Three different potential predictors of forecast error – ensemble spread, mean errors of recent forecasts and the local gradient of the predicted field – were compared. The comparison was performed using the forecasts of 500 hPa geopotential and 2-m temperature of the ECMWF ensemble prediction system at lead times of 96, 168 and 240 h, over North America for each day in 2004. Ensemble spread wa...

Four-dimensional variational (4D-Var) data assimilation method is used to find the optimal initial conditions by minimizing a cost function in which background information and observations are provided as the input of the cost function. The optimized initial conditions based on background error covariance matrix and observations improve the forecast. The targeted observations determined by usin...

Price-earnings (P/E) ratios should be positively related to growth and negatively related to interest rates and risk. Whereas earlier investigations of the determinants of P/E ratios find these links to be weak, results of recent research estimating the cost of capital imply stronger links. The two sets of research employ different sets of proxies for P/E ratios (trailing vs. forward ratios), g...

Four dimensional variational (4D-Var) Data Assimilation (DA) method is used to find the optimal initial conditions by minimizing a cost function in which background information and observations are provided as the input of the cost function. The optimized initial conditions based on background error covariance matrix and observations improve the forecast. The targeted observations determined by...