Use of Dynamical Adaptation in Research Impact Studies Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Martina Tudor Meteorological and Hydrological Service Grič 3, HR Zagreb, Croatia

The Problem new road in an area with strong Bura need to estimate expected wind speeds experience with the Maslenica Bridge insufficient spatial density of measurements high resolution dynamical adaptation significantly improves the large scale wind fields when the main forcing is the pressure gradient over mountains, as it is the case with bura expected wind speeds were estimated using operational 2-km resolution dynamical adaptation for a few extreme weather cases Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

The Area the part related to this study, the highway will cross the Velebit mountain and Velebit channel across the Maslenica Bridge highways in Croatia (green are built and red are planned) mountainous area Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria The Study The highway will connect inland and coastal parts passing through an area with frequent strong Bura events. When the original impact study for the highway was done, the data was available only from the automatical meteorological stations on Maslenica Bridge and Sv. Rok Tunnel. Dynamical adaptation of the surface wind speed has already proven to be very good for Maslenica Bridge in strong bura situations on a study on MAP IOP 15 case. ALADIN model was used to estimate the strength of the wind along the new road. Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

Dynamical Adaptation Operational version was used: input 8-km resolution wind field is interpolated to 2- km resolution grid and then dynamicaly adapted numerical model ALADIN is run for 30 min with 60- sec time-step with 2-km resolution part of the physics describing the moist and radiation processes is excluded number of levels in the upper troposphere and stratosphere is reduced can not predict local thermal circulation or circulation caused by convection processes Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

The representation of terrain Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia 8-km resolution 2-km resolution Terrain height in the ALADIN/ Croatia domain (top), zoom of it (top, right) and in the dynamical adaptation domain (right).

MAP IOP 15 Measurement data, ALADIN Croatia forecasts and dynamical adaptation of surface wind for Maslenica from 6th to 11th November Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

The first study Sv. Rok Tunel Maslenica Bridge Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia Surface wind field (left) and vertical cross-section along lat=44.24 (right) with 2-km resolution for 16th December 1999, 21 UTC. Arrows on both pictures represent the direction of the horisontal wind, and shaded areas correspond to the wind speed in (m/s). Maslenica BridgeSv. Rok Tunel

New data after the construction of the road began, instruments of a few new automatic meteorological stations were set up View from the exit from the Ledenik tunnel Baričević viaduct and the measuring site Maslenica Bridge Velebit Channel Novigrad Sea Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

Dynamical adaptation 2 2-km resolution dynamical adaptation forecast results were compared to the measurements on new stations for one case of bura, operational wind speed forecasts were compared to the two alternatives; dynamical adaptation was run with full physics full 48 hour forecast was run with 2-km resolution The results prove that the choice of the operational dynamical adaptation setup for the estimation of the expected wind speed in extreme cases was good. Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

operationalfull physics forecast Surface wind for the operational dynamical adaptation (top, left), dynamical adaptation using the whole physics package (top) and with full forecast integration on the dynamical adaptation domain (left). Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

operationalfull physics forecast Vertical wind cross-section along lat=44.24 for the operational dynamical adaptation (top, left), using the whole physics package (top) and forecast with 2-km resolution. Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

Baričević ViaductLedenik Tunnel Maslenica BridgePag Bridge Comparison with measurements Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

Comparison with measurements 2 Baričević ViaductLedenik Tunnel Measurement data, ALADIN Croatia forecasts and operational dynamical adaptations of surface wind for Maslenica for February Second Workshop on Statistical and Dynamical Adaptation May 2003, Vienna, Austria Meteorological and Hydrological Service of Croatia

Conclusions this approach works well when the wind is strong enough to overcome the circulation induced by local thermal or convection induced circulation therefore, it represents a powerfull tool for estimation of the expected wind speed during the extreme weather events induced by pressure gradient forcings however, it has limited ability in extreme weather events including convection.