Monthly Weather Review Victoria October 2008 Monthly Weather Review Victoria October 2008
Total Page:16
File Type:pdf, Size:1020Kb
Monthly Weather Review Victoria October 2008 Monthly Weather Review Victoria October 2008 The Monthly Weather Review - Victoria is produced twelve times each year by the Australian Bureau of Meteorology's Victoria Climate Services Centre. It is intended to provide a concise but informative overview of the temperatures, rainfall and significant weather events in Victoria 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 Victoria Climate Services Centre Bureau of Meteorology 1010 Latrobe St. DOCKLANDS- MELBOURNE VIC 3008 AUSTRALIA By telephone (03) 9669 4956 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 Victoria 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 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 2008 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 IDCKGC26R1. This version prepared on 12 March 2009, revising an issue prepared on 1 December 2008. ISSN 1836-3016 Cover photograph The Melbourne CBD seen from Docklands. Photograph by Trish McBride, 28 April 2008. Used with permission. Monthly Weather Review Victoria October 2008 Overview With a high frequency of northerly winds blowing Extremes in October 2008 from the desert, maximum temperatures were between 1 and 2 °C above normal along the coastal Hottest day fringe, but inland conditions were much hotter, with (Highest daily maximum temperature) temperatures as much as 3 to 4 °C above normal. 38.9 °C at Mildura Airport on the 30th The very dry atmosphere, and mostly clear skies, Warmest days on average promoted radiational cooling overnight so, even (Highest mean daily maximum temperature) though the days were hot, minimum overnight 26.6 °C at Mildura Airport temperatures were mostly close to normal. Western Coolest days on average and central parts of the State experienced night-time (Lowest mean daily maximum temperature) temperatures that averaged as much as 1 °C below 9.5 °C at Mount Hotham normal. Coldest day (Lowest daily maximum temperature) The very dry atmosphere allowed for fronts to pass -0.9 °C at Mount Baw Baw on the 6th through the State with very little moisture. As a Coldest night consequence, the month was exceptionally dry - (Lowest daily minimum temperature) large areas of the State registered less than 20% of -6.7 °C at Mount Hotham on the 7th the usual allocation of rainfall. Only in the far east, Coolest nights on average did we find areas with at least 50% of average rainfall (Lowest mean daily minimum temperature) 1.6 °C at Mount Hotham Warmest nights on average (Highest mean daily minimum temperature) 11.6 °C at Melbourne Regional Office Warmest night (Highest daily minimum temperature) 22.6 °C at Walpeup Research on the 26th Wettest overall (Highest total rainfall) 81.0 mm at Wyelangta Driest overall (Lowest total rainfall) 0 mm at Watchem 0 mm at Yea River @ Devlins Bridge Wettest day (Highest daily rainfall) 68.8 mm at McKillop's Bridge (Snowy River at McKill on the 4th Highest wind gust 117 km/h at Mount Buller on the 27th 117 km/h at Wilsons Promontory Lighthouse on the 27th Significant weather Hail 6th- Small hail reported in Pascoe Vale and Melton 19th - Large hail reported in Victoria. Winds 2nd. Maximum wind gusts of 113 km/h recorded at Mt. Hotham. 27th. Maximum wind gusts of 117 km/h recorded at Wilsons Promontory. page 1 Monthly Weather Review Victoria October 2008 Synoptic summary The month began with a "mid-latitude" blocking anticyclone over the Tasman Sea, and this feature repeated itself several times during the month. As a consequence, October 2008 saw a number of very warm spells, with northerly winds directed across the State around the bloocking highs. Fronts in the westerlies (mostly) weakened as they approached the longitudes of the block, and this (weakening) allowed for relatively little rainfall. page 2 Monthly Weather Review Victoria October 2008 Daily mean sea level pressure analyses 1 October 2008 2 October 2008 3 October 2008 4 October 2008 5 October 2008 6 October 2008 7 October 2008 8 October 2008 9 October 2008 10 October 2008 11 October 2008 12 October 2008 13 October 2008 14 October 2008 15 October 2008 16 October 2008 17 October 2008 18 October 2008 page 3 Monthly Weather Review Victoria October 2008 19 October 2008 20 October 2008 21 October 2008 22 October 2008 23 October 2008 24 October 2008 25 October 2008 26 October 2008 27 October 2008 28 October 2008 29 October 2008 30 October 2008 31 October 2008 page 4 Monthly Weather Review Victoria October 2008 Temperatures The mean temperature for Victoria in October 2008 Maximum temperatures was 13.49 °C, which is 1.45 °C above the long-term average. The hottest day was 38.9 °C at Mildura Airport on the 30th. The warmest days on average were 26.6 °C at New temperature records Mildura Airport. Record highest October mean maximum temperature The coolest day was -0.9 °C at Mount Baw Baw on Years the 6th. New Old record of record record East Sale Airport 21.6 21.3 in 1977 64 The coolest days on average were 9.5 °C at Mount Hotham. Record highest October mean maximum temperature for at least 20 years Anomalies of mean daily maximum temperature in Observed Years October 2008 this Most recent since month higher higher Kerang 25.8 25.9 in 1940 61 Record lowest October daily minimum temperature Years New record Old record of record on the 22nd Noojee (Slivar) -0.6 on the 23rd 0.0 27 in 2006 Record highest October daily minimum temperature Years New record Old record of record on the 13th Ouyen (Post Office) 22.5 on the 26th = 22.5 52 in 1977 Decile rank of mean daily maximum temperature in October 2008 There could be discrepancies between the values shown on these maps and those at individual locations, as a result of the way the maps are generated. page 5 Monthly Weather Review Victoria October 2008 Minimum temperatures The coldest night was -6.7 °C at Mount Hotham on the 7th. The coolest nights on average were 1.6 °C at Mount Hotham. The warmest nights on average were 11.6 °C at Melbourne Regional Office. The warmest night was 22.6 °C at Walpeup Research on the 26th. Anomalies of mean daily minimum temperature in October 2008 Decile rank of mean daily minimum temperature in October 2008 There could be discrepancies between the values shown on these maps and those at individual locations, as a result of the way the maps are generated. page 6 Monthly Weather Review Victoria October 2008 Rainfall The wettest overall was 81.0 mm at Wyelangta. Record lowest October total rainfall for at least 20 years Observed Years The wettest single day 68.8 mm at McKillop's Bridge this Most recent since month lower lower (Snowy River at McKill on the 4th. Anakie 10.2 4.4 in 1914 94 Wickliffe 11.6 7.6 in 1914 94 Record lowest October total rainfall Moutajup 11.8 7.5 in 1914 93 Years New Nicholson (Yendalock) 13.2 10.6 in 1911 92 record Old record of record Yatchaw (Amaroo) 12.0 11.5 in 1914 91 Morrisons (Ballark) 8.2 8.4 in 1967 119 Watchem 0.0 0.0 in 1914 89 Seaspray (Burong) 3.6 3.8 in 1914 110 Casterton (Roseneath) 6.6 0.0 in 1914