Workshop on Predictability, dynamics and applications research using the TIGGE and S2S ensembles

The primary variables forecast by the U.S. tropical cyclone (TC) forecast centers, National Hurricane Center (NHC) and Joint Typhoon Warning Center (JTWC), are TC track, intensity, and radius of gale-force winds. For all three variables the primary forecast guidance products used by the forecasters are multi-model ensemble mean or consensus forecasts derived using the forecasts from global...

Forecasting temperature and precipitation on subseasonal timescales beyond two weeks lead-time is at the limits of predictability and modeling capabilities. The NOAA Climate Prediction Center (CPC) relies on both dynamical and statistical models to make operational and experimental, above and below median, temperature and precipitation forecasts for weeks 3 and 4. Both statistical and...

We introduce isotonic distributional regression (IDR), a nonparametric technique for the generation of calibrated probabilistic forecasts from numerical weather prediction (NWP) model output. IDR learns calibrated predictive distributions directly from training data, subject to natural monotonicity constraints, without invoking any parametric distributional assumptions.

In a nutshell, IDR...

A Bayesian framework for postprocessing multi-ensemble weather forecasts

Clair Barnes (1), Richard E. Chandler (1) & Christopher M. Brierley (2)
(1) Department of Statistical Science, University College London
(2) Department of Geography, University College London

Ensemble weather forecasts often under-represent uncertainty, leading to overconfidence in their predictions. Multi-model...

Located in the tropical Southwest Pacific, New Caledonia is prone to heavy rainfall events that may be related either to tropical or to mid-latitude perturbations. Precipitation over New Caledonia should therefore exhibit some subseasonal predictability owing to large-scale drivers, such as ENSO and the Madden-Julian Oscillation. This study aims to assess the skill in predicting precipitation...

Subseasonal Prediction of European Summer Heat Waves in the S2S Hindcast Ensembles

Authors: Ole Wulff and Daniela Domeisen
Affiliation: ETH Zurich, Switzerland

Due to their devastating impact, the prediction of heat waves beyond the weather forecasting range is of great significance to society. The potential for successful subseasonal predictions of summer heat waves stems from e.g....

We utilize the Guan and Waliser (2015) atmospheric river (AR) detection algorithm and DeFlorio et al. (2018) AR activity forecast approach on three operational subseasonal forecast systems (ECMWF, NCEP, and ECCC) to predict AR activity over the eastern Pacific Ocean and western N. America, with a focus on subseasonal variations, and in particular the week-3 lead time. The predictand for these...

Many people living in East Africa are significantly exposed to risks arising from climate variability. Droughts and floods in the region are common; poor performance of the rainy season in 2011 and 2016 led to widescale threats to food security and flooding in 2018 led to significant impacts on human life.

The project ForPAc (Toward Forecast-Based Preparedness Action, funded by NERC & DFID)...