Embed Size (px)
DESCRIPTION
Review of Northern Winter 2011/12 Mike Blackburn National Centre for Atmospheric Science, University of Reading Seasonal Climate Discussion 2 April 2012. NCAS Seasonal Climate Discussion, 2 April 2012. Summary Drivers for global circulation - La Niña, MJO, sea-ice, (stratosphere) - PowerPoint PPT Presentation
Citation preview
NCAS Seasonal Climate Discussion, 2 April 2012
Review of Northern Winter 2011/12
Mike Blackburn
National Centre for Atmospheric Science, University of Reading
Seasonal Climate Discussion2 April 2012
Summary
• Drivers for global circulation
- La Niña, MJO, sea-ice, (stratosphere)
• Observed regional anomalies
- UK and European precipitation, windstorms
• Large scale circulation
- Teleconnection patterns, Atlantic jet, global anomalies
- Winter onset in Europe
- Eurasian blocking / cold period Jan/Feb
NCAS Seasonal Climate Discussion, 2 April 2012
La Niña, 2011/12
NOAA ESRL
SST anomaly DJF 11/12
OLR anomaly DJF 11/12
NOAA Climate Diagnostics Bulletin
La Niña, compare with 2010/11
NOAA ESRL
SST anomaly DJF 10/11
OLR anomaly DJF 10/11
SST anomaly DJF 11/12
OLR anomaly DJF 11/12
Tropical variability - atmosphere
NOAA CPC (pentad averages)
Active MJO: strongest late Autumn and late Winter
NOAA CPC
Forecast: phase good but amplitude weak in Nov.
MJO activity Oct-Nov 11 (with EC monthly forecasts)
MJO activity JFM12 (with EC monthly forecasts)
NOAA CPC
Last month: eastward propagation well forecast
Arctic sea-ice extent
NOAA CPC
Maximum sea-ice extent, March 2012
Arctic sea-ice: concentration anomalies
NOAA CPC
Northern Hemisphere Stratosphere Winter 2011/12
Met Office stratospheric analyses, processed at Reading
• Strong early vortex
• Disturbed vortex late Jan / early Feb
• 1991-2004 climatology and range
- Observed UK / European anomalies -
UK temperature anomaly DJF 2011-12
UK Met Office
Jan 2012
Dec 2011
DJF 11-12
Feb 2012
UK precipitation anomaly (% normal) DJF 2011-12
UK Met Office
Jan 2012
Dec 2011
DJF 11-12
Feb 2012
UK precipitation anomaly (% normal) 2011
UK Met Office
SON 2011JJA 2011
Annual 2011
DJF 11-12
MAM 2011DJF10-11
European precipitation anomalies (%)
NOAA ESRL
February 2012
January 2012DJF 2011/12
Early Winter windstorms
UK Met Office
8 December, 18 UTC 3 January, 12 UTC
Cyclone “Friedhelm”
DIAMET flight
Extreme gusts, 165 kt, Cairngorm
Early Winter windstorms
ECMWF analysis
8 December, 18 UTC 3 January, 12 UTC
Cyclone “Friedhelm”
- Large scale circulation -
Teleconnection patterns
NOAA CPC
AO
NAO
PNA
Z500
Pmsl
Z500
Jet streams – DJF 2011-12
NOAA ESRL
DJF 2011-12Z250 anom
Jet streams – DJF 2011-12
NOAA ESRL
DJF climateZ250 anom
Jet streams – DJF 2011-12
NOAA ESRL
December January
February March
1 Dec 2011 10 Mar 2012
Atlantic jet: U850 latitude-time Tim Woollings
1 Dec 2010 10 Mar 2011
Atlantic jet: U850 latitude-time Tim Woollings
1 Dec 2009 10 Mar 2010
Atlantic jet: U850 latitude-time Tim Woollings
Winter onset - 250hPa height(approx) weekly averages: November - December 2011
ECMWF analyses, processed at University of Reading
Dec 02-12 Dec 09-16Nov 25 - Dec 02
Nov 18-23Nov 11-16Nov 04-11
European Blocking : Winter 2011/12
NOAA ESRL / CPC
Z250, 55°-70°N
(weak throughout December)
Jet streams – Eurasian blocking period
NOAA ESRL
20 Jan to 10 Feb 2012 (Eurasian blocking)
15 Feb to 18 Mar 2012 (Atlantic ridge extends
into Europe)
250hPa height – hemispheric planetary wave pattern : (approx) weekly averages: Jan – Feb 2012
ECMWF analyses, processed at University of Reading
Jan 20-27Jan 13-20Jan 06-11
Feb 03-10 Feb 10-17Jan 27 – Feb 03
European anomalies – February 05-11
NOAA ESRL
• Eurasian blocking, extensive severe cold, fatalities
Precipitation totalTemperature anomaly
- END -
