Met office seasonal forecasting for winter 2010 11
Download
1 / 32

Met Office seasonal forecasting for winter 2010-11 - PowerPoint PPT Presentation


  • 142 Views
  • Uploaded on

Met Office seasonal forecasting for winter 2010-11. Jeff Knight (with thanks to many colleagues). The main event: December. December 2010. Snow at Land’s End. Courtesy of Mike Kendon (NCIC). Public execution of Charles 1 st 1649 (only 10 years before series starts). December 2010.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Met Office seasonal forecasting for winter 2010-11' - shamus


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Met office seasonal forecasting for winter 2010 11

Met Office seasonal forecasting for winter 2010-11

Jeff Knight (with thanks to many colleagues)



December 2010
December2010

Snow at

Land’s End

Courtesy of Mike Kendon (NCIC)


December 2010 central england temperature series

Public execution of Charles 1st 1649 (only 10 years before series starts)

December 2010

The coldest December since 1890

December 2010: Central England Temperature series

3 voyages of Captain Cook 1768 - 1779

Queen Victoria’s coronation 1838

World War 11914-1918

The second coldest December in a series from 1659

Courtesy of Mike Kendon (NCIC)



2009-10 and 2010-11

Christmas Eve 2010 Satellite Receiving Station, Dundee University

1150 GMT 7 January 2010Photo: NASA/GSFC, MODIS Rapid Response.



Djf met office seasonal forecast for uk government
DJF Met Office Seasonal Forecastfor UK Government

Outlook for December 2010 – February 2011

For the period December 2010-February 2011, there is a 25% chance of mild conditions, a 30% chance of near-average and a 45% chance of cold conditions over northern Europe.

For precipitation, there is a 25% chance of wet conditions, a 35% chance of near-average and a 40% chance of dry conditions over northern Europe.



Temperature terciles from nov
Temperature terciles from Nov

L85 GloSea (1996-2009 climate)


Precipitation terciles from nov 1996 2009 climatology
Precipitation terciles from Nov(1996-2009 climatology)

L85 GloSea (1996-2009 Climate)


Nino3 4 plumes glosea4 ec eurosip
Nino3.4 plumes: GloSea4-EC-EUROSIP

Charts courtesy of ECMWF


Cluster analysis fereday et al 2008 j climate
Cluster analysisFereday et al. (2008), J. Climate

  • 6 two month seasons, 10 clusters per season

  • North Atlantic / Europe region

  • Clusters from observed 1850-2003 daily mean MSLP dataset

  • For 2004 onwards use NCEP reanalysis

  • Remove seasonal mean from NCEP MSLP

  • Assign each field to closest cluster


Nd 2010 cluster frequencies
ND 2010 cluster frequencies

Highest number of days for ~100 and ~50 years respectively



Oct nov north atlantic sst
Oct-Nov North Atlantic SST

October 2011

14-21 Nov 2011


North atlantic sub surface temperature
North Atlantic Sub-Surface temperature

October

May

Rodwell and Folland (2002), Q. J. R. Meteorol. Soc.


Quasi biennial oscillation
Quasi-Biennial Oscillation

W phase of QBO → stronger polar vortex, less chance of a stratospheric warming event

So perhaps switch to zonal at end of winter?

This is also the signal from La Niña









La ni a teleconnections
La Niña Teleconnections

  • During La Niña the rainfall that normally falls out over the Pacific shifts west




Conclusions
Conclusions

  • GloSea4 did a reasonable job in predicting the likelihood of a cold winter

  • In later forecasts, however, it wanted to retain the cold for too long

  • Consistency with EuroSIP and other models

  • Other factors such as La Niña, Atlantic SSTs and the QBO were considered alongside models

  • Potential additional influences were the continuing low solar activity (Ineson et al., 2011), low sea-ice, ...


Advertisement
Advertisement

For various long-range forecasts including decadal global temperature forecasts and seasonal tropical storm forecasts:

http://www.metoffice.gov.uk/science/specialist/long-range

For the seasonal probability maps, ENSO forecast and skill scores:

http://www.metoffice.gov.uk/science/specialist/seasonal




ad