Skill of a Ceiling and Visibility Local Ensemble Prediction System (LEPS) according to Fog-Type Prediction at Paris-Charles de Gaulle Airport

Abstract

A specific event, called a low-visibility procedure (LVP), has been defined when visibility is under 600 m and/or the ceiling is under 60 m at Paris-Charles de Gaulle Airport, Paris, France, to ensure air traffic safety and to reduce the economic issues related to poor visibility conditions. The Local Ensemble Prediction System (LEPS) has been designed to estimate LVP likelihood in order to help forecasters in their tasks. This work evaluates the skill of LEPS for each type of LVP that takes place at the airport area during five winter seasons from 2002 to 2007. An event-based classification reveals that stratus base lowering, advection, and radiation fogs make up for 78% of the LVP cases that occurred near the airport during this period. This study also demonstrates that LEPS is skillful on these types of event for short-term forecasts. When the ensemble runs start with initialized LVP events, the prediction of advection fogs is as skillful as the prediction of radiation fog events and stratus base lowering. At 3 and 6 h before the runs where LVP events were initialized, LEPS still shows positive skill for radiation fog events and stratus base lowering cases.

Visibility monitoring using conventional roadside cameras – Emerging applications

“…In the future, such initiatives might make it possible to monitor visibility reduction at the scale of a road itinerary. Prediction, which will soon be possible for airports (Roquelaure et al, 2009), might be envisioned.…”

Forecasting Low-Visibility Procedure States with Tree-Based Statistical Methods

“…Glahn et al (2017) combined this system with the physically-based forecasts of Benjamin et al (2016) to improve the performance. Other statistical techniques to forecast visibility are, for example, neural networks (e.g., Pasini et al 2001;Marzban et al 2007), Bayesian model averaging (e.g., Roquelaure et al 2009), or decision trees (e.g., Bartoková et al 2015;Dutta and Chaudhuri 2015). Herman and Schumacher (2016) compared various statistical methods for visibility predictions at airports and found that no specific model performs best overall.…”

Influence of Environmental Conditions on Forecasting of an Advection-Radiation Fog: A Case Study from the Casablanca Region, Morocco

“…Adverse visibility in foggy conditions often leads to serious accidents for air, road and marine traffic. Therefore, fog is a potentially disastrous weather phenomenon that is of widespread concern (e.g., Taylor, 1917;Musson-Genon, 1987;Duynkerke, 1991;Koracin et al, 2001;Bergot et al, 2005;Roquelaure et al, 2009) and has been studied extensively from different points of view (Gultepe et al, 2007): climatology studies (e.g., Tarif and Rasmussen, 2007;Bari et al, 2016), remote sensing studies (e.g., Cermak and Bendix, 2007), statistical forecasting (e.g., Hilliker and Fritsch, 1999;, and numerical modeling (e.g., Cuxart and Jiménez, 2012;Bergot et al, 2014.…”

“…Over continental stations, the main types of fog are radiation fog and cloud base lowering fog (Roquelaure et al, 2009). However, not all types of fog can occur everywhere.…”