Oscillation Teleconnections polar map CDAS NH 500-hPa HT Heights (5 d rm) 30 may 2013:
<p>Analyzed 500-hPa heights and anomalies. Image is an five-day mean, centered on the date indicated in the title, of 500-hPa heights and anomalies from the NCEP Climate Data Assimilation System (CDAS).  Contour interval for heights is 120 m, anomalies are indicated by shading. Anomalies are departures from the 1979-95 daily base period means. (Text after NOAA, <a rel="nofollow" class="external text" href="http://www.cpc.ncep.noaa.gov/products/intraseasonal/z500_nh_anim.shtml">Northern Hemisphere 500 hecto Pascals Height Anomalies Animation</a>)
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Extracted from 30-day loop; polar map was rotated 90° (Europe at bottom) to illustrate inverse omega constellation of eastern european low between atlantic and scandinavian highs, causing severe floods of May/June in Central Europe.
NOAA  / National Weather Service / National Centers for Environmental Prediction / Climate Prediction Center Internet Team<br>(file: <a href="//commons.wikimedia.org/wiki/User:W!B:" title="User:W!B:">W!B:</a>)
2013-05/06 <br>(file: 2013-06-07)
NOAA NCEP CPC &gt; Climate &amp; Weather Linkage &gt; Teleconnections &gt; North Atlantic Oscillation <a rel="nofollow" class="external free" href="http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.shtml">http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.shtml</a>