TiggerToo
Well-known member
what's the difference?
cyclonic vs variable
- Thread starter TiggerToo
- Start date
D
Deleted member 36384
Guest
Cyclonic indicates that there will be considerable change in wind direction across the path of a depression within the forecast area. I have always associated this with the centre of the low passing over my area, for example.
Variable is a change in direction not associated with the path of a depression e.g. in a coll or centre of high pressure area.
Variable is a change in direction not associated with the path of a depression e.g. in a coll or centre of high pressure area.
oldharry
Well-known member
Cyclonic means the winds will shift in a predictable pattern, If the depression is passing north of you it will usually back towards the east or SE then veering maybe right round to NW in the forecast period as a depression passes through. Exact wind changes will depend on where you are in relation to the centre of the dperssion. If the depression is passing south of you then the above trends will be reversed with the winds backing from a S or SE quarter round the through E to N and then to NW. Wind speeds can pick up to full gale or worse with cyclonic winds, particularly locally within a forecast area.
Variable simply means there will be periods of breeze of random directions - rarely more than F3 or so, though there can be occasional local exceptions particularly in mountainous regions.
Variable simply means there will be periods of breeze of random directions - rarely more than F3 or so, though there can be occasional local exceptions particularly in mountainous regions.
TiggerToo
Well-known member
so cyclonic will be variable, but not all variable are cyclonic?
D
Deleted member 36384
Guest
Yes, but I would not assume that the wind will locally shift in a predictable way as old harry states. I would agree that the wind will settle into a predictable direction but at the time of cyclonic winds they could come from any direction.
Salty John
Active member
Cyclonic winds follow the predictable pattern of anticlockwise circulation around a low in the northern hemisphere. If you know where the centre of the low is you can predict the pattern of wind direction change as the low moves past you.
Variable wind is just that - variable, not following a predictable cyclonic pattern.
Variable wind is just that - variable, not following a predictable cyclonic pattern.
Skysail
Well-known member
Variable winds can happen between a High and a Low when the winds oppose one another.
VO5
New member
Cyclonic means anticlockwise circulation of air around an area of low pressure
(the opposite in the Southern hemisphere). There is the additional implication that winds may be steady, although obviously this is not always the case.
Variable means the wind is expected to wander in different directions and additionally, again, it is implied that wind strengths may vary.
(the opposite in the Southern hemisphere). There is the additional implication that winds may be steady, although obviously this is not always the case.
Variable means the wind is expected to wander in different directions and additionally, again, it is implied that wind strengths may vary.
Yes but you have not understood the underlying issue if that is your final take-away.
Variable does not = vary.
Vary can imply change in a consistent pattern, which is what happens when the weather forecast says "cyclonic".
D
Deleted member 36384
Guest
The OP is referring to the term as used in the UK Shipping Forecast which has a special meaning as opposed to the definition of a cyclonic wind direction with regards to low pressure. The definition I gave in my first response is almost verbatim from the Met Office.
The key point in the shipping forcast is that the direction of wind will be irregular due to the centre of a depression passing overhead (or nearby) and as such one can predict how the wind will settle down as the centre of the depression tracks relative to your location.
I have always understood variable to mean that the direction is variable i.e. a constant direction can not be predicted based on the position of high and low pressure relative to the forecast area.
The key point in the shipping forcast is that the direction of wind will be irregular due to the centre of a depression passing overhead (or nearby) and as such one can predict how the wind will settle down as the centre of the depression tracks relative to your location.
I have always understood variable to mean that the direction is variable i.e. a constant direction can not be predicted based on the position of high and low pressure relative to the forecast area.
sailor211
Active member
+1 QUOTE=BlowingOldBoots;3375164]The OP is referring to the term as used in the UK Shipping Forecast which has a special meaning as opposed to the definition of a cyclonic wind direction with regards to low pressure. The definition I gave in my first response is almost verbatim from the Met Office.
The key point in the shipping forcast is that the direction of wind will be irregular due to the centre of a depression passing overhead (or nearby) and as such one can predict how the wind will settle down as the centre of the depression tracks relative to your location.
I have always understood variable to mean that the direction is variable i.e. a constant direction can not be predicted based on the position of high and low pressure relative to the forecast area.[/QUOTE]
The key point in the shipping forcast is that the direction of wind will be irregular due to the centre of a depression passing overhead (or nearby) and as such one can predict how the wind will settle down as the centre of the depression tracks relative to your location.
I have always understood variable to mean that the direction is variable i.e. a constant direction can not be predicted based on the position of high and low pressure relative to the forecast area.[/QUOTE]
snowleopard
Active member
In short, 'variable' means they don't know.
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