.....is that what I think it is.....

EGKB 181120Z 29003KT 9999 VA NSC 15/02 Q1015
EGKB 181050Z 29002KT 9999 VA NSC 14/02 Q1015
EGKB 181020Z 29003KT 9999 VA NSC 14/02 Q1015
EGKB 180950Z 36001KT CAVOK 13/03 Q1015
EGKB 180920Z 17001KT CAVOK 12/03 Q1015
EGKB 180850Z 32002KT CAVOK 12/04 Q1015


Phil

"Phil Layton" wrote in message
...
....is that what I think it is.....

EGKB 181120Z 29003KT 9999 VA NSC 15/02 Q1015
EGKB 181050Z 29002KT 9999 VA NSC 14/02 Q1015
EGKB 181020Z 29003KT 9999 VA NSC 14/02 Q1015
EGKB 180950Z 36001KT CAVOK 13/03 Q1015
EGKB 180920Z 17001KT CAVOK 12/03 Q1015
EGKB 180850Z 32002KT CAVOK 12/04 Q1015


Phil

.... indeed - 'volcanic ash'. They might send some reports to Exeter
which in turn might get on the web page I referenced elsewhere.

Martin.


--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023

On Apr 18, 12:43*pm, "Martin Rowley"
wrote:
"Phil Layton" wrote in message

...

....is that what I think it is.....

EGKB 181120Z 29003KT 9999 VA NSC 15/02 Q1015
EGKB 181050Z 29002KT 9999 VA NSC 14/02 Q1015
EGKB 181020Z 29003KT 9999 VA NSC 14/02 Q1015
EGKB 180950Z 36001KT CAVOK 13/03 Q1015
EGKB 180920Z 17001KT CAVOK 12/03 Q1015
EGKB 180850Z 32002KT CAVOK 12/04 Q1015

Phil

... indeed - 'volcanic ash'. They might send some reports to Exeter
which in turn might get on the web page I referenced elsewhere.

Martin.

--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N * Long: 01.88W
NGR: SU 082 023

I'm 5 miles west of Biggin Hill and the sky was quite milky/hazy
this morning, less so now, but no more than I have seen a number of
times in the past. But how do they know it's volcanic ash? Its
appearance is no different from normal dust, rather a lot of it. And
what is the property of volcanic ash, as opposed to dust particles,
that makes it dangerous to aircraft? My guess is that its melting
point is lower, but not by very much. All these things are modified
silicates, after all.

Tudor Hughes, Warlingham, NE Surrey, 556 ft.

.... just looked up the WMO catalogue for w'w' (present weather for a
METAR) and I'm pretty sure that this use is incorrect. 'VA' is listed
in the column for 'obscuration', i.e., meteors causing marked
reduction in visibility. The report has VVVV = 9999 (10km or more),
and as such doesn't require a present weather. I suspect they are
looking at what we are seeing elsewhere (haze, whether surface based
or elevated).

There's a lot of restlessness in the aviation world now (big
boys/commercial) and I suspect that we'll see some movement over the
next 12-18 hours on all this. The envelope of risk as indicated in the
VAAC bulletins is no doubt correct - whether the ash/dust/etc., is all
the same density/threat throughout that envelope is doubtful.

See:-
http://news.bbc.co.uk/1/hi/business/8628034.stm

Martin.



--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023

On Apr 18, 4:09*pm, "Martin Rowley"
wrote:
... just looked up the WMO catalogue for w'w' (present weather for a
METAR) and I'm pretty sure that this use is incorrect. 'VA' is listed
in the column for 'obscuration', i.e., meteors causing marked
reduction in visibility. The report has VVVV = 9999 (10km or more),
and as such doesn't require a present weather. I suspect they are
looking at what we are seeing elsewhere (haze, whether surface based
or elevated).

There's a lot of restlessness in the aviation world now (big
boys/commercial) and I suspect that we'll see some movement over the
next 12-18 hours on all this. The envelope of risk as indicated in the
VAAC bulletins is no doubt correct - whether the ash/dust/etc., is all
the same density/threat throughout that envelope is doubtful.

See:-http://news.bbc.co.uk/1/hi/business/8628034.stm

Martin.

--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N * Long: 01.88W
NGR: SU 082 023

Just noticed a thin layer of dust on the car outside, wouldn't have
normally commented, but it is pretty gray/black when you run your
fingers through it.

Keith (Southend)

"Tudor Hughes" wrote in message
...
On Apr 18, 12:43 pm, "Martin Rowley"
wrote:
"Phil Layton" wrote in message

...

....is that what I think it is.....

EGKB 181120Z 29003KT 9999 VA NSC 15/02 Q1015
EGKB 181050Z 29002KT 9999 VA NSC 14/02 Q1015
EGKB 181020Z 29003KT 9999 VA NSC 14/02 Q1015
EGKB 180950Z 36001KT CAVOK 13/03 Q1015
EGKB 180920Z 17001KT CAVOK 12/03 Q1015
EGKB 180850Z 32002KT CAVOK 12/04 Q1015

Phil

... indeed - 'volcanic ash'. They might send some reports to Exeter
which in turn might get on the web page I referenced elsewhere.

Martin.

--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023

I'm 5 miles west of Biggin Hill and the sky was quite milky/hazy
this morning, less so now, but no more than I have seen a number of
times in the past. But how do they know it's volcanic ash? Its
appearance is no different from normal dust, rather a lot of it. And
what is the property of volcanic ash, as opposed to dust particles,
that makes it dangerous to aircraft? My guess is that its melting
point is lower, but not by very much. All these things are modified
silicates, after all.

Tudor Hughes, Warlingham, NE Surrey, 556 ft.

"Martin Rowley" wrote ...
... just looked up the WMO catalogue for w'w' (present weather for a
METAR) and I'm pretty sure that this use is incorrect. 'VA' is
listed in the column for 'obscuration', i.e., meteors causing marked
reduction in visibility. The report has VVVV = 9999 (10km or more),
and as such doesn't require a present weather. I suspect they are
looking at what we are seeing elsewhere (haze, whether surface based
or elevated).


.... forget that: I'm wrong and they are right; VA (volcanic ash) *is*
to be reported whenever observed. Have now had time to delve deeper
into the regs. Whether it's possible to distinguish such at a great
distance from the source is another matter of course.

Martin.


--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023

Martin Rowley wrote:

"Martin Rowley" wrote ...
... just looked up the WMO catalogue for w'w' (present weather for a
METAR) and I'm pretty sure that this use is incorrect. 'VA' is listed in
the column for 'obscuration', i.e., meteors causing marked reduction in
visibility. The report has VVVV = 9999 (10km or more), and as such doesn't
require a present weather. I suspect they are looking at what we are
seeing elsewhere (haze, whether surface based or elevated).


... forget that: I'm wrong and they are right; VA (volcanic ash) is to be
reported whenever observed. Have now had time to delve deeper into the regs.
Whether it's possible to distinguish such at a great distance from the source
is another matter of course.

Martin.

Although I didn't do so I reckon that reporting the present weather here as VA
would have been justified yesterday. The visibility was certainly reduced by
particles in suspension. The deposit on smooth surfaces was dark grey dust that
sparkled in the sunshine and felt very abrasive. Last night while I was walking
our daughter's dog along dark country lanes I was very surprised by the
concentration of particles visible in a vertical torch beam. The particles
glinted in the beam, much like they had sparkled in the sun. The RH at the time
was around 70 percent so there's no possibility that it was water droplets. No
deposit to be seen this morning, though. The rain has washed it all away.

Norman

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.