Subseasonal-to-Seasonal Predictability Assessment of an Early Heat Wave in the Eastern Mediterranean in May 2020

Greece experienced an unusual heat wave in mid-May 2020, since it was observed earlier than the common Mediterranean heat wave period. On May 16th, the maximum air temperature at Kalamata (southern Greece) was 40 °C, and at Aydin (western Turkey) it was 41.6 °C. There was a significantly high climatological anomaly (ref: 1979–2009) relating to temperature at 850 hPa over Greece and Turkey from May 12 to May 20. The aim of this study was to evaluate how well this extreme event can be predicted at subseasonal timescales, since it is not a well-researched scientific topic by weather forecasters in the Eastern Mediterranean. Global forecasts from six meteorological centers (ECMWF, UKMO, NCEP, CMA, KMA, HMCR) and WRF simulations produced via CFS (NCEP) analyses and forecasts were examined for lead times ranging from 2 to 6 weeks ahead. The results show that skillful forecasts started 2.5 weeks before the event’s onset.