Weather Banter - Low on Sunday

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- - Low on Sunday (https://www.weather-banter.co.uk/uk-sci-weather-uk-weather/143030-low-sunday.html)

Enough of this snow nonsense, how about some baroclinic instability
for a change.

http://picasaweb.google.com/richsdix...64946187771458

All of the (available) models coming in to line for a system for
Sunday. Credit it where it's due, this was signalled first by the GFS
on Sunday before any others - typically I wrote it off as the usual
GFS fantasy.

The direction is the interesting one for me - similar path to the
October Storm so no doubt some warm air locked into this one which can
only aid the potential for rapid cyclogenesis.

Richard

On 24 Feb, 11:10, Richard Dixon wrote:
Enough of this snow nonsense, how about some baroclinic instability
for a change.

http://picasaweb.google.com/richsdix...ation#54417649...

The direction is the interesting one for me - similar path to the
October Storm so no doubt some warm air locked into this one which can
only aid the potential for rapid cyclogenesis.

THE October storm

THE October STORM!!!!! do you mean? The OCTOBER one?????
The one in October like all the others that we not in the Home
Counties get?

And to think the Caledonians are the ones who wear skirts in the thick
of it. Maybe it is to assist -if not ease nature, when things get
hairy?

But what sort of pressures are you imagining?

(Bit tongue in cheek that last as precipitation hardly depends on
severe systems, does it.)

On 24 Feb, 11:33, Weatherlawyer wrote:

THE October storm

1987. Google it. If you're bleating about the SE-centric nature of
this storm it was severe one for any location in the UK. You don't see
120 mph gusts (Shoreham Airport) at low level very often.

But what sort of pressures are you imagining?

Sub 970-mb - but with windstorms typically it's the pressure gradient
that's more important. A tight 975mb system can potentially be more
damaging than a flabby, decaying 955mb low.

(Bit tongue in cheek that last as precipitation hardly depends on
severe systems, does it.)

Says who? The latent heat release will aid both precipitation release
and windstorm intensity in this case.

Richard

On 24 Feb, 11:10, Richard Dixon wrote:
Enough of this snow nonsense, how about some baroclinic instability
for a change.

http://picasaweb.google.com/richsdix...ation#54417649...

All of the (available) models coming in to line for a system for
Sunday. Credit it where it's due, this was signalled first by the GFS
on Sunday before any others - typically I wrote it off as the usual
GFS fantasy.

The direction is the interesting one for me - similar path to the
October Storm so no doubt some warm air locked into this one which can
only aid the potential for rapid cyclogenesis.

Richard

Also, of some concern, the highest astronomical tide for 2 years
occurs next Tuesday, high enough to give some overtopping of
harboursides under for ordinary conditions. Even on Sunday the tide is
very large, so if the pressure does drop as much as predicted there
could be some real problems.

The only good thing (as far as the coast of Cornwall is concerned) is
that the rapid development & movement of the low means the swell
shouldn't get too large. (It's not currently forecast to be that big).
It's when deep depressions move slowly north from Biscay you get the
really big (20-30') swells developing, but it will be rough. At the
moment Biscay and southern Brittany seem to be the main areas of risk.

Certainly one to watch.

Graham
Penzance Mild again Last nights min 7.6C.

On 24 Feb, 11:40, Richard Dixon wrote:
On 24 Feb, 11:33, Weatherlawyer wrote:

THE October storm

1987. Google it. If you're bleating about the SE-centric nature of
this storm it was severe one for any location in the UK. You don't see
120 mph gusts (Shoreham Airport) at low level very often.

But what sort of pressures are you imagining?

Sub 970-mb - but with wind-storms typically it's the pressure gradient
that's more important. A tight 975mb system can potentially be more
damaging than a flabby, decaying 955mb low.

(Bit tongue in cheek that last as precipitation hardly depends on
severe systems, does it.)

Says who?

I do. Read the headers.

The latent heat release will aid both precipitation release
and wind-storm intensity in this case.

Crap!
28th Feb: 16:38.
What am I supposed to do with that?

Wisely I beat a retreat.

Let's have a go then.

A lot of volcanic activity takes place with spells at 4 and 10 o'clock
or more especially just after. So that faction in the equation is a
difficulty that is ignored by computer runs.

And the ensuing garbage in garbage out difficulty presents itself. But
yes cyclogenesis is on the cards as it is 1 1/2 hours off 3/9d ones.

(That's the stalls for those who don't remember the price of a night
at the Plaza.)

Someone remind me of the year of that "most unusual" breeze so I can
look up the time of the phases please.

On 24 Feb, 12:02, Weatherlawyer wrote:

A lot of volcanic activity takes place with spells at 4 and 10 o'clock
or more especially just after. So that faction in the equation is a
difficulty that is ignored by computer runs.

And the ensuing garbage in garbage out difficulty presents itself. But
yes cyclogenesis is on the cards as it is 1 1/2 hours off 3/9d ones.

Translation please.

Someone remind me of the year of that "most unusual" breeze so I can
look up the time of the phases please.

I refer the quirky gentleman to my original reply.

Richard

On 24 Feb, 12:16, Richard Dixon wrote:
On 24 Feb, 12:02, Weatherlawyer wrote:

A lot of volcanic activity takes place with spells at 4 and 10 o'clock
or more especially just after. So that faction in the equation is a
difficulty that is ignored by computer runs.

And the ensuing garbage in garbage out difficulty presents itself. But
yes cyclogenesis is on the cards as it is 1 1/2 hours off 3/9d ones.

Translation please.

Someone remind me of the year of that "most unusual" breeze so I can
look up the time of the phases please.

I refer the quirky gentleman to my original reply.

I was trying to find the post I made earlier (before you graced us
with your no be prescience.)

I vaguely remember Paul Bartlett being credited with the invention of
the term Spanish Flume. Bit of a log jam with that though. I may be
confusing it with the Bartlett High (a phenomenon requiring high
pressures
http://weatherfaqs.org.uk/node/117
And "this has come to be regarded as a 'slug'" to which I applied the
term stall.)

Lunar phases at 3 and 9 o'clock are likely to produce thundery
weather. Hence I used the term 3 and 9.

I should have been more patient with you. I apologise.

Here is a brief resume:
"Spanish Plume"
16.07.07 08:18

Most people will have heard of the phrase “three fine days and a
thunderstorm”. Of course, when the UK does experience spells of hot,
sunny weather, they may last just a day or two, but sometimes a week
or more.

Longer spells of hot weather in summer seem to be becoming more common
as our climate changes, but the phrase above does rather nicely sum up
the phenomenon known as the “Spanish Plume”.

It typically starts off when a ridge of high pressure extends over the
UK from the Azores. This area of high pressure then moves eastwards
slowly over the course of a few days, giving increasingly sunny, hot
weather.

At the same time, a low pressure system attempts to drive in from the
west but is held up by the high pressure system, and as a result, warm
southerly winds are pumped northwards from Spain.

The air is very warm in its lower layers, and because of this, it
picks up huge amounts of moisture at the surface as it tracks over the
Bay of Biscay. Importantly, the air above the surface layer is warm,
but much drier, as it has originated from the Spanish interior.

This warm air aloft creates a “cap” on the atmosphere, preventing deep
convection as it moves north. Sometimes, severe storms break out over
France first if the cap is eroded by high surface temperatures.

As the air moves north over southern England, the low pressure system
to the west and its associated cold front usually encroach eastward
with the upper trough.

This results in the warm, dry air aloft cooling dramatically creating
a sharp drop in temperature with height. The humid air near the
surface is forced up by the massive instability generating
thunderstorms, sometimes severe if the conditions are right.

July 1 1968 was a classic example of a Spanish Plume, with very warm
air in the lower atmosphere, and a surface low pressure system near
south west England. These two factors created a very volatile
atmosphere.

Severe thunderstorms broke out later in the day, particularly in
northern and western parts, after highs of 34C (93F) in Hampshire and
32C (90F) widely across the south east.

Slapton, in Devon, reported massive hailstones of around 7cm in
diameter, caused by repeated circulation in the powerful updraughts
and down draughts associated with severe thunderstorms.

The weekend brought a Spanish Plume, with obsidian skies, sonorous
thunder, and riotous electrical fulmination; in short, thunderstorms.

By: Julian Mann
http://www.meteogroup.co.uk/uk/home/...ish_plume.html

Forgive me not looking up the uk.sci.weather faqs but the search
results kept turning up Martin's old pages, now sadly 404-ing.

Here is what the present FAQs says about the Spanish Plume:
"... to acquire the characteristics of an air mass . Spanish Plume A
catchy name applied to what is in reality quite a complex process ..."

Which is where I came in is it not?

On 24/02/10 12:16, Richard Dixon wrote:
And the ensuing garbage in garbage out difficulty presents itself. But
yes cyclogenesis is on the cards as it is 1 1/2 hours off 3/9d ones.
Translation please.

I would have thought even Michael would have got the hang of dismal
Guernsey by now. It should have read "1 1/2 hours off 19p".

--
Graham P Davis, Bracknell, Berks., UK. E-mail: newsman not newsboy
"I wear the cheese. It does not wear me."

On 24 Feb, 13:22, Graham P Davis wrote:
On 24/02/10 12:16, Richard Dixon wrote:

And the ensuing garbage in garbage out difficulty presents itself. But
yes cyclogenesis is on the cards as it is 1 1/2 hours off 3/9d ones.
Translation please.

I would have thought even Michael would have got the hang of dismal
Guernsey by now. It should have read "1 1/2 hours off 19p".

Is anybody sure what makes a Spanish Plume
I'm feeling a little under the weather?
When it happens we'll know just how the wind blows
And we will all get there together
Are the isobars close? Does anybody know?
Or will waiting till late make us clever?

Ooh and it makes me wonder
Ooh and it makes me wonder
And we're scrying the stairway to heaven

The signs on the wall say it's a close call
I'm not the only one whose words have two meanings
Or not as the case may be but who listens to me?
Sometimes all of our thoughts are misgiven

It's at sixes and sevens when there's thetas, threes and nines
It's those bloody half past fours that house the devil.
And make me wonder
Ooh, it makes me wonder

The best that we get is the wind from the west
For it's seldom the east is so giving
In my thoughts I have seen lots of things that might have been
But the relative pressures all look like breaking even

Ooh, it makes me wonder
Ooh, it really makes me wonder

On 24 Feb, 14:14, Weatherlawyer wrote:
On 24 Feb, 13:22, Graham P Davis wrote:

On 24/02/10 12:16, Richard Dixon wrote:

And the ensuing garbage in garbage out difficulty presents itself. But
yes cyclogenesis is on the cards as it is 1 1/2 hours off 3/9d ones.
Translation please.

I would have thought even Michael would have got the hang of dismal
Guernsey by now. It should have read "1 1/2 hours off 19p".

Is anybody sure what makes a Spanish Plume
I'm feeling a little under the weather?
When it happens we'll know just how the wind blows
And we will all get there together
Are the isobars close? Does anybody know?
Or will waiting till late make us clever?

Ooh and it makes me wonder
Ooh and it makes me wonder
And we're scrying the stairway to heaven

The signs on the wall say it's a close call
I'm not the only one whose words have two meanings
Or not as the case may be but who listens to me?
Sometimes all of our thoughts are misgiven

It's at sixes and sevens when there's thetas, threes and nines
It's those bloody half past fours that house the devil.
And make me wonder
Ooh, it makes me wonder

The best that we get is the wind from the west
For it's seldom the east is so giving
In my thoughts I have seen lots of things that might have been
But the relative pressures all look like breaking even

Ooh, it makes me wonder
Ooh, it really makes me wonder

Altogether now! http://www.youtube.com/watch?v=ugxFcmZXDyc

Graham
Penzance