Talk:Helm Wind

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A photo to illustrate the dramatic cloud formation of the Helm Bar would add to the value of this article.
I would put a photo of its "Mallerstang little brother" here, but one of the Bar over Cross Fell should have priority. (The photo taken from Appleby would be fine - and if this was taken by the anonymous 81.158.33.108 who added the link, perhaps he/she might think of uploading the image)? John Hamilton (talk) 13:09, 20 November 2007 (UTC)

Apart from some minor grammatical tinkering recently by the anonymous 88.104.215.121, there has been no important addition/modification for over a year. So, as there was no response to my comment, above, I added my photo of the Mallerstang branch of this phenomenon. Come on, surely someone has a suitable illustration of the "main" helm bar over Cross Fell? John Hamilton (talk) 12:30, 18 January 2009 (UTC)

Cross Fell

The Cross fell article links here, but has an extensive discussion of the wind - which I have moved here:

The Helm Wind is a local phenomenon. An east wind causes air to rise slowly to the summit of the ridge and cool as it does so. At the summit, the dense, cool air drops rapidly down the steep western slope (causing the Helm Wind) and forces warmer ambient air to rise. Moisture in the ambient air condenses to form the Helm Bar – a stationary handle of thin cloud running along and outwards from the edge of the summit (see Picture Gallery below). The Helm Wind can be very strong where it is channelled down gullies in the side of the escarpment. It is experienced particularly in the villages of Milburn and Kirkland.<ref>The Helm Bar: [http://www.dufton.org.uk/the_helm_bar.htm an account]</ref> A Helm Wind also occurs at the head of the Eden Valley, in Mallerstang. A similar feature can be found around Table Mountain near Cape Town, South Africa, where the local equivalent of the Helm Bar is known as the Table Cloth.

Sf5xeplus (talk) 23:42, 7 January 2011 (UTC)

It looks like you have done some good work in pruning "Cross Fell". If you are happy about the description of Helm wind that had been there, and which you have moved to this talk page, I would encourage you to incorporate it (or an edited form) into this article. Feline Hymnic (talk) 12:09, 8 January 2011 (UTC)

Explanation

I have imported some text from the fohn wind article which helps explain the phenomena, although one editor doesn't seem to appreciate the importance of explanation in this article. If he dislikes some parts then he can edit down or modify accordingly. Peterlewis (talk) 20:02, 28 July 2011 (UTC)

My objection is not to the inclusion of a brief explanation of what the fohn is, but the inclusion of information about its effects in other parts of the world than Cumbria. There are two sentences that I have a problem with. "Föhn winds can raise temperatures by as much as 30 °C (54 °F) in just a matter of hours." That could be seriously misleading in the context of this article. Such a rise in temperature has been known in the lee of the Rockies, but nothing even close to that magnitude has ever been observed with the Helm Wind. "Central Europe enjoys a warmer climate due to the Föhn, as moist winds off the Mediterranean Sea blow over the Alps." What happens in Central Europe is totally irrelevant for this article, as well as I believe being an exaggeration (though I'm not an expert on the climate of that region, I believe the fohn typically affects a fairly small region and blows for only a few days a year). The Pennines just aren't high enough to produce effects on the same order as those in the lee of Rockies and the Alps. The article already gives a perfectly adequate description of the Fohn without those two sentences, and anybody wanting further information only has to click on the link to the Fohn article. JH (talk page) 21:20, 28 July 2011 (UTC)

On further reflection, I'm not sure that the wind should be described as a fohn at all, since the air on an easterly wind would rarely be moist enough for the relatively modest altitude of the Pennines to cause enough uplift to induce rainfall near the summit and hence the air to be drier on its descent on the far side. JH (talk page) 08:15, 18 August 2011 (UTC)

So what is the Helm wind exactly? Nothing more than a normal easterly wind that produces a couple of interesting cloud effects? — Preceding unsigned comment added by 213.86.253.67 (talk) 15:31, 12 December 2016 (UTC)

Pretty much, I think, though I'm no expert. I think the interaction of the wind with the local topography, as well as producing the Helm Bar, can also make the wind rather stronger. JH (talk page) 16:28, 12 December 2016 (UTC)

Makes sense. My semi-educated guess is that the rising, warmed air which produces the Helm bar creates a partial vacuum in the valley, which pulls the air down off the fells, increasing the strength of the wind. Like you I am no expert.

Not a foehn

After further reflection (see section above) I don't think that the Helm Wind can be properly classed as a foehn, so have edited the article accordingly. The ridge over which the wind flows isn't high enough, and the air (coming from the east) is rarely moist enough, for the uplift to cause substantial precipitation over the high ground, something that's necessary for the foehn effect to occur. I'm not aware of any measurements showing an increase in temperature on the lee side compared to somewhere at a similar height on the upwind side. (Unlike in some coastal places in north Wales, where a foehn effect of a few degrees has been shown occasionally to occur when a southerly blows over Snowdonia.) However if there's a meteorology book or paper that can be cited to say that I'm wrong, then I will of course withdraw my objection. JH (talk page) 19:17, 8 November 2011 (UTC)

Which cloud is the Helm Bar?

I'm not sure that the description of the Helm Bar as "a line of clouds over the fells" is correct. The article below (cited in this article) describes the Helm Bar as the long, narrow cloud that forms over the valley bottom. The parallel cloud that forms over the fells is the Helm Cloud: you are 100% correct. I have attempted to get it corrected but person who wrote original page wont accept this as fact. Or admit his page is wrong. http://www.weatheronline.co.uk/reports/wind/The-Helm-Wind.htm — Preceding unsigned comment added by 213.86.253.67 (talk) 11:16, 13 December 2016 (UTC)