Precipitation types the preceding adjective "freezing", becoming known as freezing rain or freezing drizzle. Frozen forms of precipitation include snow, ice needles, sleet, hail, and graupel. Their respective intensities are classified either by rate of fall, or by visibility restriction. Precipitation falls in many forms, or phases. They can be subdivided into: The parenthesized letters are the METAR codes for each phenomenon. Precipitation occurs when local air becomes saturated with water vapor, and can no longer maintain the level of water vapor in gaseous form. This occurs when less dense moist air cools, usually when an airmass rises through the atmosphere. However,
The Great Snow of 1717 February 27 or March 1. On February 27 a typical New England nor'easter passed through, with snow falling on some areas and other places receiving a mix of snow, sleet, and rain. The first major snowstorm occurred on March 1, with another on the 4th, and a third, the worst among the three, on the 7th. At some points, the snow would lighten and stop, but the sky would remain cloudy, showing no signs of clearing. Some of the oldest Native Americans had said that even their ancestors never spoke of a storm of this magnitude. Boston received around of