Abstract: An empirical study based on three years (1981?83) of monthly mean data revealed that colocated anomalies in precipitation (?PP) and vertical motion at 500 mb (??) are moderately well correlated over the United States,in ...

Abstract: The influence of cloud amount on the earth's climate is studied with an energy balance climate model. Planetary albedo and infrared radiation are parameterized in terms of cloud amount and surface temperature. For the ...

Abstract: In the literature, the use of analogues for short-range weather forecasting has practically been discarded. This is because no good matches for today's extratropical large-scale flow patterns can be found in a 30-year data ...

Abstract: We address whether there are pairs of instantaneous 500-mb flow patterns that are, relative to the climatology, as much as possible each other's opposite (which we term ?mirror images? or ?antilogs?), and we investigate ...

Abstract: A bias in skill may exist in statistical forecast methods in which the verification datum is withheld from the developmental data (cross-validation methods). Under certain circumstances this bias in skill can become ...

Abstract: A study of long records of monthly mean air temperature (MMAT) for many stations in the Netherlands indicates that the atmosphere's response to surface boundary forcing is often of a very simple local nature. In the Dutch ...

Abstract: The level of month-to-month persistence of anomalies in the monthly mean atmospheric circulation was determined from a 29-year data set of Northern Hemisphere analyses of 500 mb height, surface pressure and 500?1000 mb ...

Abstract: An objective and practical limit of predictability for NWP models is proposed. The time T0 is said to be the limit of predictability if model forecast beyond T0 has no extra skill over persisting the T0 forecast. The ?skill? ...

Abstract: This paper presents a study on simple and inexpensive techniques for extension of NMC's Medium Range Forecasting (MRF) model. Three control forecasts are tested to make 1-day extensions of 500-mb height fields initiated ...

Abstract: A method is proposed to calculate measures of forecast skill for high, medium and low temporal frequency variations in the atmosphere. This method is applied to a series of 128 consecutive 1 to 10-day forecasts produced ...