COASTAL FRONTOGENESIS AND PRECIPITATION DURING ERICA IOP-2

The inverted trough and coastal front that occurred during ERICA IOP 2 were studied in order to assess the ability of an operational mesosca le model, the Canadian Regional Finite Element Model, to provide credi ble forecast guidance concerning the regional distribution of precipit ation associated with such events. The observed distribution of the he aviest precipitation was dependent on the orientation and inland penet ration of the coastal front and its associated (geostrophic) frontogen etic forcing, although considerable local variability was evident. The observations indicate that the front penetrated inland along a line w est of Boston through east-central Connecticut. The model, which perfo rmed exceptionally well in forecasting the eventual development of the main cyclone, correctly forecast the existence and general location o f the inverted trough and coastal front and thereby gave indications o f the development of heavy snowfall within the coastal region of New Y ork-New England 18-24 h in advance. However, detailed modeling of the coastal front itself is still beyond the scope of current operational models. In the case studied, the position of the regional environment in which the coastal front forms was forecast incorrectly, preventing a precise regional forecast of the precipitation distribution.