Transcript Weather forecasting

Weather forecasting
EG1204 Earth Systems
Dr Jonathan Lageard
Weather
• ‘Overall state of the atmosphere on a time-scale
of minutes to months’ Thomas & Goudie, 2000 p527
• Weather describes specific conditions
rain, temperatures, dew-point, wind speed and
direction, visibility…
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 p527
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Climatic regions / climate graphs
Mid-latitude weather (UK)
Weather monitoring / forecasting
Weather & climate practical
Hadley cell regime Thompson 1998, p
Holden 2005, p30
Global temperature patterns (Jan)
Global rainfall patterns
Holden, 2005 p39
Barry & Chorley 2003 p43
Source Flohn 1957 in Barry & Chorley, 1996 p340
Climate graphs
Landes-Pyrenees Properties, 2007
London climate graph
Cool Antarctica, 2007
Weather maps
Stirling, 1997 p25
Synoptic weather chart, Met Office 2000
Air Ministry 1941. The Weather Map.
London, HMSO
Weather systems
Stirling, 1997 p28
Aerospace Technology, 2007
Jetstreams
Air masses: Source regions
Fronts
Mid-latitude weather (UK)
Model of N hemisphere
atmospheric circulation
Thompson 1998 p107 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, p215
Cloud patterns associated
with a depression
Thompson, 1998 p151
Depression tracks
(courses)
Stirling, 1997 p30
North Sea storm surge 31st January to
1st 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 p28
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
14th March…’
Met Office, 2007
Directed reading:
• Mountain weather / local climates –
Holden 2005 pp80-96
• UK weather system variants Met Office
2007 – Learning – Weather resources –
Higher - weather systems
• Hurricanes (storm of 1987 – Met Office,
2007, Barry & Chorley 2003 pp269-275)
Suggested reading
• Barry RG & Chorley RJ 2003. Atmosphere, Weather and Climate
(8th 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 pp27-96).
• 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.