air mass
noun
: a body of air extending hundreds or thousands of miles horizontally and sometimes as high as the stratosphere and maintaining as it travels nearly uniform conditions of temperature and humidity at any given level
Example Sentences
Recent Examples on the Web High dew points near 70 are likely by Tuesday ahead of a cooler and drier air mass for the middle of next week. 
Dave Epstein, BostonGlobe.com, 9 Sep. 2022 Because an air mass is being constantly replenished and fed into these storms, that can quickly lead to a 10 or 20% increase in precipitation totals. Matthew Cappucci, Anchorage Daily News, 23 Aug. 2022 The storm potential this afternoon and evening is predicated on the arrival of a cold front from the northwest, intersecting an unstable and humid air mass along and ahead of it. Jason Samenow, Washington Post, 25 July 2022 Much of Wisconsin will be in the grip of a warm, humid, unstable air mass on Saturday. Joe Taschler, Journal Sentinel, 21 July 2022 The storms weren’t overly intense and didn’t reach severe levels, but the exceptionally humid air mass in place translated to heavy downpours. Matthew Cappucci, Washington Post, 9 Aug. 2022 While that will cap temperatures slightly lower - between 98 and 102 degrees - the juicy air mass in place will help heat indexes top 105 degrees. Matthew Cappucci, Anchorage Daily News, 20 July 2022 As a warm front lifts northward across the Plains, the sticky air mass that settles in and the daytime heating from the sun will help induce thunderstorm development into the early afternoon hours. Derek Van Dam, CNN, 12 May 2022 Tomorrow night: Like the previous two nights, the clear skies and chilly air mass (for the time of year) allow for a cool, crisp night. Washington Post, 9 May 2022 See More
Dave Epstein, BostonGlobe.com, 9 Sep. 2022 Because an air mass is being constantly replenished and fed into these storms, that can quickly lead to a 10 or 20% increase in precipitation totals. Matthew Cappucci, Anchorage Daily News, 23 Aug. 2022 The storm potential this afternoon and evening is predicated on the arrival of a cold front from the northwest, intersecting an unstable and humid air mass along and ahead of it. Jason Samenow, Washington Post, 25 July 2022 Much of Wisconsin will be in the grip of a warm, humid, unstable air mass on Saturday. Joe Taschler, Journal Sentinel, 21 July 2022 The storms weren’t overly intense and didn’t reach severe levels, but the exceptionally humid air mass in place translated to heavy downpours. Matthew Cappucci, Washington Post, 9 Aug. 2022 While that will cap temperatures slightly lower - between 98 and 102 degrees - the juicy air mass in place will help heat indexes top 105 degrees. Matthew Cappucci, Anchorage Daily News, 20 July 2022 As a warm front lifts northward across the Plains, the sticky air mass that settles in and the daytime heating from the sun will help induce thunderstorm development into the early afternoon hours. Derek Van Dam, CNN, 12 May 2022 Tomorrow night: Like the previous two nights, the clear skies and chilly air mass (for the time of year) allow for a cool, crisp night. Washington Post, 9 May 2022 See More Word History
First Known Use
1882, in the meaning defined above