Monthly Weather Review Northern Territory June 2012 Monthly Weather Review Northern Territory June 2012 The Monthly Weather Review - Northern Territory is produced twelve times each year by the Australian Bureau of Meteorology's Northern Territory Climate Services Centre. It is intended to provide a concise but informative overview of the temperatures, rainfall and significant weather events in Northern Territory 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 Northern Territory Climate Services Centre Bureau of Meteorology PO Box 40050 Casuarina NT 0811 AUSTRALIA By telephone (08) 8920 3813 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 Northern Territory 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. Mean temperatures are the average of the daily maximum and daily minimum temperatures. 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 10 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 2012 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 IDCKGC22R1. Prepared on 24 July 2012. ISSN 1836-392X Cover photograph The Robinson River. Photograph by Gavin Heathertington-Tait, 31 May 2007. 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 Northern Territory June 2012 Overview Minimum temperatures across the NT were Significant weather noticeably cool this month with the area averaged minimum temperature ranking as the second lowest Top End Bushfires June on record. The sub-tropical ridge was the In June, the fire danger index (FDI) in the Top End dominant climate influence on the NT this month. A reached severe levels for the first time this year. Dry series of strong high pressure systems moving across fuel and gusty winds fanned bush fires across the southern and central Australia consistently pushed Top End. There were many other fires during the fresh, cool air north and blocked any rain-bearing month that threatened farms and property in the systems from reaching the Alice Springs District. Darwin rural area, however significant damage from these fires was minimal. Extremes in June 2012 On the 17th and 18th, a strong high pressure system over SA directed gusty, dry winds from the south to Hottest day the Top End, increasing Fire Dangers, particularly (Highest daily maximum temperature) over the northwest Top End. There were many fires 36.0 °C at Timber Creek on the 15th around the western Top End during this period. on Warmest days on average the 18th one fire threatened the Batchelor area, (Highest mean daily maximum temperature) including 27 homes and sheds, 8 mango orchards, 31.5 °C at Noonamah AWS 200 head of stock and the Batchelor airstrip. Coolest days on average (Lowest mean daily maximum temperature) Synoptic summary 18.4 °C at Kulgera Coldest day The month started with a ridge, centered over the (Lowest daily maximum temperature) Southern Ocean, which extended across South 13.5 °C at Arltunga on the 22nd Australia and into the Northern Territory. Cool and 13.5 °C at Arltunga on the 24th dry conditions persisted until the 10th, due to a Coldest night blocking cut-off low that developed over eastern (Lowest daily minimum temperature) Australia on the 4th, and moved into the Tasman Sea −3.4 °C at Alice Springs Airport on the 24th on the 6th. The pressure gradient eased over the −3.4 °C at Alice Springs Airport on the 25th Territory, humidity and moisture returned as the −3.4 °C at Alice Springs Airport on the 26th high moved into the Tasman Sea. A weak trough Coolest nights on average developed over the western border and propagated (Lowest mean daily minimum temperature) east across the Territory on the 13th with no 2.1 °C at Alice Springs Airport significant rainfall due to the dry southeastelies at Warmest nights on average the surface, ahead of another developing high over (Highest mean daily minimum temperature) southern Indian Ocean. The high pressure system 23.4 °C at Cape Wessel moved eastwards across the continent until the Warmest night 20th, before another weak short wave trough (Highest daily minimum temperature) developed over the western boarder on the 21st and 25.1 °C at Cape Don on the 2nd propagated east. A series of high pressure systems Warmest on average overall with associated dry, cool and windy conditions (Highest mean temperature) affected the Northern Territory until the end of the 25.8 °C at Cape Wessel month. Coolest on average overall (Lowest mean temperature) 10.0 °C at Kulgera Wettest overall (Highest total rainfall) 20.3 mm at Calvert Hills Wettest day (Highest daily rainfall) 14.8 mm at Merlin Mine on the 16th Highest wind gust 67 km/h at Tennant Creek Airport on the 24th page 1 Monthly Weather Review Northern Territory June 2012 Daily mean sea level pressure analyses 1 June 2012 2 June 2012 3 June 2012 4 June 2012 5 June 2012 6 June 2012 7 June 2012 8 June 2012 9 June 2012 10 June 2012 11 June 2012 12 June 2012 13 June 2012 14 June 2012 15 June 2012 16 June 2012 17 June 2012 18 June 2012 page 2 Monthly Weather Review Northern Territory June 2012 19 June 2012 20 June 2012 21 June 2012 22 June 2012 23 June 2012 24 June 2012 25 June 2012 26 June 2012 27 June 2012 28 June 2012 29 June 2012 30 June 2012 page 3 Monthly Weather Review Northern Territory June 2012 Temperatures The mean temperature for Northern Territory in June 2012 was 18.70 °C, which is 1.58 °C below the long-term average. The warmest on average was Cape Wessel with 25.8 °C, followed by Cape Don with 25.5 °C, and then McCluer Island with 24.3 °C. The coolest on average was Kulgera with 10.0 °C, followed by Arltunga with 10.6 °C, and then Alice Springs Airport with 11.0 °C. New temperature records Record lowest June daily minimum temperature Years New record Old record of record Victoria River Downs 2.2 on 25th 2.5 on 19th in 1976 45 Yulara Aero -1.8 on 22nd -1.3 on 24th in 2002 26 Record lowest June mean minimum temperature Years New record Old record of record Gove Airport 19.2 19.3 in 2011 33 Elliott 9.5 = 9.5 in 1982 31 Record lowest June mean temperature Years New record Old record of record Gove Airport 23.2 23.5 in 1967 33 page 4 Monthly Weather Review Northern Territory June 2012 Maximum temperatures Anomalies of mean daily maximum temperature in June 2012 Mean daily maximum temperatures were below average across most of the Northern Territory, with the exception of the central Alice Springs District where maximum temperatures remained slightly above average. There were no new maximum temperature records set this month. The hottest day was all reported on the 15th at Timber Creek with 36.0 °C , followed by Kidman Springs with 34.9 °C, and then Bradshaw with 34.8 °C. The warmest days on average were at Noonamah with 31.5 °C, followed by Middle Point with 31.3 °C, and then Jabiru Airport with 31.2 °C.