Highest wind gust 117 km/h at Cape Willoughby on the 19th page 1 Monthly Weather Review South Australia November 2009 Significant weather Barmera area and a 91 km/h wind gust at Renmark Airport. Severe Thunderstorms 18 November 2009 Severe Winds 2 November High based thunderstorms in eastern districts on 18 November caused localised gusty winds, but minimal Southerly winds were briefly gale force at rain. At Yunta (Northeast Pastoral), there were 60−65 km/h with gusts to 87 km/h at Port Augusta severe wind gusts from two separate storms, one (Flinders) immediately following a strong cold front wind gust to 111 km/h and another to 95 km/h. which moved through late afternoon on 2 November. 19 November 2009 28 November 2009 High based thunderstorms associated with a front formed in a band from the NT border to the A deep low pressure system south of Kangaroo Nullarbor coast early afternoon on 19 November. Island tracked northeast and crossed the Lower The band tracked right across the State during the South East coast late on 28 November. Strong to gale afternoon and evening, bringing squally winds and force and squally northwest to southwest winds on lightning strikes to all districts, and starting many the northern flank of this low blew throughout the crop and bush fires. Some of the higher wind gusts day, causing scattered, mostly tree related wind recorded were 117 km/h at Cape Willoughby damage and power outages across southern SA. The (Kangaroo Island), 102 km/h at Edithburgh (Yorke SES responded to about 400 calls for assistance. Peninsula) and 98 km/h at Tarcoola (Northwest Wind gusts of 90−100 km/h were recorded at Pastoral), Cape Jaffa and Mount Gambier (Lower Snowtown (Mid North), Mount Crawford and Kuitpo South East). (Mount Lofty Ranges) and Cape Willoughby (Kangaroo Island). Winds were briefly gale force at 21 November 2009 Kadina (Yorke Peninsula). Thunderstorms associated with a low pressure trough affected the northern arts of the Pastoral districts on 21 November. At Todmorden Station (Northwest Pastoral), 34 mm of rain fell in about an hour with 1 cm diameter hailstones. At Marree (Northeast Pastoral), wind gusts to 111 km/h were recorded. 25 November 2009 A moist unstable airmass associated with a strong upper low over the north of SA led to thunderstorms in northern and eastern districts during the afternoon and evening of 25 November. Torrential rain was reported at Peterborough (Flinders) and squally winds brought down trees and power lines and damaged several buildings in several Riverland towns, including Barmera, Cobdogla, Glossop and Waikerie. 26 November 2009 Further thunderstorms produced localised heavy rain and flash flooding in parts of the Riverland and Murraylands during the afternoon of 26 November. Recorded rainfalls include 35 mm in an hour at Paringa and 25 mm in 30 minutes near Murtho (Riverland). Near Ki-Ki (Murraylands), 96 mm was recorded, much of it occurring with thunderstorms mid afternoon. 27 November 2009 Thunderstorms developed along a front and moved across eastern SA during the afternoon of 27 November. Wind, heavy rain and dust accompanied the storms as they swept through the Riverland, causing damage to trees and vineyards in the page 2 Monthly Weather Review South Australia November 2009 Synoptic summary upper low, producing local heavy rain falls and thunderstorms. The remainder of the state On the first of the month a trough moved into the continued to be warm and dry. western districts and a low pressure system developed to the south of South Australia which was A low pressure system developed south of Western preceded by warm to hot conditions to most of the Australia on the 25th and moved eastward to be state. With the passage of these weather systems located over Tasmania by the 29th. The front cooler conditions was gradually experienced over associated with the low passed over the western large areas of the state. The low pressure system areas of the state on the 26th and the eastern moved southeast towards Tasmania. districts on the 27th. Following the low pressure system a high pressure With this complex low pressure system located south ridge pushed into the Great Australian Bight, from of Kangaroo Island, on the 28th, a second front the west, bringing strong south-westerly winds and moved over the state bringing further showers and isolated showers gradually extending over most of strong to gale force gusty winds over the southern the state during the 3rd and 4th.