Operational Oceanographic Forecasts in the Thermaikos Gulf: The WaveForUs Project Y.N. Krestenitis 1,* , Y. Androulidakis 1 , K. Kombiadou 1 , Ch. Makris 1 , V. Baltikas 1 and G. Kalantzi 2 1 Laboratory of Maritime Engineering and Maritime Works, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece 2 OMIKRON Ltd, 15 th km Thessaloniki-Moudania, 57001 Thermi, Thessaloniki, Greece *Corresponding author: E-mail: ynkrest@civil.auth.gr, Tel +30 2310995654, Fax: +30 2310995649 Abstract Sea state (wave, circulation, storm surge) modelling and forecasting in Greece, are notions well understood, investigated and implemented but only within the scientific community and mainly for research purposes. When it comes to practical implementations, there is poor distribution of the available information to every-day Greek users. Especially for Thermaikos Gulf (NW Aegean Sea), an area of high environmental significance and where a broad spectrum of sea-based activities (tourism, aquacultures, marine transportations, sea-related recreational and nautathletic activities etc) takes place, the availability of high-resolution, gridded sea state prognoses is very low. Under this reasoning, a state-of-the-art forecasting system (WaveForUs: Wave climate and coastal circulation Forecasts for public Use) is implemented that will deliver 3-day forecasts of wave, circulation and storm surges for the Thermaikos Gulf; the forecasts will be disseminated to the public via television broadcasts and internet applications. The WaveForUs platform will soon be fully functional and aspires to provide Greek users with an invaluable tool for their sea-based activities. The present paper focuses on presenting the calibration/validation of the sea-state models of the system. The validation and calibration of the models is still ongoing, however the results of hindcasting simulations and of preliminary products are satisfactory and compare well with in-situ and satellite/modelling data. Keywords: waves, storm surges, circulation, modelling, sea state forecasts 1. INTRODUCTION WaveForUs (Wave climate and coastal circulation Forecasts for public Use) is a newly implemented forecasting system that uses state-of-the-art weather, wave, hydrodynamic circulation and storm surge modelling in order to produce daily, user-friendly 3-day sea state forecasts in the Thermaikos Gulf (NW Aegean Sea) and deliver them to users through television, internet and GIS applications. The structure of the WaveForUs system is graphically depicted in Figure 1; it consists of the modelling platform, which essentially includes the various forecasting models, and of the forecast dissemination platform. The present work focuses on the presentation of the modelling system (Figure 1) that consists of the WRF-ARW atmospheric model [1,2], WaveWatch III wave propagation model [3], POM coastal circulation model [4] and HRSS storm surge model [5]. The meteorological outputs (wind and pressure fields, precipitation, surface radiation and heat fluxes, air temperature etc) are used by the sea-state models, which in turn, produce 3-day prognoses of wave fields (significant wave height and direction), circulation (currents) and thermohaline properties of seawater and Sea Level Heights (SLH). The application area extends southwards to the Cape of Kassandra (39.97˚N). It is noted that each of the model runs in a coupled manner within a coarser and broader field than the one of the study area, in order to obtain the necessary boundary conditions. Daily television broadcasts are planned and will soon deliver forecasts of wave and SLH