Summary (Long range weather forecasts. II The correlation ellipses).The description of the method for determination of long range weather conditions, as presented by the Kon. Ned. Meteorologisch Instituut at De Bilt, is continued.The formulae lead to the construction of socalled correlation ellipses which are of great use to find the best new variables to be added in order to improve correlation. The calculus is very simplified by this method, which deals with the complicated correlation phenomena; reliable results can only be obtained by careful applicatio