ECHAM/s Winter '07 / '08 Outlook - September

The German Climate Model...known as ECHAM...extended forecast for NHEMI sea-level deviations in hPa (1 hPa = 1 mb) are shown below. Not sure when it was initialized -- best guess is September -- or how often it/s updated.


October
Main feature is the strong suggestion of a +AO...which doesn/t appear to be born out by its observed index; however...some of its physical features (HIGH over N Pole; broad trof across E CONUS and the ATL Ocean) are roughly in the right places.

November
Strong omega block along the International Dateline...which teleconnects to a trof W - ridge E L/W pattern over CONUS. E of the block...storm track over Siberia would favor enhanced snow pack and development of Siberian HIGH. Trof along W CONUS has connection to HI Is. and the so-called 'Pineapple Express.'

December
Weak +PNA pattern with positive anomaly over AK and broad trof across lower 48. Rex block in the E ATL and negative anomaly INVOF Azores suggests the presence of a -NAO variant.

January
The positive anomaly over W CN suggests +PNA and the negative anomalies W of Greenland and INVOF the Azores favors -NAO...which implies cold and stormy conditions for E CONUS. Strength of positive anomaly over Netherlands could result from a high-latitude block.

February
Pressure anomaly couplet in N ATL Ocean points decidely to +NAO. ATL ridge axis extends W across CONUS suggesting 'mild' mid-winter temperatures in the E.