Intro

ЯOTOR: generatoR Of weather-Type-sequences fOr euRope

Abstract

1: Hydroclimatic extremes are mainly caused by persisting circulation patterns or by critical sequences.

2: Weather generators are used to estimate return periods of such events by resampling observed weather parameters under stationary climate conditions.

3: State of the art approaches usually based on the impact: the meteorological variables.

4: Taken into the account an existing classification of large-scale weather-types in Europa we have both: information about the cause and the impact.

5: Here, we use the cause of local weather characteristics to derive rules for seasonal weather-type transistions from a 30-year training period using a decision tree approach.

6: This is valid for whole Europe. A 1000 year daily time series of possible weather-type sequences is generated following the derived rules.

7: The long-term averaged local impacts (precipitation) is assigned to each weather-type and month, respectively (day-to-day mapping).

8: New extremes of precipitation (wet/dry) arise be the weather-type persistence

9: calculating moving sums and derive extreme values