Weather forecasting EG 1204 Earth Systems Dr Jonathan

Weather forecasting EG 1204 Earth Systems Dr Jonathan Lageard

Weather • ‘Overall state of the atmosphere on a time-scale of minutes to months’ Thomas & Goudie, 2000 p 527 • Weather describes specific conditions temperatures, dew-point, wind speed and direction, visibility… rain, Weather forecasting • ‘The science of predicting the future state of the atmosphere from very short periods of less than one hour up to 7 -10 days ahead’ Thomas & Goudie, 2000 p 527

content • • Climatic regions / climate graphs Mid-latitude weather (UK) Weather monitoring / forecasting Weather & climate practical

Hadley cell regime Thompson 1998, p Holden 2005, p 30 Global temperature patterns (Jan) Barry & Chorley 2003 p 43 Global rainfall patterns Holden, 2005 p 39

Source Flohn 1957 in Barry & Chorley, 1996 p 340

Climate graphs Landes-Pyrenees Properties, 2007 London climate graph Cool Antarctica, 2007

Weather maps Stirling, 1997 p 25 Synoptic weather chart, Met Office 2000 Air Ministry 1941. The Weather Map. London, HMSO

Weather systems Stirling, 1997 p 28

Aerospace Technology, 2007 Jetstreams Air masses: Source regions Fronts

Mid-latitude weather (UK) Model of N hemisphere atmospheric circulation Thompson 1998 p 107 based on Hanwell 1980

Depressions (cyclonic systems) b) plan form / synoptic chart a) cross-sectional model STAGES: Embryo: Tm & Pm air mix warm air less dense rises in spiral Low Pressure Mature: Pressure falls warm air rises in warm sector winds inward blowing anticlockwise Coriolis force Decay: Cold front catches warm front = Occlusion

What does a depression look like? Met Office, 2007

Weather associated with the passage of a depression Waugh 1995, p 215 Cloud patterns associated with a depression Thompson, 1998 p 151

Depression tracks (courses) Stirling, 1997 p 30 North Sea storm surge 31 st January to 1 st February 1953 Impacts: coastal areas UK, Belgium & Netherlands Economic damage and community disruption 2, 000+ people died across the three countries. Jonkman SN & Kelman I, 2005

Anticylcones Stirling, 1997 p 28 Large masses of subsiding warm dry air (settled weather) winds outward-blowing, clockwise Associated weather Summer: hot days (heatwave), rapidly cooling night, land-sea breezes, temperature inversions Winter: similar, but cold / snow, fog / frost

Weather system terminology Musk, 1988

Weather forecasting: tools / data Met Office, 2007 Met station, Muckross House, Killarney NP

Instruments: Met Office, 2007

Met Office, 2007

Met Office, 2007 Satellite images http: //www. metoffice. co. uk/ UK observations regional map (Met Office, 2007)

Met Office, 2007

‘We interrupt TMS to bring you the following gale warning issued by the Met office at 17. 25 GMT Wedesday 14 th March…’ Met Office, 2007

Directed reading: • Mountain weather / local climates – Holden 2005 pp 80 -96 • UK weather system variants Met Office 2007 – Learning – Weather resources – Higher - weather systems • Hurricanes (storm of 1987 – Met Office, 2007, Barry & Chorley 2003 pp 269 -275)

Suggested reading • Barry RG & Chorley RJ 2003. Atmosphere, Weather and Climate (8 th Edition). London, Routledge. • Earth Science and Geography, Keele University 2007. The Weather at Keele (Keele Weather station). http: //www. esci. keele. ac. uk/weather/ (accessed 13. 3. 07) • Holden J (Ed) 2005. An Introduction to Physical Geography and the Environment. Harlow, Pearson. (Atmospheric processes, global climates, local & regional climates pp 27 -96). • Met Office 2007. Met Office homepage. http: //www. metoffice. gov. uk/index. html (accessed 12. 3. 07) Folllow links to Learning – Weather resources - Higher • O’Hare G, Sweeney J & Wilby R 2005. Weather, Climate and Climate Change. Harlow, Pearson. • Stirling R 1997. The Weather of Britain. Routledge. • Thomas DSG and Goudie A 2000. The Dictionary of Physical Geography. Oxford, Blackwell. • Thompson RD 1998. Atmospheric Processes and Systems. London, Routledge.