black frost

black frost (countable and uncountable, plural black frosts)

1. (botany) Cold so intense as to freeze vegetation and turn it black, without the formation of hoar frost.

   Synonym: killing frost

2. (chiefly nautical) A mist of very cold droplets that freeze upon impact and coat objects (such as parts of a ship) with ice, potentially causing a ship to capsize.
   • 1955, World Fishing‎, IPC Industrial Press, →LCCN, →OCLC, page 106:

     The question was raised because of the trawlers of the lost Hull trawlers Lorella and Roderigo, which, it has been suggested, were not adequately warned of the freak black frost conditions by shore-based radio stations.

   • 1962, Jeremy Tunstall, The Fishermen‎, MacGibbon & Kee, →ISBN, →LCCN, →OCLC, page 97:

     ‘Black Frost is like a dense mist and when it lifts it leaves ice all over the ship the ropes round the masts are sometimes 1½ feet in diameter. When black frost hits a ship men are allowed to drink rum by the bottle to keep themselves warm.’

   • 1970, The Marine Observer. Published by the Authority of the Meteorological Committee, Air Ministry, London. The Review of the Marine Division in Cooperation with Voluntary Marine Observers‎, page 29:

     The air temperature is most important and a sudden drop may well indicate imminent icing conditions. This drop is often made obvious by the formation of Arctic frost-smoke fog , or ‘black frost’ as it is known by fishermen. It occurs quite frequently in these waters when a sea-air temperature difference exceeds 10 degC and is regarded by fishermen with some apprehension, but there seems little justification for this unless the portent of icing conditions developing is the reason.

   • 2009 June 30, Ernest Cleveland, Trawlers and Trawler Folk‎, Pneuma Springs Publishing, →ISBN, →OCLC, page 100:

     The dreaded black frost, that penetrated into every part of ones body and the ship, that enveloped everything, spread a thick coating of ice on rigging, stays and all it embraced, running up the masts, surmounting the superstructure and even the very clothes we wore.

   • 2011 June 30, Katie Flynn, Liverpool Taffy: Family Saga‎, Random House, →ISBN, →OCLC, page 175:

     The ship was iced up worse than Dai had ever known it and a heavy swell was running, so when the black frost began to rise from the water everyone had been too busy to notice it. You can't see black frost, but you can feel it; it is black frost which causes each breath you take to include tiny particles of ice, and ice in the lungs can kill a man.