Force Majeure Weather Modeling

Authored by: Gui Ponce de Leon

Although adverse weather has impacted construction since before the pyramids, and when unusually severe is typically only deserving of a time extension without compensation, weather issues continue to generate their fair share of disputes. Even if not disputed, all significant grass root construction projects face weather impact issues that the parties may wish to recognize on an ongoing basis. Existing weather modeling methods can be cumbersome, overly technical, and resource intense. In searching for practical approaches, the authors have developed new methodologies for modeling force majeure weather that provide objective evaluation of adverse weather impacts, for forensic as well as contemporaneous applications. Guidance for calculating normal adverse weather and force majeure weather day losses is provided, with examples to illustrate the new concepts. The focus of this paper is on the technical aspects of normal adverse weather and force majeure weather as opposed to the legal aspects.