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Daily Weather Summary Help

Note that all times are the clock time in force in the relevant state or territory

Go here for information on how to save the Daily Weather Summary on your computer.

The National Daily Weather Summary summarises significant, unusual and noteworthy weather around Australia on a day-by-day basis. While the format has evolved, AWN has been providing a daily summary since it began in 1996 -- archives are available off the Daily Weather Summary index pages.

While the graphics and statistical information is updated automatically, the Weather Events section is written in my spare time so, unfortunately, doesn't always get updated to a strict schedule and there are gaps at times that I am busy.

Graphics: These are sourced from the Bureau of Meteorology. See today's summary for the times they become available. Click on the charts or the links under them to open full-sized versions. These open in separate windows, allowing you to click between them to make comparisons.

Statistics: It takes until the afternoon of the following day for all the information to become available (see today's summary for the times). I source this information from synoptic and automatic weather station reports from the Bureau, but it is also supplemented with daily downloads of information from the Bureau's National Climate Centre and the SILO rainfall database, which is the most complete Australian real-time rainfall database on the web. Some important points to note:

  • Records set today: These are currently entered manually, usually a day or two after the event. I use a computer program to check the day's temperatures and rainfall against a database of high daily rainfall, and high maximum and low minimum temperature records. As part of the current improvements to AWN's data management, I hope to automate and broaden the scope of this section soon.
  • Minimum and grass (or terrestrial) minimum readings are for the 24 hours to 9am and are initially received to the whole degree. These are replaced with more accurate readings later in the day.
  • Maximum temperatures are for the 24 hours FROM 9am. Observers report an interim maximum to 3pm, but this is replaced with the official more accurate figure when the instruments are read at 9am the next morning. It frequently gets hotter after 3pm local time (especially when daylight savings time is in force), so the interim figures are often revised upwards.
  • Rainfall, evaporation and wind run are recorded by observers for the 24 hours to 9am and are available same day.
  • Maximum wind gust and sunshine are recorded for the 24 hours midnight to midnight, and are reported by observers at their 9am observations on the following day.
  • Wind run is measured by a cup anemometer and represents the length of air passing the station over 24 hours. Divide by 24 to get an average speed.
  • Downpours are measurements of short-term heavy rainfall (periods of 6 hours down to 1 minute). These are calculated from AWS routine and special reports and 3-hourly synoptic reports. The criteria for inclusion vary depending on the duration reported; for example, durations of less than 5 minutes are reported if the rainfall rate exceeds 80mm/hour while durations of 3 hours are reported if rainfall rate exceeds 5mm/hour. There is inevitably some duplication within time periods, but this helps to define the timing of the heavy rain. While AWSs are programmed to send special reports during heavy rain, this list is not an exhaustive one.
  • Highest gusts and Gales and gusts seem to be reporting the same thing, but there are a few differences. Highest gusts are the official maximum wind gust reported for the 24 hours midnight to midnight. At manual observing stations, such as airports, a Dines Anemograph is used providing an extremely accurate measurement that the observer reads off a chart. At AWSs, the maximum gust is recorded by a cup anemometer. Gales and gusts are reported from routine and special reports received from AWSs through the day. Note that two measures are given, the gust speed , usually measured over a few seconds, and the average or sustained speed, which is usually the average over a 10-minute period. Variations between the reported maximum gust in the two parts of the Daily Weather Summary can happen for a variety of reasons. The top gust may not have been reported in the routine or special reports through the day, but is picked up in the whole-of-day statistics. Or the top gust reported in real time through the day from an airport may have been measured by a cup anemometer while the whole-of-day reading is from a Dines.
  • Late rainfall reports. Australia is fortunate in having thousands of voluntary rainfall observers that read gauges at 9am daily, record the rainfall on a form and post the form off the the Bureau at the end of the month. This data is entered into the computer and becomes available some time afterwards. While about 2000 rainfall observations are reported daily to the Bureau, another 6000 or so come later by post. Rainfall is the meteorological element that is most variable over space and time, so these additional reports add immensely to the weather record. I re-run the program that produces the Daily Weather Summary several months after each day to pick up these late reports -- check the date of the latest run at the top of the statistical section.
  • Quality control. The data is automatically processed when first entered, and no quality control is undertaken. When I replace the Weather Events text with weather news or any other comment, I look through the data and remove or correct any obvious errors, but others may remain. When the program is re-run several months later to pick up late rainfall reports, it also picks up any quality control work that has been undertaken to that time by the Bureau.

Weather events: The day's significant, newsworthy or major weather events are described here, but there are a few caveats:

  • AWN is a spare-time activity of one individual. There will be blanks in the record. Some events will produce a sizable story while equivalent events at another time will just get a few lines. I would love to consistently and accurately report all events, but time doesn't always allow that.
  • Stories tend to be written a day or more after the event. I find that it takes that long for sufficient accurate information to become available and for facts to be confirmed by more than one source. For weather news as it happens, your best sources are ABC News and the very active breaking weather forum on Weatherzone.
  • Sometimes, well after an event, I will incorporate additional or corrected information that I become aware of. These stories are marked as for a few weeks in the headline indexes.
  • Where possible, I add links to more detailed reports of events on other sites if I am aware of them.
  • The sources I use to prepare weather event stories, in addition to the ABC and the Weatherzone forums, include all Australian press available via Google News, the websites of numerous government agencies, personal contacts and of course the huge resources of the Bureau of Meteorology.

If you want to save the Daily Weather Summary to your computer:

You have two options. The following apply to Internet Explorer, but the situation is similar with other browsers.

  1. Save the whole page, together with the graphics. Click File, then Save As. In the Save as type selection box, make sure that "Web page, complete" is selected. Navigate to the folder where you want to store the page, rename it if you wish, then click Save. The document and graphics will take up about 250kb on your hard disk for an average day.
  2. Save the page without the graphics. If you follow the directions in 1, but select "Web page, HTML only", you will save the full page without the graphics, but it will look terrible. That's because it is missing the stylesheet that contains font and formatting information. If you download the stylesheet and place it correctly on your hard disk, the page will look the same as it does on the Web (minus the graphics, of course.) Do the following:
    1. Create a folder structure like the one at right. You can call the folders anything, but the "styles" folder must be called "styles".
    2. Right click this link, and save the stylesheet file into the "styles" folder you have just created.
    3. Finally, save each day's summaries into a subfolder under the summaries folder. Now when you open them, they will read the style sheet in the styles folder and will look ok. Each day's DWS, without the graphics, takes up between 40 and 80kb, depending on the amount of data. If you save the files using their original filename rather than the one that Internet Explorer suggests, you will be able to use the links on the calendar on the left of the screen to navigate. The original filename is always in the format yymmdd.SHTML, e.g. 050128.SHTML for 28 Jan 2005.