Climate variability and predictability from seasonal to decadal time scales
In natural resources management, the incorporation of climate predictions depends on their perceived risk and ‘skill’ (i.e. performance). Adjustments to decisions based on such predictions range from minor hedges for seasonal probability to drastic actions irreversible when a short range (weather) forecast suggests high rates of precipitation. The term seasonal-to-decadal (S2D) prediction involves climate forecasts at monthly, yearly, and now decadal time scales. However, despite steady advances in prediction capabilities at short-range lead times (hours to days), longer-range prediction is currently too inaccurate, particularly at the regional to ranch or watershed scales that matter the most for natural resources management.
In the Intermountain West, the performance of S2D climate predictions range from being less certain to virtually absent; this lack of prediction skill plagues resources management. For example, projection of water supply for the Colorado River in the 21st century is confused by uncertainties in the output from large climate model ensembles; this uncertain projection of water supply constrains water management options, especially in planning for the next decade. This talk will demonstrate the current S2D prediction capabilities and how to best use such information. Also illustrated, is how decadal prediction can potentially capture the predominant wet/dry climate cycles in the Intermountain West and associated ocean-climate dynamics, for the next 10-15 years.