I have to say that I'm at a loss as to why the warning for snow and ice
comes into force at precisely 0005 on Friday. Why not at midnight?
Surely there is no pretence that forecasting can be so precise. The
warning start at 0005 on Friday seems at odds with the current Peak
District Forecast for Thursday which says

"Turning drier, brighter and colder during the morning with scattered
wintry showers, snow showers then becoming heavy and more frequent
through the late afternoon and evening. Temporary blizzard conditions
and drifting of lying snow later in the day."

On the basis of that forecast it would appear that the warning should
come into force around 1600-1800 on Thursday, at least for this part of
the country. As is so often the case, there seems to be an absence of
'joined-up' forecasting.


--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
Twitter: @TideswellWeathr

On Wednesday, December 6, 2017 at 7:37:48 PM UTC, Norman Lynagh wrote:
I have to say that I'm at a loss as to why the warning for snow and ice
comes into force at precisely 0005 on Friday. Why not at midnight?
Surely there is no pretence that forecasting can be so precise. The
warning start at 0005 on Friday seems at odds with the current Peak
District Forecast for Thursday which says

"Turning drier, brighter and colder during the morning with scattered
wintry showers, snow showers then becoming heavy and more frequent
through the late afternoon and evening. Temporary blizzard conditions
and drifting of lying snow later in the day."

On the basis of that forecast it would appear that the warning should
come into force around 1600-1800 on Thursday, at least for this part of
the country. As is so often the case, there seems to be an absence of
'joined-up' forecasting.


--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
Twitter: @TideswellWeathr

There's the same warning of snow & ice a fair chunk of Cornwall - including the coastal areas, where the forecast looks somewhat different E.g Padstow
https://www.metoffice.gov.uk/public/...ate=2017-12-08

Even up at Bodmin, the current forecast is for rain showers rather than snow https://www.metoffice.gov.uk/public/...ate=2017-12-08

I think you'll have to be up near the top of Brown Willy to be in with much chance of seeing lying snow in Cornwall

Graham
Penzance

In article , lynagh@weather-
consultancy.com says...
I have to say that I'm at a loss as to why the warning for snow and ice
comes into force at precisely 0005 on Friday. Why not at midnight?


Because some people have difficulty understanding it.

00h00 on Friday mean midnight between Thursday and Friday or between
Friday and Saturday.

--
Alan LeHun

At least through the 1980s the convention at the Met Office was to label midnight as 00:01 Z.

Stephen.

I think, technically, 0000 doesn’t exist. It’s either 2359 denoting the end of the day and 0001 the start of the next.

On 07/12/2017 20:22, Stephen Davenport wrote:
At least through the 1980s the convention at the Met Office was to label midnight as 00:01 Z.

Stephen.


NTSLF cant even get the top of each hour right.
eg
http://www.ntslf.org/data/realtime?port=Portsmouth
come relaying the tidegauge readings for say 22:00 tonight , their www
clock will say 21:60

In message , N_Cook
writes
On 07/12/2017 20:22, Stephen Davenport wrote:
At least through the 1980s the convention at the Met Office was to
label midnight as 00:01 Z.

Stephen.


NTSLF cant even get the top of each hour right.
eg
http://www.ntslf.org/data/realtime?port=Portsmouth
come relaying the tidegauge readings for say 22:00 tonight , their www
clock will say 21:60

Good grief! If they can't even get that right, what confidence can one
have that they are reporting the gauge readings correctly?
--
John Hall "George the Third
Ought never to have occurred.
One can only wonder
At so grotesque a blunder." E.C.Bentley (1875-1956)

0000 does exist. It's 2400 that doesn't. But to remove doubt about what day is meant, 0001 or 2359 are used.

--
Freddie

On 07/12/2017 22:01, John Hall wrote:
In message , N_Cook writes
On 07/12/2017 20:22, Stephen Davenport wrote:
At least through the 1980s the convention at the Met Office was to
label midnight as 00:01 Z.

Stephen.


NTSLF cant even get the top of each hour right.
eg
http://www.ntslf.org/data/realtime?port=Portsmouth
come relaying the tidegauge readings for say 22:00 tonight , their www
clock will say 21:60

Good grief! If they can't even get that right, what confidence can one
have that they are reporting the gauge readings correctly?

Its been like that since they started, this morning I just checked and
08:00 was 07:60.
Of more concern is the so often repeated crapping out of the tide gauges
just when you need them, at the onset of a surge.
Bubbler gauges were supposed to be immune from the weather effects on
float types. From a top oceanographer, that crapouting is due to
problems in the software/firmware, or even rapid air pressure changes
from the compensator sensor. The bubbler system works fine throughout
apparently. He did not go into detail, but its probably due to waves
from the storm usually associated with a surge, inducing high frequency
pressure changes, that the firmware interprets as interference and dumps
the data, recording nulls .

On Thursday, December 7, 2017 at 10:04:38 PM UTC, John Hall wrote:
In message , N_Cook
writes
On 07/12/2017 20:22, Stephen Davenport wrote:
At least through the 1980s the convention at the Met Office was to
label midnight as 00:01 Z.

Stephen.


NTSLF cant even get the top of each hour right.
eg
http://www.ntslf.org/data/realtime?port=Portsmouth
come relaying the tidegauge readings for say 22:00 tonight , their www
clock will say 21:60

Good grief! If they can't even get that right, what confidence can one
have that they are reporting the gauge readings correctly?
--
John Hall "George the Third
Ought never to have occurred.
One can only wonder
At so grotesque a blunder." E.C.Bentley (1875-1956)

For sea conditions I rather like this site - http://www.channelcoast.org/data_man...e_data/charts/

Click the site name and you get this (in the case of Perranporth) http://www.channelcoast.org/data_man...arts/?chart=76

As you can see, whilst the significant wave height (the figure normally quotes) is now around 4m, the peak wave height is now 7m - quite large, but note how short the period is, so not powerful, just a typical rough sea.

In Cornwall, away from the estuaries, it's wave height/period & wave setup surges which are normally the most important, rather than the tide being 0.3m above astronomical predictions.

You also get SST, wave direction & full data on the wave spectra http://www.channelcoast.org/data_man...a&disp_option=

It's really rather good, pointed out to me by Nick G originally, if I remember rightly.

Anyway, as northerly blasts go, pretty half hearted here, still around 6C.

Graham
Penzance