The National Weather Service is conducting a preliminary survey of damage caused by a tornado warning in Allegheny, Westmoreland County. The survey will go from West Mifflin to North Huntingdon Township and will be completed by Wednesday afternoon. This follows severe storms that swept through the area shortly after midnight. The National Weather Services will be monitoring damage from Allegheny County into Westmorely County. Local residents have been sharing their experiences of the storm, which resulted in significant structural damage. The assessment of the damage is expected to be completed within hours.