Why is the 540 isopleth significant on a 1000-500 thickness chart?

On Aug 16, 3:41*pm, wrote:
Why is the 540 isopleth significant on a 1000-500 thickness chart?

Thickness below 540 generally indicates a zero percent chance of
frozen precipitation (i.e. snow) so that is pretty significant.

On Aug 19, 8:11*am, A1C Watkins wrote:
On Aug 16, 3:41*pm, wrote:

Why is the 540 isopleth significant on a 1000-500 thickness chart?

Thickness below 540 generally indicates a zero percent chance of
frozen precipitation (i.e. snow) so that is pretty significant.

The dartboard shown in such charts indicate heights I take it. Thus
the dots joined are for pressures on one plane and heights on the
other so (not counting my own) what does thickness mean?

Almost. Your on the right track. Thickness below 540 means the air
column IS cold enough to support frozen precipitation such as snow.
The 540 isopleth on a 1000-500 mb chart is considered the "snow line".
As the value decreases, the colder the air.

On Tue, 19 Aug 2008 00:11:06 -0700 (PDT), A1C Watkins
wrote:

On Aug 16, 3:41*pm, wrote:
Why is the 540 isopleth significant on a 1000-500 thickness chart?

Thickness below 540 generally indicates a zero percent chance of
frozen precipitation (i.e. snow) so that is pretty significant.

The thickness is measured in decameters between 1000mb and 500mb.
Cold air decreases the thickness layer because it is more dense. Warm
air increases the thickness layer because of less density.

On Tue, 19 Aug 2008 15:58:34 -0700 (PDT), Weatherlawyer
wrote:

On Aug 19, 8:11*am, A1C Watkins wrote:
On Aug 16, 3:41*pm, wrote:

Why is the 540 isopleth significant on a 1000-500 thickness chart?

Thickness below 540 generally indicates a zero percent chance of
frozen precipitation (i.e. snow) so that is pretty significant.

The dartboard shown in such charts indicate heights I take it. Thus
the dots joined are for pressures on one plane and heights on the
other so (not counting my own) what does thickness mean?

On Aug 24, 2:54*am, wrote:
Almost. *Your on the right track. *Thickness below 540 means the air
column IS cold enough to support frozen precipitation such as snow.
The 540 isopleth on a 1000-500 mb chart is considered the "snow line".
As the value decreases, the colder the air.

On Tue, 19 Aug 2008 00:11:06 -0700 (PDT), A1C Watkins

wrote:
On Aug 16, 3:41*pm, wrote:
Why is the 540 isopleth significant on a 1000-500 thickness chart?

Thickness below 540 generally indicates a zero percent chance of
frozen precipitation (i.e. snow) so that is pretty significant.

If you knew the fookin answer, what did you ask the fookin question
for?

On Sun, 24 Aug 2008 11:15:07 -0700 (PDT), Weatherlawyer
wrote:

Is this not a discussion group? Asking a question opens the door for
discussion. A1C Watkins responded. Although on the right track, was
going in the wrong direction. Watkins might just learn something
about the weather.

For the sake of discussing the weather, I take no shame in asking
questions I may or may not know the answer to.



If you knew the fookin answer, what did you ask the fookin question
for?

On Aug 25, 5:58*am, wrote:

For the sake of discussing the weather, I take no shame in asking
questions I may or may not know the answer to.

You wouldn't happen to be a troll called Dawlish perchance?

If or if not so, here is something you may or may not like answers to
or know or not know the answers to:

http://en.wikipedia.org/wiki/Von_K%C..._vortex_street

Stuff on there about the fish-tail way that fluids behave when an
obstruction causes pressure changes in the fluidity of said fluid.

For the uninitiated:
It's not so much the knock-on effect of the fluid going around the
obstacle as in for example wind flowing in a stream in which a
telegraph pole has been inserted. It is more the knock on effect that
the pressure changes introduce.

The molecules hit the barrier and dam up. The dam bursts and a drop in
pressure takes place.

Physical deformities are introduced and physical changes take place in
the stream. If it is air heavily laden with water at the dew-point,
for example, precipitation may occur.
/for the uninitiated.

Is this a form of channeling or is it more likely to be the end
product of channeling?

Do you know enough about fluid mechanics to comment on whether the so
called dimensionless numbers used in it, resemble the articulation of
shapes in trigonometry?

For the uninitiated:
One such number is taken on by the above phenomenon to dictate the
windspeeds / wire length temperature deformations and air pressures
required to make telegraph wires "sing".

It obviously varies with wind speed and the lengths of the wires
between poles.

But also obviously varies with the mass of the wire and the tension of
it as well as the mass of the air at any particular time.
/for the uninitiated.

On Aug 26, 10:55Â*am, Weatherlawyer wrote:
On Aug 25, 5:58Â*am, wrote:



For the sake of discussing the weather, I take no shame in asking
questions I may or may not know the answer to.

You wouldn't happen to be a troll called Dawlish perchance?

If or if not so, here is something you may or may not like answers to
or know or not know the answers to:

http://en.wikipedia.org/wiki/Von_K%C..._vortex_street

Stuff on there about the fish-tail way that fluids behave when an
obstruction causes pressure changes in the fluidity of said fluid.

For the uninitiated:
It's not so much the knock-on effect of the fluid going around the
obstacle as in for example wind flowing in a stream in which a
telegraph pole has been inserted. It is more the knock on effect that
the pressure changes introduce.

The molecules hit the barrier and dam up. The dam bursts and a drop in
pressure takes place.

Physical deformities are introduced and physical changes take place in
the stream. If it is air heavily laden with water at the dew-point,
for example, precipitation may occur.
/for the uninitiated.

Is this a form of channeling or is it more likely to be the end
product of channeling?

Do you know enough about fluid mechanics to comment on whether the so
called dimensionless numbers used in it, resemble the articulation of
shapes in trigonometry?

For the uninitiated:
One such number is taken on by the above phenomenon to dictate the
windspeeds / wire length temperature deformations and air pressures
required to make telegraph wires "sing".

It obviously varies with wind speed and the lengths of the wires
between poles.

But also obviously varies with the mass of the wire and the tension of
it as well as the mass of the air at any particular time.
/for the uninitiated.

Dimensionless numbers in fluid dynamics
Archimedes • Atwood • Bagnold • Biot • Bond • Brinkman • Capillary •
Cauchy • Damköhler • Dean • Deborah • Eckert • Ekman • Eötvös • Euler
• Froude • Galilei • Graetz • Grashof • ‎Görtler • Hagen • Knudsen •
Laplace • Lewis • Mach • Magnetic Reynolds • Marangoni • Morton •
Nusselt • Ohnesorge • Péclet • Prandtl • Rayleigh • Reynolds •
Richardson • Roshko • Rossby • Rouse • Ruark • Schmidt • Sherwood •
Stanton • Stokes • Strouhal • Suratman • Taylor • Weber • Weissenberg
• Womersley

http://en.wikipedia.org/wiki/Strouhal-Number

On Tue, 26 Aug 2008 02:55:16 -0700 (PDT), Weatherlawyer
wrote:

You wouldn't happen to be a troll called Dawlish perchance?

No. Why would you think I am a troll anyway. Should I be insulted?

If or if not so, here is something you may or may not like answers to
or know or not know the answers to:

http://en.wikipedia.org/wiki/Von_K%C..._vortex_street

Stuff on there about the fish-tail way that fluids behave when an
obstruction causes pressure changes in the fluidity of said fluid.

Thanks for the link, I found it interesing and informative too.

The molecules hit the barrier and dam up. The dam bursts and a drop in
pressure takes place.

Yup. pretty much why airplanes fly.



Physical deformities are introduced and physical changes take place in
the stream. If it is air heavily laden with water at the dew-point,
for example, precipitation may occur.

As the air pressure drops, adibatic cooling occures. If the parcel
being cooled containes sufficent moisture, clouds will form and
precipitation may occur.


Is this a form of channeling or is it more likely to be the end
product of channeling?

Yes and yes.


Do you know enough about fluid mechanics to comment on whether the so
called dimensionless numbers used in it, resemble the articulation of
shapes in trigonometry?

not really

For the uninitiated:
One such number is taken on by the above phenomenon to dictate the
windspeeds / wire length temperature deformations and air pressures
required to make telegraph wires "sing".

An at home expirement to illistrate what your saying is use a
rubberband and blow accross it. Streach it for a higher pitch etc.

Thanks for bringing up some interesting concepts.



It obviously varies with wind speed and the lengths of the wires
between poles.

But also obviously varies with the mass of the wire and the tension of
it as well as the mass of the air at any particular time.
/for the uninitiated.