"Rain and snow" redirects here. For the folk song, see Rain and Snow.
Rain and snow mixed (American English) or sleet (Commonwealth English) is precipitation composed of a mixture of rain and partially melted snow. Unlike ice pellets, which are hard, and freezing rain, which is fluid until striking an object where it fully freezes, this precipitation is soft and translucent, but it contains some traces of ice crystals from partially fused snowflakes, also called slush. In any one location, it usually occurs briefly as a transition phase from rain to snow or vice-versa, but hits the surface before fully transforming. Its METAR code is RASN or SNRA.[1]
This precipitation occurs when the temperature in the lowest part of the atmosphere is slightly above the freezing point of water (0 °C or 32 °F). The depth of low-level warm air (below the freezing level) needed to melt snow falling from above to rain varies from about 230–460 m (750–1,500 ft) and depends on the mass of the flakes and the lapse rate of the melting layer. Rain and snow typically mix when the melting layer depth falls between these values as rain starts forming when in that range.[4]
Rain-snow-mix soundings; left diagram shows typical skew-T appearance, while right diagram shows variations which result in mixtures of rain and snow
"Wintry showers" or "wintry mixes"edit
Wintry showers is a somewhat informal meteorological term, used primarily in the United Kingdom, to refer to various mixtures of rain, graupel and snow at once. Though no "official" criteria exist for the term, in the United Kingdom the term is not used when any significant accumulation of snow on the ground takes place. It is often used when the temperature of the ground surface is above 0 °C (32 °F), preventing accumulation from occurring even if the air temperature near the surface is marginally below 0 °C (32 °F); but even then, the falling precipitation must generally have something else other than exclusively snow.
In the United States, wintry mix generally refers to a mixture of freezing rain, ice pellets, and snow.[5] In contrast to the usage in the United Kingdom, in the United States it is usually used when both air and ground temperatures are below 0 °C (32 °F). Additionally, it is generally used when some surface accumulation of ice and snow is expected to occur. During winter, a wide area can be affected by the multiple mixed precipitation types typical of a wintry mix during a single winter storm, as counterclockwise winds around a storm system bring warm air northwards ahead of the system, and then bring cold air back southwards behind it. Most often, it is the region ahead of the approaching storm system which sees the wintry mix, as warm air moves northward and above retreating cold air in a warm front, causing snow to change into ice pellets, freezing rain and finally rain. The reverse transition can occur behind the departing low-pressure system, though it is more common for precipitation to freeze directly from rain to snow, or for it to stop before a transition back.
^. Lexico Dictionaries - English. Archived from the original on August 15, 2019.
External linksedit
January 19, 2024
rain, snow, mixed, rain, snow, redirects, here, folk, song, rain, snow, american, english, sleet, commonwealth, english, precipitation, composed, mixture, rain, partially, melted, snow, unlike, pellets, which, hard, freezing, rain, which, fluid, until, strikin. Rain and snow redirects here For the folk song see Rain and Snow Rain and snow mixed American English or sleet Commonwealth English is precipitation composed of a mixture of rain and partially melted snow Unlike ice pellets which are hard and freezing rain which is fluid until striking an object where it fully freezes this precipitation is soft and translucent but it contains some traces of ice crystals from partially fused snowflakes also called slush In any one location it usually occurs briefly as a transition phase from rain to snow or vice versa but hits the surface before fully transforming Its METAR code is RASN or SNRA 1 Contents 1 Terminology 2 Formation 3 Wintry showers or wintry mixes 4 See also 5 References 6 External linksTerminology editThis precipitation type is commonly known as sleet in most Commonwealth countries 2 However the United States National Weather Service uses the term sleet to refer to ice pellets instead 3 Formation editThis precipitation occurs when the temperature in the lowest part of the atmosphere is slightly above the freezing point of water 0 C or 32 F The depth of low level warm air below the freezing level needed to melt snow falling from above to rain varies from about 230 460 m 750 1 500 ft and depends on the mass of the flakes and the lapse rate of the melting layer Rain and snow typically mix when the melting layer depth falls between these values as rain starts forming when in that range 4 nbsp Rain snow mix soundings left diagram shows typical skew T appearance while right diagram shows variations which result in mixtures of rain and snow Wintry showers or wintry mixes editWintry showers is a somewhat informal meteorological term used primarily in the United Kingdom to refer to various mixtures of rain graupel and snow at once Though no official criteria exist for the term in the United Kingdom the term is not used when any significant accumulation of snow on the ground takes place It is often used when the temperature of the ground surface is above 0 C 32 F preventing accumulation from occurring even if the air temperature near the surface is marginally below 0 C 32 F but even then the falling precipitation must generally have something else other than exclusively snow In the United States wintry mix generally refers to a mixture of freezing rain ice pellets and snow 5 In contrast to the usage in the United Kingdom in the United States it is usually used when both air and ground temperatures are below 0 C 32 F Additionally it is generally used when some surface accumulation of ice and snow is expected to occur During winter a wide area can be affected by the multiple mixed precipitation types typical of a wintry mix during a single winter storm as counterclockwise winds around a storm system bring warm air northwards ahead of the system and then bring cold air back southwards behind it Most often it is the region ahead of the approaching storm system which sees the wintry mix as warm air moves northward and above retreating cold air in a warm front causing snow to change into ice pellets freezing rain and finally rain The reverse transition can occur behind the departing low pressure system though it is more common for precipitation to freeze directly from rain to snow or for it to stop before a transition back See also editFreezing rain Ice pellets Sleet disambiguation Slush Winter weatherReferences edit Rain and snow mixed AMS Glossary Glossary ametsoc org 2012 01 26 Retrieved 2019 06 13 SLEET meaning in the Cambridge English Dictionary Dictionary cambridge org Retrieved 2019 06 13 Glossary NOAA s National Weather Service W1 weather gov 2009 06 25 Retrieved 2019 06 13 Crh noaa gov wintry mix Definition of wintry mix in English by Lexico Dictionaries Lexico Dictionaries English Archived from the original on August 15 2019 External links editAMS Glossary Retrieved from https en wikipedia org w index php title Rain and snow mixed amp oldid 1197211648, wikipedia, wiki, book, books, library,
