Virtual Workshop: Warm Conveyor Belts – a challenge to forecasting
Session
Conveners
Session 4
- David Lavers (ECMWF)
Extreme precipitation associated with extratropical cyclones can lead to flooding if cyclones track over land. However, the dynamical mechanisms by which moist air is transported into cyclones is poorly understood. In this paper we analyze airflows within a climatology of cyclones in order to understand how cyclones redistribute moisture stored in the atmosphere. This analysis shows that...
We explore the sensitivity and predictability of warm conveyor belts (WCBs) within extratropical cyclones that were observed intensively during the North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX) in the fall of 2016. We utilize the moist adjoint for the Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS) to quantify the initial state and forecast sensitivity, as...
Water management and flood control are major challenges in the Western U.S. They are heavily influenced by atmospheric river (AR) storms that produce both beneficial water supply and hazards, e.g., 84 % of all flood damages in the West (up to 99% in key areas) are associated with ARs. However, AR landfall forecast position errors can exceed 200 km at even 1-day lead time and yet many...
We will briefly summarize the results from two related studies. In the first study, the initial-state sensitivity and optimal perturbation growth for 24- and 36-h forecasts of low-level kinetic energy and precipitation over California during a series of atmospheric river (AR) events that took place in early 2017 are explored using adjoint-based tools from the Coupled Ocean–Atmosphere Mesoscale...