https://www.fnmoc.navy.mil/products/...sstanomaly.gif

Looks like the cool SST anomaly has now gone from south of the Grand
Banks, the first peice of the jigsaw to come apart :-0
Oh dear!
--
Keith (Southend)
http://www.southendweather.net

"Keith (Southend)" wrote in message
...
https://www.fnmoc.navy.mil/products/...sstanomaly.gif

Looks like the cool SST anomaly has now gone from south of the Grand
Banks, the first peice of the jigsaw to come apart :-0
Oh dear!
--
Keith (Southend)
http://www.southendweather.net

Oh No! UKMO were 'banking' on that. Liam Donaldson had a 'Grand' on it.

Keith (Southend) wrote:


https://www.fnmoc.navy.mil/products/...sstanomaly.gif

Looks like the cool SST anomaly has now gone from south of the Grand
Banks, the first peice of the jigsaw to come apart :-0
Oh dear!

It never looked particularly strong to me and disappeared in June, soon
after the Met Office issued their first winter forecast. However, it
returned a few weeks later so perhaps we can hope this is just another
hiccough. I've noticed this behaviour before in June and is probably more
to do with short-period normals than a change in the actual SST. I can't
recall whether October has exhibited the same problem.

--
Graham Davis
Bracknell

Graham P Davis wrote:
Keith (Southend) wrote:


https://www.fnmoc.navy.mil/products/...sstanomaly.gif

Looks like the cool SST anomaly has now gone from south of the Grand
Banks, the first peice of the jigsaw to come apart :-0
Oh dear!


It never looked particularly strong to me and disappeared in June, soon
after the Met Office issued their first winter forecast. However, it
returned a few weeks later so perhaps we can hope this is just another
hiccough. I've noticed this behaviour before in June and is probably more
to do with short-period normals than a change in the actual SST. I can't
recall whether October has exhibited the same problem.


Thanks Graham,
I guess it's a bit like saying October is warmer than average but only
looking at the first 2 weeks, add the last two weeks to the equation and
the comparison is more complete.

However, it's got me thinking as to what determines the SST anomaly?
1. A subtle change in direction of the Gulf Stream.
2. Ice melt coming down from Labrador.
3. Pressure patterns and wind direction.
4. Current/previous weather experienced in the area.

Regards
--
Keith (Southend)
http://www.southendweather.net

"Keith (Southend)" wrote in message
...
Graham P Davis wrote:
Keith (Southend) wrote:



https://www.fnmoc.navy.mil/products/...sstanomaly.gif

Looks like the cool SST anomaly has now gone from south of the Grand
Banks, the first peice of the jigsaw to come apart :-0
Oh dear!


It never looked particularly strong to me and disappeared in June, soon
after the Met Office issued their first winter forecast. However, it
returned a few weeks later so perhaps we can hope this is just another
hiccough. I've noticed this behaviour before in June and is probably more
to do with short-period normals than a change in the actual SST. I can't
recall whether October has exhibited the same problem.


Thanks Graham,
I guess it's a bit like saying October is warmer than average but only
looking at the first 2 weeks, add the last two weeks to the equation and
the comparison is more complete.

However, it's got me thinking as to what determines the SST anomaly?
1. A subtle change in direction of the Gulf Stream.
2. Ice melt coming down from Labrador.
3. Pressure patterns and wind direction.
4. Current/previous weather experienced in the area.

Yes.

Cheers, Alastair.

Alastair McDonald wrote:
"Keith (Southend)" wrote in message
...

Graham P Davis wrote:

Keith (Southend) wrote:




https://www.fnmoc.navy.mil/products/...sstanomaly.gif

Looks like the cool SST anomaly has now gone from south of the Grand
Banks, the first peice of the jigsaw to come apart :-0
Oh dear!


It never looked particularly strong to me and disappeared in June, soon
after the Met Office issued their first winter forecast. However, it
returned a few weeks later so perhaps we can hope this is just another
hiccough. I've noticed this behaviour before in June and is probably more
to do with short-period normals than a change in the actual SST. I can't
recall whether October has exhibited the same problem.


Thanks Graham,
I guess it's a bit like saying October is warmer than average but only
looking at the first 2 weeks, add the last two weeks to the equation and
the comparison is more complete.

However, it's got me thinking as to what determines the SST anomaly?
1. A subtle change in direction of the Gulf Stream.
2. Ice melt coming down from Labrador.
3. Pressure patterns and wind direction.
4. Current/previous weather experienced in the area.


Yes.

Cheers, Alastair.





I take it that means all of the above?

--
Keith (Southend)
http://www.southendweather.net

Keith (Southend) wrote:


Thanks Graham,
I guess it's a bit like saying October is warmer than average but only
looking at the first 2 weeks, add the last two weeks to the equation and
the comparison is more complete.

More that the average for October could be colder than average. ;-)

What I mean is that the normals are short-term (ten years or so?) and some
kinks might show up in some months when compared with longer-term data, say
150 years.



However, it's got me thinking as to what determines the SST anomaly?
1. A subtle change in direction of the Gulf Stream.
2. Ice melt coming down from Labrador.
3. Pressure patterns and wind direction.
4. Current/previous weather experienced in the area.


Yes.

Cheers, Alastair.





I take it that means all of the above?


I'd say (3) is responsible for almost all of the development of major SST
anomalies in the area.

(1) A subtle change in the Gulf Stream direction would be too subtle to make
a difference over a sufficiently large area. The usual eddies show up as a
series of small bulls-eyes on an anomaly chart if the resolution is too
fine. Any general northward or southward displacement is likely to be
caused by (3).

(2) Ice melt may make some difference but it would be swamped by other
factors. About 35 years ago, some of the long-range-forecasting team at the
Met Office blamed exceptional cooling of the North Atlantic on the melting
of an unusually large number of icebergs. I pointed out to them - after
having my boss check my reasoning and calculations - that (a) the cooling
began before the icebergs reached the Grand Banks and started melting, and
(b) the cooling of the area in question achieved by melting all the
icebergs, allowing for all of them to be of large size, and restricting
wind mixing to a unreasonably shallow depth, would only amount to 0.1C - an
order of magnitude too small. The cooling - and the unusually large number
of icebergs - was caused by persistent, cold, NW winds in the Davis Strait
and along the Labrador coast; i.e., (3) was again the cause.

(4) I think this is saying much the same as (3) or, if not, is caused by it.



--
Graham Davis
Bracknell