yashicamat
Part-timer
Reged: 02/03/2003
Posts: 4208
Loc: Cheshire, UK
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. . . I wish it'd go away, I've got all this velvia and loaded up the Hassy, but with all this haze it's no good for landscapes. 
Does anyone know any meteorological secrets for predicting when clear weather (blues skies, good visibility etc.) are most likely? I'm guessing it's to do with dust in the upper atmosphere, which I presume is in turn due to desert areas which wind has picked up sand from?
Thanks. 
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Rob BSRIPN
if something's not worth doing, it's worth forgetting about
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beejaybee
Marvin
Reged: 18/07/2007
Posts: 4980
Loc: Really Here In Name Only
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Quote:
Does anyone know any meteorological secrets for predicting when clear weather (blues skies, good visibility etc.) are most likely?
Secrets, no, but a cold front moving through means transparent skies & good visibility following. Maybe showers too, the light to medium sort rather than nasty thundery ones, especially if near a windward coast.
I think you'll find most of the "haze" is industrial pollution from the Continent. Certainly in the UK the transparency tends to be much better when the wind is from the North or North West than when it is from the South or South East.
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frank1
addict
Reged: 14/06/2005
Posts: 628
Loc: the big smoke islington
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You can get filters for this but not on the nhs 
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NorthernMonkey
enthusiast
Reged: 01/05/2007
Posts: 271
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You'll need to learn to read a synoptic met chart. It's not very hard, but even the BBC have dumbed down their weather forecast to exclude them now
Foretunately, they are available on the internet here http://www.mwis.org.uk/synoptic.php or if you hunt around on the met office site.
Generally, the weather after a cold front (the lines with triangles rather than semi-circles) will give white fluffy clouds, and good visibility, but can also bring heavy showers at time.
The Taf for an airfield nearby will also give you the horizontal visibility, up to a maximum of 10km, for the next 24 hrs, but aren't ver user friendly to read.
EG, Newcastle is available here
http://en.allmetsat.com/metar-taf/united-kingdom-ireland.php?icao=EGNT
the TAF (forecast) says
EGNT 120431Z 121212 07010KT 8000 FEW006 PROB30 1218 4000 BR BKN006 BECMG 1821 0400 FG BKN000 PROB30 2107 5000 HZ NSC BECMG 0710 CAVOK
the numbers 8000 means 8000m vis, Prob30 4000 BR is 30% probability 4000m in mist, becoming, between 1800, and 2100 this evening (GMT time, not local) 0400m in fog, and between 2100 and 0700 tomorrow, 5000m vis in haze, between 07 and 10 tomorrow CAVOK (cloud and visibility OK) so no clouds below 5000ft, and vis >10k
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yashicamat
Part-timer
Reged: 02/03/2003
Posts: 4208
Loc: Cheshire, UK
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Thanks for the replies.
Yeah now you mention it they have removed that aspect from the forcasts! I can remember my geography A-level when it came to weather charts, but I was wondering if there was more to it. Bring on the cold fronts!
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Rob BSRIPN
if something's not worth doing, it's worth forgetting about
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NorthernMonkey
enthusiast
Reged: 01/05/2007
Posts: 271
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Visibility is more connected with atmospheric stability. A very stable atmosphere causes the haze to be trapped down low. Instability causes the rubbish in the air to be sucked up, and deposited, by rain somwewhere.
Generally, the air following a cold front will be less stable, and the air in an area of high pressure (like this weekend) will be more stable. So post-cold front is your best bet for clear weather.
ELR, or environmental lapse rate is the measure of temperature change over height, measured in C/1000ft (nice metric/imperial combination ), and is available on the met office website if you care to hunt for long enough.
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Benchmark
Is it safe?
Reged: 12/07/2005
Posts: 3034
Loc: Sedgefield, Co Durham
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Quote:
Thanks for the replies.
Yeah now you mention it they have removed that aspect from the forcasts! I can remember my geography A-level when it came to weather charts, but I was wondering if there was more to it. Bring on the cold fronts!
We also have a slightly different problem here on the north east coast. Wind from the east or north east is usually cool (or b***** cold), but often incredibly clear. However, at this time of the year we often suffer with 'sea fret', caused by a combination of warm, moist air from the land meeting the very cold water of the North Sea.
We have had thick fog here for the past few mornings, and very hazy sunshine during the day; but ten miles further inland it is hot, dry and very clear.
I am sure someone here will be able to provide a better meteorological explanation.
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Nigel CRIPN and Bar
Beware of the Dark Slide
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yashicamat
Part-timer
Reged: 02/03/2003
Posts: 4208
Loc: Cheshire, UK
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Quote:
Quote:
Thanks for the replies.
Yeah now you mention it they have removed that aspect from the forcasts! I can remember my geography A-level when it came to weather charts, but I was wondering if there was more to it. Bring on the cold fronts!
We also have a slightly different problem here on the north east coast. Wind from the east or north east is usually cool (or b***** cold), but often incredibly clear. However, at this time of the year we often suffer with 'sea fret', caused by a combination of warm, moist air from the land meeting the very cold water of the North Sea.
We have had thick fog here for the past few mornings, and very hazy sunshine during the day; but ten miles further inland it is hot, dry and very clear.
I am sure someone here will be able to provide a better meteorological explanation.
So if it's clear as it approaches you but it's filthy by the time it gets here (on an Easterly) then it must be you lot that are making it mucky! 
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Rob BSRIPN
if something's not worth doing, it's worth forgetting about
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Benchmark
Is it safe?
Reged: 12/07/2005
Posts: 3034
Loc: Sedgefield, Co Durham
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Quote:
Quote:
Quote:
Thanks for the replies.
Yeah now you mention it they have removed that aspect from the forcasts! I can remember my geography A-level when it came to weather charts, but I was wondering if there was more to it. Bring on the cold fronts!
We also have a slightly different problem here on the north east coast. Wind from the east or north east is usually cool (or b***** cold), but often incredibly clear. However, at this time of the year we often suffer with 'sea fret', caused by a combination of warm, moist air from the land meeting the very cold water of the North Sea.
We have had thick fog here for the past few mornings, and very hazy sunshine during the day; but ten miles further inland it is hot, dry and very clear.
I am sure someone here will be able to provide a better meteorological explanation.
So if it's clear as it approaches you but it's filthy by the time it gets here (on an Easterly) then it must be you lot that are making it mucky!
That must be the meteorological explanation I was grasping for.
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Nigel CRIPN and Bar
Beware of the Dark Slide
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yashicamat
Part-timer
Reged: 02/03/2003
Posts: 4208
Loc: Cheshire, UK
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Quote:
That must be the meteorological explanation I was grasping for.
Yep! 
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Rob BSRIPN
if something's not worth doing, it's worth forgetting about
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Benchista
Wich Tyler
Reged: 11/08/2000
Posts: 37886
Loc: Everywhere and nowhere, baby
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Quote:
Quote:
Thanks for the replies.
Yeah now you mention it they have removed that aspect from the forcasts! I can remember my geography A-level when it came to weather charts, but I was wondering if there was more to it. Bring on the cold fronts!
We also have a slightly different problem here on the north east coast. Wind from the east or north east is usually cool (or b***** cold), but often incredibly clear. However, at this time of the year we often suffer with 'sea fret', caused by a combination of warm, moist air from the land meeting the very cold water of the North Sea.
We have had thick fog here for the past few mornings, and very hazy sunshine during the day; but ten miles further inland it is hot, dry and very clear.
I am sure someone here will be able to provide a better meteorological explanation.
Or a Haar, as Morten Harket probably wouldn't say. As I understand it, your explanation is spot on. Many's the time as a kid we would set out on the seemingly endless journey to the coast only to be met by a sea fret somewhere around Fylingdales Moor. I had almost forgotten the phenomenon until we moved to Edinburgh and encountered the haar.
Still, it's been glorious here for days - no sign of haze. 
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Nick
www.nbrphoto.com
Light and Shade II - the new blog
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