Pressure Nomenclature

[rob-lancs]

Very posh wysiwyg editor.

Anyway, are there specific names for a pressure system, specifically low although I assume it'll just be adding cyclone to the end, when the isobars surround the low pressure or when it doesn't. Not sure if that makes sense but I've a chart in front of me with your typical cold and warm fronts with an L where the fronts meet and was wondering if there's a scientific word for this type of low and if so are their any other words for other types of low?

Edited December 6, 2006 by rob-lancs

[rob-lancs]

Maybe it's not clear.

There's a low pressure at 991 to the east of Greenland, the isobars don't particularly surround it as High pressure is dominating to the west of spain.

South of the low is a trough which leads to another low between 1000 and 1004. This has the warm and cold fronts, is it possible two name these different types of low?

http://www.wetterzentrale.de/archive/1999/...cka19990716.gif

This is six hours before on the METO chart. Maybe it's just the way the yanks interpreted it?

[Nick F]

Very posh wysiwyg editor.

Anyway, are there specific names for a pressure system, specifically low although I assume it'll just be adding anticyclone to the end, when the isobars surround the low pressure or when it doesn't.

Bit lost in what you are trying to fathom, but a low is a cyclone and a high an anticyclone - other words I can think of for lows are depressions, troughs or for a high: ridge.

Atlantic depressions normally start off as a wave in a frontal boundary between tropical maritime air and polar maritime air, with awarm sector developing as warm air tries to move North and cold air South, eventually the cold front catches up the warm front, as it moves faster, and the warm air is lifted to form an occlusion towarfds the centre of the low. Finally the cold fron catches upp the whole of the warm front and all is left is an occlusion around the low which has reached a mature life stage and it has already began to 'fill' and isobars slacken. There are lows that don't form this way, such as thundery or 'heat' lows that form over Europe during the summer and don't intially have fronts but may develop them, also polar lows which form when a cold pool crossing off an ice or snow field in the Arctic circle moves over 'warmer' seas and causes strong convection and eventually a tight low pressure circulation.

[rob-lancs]

Nick managed to edit my schoolboy error. I've found some sort of chart and tried to explain it again above.

[rob-lancs]

Does this help?

[Somerset Squall]

I'm still not entirely sure what you mean but could you be talking about a secondary low/depression?

[rob-lancs]

Secondary low could be a way of describing it I suppose.