BrendanS
Well-known member
Simon is a bit shy about posting this stuff, for fear of being seen as commercial. I however have no such hang ups! <g>
Conversation at the bar starter 1:
Hi all,
Just thought I'd try out a new idea...a late Sunday/early Monday weather
forecast, discussing the weather of the week ahead, what to look out for
etc. and why it is occuring. It's an idea I've had for a time, but have
decided to do something about today. This is not a forecast as such, but
more a discussion of ideas, similar to the sort of things we talk about
in Weather School. You may find it of use, you may not, but I'd be
pleased to hear your views.
WEEK BEGINNING MONDAY 16TH AUGUST 2004
======================================
HEADLINE: HOW LOW CAN YOU GO...DEPRESSION WON'T LIFT
As a forecaster the week ahead isn't to difficult to predict. All
forecast models are going for low pressure developing to the west of
Ireland, with the remnants of a former hurricane stoking things up
around mid-week. We know then that things will be turning more
unsettled.
The hurricane track has been interesting this year and has been "firing"
the storms out into the western Atlantic, where they have become quite
benign. However, by the time that they get close to UK shores they have
been "pepping up" and forming deeper lows. I'm pondering why this could
be?
Looking at the Sea Surface Temperature Anomaly chart (see
.fnmoc.navy.mil/products/OTIS/US058VMET-GIFwxg.OTIS.glbl_sstanomaly.gif)
there is an area of colder water in the central North Atlantic (by as
much as 4C below normal). Now, this has me thinking. If the cold water
is there then the effect could be that as depression track across it,
there is less convection available to intensify the depression, so the
lows coming across the Atlantic are fairly weak. That is until they
reach the UK shores (or close by) where temperatures are above normal.
This provides the extra energy need to deepen the lows quickly, hence
the reason for the deepening we are going to see this week.
Another reason for the deepening is that as they head south they come
under the influence of the jet stream, enabling deepening to take place,
and then routing towards the UK.
Another thing to note on the anomaly chart is the warmer than normal
water north of the Equator in the western Atlantic. This is hurricane
breeding ground at this time of year, and so with that effect could we
see more hurricanes than usual kicking off? This could have a knock on
effect to our weather over the coming weeksn as more storms are
introuduced to the Atlantic?
Anyhow, for now the model output for this week shows the low pressure
deepening and becoming complex around the UK, so it will never be
particularly good. I'd plump for heavy rain or showers on most days.
Strong winds are also a possibility.
There is little difference between the output of the various national
weather services at present and that is usually a good indication that
things are going according to plan.
Hope that that has been useful and interesting. Let me know what you
think.
<hr width=100% size=1>Me transmitte sursum, caledoni
Conversation at the bar starter 1:
Hi all,
Just thought I'd try out a new idea...a late Sunday/early Monday weather
forecast, discussing the weather of the week ahead, what to look out for
etc. and why it is occuring. It's an idea I've had for a time, but have
decided to do something about today. This is not a forecast as such, but
more a discussion of ideas, similar to the sort of things we talk about
in Weather School. You may find it of use, you may not, but I'd be
pleased to hear your views.
WEEK BEGINNING MONDAY 16TH AUGUST 2004
======================================
HEADLINE: HOW LOW CAN YOU GO...DEPRESSION WON'T LIFT
As a forecaster the week ahead isn't to difficult to predict. All
forecast models are going for low pressure developing to the west of
Ireland, with the remnants of a former hurricane stoking things up
around mid-week. We know then that things will be turning more
unsettled.
The hurricane track has been interesting this year and has been "firing"
the storms out into the western Atlantic, where they have become quite
benign. However, by the time that they get close to UK shores they have
been "pepping up" and forming deeper lows. I'm pondering why this could
be?
Looking at the Sea Surface Temperature Anomaly chart (see
.fnmoc.navy.mil/products/OTIS/US058VMET-GIFwxg.OTIS.glbl_sstanomaly.gif)
there is an area of colder water in the central North Atlantic (by as
much as 4C below normal). Now, this has me thinking. If the cold water
is there then the effect could be that as depression track across it,
there is less convection available to intensify the depression, so the
lows coming across the Atlantic are fairly weak. That is until they
reach the UK shores (or close by) where temperatures are above normal.
This provides the extra energy need to deepen the lows quickly, hence
the reason for the deepening we are going to see this week.
Another reason for the deepening is that as they head south they come
under the influence of the jet stream, enabling deepening to take place,
and then routing towards the UK.
Another thing to note on the anomaly chart is the warmer than normal
water north of the Equator in the western Atlantic. This is hurricane
breeding ground at this time of year, and so with that effect could we
see more hurricanes than usual kicking off? This could have a knock on
effect to our weather over the coming weeksn as more storms are
introuduced to the Atlantic?
Anyhow, for now the model output for this week shows the low pressure
deepening and becoming complex around the UK, so it will never be
particularly good. I'd plump for heavy rain or showers on most days.
Strong winds are also a possibility.
There is little difference between the output of the various national
weather services at present and that is usually a good indication that
things are going according to plan.
Hope that that has been useful and interesting. Let me know what you
think.
<hr width=100% size=1>Me transmitte sursum, caledoni
