Which came first? The low pressure or the storm?
 

The chicken or the egg? :)

Which came first? The low pressure or the storm?

In simple terms, help a dummy understand if the low pressure causes the storm,
or is the low pressure a byproduct of the storm?

And why in the hell does the pressure rise and fall?

Thanks,
Joe

Which came first? The low pressure or the storm?
 

Joe wrote:
The chicken or the egg? :)

Which came first? The low pressure or the storm?

In simple terms, help a dummy understand if the low pressure causes the storm,
or is the low pressure a byproduct of the storm?

And why in the hell does the pressure rise and fall?

Why does one have to precede the other? Why can't they
co-evolve?

Pressure rises because air moves into a column. More
air in the column = more weight = higher pressure.

Scott

Which came first? The low pressure or the storm?
 

Joe wrote in message . ..
The chicken or the egg? :)

Which came first? The low pressure or the storm?

The high pressure, the warm one over the azores and the cold one above
Canada/Grenland

In simple terms, help a dummy understand if the low pressure causes the storm,
or is the low pressure a byproduct of the storm?

Most often a byproduct if it's an extratopical storm, cold air
travelling south want to go to the east and warm air travelling north
want to go to the west, therefore a low pressure will build west of
the cold air going south and east of the warm air going north. (The
special geography and winds around Iceland often cause a stationary
low that traps extratropical lows)

http://www.eoascientific.com/campus/...ew_interactive
http://www.westwind.ch/?page=gfsm (slp h500; 10m winds; 850 hpa)

- The most nasty winds is often the northerly winds east of the low
and right before/after the cold front south and west of the low.

And why in the hell does the pressure rise and fall?

Often extratropical lows and the high pressure ridges between those.

Thanks,
Joe

Helpful ?

Which came first? The low pressure or the storm?
 

"Joe" wrote in message
...
The chicken or the egg? :)

Which came first? The low pressure or the storm?

In simple terms, help a dummy understand if the low pressure causes the
storm,
or is the low pressure a byproduct of the storm?

And why in the hell does the pressure rise and fall?

Thanks,
Joe


OK, I'm thinking I'm back in front of my 8th. grade Earth Science class
and a student has asked a question, actually several questions. Let's take
the second one first. When we refer to air pressure, we are referring to a
measure of the pressure/weight pushing down on the earth's surface of a
column of air extending from the surface of the earth to the top of the
atmosphere. On average the weight of a 1" square column of air is 14.7 lbs.
If that air is heated by the sun, it will become less dense and begin to
rise. Hence the weight of that rising column of air pushing down on the
earth's surface is less than it was before, producing a lower pressure. On
the other hand, if that column of air were to lose some heat energy, that is
cool down, it would become more dense/heavier and exert a higher pressure.

The second question is a little more difficult, but here goes. I would
suggest that the lower pressure precedes a storm at least in an observable
sense. When air is heated by the sun, it will expand and become less dense,
and rise. This will cause a lowering of the air pressure. Remember, air
pressure is a measure of the weight of air on the surface of the earth. Air
will begin to flow in from surrounding areas to replace the air that is
rising. A number of factors including the Coreolis Effect will eventually
cause the "low pressure area" to begin to develop a counter-clockwise motion
in the northern hemisphere.. This motion is similar to water flow down a
drain. At some point the characteristics of a "storm" will develop; clouds
and eventually precipitation. Hope this helps a bit.

Neil

Which came first? The low pressure or the storm?
 

Joe climbed onto an orange crate and shouted:

The chicken or the egg? :)

Which came first? The low pressure or the storm?

In simple terms, help a dummy understand if the low pressure causes the storm,
or is the low pressure a byproduct of the storm?

The low pressure *is* the storm. It doesn't make any sense to
disconnect the two.

And why in the hell does the pressure rise and fall?

If I knew a universal answer to that, I'd get the Rossby Medal.



--
"I am a whole-hearted believer in spreading the arts around. A lot
of people won't want them, but everywhere there will be some people,
all ages, 'naturals' I like to call them, to whom the discovery of
these arts will be like finding water in the desert. And if this
spreading around costs millions, then let it cost millions. It is
public money well spent, which is more than can be said about a great
deal of public money." -- J B Priestley

Which came first? The low pressure or the storm?
 

(O18-C-O16) wrote in message . com...
Joe wrote in message . ..
The chicken or the egg? :)

Which came first? The low pressure or the storm?

The high pressure, the warm one over the azores and the cold one above
Canada/Grenland

In simple terms, help a dummy understand if the low pressure causes the storm,
or is the low pressure a byproduct of the storm?

Most often a byproduct if it's an extratopical storm, cold air
travelling south want to go to the east and warm air travelling north
want to go to the west, therefore a low pressure will build EAST of
the cold air going south and WEST of the warm air going north. (The
special geography and winds around Iceland often cause a stationary
low that traps extratropical lows)

_East&west corrected, the southwesterly mild air side of a low is to
the East, the cold polar to the west_

There was an example of low pressure first, tropical storm Karl going
extratropical on the gfs forecast 06, check it out.
http://www.eoascientific.com/campus/...ew_interactive
http://www.westwind.ch/?page=gfsm (slp h500; 10m winds; 850 hpa)

- The most nasty winds is often the northerly winds east of the low
and right before/after the cold front south and west of the low.

And why in the hell does the pressure rise and fall?

Often extratropical lows and the high pressure ridges between those.

Thanks,
Joe

Helpful ?