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A friend claimed that areas near lakes or the sea have less snow, a theory she heard on a visit to Lancaster, England, which is near the Lake District as well as the Irish Sea and so would feel the effect of this phenomenon.

I’ve reviewed the information I can find on lake-effect snow and everything I can find suggests the opposite. Is this a real phenomenon? Why does it happen?

David Kendal
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  • Confounding issue: Snow in built-up areas tends to be dirtier and melts faster. http://www.livescience.com/3223-soot-stained-snow-melts-sooner.html – Oddthinking Dec 29 '13 at 23:35
  • It's a complex question, definitely. Key is that lake/ocean-effect flow generally requires long distances of strong wind flow over water significantly warmer than the air (and thus require fairly big lakes/seas). LES is most common in the early part of winter. Cold bodies of water, like the Pacific Ocean in the US, can generally reduce snowfall... and later in winter, even the Great Lakes, as they cool/freeze, can be a small negative. There's all kinds of factors based upon specific storm dynamics. But you can dig through at least a bit of US data at https://www.nohrsc.noaa.gov/snowfall/ – JeopardyTempest Aug 06 '18 at 06:52
  • As to why, LES happens, the basic idea is that warm lake bodies evaporate a great deal of water into the cold air. And there is often convergence due to the differing surface roughness causing additional lift. Whereas I suppose cold water would tend to decrease instability which would hinder surface-based lift. – JeopardyTempest Aug 06 '18 at 06:57
  • More obviously, the sea is at sea level, and lakes will generally form in the local altitude minimum of the surrounding area, so moving inland / toward higher altitude will decrease temperature at a [lapse rate of between 4 and 10 celcius](https://en.wikipedia.org/wiki/Lapse_rate) per 1000m in altitude, thus increasing the chance of precipitation falling as snow. – StuartLC Jan 25 '21 at 21:23
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    Probably a better question for https://earthscience.stackexchange.com/ – LShaver May 14 '23 at 17:56
  • @Oddthinking - Not sure why that's a confounding factor. How quickly snow melts doesn't change how much of it falls in the first place. – PoloHoleSet May 15 '23 at 20:10
  • @PoloHoleSet: I guess you read "have less snow" mean "less snow falls" and I read it as "there is less depth of snow on the ground". The fact that there is no notable claim here is hurting us. – Oddthinking May 15 '23 at 20:30
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    @Oddthinking - having always lived around the Great Lakes in the USA, and always been impacted, regionally, by "lake effect," yes, I 100% view the impacts of bodies of water to be ones of direct, physical impacts (snowfall due to the physical effects of large bodies of water), and not secondary, societal impacts (population concentrating in those areas for assorted societal reasons). Good point about needing a more concrete claim to point to. – PoloHoleSet May 15 '23 at 20:39

1 Answers1

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Yes, they do have less snow

...because large bodies of water do affect the climate in its immediate surroundings.

Large bodies of water act as heat reservoirs in winter (and heat sinks in summer). This means that the onset of winter will be later in the year near a coast, because the heat from the water will raise the ambient air temperature.

Below is a map over Sweden, from the Swedish Meteorological and Hydrological Institute, showing the average date of when meteorological winter begins (source, in Swedish).

You can see that near the coasts, winter comes noticeably later. Also large lakes — Vänern, Vättern and Storsjön can be seen clearly — delay the onset of winter.

And you can also see where Norway and the Scandinavian Mountains "shields" large parts of western Sweden from the warm winds of the upper part of the Gulf Stream.

enter image description here

Mad Scientist
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