| ABSTRACT | Since the natural and human systems have been affected by the extreme weather events more frequent and severe in recent decades, the capacity of regional climate model to simulate extremes are investigated. To assessing the changes in the extreme events over Turkey and the neighboring region, high resolution regional climate simulation (double nested from 50-km to 10-km) forced by NCEP/NCAR Reanalysis has been accomplished by using ICTP-RegCM3 and analyzed for the period of 1961-2008. Daily temperature and precipitation simulations are used to calculate extreme weather indices and their trends. The selected extreme indices, which are defined by World Meteorological Organization (WMO) and World Climate Research Programme (WCRP), have been mainly analyzed into two groups: temperature and precipitation indices. Extreme hot days (TX35), summer days (SU), warm nights (TN90p), warm days (TX90p), Extreme warm days (TX99p) are picked for temperature indices and very wet days (R95p), wet days (RR1), heavy rainy days (R10mm), excessive heavy rainy days (R20mm), consecutive dry days (CDD) are calculated for precipitation indices. 187 Meteorological station of Turkey are used to define imperfections of the model. The results have been analyzed inter-annually to define extreme’s frequency and intensity. The long-term averages of selected extreme indices show that the model results are consistent with observations in both daily temperature and precipitation variables. The biases present that the model results capture general patterns of all precipitation indices quite well. However the model overestimates all precipitation indices and especially bias of RR1 (wet days) changes between 50 to 100 days in the northern part of Turkey. Similarly, calculated temperature indices except TX99P capture the main characteristics of climatology quite well with respect to the observations. The anomaly for the period of 1991-2008 has been also calculated for all the indices. The changes in wet days (RR1) for this period indicate negative signal which is in the range of 2-15 days over the north of Anatolian peninsula. Moreover, recent changes in CDD demonstrates that increasing signal is quite obvious over the southern part of Turkey. All temperature indices represent positive signal over the most of the model domain. Especially, SU (summer days) TN90p (warm nights) and TX90p (warm days) increase in the range of 10-25 days. Furthermore, time series of eac |