Event Presentation: Weather forecasting: It's the BOM

Editor's Notes

• #2: Introduction; self introduction of panel Jane Reilly, Duncan Tippins and Paul Lainio Introduction of session; This session guides the audience through the major steps which occurred leading to the way in which the Bureau in SA forecasts today. Question 1/ How long have people forecast the weather? Answer 1/ Forever. People have always observed the weather to determine their activities. For instance; when planning hunting activities early people would have delayed venturing outside if there was a thunderstorm approaching. Q2/ What was the first big step toward modern meteorology? A2/ The development of methods to measure/describe the atmosphere/weather. Systematic measurement helped people to get a shared understanding of the weather. Measurements meant the description of the weather was no longer subject to a personal interpretation. Wind Vane Tower of Winds Athens 2BC 15’th century Cardinal Nicholas deCusa hygrometer 16’th century thermometer – many contributors (currently 2 scales celicius and farenheit) 1643 Torricelli – barometer.
• #3: Crimean War Oct 1853 to Feb 1856. Russian Empire versus alliance of French, British, Ottoman Empire and Kingdom of Sardina. Nov 14-16 1854. Naval disaster in Crimean war . 1 French warship, 38 merchant vessels destroyed by storm. Storm path was reconstructed and demonstrated real time synoptic maps could have given commanders 1 day to prepare. As a result a National Storm Warning service set up in France. Q/ What technological development was needed to achieve this first forecasting service? A/ This next big step in meteorology required a rapid means of communication. Morse Code. Invented 1830’s to 1840’s. Meant weather observations could be taken simultaneously and a snapshot of the weather (synoptic chart). These could be sequenced to track the motion and evolution of weather patterns and then linearly pushed forward in time to produce a forecast.
• #4: There are about 10,000 surface weather observations across the world. Density of observations varies significantly because; Prosperity Communication Transport International aid Costs about $10,000/year to run an Automatic Weather Station. Many data sparse areas. Q/ What was the breakthrough (BIG STEP) forward in meteorology that helped fill in the gaps. A/ Weather satellite. 1960 Tiros 1. Now MTSAT 1R Japanese satellite covers Australia and this hemisphere. Part of a series of geostationary satellites across the globe. Also Radar developed during WWII Q/ What other ways do we observe the weather? A/ Weather balloons, aircraft, ships, radar profiler etc. Billions of dollars invested but by using observations we can only forecast 24 hours. We use Models to forecast beyond Day1.
• #5: Morse Code developed 1830’s-1840’s. 1872 Overland telegraph Australia. Postulated west to east travel of weather. April 1881. Inter-colonial meeting established data standards and sharing and use of isobaric maps. The Government Astronomers believed: “ Isobaric maps are the best way of conveying to the public the passage of barometric depressions “ First SA Forecast in 1888. Broad forecast but in some ways quite similar to the way in which forecasts are created today. All states ran their own Weather Offices and it wasn’t until 1908 that the Commonwealth BoM was created resulting in clear standards nationally for observing the weather and creating forecasts from the same base. Q/ What is celebrated on 23 March each year? A/ International Meteorological Organisation created in 1873. Replaced by World Meteorological Organisation decreed by convention on 23 March 1950 and started 1951.
• #15: Introduction; self introduction of panel Jane Reilly, Duncan Tippins and Paul Lainio Introduction of session; This session guides the audience through the major steps which occurred leading to the way in which the Bureau in SA forecasts today. Question 1/ How long have people forecast the weather? Answer 1/ Forever. People have always observed the weather to determine their activities. For instance; when planning hunting activities early people would have delayed venturing outside if there was a thunderstorm approaching. Q2/ What was the first big step toward modern meteorology? A2/ The development of methods to measure/describe the atmosphere/weather. Systematic measurement helped people to get a shared understanding of the weather. Measurements meant the description of the weather was no longer subject to a personal interpretation. Wind Vane Tower of Winds Athens 2BC 15’th century Cardinal Nicholas deCusa hygrometer 16’th century thermometer – many contributors (currently 2 scales celicius and farenheit) 1643 Torricelli – barometer.
• #16: The chart should look something like this. You will note the exercise has quite a few observations over ocean areas to the south of Australia. On a real weather chart there are very few observations in these parts. Meteorologists use the few observations they have in combination with satellite interpretation.
• #19: Models are developed independently and they use maths and physics equations to simulate the atmosphere. Different equations can be used depending on State of the science in that country Power of supercomputers Ability to ingest different types of observations Means that the output can vary considerably especially at days 5, 6, 7 and especially during rapidly changing weather situations. Meteorologists must understand the long term skill of the model, bias, internal consistency and compare against other models to acieve the best forecast possible.
• #21: As above
• #22: By editing the weather elements 3 hourly for 3 days then 6 hourly to 7 days the weather is described across the state.
• #23: Multiple ‘official’ forecast outputs are possible
• #24: Massive database. Can be accepted by external clients and put direct into geospatial data systems. This can assist with better planning and operations as weather data can be viewed in concert with any other data the client has (eg CFS unit locations).
• #25: Working out what is relevant and important is easy for a person but GFE uses rules.
• #28: There can be quite marked differences between a location forecast and an area forecast.
• #32: Answer is 1 and 2 (previous slide)
• #35: This is the text produced automatically.
• #36: The NexGenFWS can provide information to explain the probability and likely amount of rainfall.
• #37: It is easy to read the rainfall probability and the Rainfall amount together. However, these are entirely separate components. We have seen that rainfall probability is for >0.2mm. Rainfall amount is the 25% to 50% chance of receiving rainfall. It gives the likely amount of rain. The calculation indicates the amount that at least 50% of people will receive.
• #38: Forecasters are presented with a forecast map for temperature across SA for tomorrow. Forecasters then adjust that map based on all the knowledge they have available. This includes weather station data, satellite and radar information. It also includes a range of computer models for which the forecasters understand the strengths, weakness and bias’ of the data. The adjusted data then becomes the temperature forecast for tomorrow. Forecast maps are then adjusted for days 2 – 7. Forecast maps are then adjusted for Rainfall, Winds, Humidity etc. When all this is completed each location across the state has 7 days of information about temperature, rain, winds, humidity etc. In other words all locations have a 7-day forecast.
• #45: Note that output is available every 3 hours for 3 days for most weather parameters and every 6 hours for the remaining time to 7 days.
• #46: The Forecast Explorer is likely to be upgraded during 2011/2012 so it will be able to display observations and forecasts. It will be zoomable, you will be able to pan and it will work much like Google Maps.