jet-stream images For BBC programme Five Miles High Mike Blackburn, Brian Hoskins University of Reading August 2007 Colours on the maps show wind speed Arrows show the wind direction all values are in metres per second Slightly more than double (x2.2) to get miles per hour

Climatological jet-streams Northern Winter DJFSouthern Summer DJF

Climatological jet-streams Northern Summer JJASouthern Winter JJA

Extreme seasons Northern Winter (Climatology)Northern Winter 1963 Not very clear – next slide better – Atlantic sector

Extreme seasons Northern Winter (Climatology)Northern Winter 1963 Note colour scale ms -1 Persistent blocking anticyclone, diverting the jetstream Leads to cold winters in western Europe (more continental)

Extreme seasons Northern Summer (Climatology)Northern Summer 1976 Note colour scale ms -1 Persistent blocking anticyclone, diverting the jetstream Leads to hot summers in western Europe (more continental)

Extreme seasons Northern Summer (Climatology)Northern Summer 2007 Note colour scale ms -1 Very wet in UK and surrounding countries Major UK rainfall events: June 13-15; June 25, July 20 Persistent waves on the jet-stream, with a trough of low pressure near the UK

Summer 2007 animation Northern Summer day averages Wind speed at 250 hPa This is an animation in.gif format