Retrospective sub-seasonal forecasts of extreme precipitation events in the Arabian Peninsula using convective-permitting modeling

This work demonstrates the potential of extreme cool-season precipitation forecasts in Arabian Peninsula (AP) at sub-seasonal time scales, identifies regions and periods forecast opportunity, investigates predictability synoptic-scale forcing scales. To this end, we simulate 18 events using convective-permitting Weather Research Forecasting (CP-WRF) model with lateral boundary from European Centre Medium-range Forecasts to seasonal reforecasts (ECMWF S2S reforecasts). The simulations are initiated one-, two-, three-week lead times. At all times, CP-WRF improves mean accumulated extratropical synoptic regimes over west coastal central AP Red Sea compared ECMWF as evaluated against Global Precipitation Measurement Final (GPMF) King Abdullah University Science Technology reanalysis (KAUST-RA) products. Based on categorical statistics a threshold 20 mm 7 days, skillfully Jeddah, coast AP, up time. relative operating characteristic curve reconfirmed high skill CP-WRF, an area under above 0.5 most Finally, correlation coefficients between reforecast interim 500 hPa geopotential heights higher associated regime than those tropical regime, regardless Therefore, can potentially improve accuracy winter two-and times regime.