The Stony Brook Storm Surge (SBSS) group has developed a real-time storm surge modeling system for the coastal Northeast U.S using the Advanced Circulation Model for Coastal Ocean Hydrodynamics (ADCIRC) ocean model (http://stormy.msrc.sunysb.edu). This poster will highlight the verification of the ADCIRC over the 2007-2008 cool season (Nov – March) using several water level gauges around New York City and Long Island. The results have been compared against NOAA's Extratropical Storm Surge Model and Stevens Institute for Technology's storm surge model for the same validation days. The 60-h deterministic ADCIRC run uses hourly surface winds and sea-level pressures from the Penn State- National Center for Atmospheric Research (PSU- NCAR) Mesoscale model (MM5) down to 12-km grid spacing. For the 0000 UTC cycle, ADCIRC is also run 48-h using 8 separate ensemble members, including 5 members from the MM5 and 3 members from the Weather Research and Forecasting (WRF-ARW) model. The MM5/WRF ensemble members include varied initial conditions (different operational analyses) and different PBL and convective parameterizations.

During the 2007-2008 cool season ADCIRC had a negative mean error (bias) of -0.1 m on average for the 12-48 h forecast period, while the root-mean square errors (RMSEs) ranged from 0.15-0.2 m. NOAA's ET Surge model had comparable errors, with a negative bias of around -0.13 m and a RMSE of -0.17 m. The validation of Steven's modeling system will be presented at the meeting. The ADCIRC ensemble mean also had a negative bias, but its RMSEs was slightly smaller than the other ensemble members. The negative water levels are often largest for days when there are significant wave heights near the coast, which suggests the importance of including wave forcing in these surge models. The impact of using SWAN (Simulating Waves Nearshore) on ADCIRC will be tested for a few cases to quantify the influence waves on the storm surge heights.