Event

Forecast skill of the NAO in the Subseasonal-to-Seasonal Prediction Models

Wednesday, November 20, 2019 14:30to15:30

Burnside Hall Room 934, 805 rue Sherbrooke Ouest, Montreal, QC, H3A 0B9, CA

Student Seminar Series

Department of Atmospheric & Oceanic Sciences

presents

a talk by

Pei-Ning Feng
PhD student

Forecast skill of the NAO in the Subseasonal-to-Seasonal Prediction Models

As the dominant mode of climate variability in the Northern Hemisphere, the North Atlantic Oscillation (NAO) has important influence on the weather and climate. Making useful subseasonal-to-seasonal (S2S) forecasts of the NAO and understanding its sources of skill is of great interest. In this study, the prediction skill of the NAO for 10 S2S models is assessed. For all the S2S models, the NAO prediction skill is up to about 13-17 days when the correlation between the forecast and observation drops to 0.5. The models with a higher vertical resolution and better-resolved stratosphere (high top) generally have better skills than those with a lower vertical resolution (low top).

To understand the possible sources of prediction skill of the NAO, the reforecasts started from different initial conditions are compared. We select cases according to phases of the quasi-biennial oscillation (QBO), phases of the NAO, and the properties of the Madden-Julian Oscillation (MJO) in the initial condition. When the initial conditions are associated with the negative phase of the NAO or an active MJO event, the prediction skill is generally better in the S2S models.