Weather forecasting is complex and not always accurate, moreover, it is generally defined by its very nature as a process that has to deal with uncertainties. In a previous work, a new weather prediction scheme was presented, which uses evolutionary computing methods, particularly, Genetic Algorithms in order to find the most timely ‘optimal’ values of model closure parameters that appear in ph...

The analysis of vorticity equation offers a possibility for validation and diagnostics of a NWP model. The source terms of the equation are related to the resolved and subgrid-scale torque due to the orography and surface properties. The terms resolved by the model can be estimated from three-dimensional numerical analyses and forecasts. In the vertically integrated equation, these terms sum up...

Weather forecasting is based on the use of numerical weather prediction (NWP) models that are able to perform the necessary calculations that describe/predict the major atmospheric processes. One common problem in weather forecasting derives from the uncertainty related to the chaotic behaviour of the atmosphere. A solution to that problem is to perform in addition to “deterministic” forecasts,...

The Earth Clouds, Aerosols and Radiation Explorer, EarthCARE, has been selected for implementation as the sixth Earth Explorer Mission of the European Space Agency’s Living Planet Programme [1]. The mission will measure three-dimensional structures of clouds and aerosols simultaneously with the respective outgoing broad band flux. These measurements would significantly contribute to the underst...

Many of the talks and posters during this year’s conference will discuss how both ensemble forecasting and atmospheric data assimilation can work synergistically together. We detail provide a brief description of the underlying theoretical basis for this research. The unifying idea is that the chaotic nature of the atmosphere can actually be put to use to improve data assimilation. Ensemble for...

Continental low stratiform clouds cover the sky about 23% of the time during the fall, winter, and spring months and play a significant role in the Earth’ radiation budget. Information about cloud structure and variability is crucial in determining areal averages of cloud radiative and microphysical properties such as over numerical weather prediction (NWP) or Global Climate Model grid cells. N...

I n 2003, the Meteorological Service of Canada (MSC) began a significant restructuring of its forecasting operations in response to financial pressures. Senior management proposed that the MSC could be made more cost effective while continuing to provide quality services by pursuing a more centralized forecasting approach and increasing the automation of forecasts via numerical weather predicti...

We compare new observations on the kinematic characteristics of the damped Lyα systems against results from numerical SPH simulations to test the predictions of hierarchical galaxy formation. This exercise is particularly motivated by recent numerical results on the cross-section of damped Lyα systems. Our analysis focuses on the velocity widths ∆v of ≈ 50 low-ion absorption profiles from our s...

The 24-hour 500-mb. barotropic forrcasts prepared by the Joint Numerical Weather Prediction Unit (JNWPU) have been investigated in 30 cases of rapid sea level cyclogenesis. Composite error maps are presented for the region of cyclogenesis. The 500-mb. errors are found t o bc significantly larger when the solenoidal field at that level is strong than when it is weak.

Warm season convective system rainfall forecasts remain a particularly difficult forecast challenge. For these events, it is possible that ensemble forecasts would provide helpful information unavailable in a single deterministic forecast. In this study, an intense derecho event accompanied by a well-organized band of heavy rainfall is used to show that for some situations, the predictability o...