Tugmistress
25-Jan-09, 21:12
ok, as suggested by kas, how i try to get a forecast for temp/rain and wind.
this'll look scary at first glance but it's not, if you followed the last thread this'll be a doddle ! (the pics on the old thread i have deleted but the whole thing is available on my site here (http://www.tugmistress.co.uk/index.php?option=com_content&task=view&id=37&Itemid=54) if you want to recap)
i use 3 charts for this, the wind taken from the '500' charts, the temp taken from the '850' charts and the rain/cloud cover taken from the '500 - 1000' charts.
i'll post these in that order so you can see (hopefully) my train of thought.
Wind
http://community.dcmag.co.uk/photos/tugmistresss_gallery/images/946513/original.aspx
Temp
http://community.dcmag.co.uk/photos/tugmistresss_gallery/images/946514/original.aspx
Cloud
http://community.dcmag.co.uk/photos/tugmistresss_gallery/images/946515/original.aspx
ok to start find our location on the map for wind, we are between the 1010mb and 1015mb isobars..... the gap is quite large so probably around 10mph winds (sustained) maybe the odd gust to around 15mph.... the direction of the wind? remember i said around a low the wind travels anti-clockwise and around a high clockwise? well this chart is a good one for you to look for which it is ..... the wind will always travel between isobars so it's either going to be southerly or northerly, which do you think it is? and how did you come to that conclusion? i'll edit this post tomorrow and give the answer, but if you want to have an educated guess then feel free to either pm me or post on here.... and i'll explain why too.
on to the temp....
first things first search for our location again lol.
you'll see a scale on the right of the chart - i don't use this i find it doesn't really tally with my thoughts lol.
we are in the yellow - yay- warmer than now! lol anyhow ....
there is a solid black line that separates the colours green from yellow, this line is 0c, the lines then turned dotted, the next one in to the green is -5c and the next one in to the yellow/orange range is the +5c - these are NOT temps on the ground but the temperature of the air at whatever height it is (not sure as don't need to know lol).
if you split the gaps down between the 0c line and the +5c line that we are located in, i would guess we are at about +0.5c on this chart. i have found that dependant on cloud cover a generalisation of add on 7-8c for daylight which is what we are dealing with as we are looking at noon next saturday 31st jan) will give the surface temp around here. we don't have any drastic geological features such as high mountains or deep valleys that will fluctuate and need a different way of working, i find this works for me in most forecasts i have been asked by various people to do.... now you see why i added a third chart of cloud cover!
cloud cover on this chart is easy to work out, white is cloud, black is clear skies lol. you can see that above us there is the faintest of cloud cover, so it should be fairly bright next saturday lunch with this high cloud that the sun should be able to shine through. the more cloud cover during the day, the less the sun will heat up the atmosphere, the less cloud cover the more it will heat up.... so looking at this i would add the 8c to the +0.5c 'area' that we are in from the previous chart, so temp at noon on 31st jan should be around 9c.
ok, any takers for the question posed? what direction will the wind be on this chart for caithness? and how did you come to that conclusion?
answer will be posted here tomorrow.
this'll look scary at first glance but it's not, if you followed the last thread this'll be a doddle ! (the pics on the old thread i have deleted but the whole thing is available on my site here (http://www.tugmistress.co.uk/index.php?option=com_content&task=view&id=37&Itemid=54) if you want to recap)
i use 3 charts for this, the wind taken from the '500' charts, the temp taken from the '850' charts and the rain/cloud cover taken from the '500 - 1000' charts.
i'll post these in that order so you can see (hopefully) my train of thought.
Wind
http://community.dcmag.co.uk/photos/tugmistresss_gallery/images/946513/original.aspx
Temp
http://community.dcmag.co.uk/photos/tugmistresss_gallery/images/946514/original.aspx
Cloud
http://community.dcmag.co.uk/photos/tugmistresss_gallery/images/946515/original.aspx
ok to start find our location on the map for wind, we are between the 1010mb and 1015mb isobars..... the gap is quite large so probably around 10mph winds (sustained) maybe the odd gust to around 15mph.... the direction of the wind? remember i said around a low the wind travels anti-clockwise and around a high clockwise? well this chart is a good one for you to look for which it is ..... the wind will always travel between isobars so it's either going to be southerly or northerly, which do you think it is? and how did you come to that conclusion? i'll edit this post tomorrow and give the answer, but if you want to have an educated guess then feel free to either pm me or post on here.... and i'll explain why too.
on to the temp....
first things first search for our location again lol.
you'll see a scale on the right of the chart - i don't use this i find it doesn't really tally with my thoughts lol.
we are in the yellow - yay- warmer than now! lol anyhow ....
there is a solid black line that separates the colours green from yellow, this line is 0c, the lines then turned dotted, the next one in to the green is -5c and the next one in to the yellow/orange range is the +5c - these are NOT temps on the ground but the temperature of the air at whatever height it is (not sure as don't need to know lol).
if you split the gaps down between the 0c line and the +5c line that we are located in, i would guess we are at about +0.5c on this chart. i have found that dependant on cloud cover a generalisation of add on 7-8c for daylight which is what we are dealing with as we are looking at noon next saturday 31st jan) will give the surface temp around here. we don't have any drastic geological features such as high mountains or deep valleys that will fluctuate and need a different way of working, i find this works for me in most forecasts i have been asked by various people to do.... now you see why i added a third chart of cloud cover!
cloud cover on this chart is easy to work out, white is cloud, black is clear skies lol. you can see that above us there is the faintest of cloud cover, so it should be fairly bright next saturday lunch with this high cloud that the sun should be able to shine through. the more cloud cover during the day, the less the sun will heat up the atmosphere, the less cloud cover the more it will heat up.... so looking at this i would add the 8c to the +0.5c 'area' that we are in from the previous chart, so temp at noon on 31st jan should be around 9c.
ok, any takers for the question posed? what direction will the wind be on this chart for caithness? and how did you come to that conclusion?
answer will be posted here tomorrow.