00Z position 10.7N 137.7E.
Winds: 140 kts, gusts 170.
Forecast track plus satellite pics can be seen he
http://www.nrlmry.navy.mil/TC.html

Met Office blog:
http://blog.metoffice.gov.uk/2015/04...r-philippines/
I'm sorry to say that their statement that "the sea temperatures are
unusually warm in this area by more than 2°C" seems to be a bit of
journalese. Admittedly they are talking about the area where the storm
formed but that still seems to me to be an exaggeration. I'm not sure
where it formed but there's only a small area of water in the
general region with an anomaly of around +2C. At it's current location,
SSTs are near normal and it's heading into an area of water that is
below normal. Mind you, it depends on which normals you're using.

There's an interesting satellite loop here showing vortices in the eye:
http://cimss.ssec.wisc.edu/goes/blog...d0600_fast.gif

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
I wear the cheese. It does not wear me.
Posted with Claws: http://www.claws-mail.org/

On Wednesday, 1 April 2015 11:17:55 UTC+1, Graham P Davis wrote:
00Z position 10.7N 137.7E.
Winds: 140 kts, gusts 170.
Forecast track plus satellite pics can be seen he
http://www.nrlmry.navy.mil/TC.html

Met Office blog:
http://blog.metoffice.gov.uk/2015/04...r-philippines/
I'm sorry to say that their statement that "the sea temperatures are
unusually warm in this area by more than 2°C" seems to be a bit of
journalese. Admittedly they are talking about the area where the storm
formed but that still seems to me to be an exaggeration. I'm not sure
where it formed but there's only a small area of water in the
general region with an anomaly of around +2C.

Seiches set up by seismic activity usually indicate the general direction of such storms with the peak arriving at the epicentre. This one has been an headache though.

You can forecast the seismic anomalies, if not yet the location, by the length of time the earthquake lists are below 5.5 M. And moreover you can do it with 20:20 hindsight as satellite data is readily available via NASA and the earthquake archives ditto from the USGS.

No excuses really.
But you know what people are like. They can be extra ordinarily dawlish when it suits them. (Not that I can understand when, why or how it suits them.)

At it's current location,
SSTs are near normal and it's heading into an area of water that is
below normal. Mind you, it depends on which normals you're using.

There's an interesting satellite loop here showing vortices in the eye:
http://cimss.ssec.wisc.edu/goes/blog...d0600_fast.gif

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
I wear the cheese. It does not wear me.
Posted with Claws: http://www.claws-mail.org/

On Wednesday, April 1, 2015 at 11:17:55 AM UTC+1, Graham P Davis wrote:
00Z position 10.7N 137.7E.
Winds: 140 kts, gusts 170.
Forecast track plus satellite pics can be seen he
http://www.nrlmry.navy.mil/TC.html

Met Office blog:
http://blog.metoffice.gov.uk/2015/04...r-philippines/
I'm sorry to say that their statement that "the sea temperatures are
unusually warm in this area by more than 2°C" seems to be a bit of
journalese. Admittedly they are talking about the area where the storm
formed but that still seems to me to be an exaggeration. I'm not sure
where it formed but there's only a small area of water in the
general region with an anomaly of around +2C. At it's current location,
SSTs are near normal and it's heading into an area of water that is
below normal. Mind you, it depends on which normals you're using.

There's an interesting satellite loop here showing vortices in the eye:
http://cimss.ssec.wisc.edu/goes/blog...d0600_fast.gif

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
I wear the cheese. It does not wear me.
Posted with Claws: http://www.claws-mail.org/

Here is an anomaly chart for the Pacific:
http://www.ospo.noaa.gov/data/sst/an....3.30.2015.gif
Since the typhoon seems to be at 140 E, it certainly seems now to be clear of warm water and entering cool/cold water.

Cheers, Alastair.

Graham

Do you know if the Japanese use a 1 minute mean when they issue tropical cyclone warnings?

As an observer here in the UK, you often got a very short peak in wind speed on a frontal passage or some kind of trough or squall line, but it would very rarely last a full 10 minutes.

According to Wikipedia "the value of a one-minute sustained wind is 14% greater than a ten-minute sustained wind".

To me a 1 minute mean is almost akin to a gust but I'm just a miserable old sod.

It would be interesting to know what does all the damage in a storm - the extreme gusts or the sustained mean speed - my money would be on the mean doing as much damage as the gust.

Bruce.

On 01/04/2015 13:51, wrote:
Graham

Do you know if the Japanese use a 1 minute mean when they issue tropical cyclone warnings?

As an observer here in the UK, you often got a very short peak in wind speed on a frontal passage
or some kind of trough or squall line, but it would very rarely last
a full 10 minutes.

According to Wikipedia "the value of a one-minute sustained wind is 14% greater than a ten-minute sustained wind".

To me a 1 minute mean is almost akin to a gust but I'm just a miserable old sod.

It would be interesting to know what does all the damage in a storm - the extreme gusts or the sustained mean speed -
my money would be on the mean doing as much damage as the gust.

My instinct would be that the repeated flexing of structures caused by
the strongest gusts would be far more structurally damaging than the
sustained deflection caused by a steady wind loading at mean speed.

I would hazard a guess that damage scales with both windspeed and the
variance of windspeed. Specific impulse delivered to a fixed obstruction
per unit time scales with windspeed squared so I reckon that the gusts
will almost always be the main destructive force.

Once the wind gets inside a structure all bets are off.

--
Regards,
Martin Brown

wrote:

Graham

Do you know if the Japanese use a 1 minute mean when they issue tropical
cyclone warnings?

As an observer here in the UK, you often got a very short peak in wind speed
on a frontal passage or some kind of trough or squall line, but it would very
rarely last a full 10 minutes.

According to Wikipedia "the value of a one-minute sustained wind is 14%
greater than a ten-minute sustained wind".

To me a 1 minute mean is almost akin to a gust but I'm just a miserable old
sod.

It would be interesting to know what does all the damage in a storm - the
extreme gusts or the sustained mean speed - my money would be on the mean
doing as much damage as the gust.

Bruce.

It's the peak gusts that do most of the damage. The force exerted by the wind
is proportional to the square of the wind speed. Therefore, for example, a 50
knot gust exerts approximately 50 percent more force than a 40 knot gust.

Unless explicitly stated otherwise, the peak winds in tropical cyclone warnings
usually refer to the peak 1-minute mean winds. Peak gust speeds are also often
given.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org

On 01/04/2015 14:11, Martin Brown wrote:
On 01/04/2015 13:51, wrote:
Graham

Do you know if the Japanese use a 1 minute mean when they issue
tropical cyclone warnings?

As an observer here in the UK, you often got a very short peak in wind
speed on a frontal passage
or some kind of trough or squall line, but it would very rarely last
a full 10 minutes.

According to Wikipedia "the value of a one-minute sustained wind is
14% greater than a ten-minute sustained wind".

To me a 1 minute mean is almost akin to a gust but I'm just a
miserable old sod.

It would be interesting to know what does all the damage in a storm -
the extreme gusts or the sustained mean speed -
my money would be on the mean doing as much damage as the gust.

My instinct would be that the repeated flexing of structures caused by
the strongest gusts would be far more structurally damaging than the
sustained deflection caused by a steady wind loading at mean speed.

I would hazard a guess that damage scales with both windspeed and the
variance of windspeed. Specific impulse delivered to a fixed obstruction
per unit time scales with windspeed squared so I reckon that the gusts
will almost always be the main destructive force.

Once the wind gets inside a structure all bets are off.

I think you're right; when claiming for wind damage to your house you
need to be able to quote gusts higher than about 38 mph (IIRC). Rain
doesn't damage houses, although it can exacerbate damage already caused
by other factors.

This was a while ago, perhaps it's all changed....

On 01/04/2015 16:20, Metman2012 wrote:
On 01/04/2015 14:11, Martin Brown wrote:
On 01/04/2015 13:51, wrote:
Graham


It would be interesting to know what does all the damage in a storm -
the extreme gusts or the sustained mean speed -
my money would be on the mean doing as much damage as the gust.

My instinct would be that the repeated flexing of structures caused by
the strongest gusts would be far more structurally damaging than the
sustained deflection caused by a steady wind loading at mean speed.

I would hazard a guess that damage scales with both windspeed and the
variance of windspeed. Specific impulse delivered to a fixed obstruction
per unit time scales with windspeed squared so I reckon that the gusts
will almost always be the main destructive force.

Once the wind gets inside a structure all bets are off.

I think you're right; when claiming for wind damage to your house you
need to be able to quote gusts higher than about 38 mph (IIRC). Rain
doesn't damage houses, although it can exacerbate damage already caused
by other factors.

This was a while ago, perhaps it's all changed....

When my (large) greenhouse got trashed by the Xmas storm of 1997 the
loss adjuster turned up having driven into the village through the
remains of several large oak trees. He took one look at the mangled
remains of my greenhouse and another at the met report I had for RAF
Leeming showing gusts to 100mph and signed off on the claim immediately.

The other scary thing about really powerful storms is you get sheets of
glass, corrugated iron, branches and plywood flying about in the air.

--
Regards,
Martin Brown