Question - Melted Hoar Frost/Rime - is it counted in Rainfall Totals?
 

A question ( I'm sure I used to know the answer!)

Should I count the 'rain' recorded by my tipping bucket by melted frost in
my rain totals, or should I note it but delete from totals?
I have had one 'tip' for today and one yesterday (i.e. 0.2mm each)
--
Roy Avis
See Bracknell Weather/Webcam updated every minute plus Historical Data link
at: http://homepage.ntlworld.com/roy.avis/WDLive/index.html
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Question - Melted Hoar Frost/Rime - is it counted in RainfallTotals?
 

On 13 Dec, 11:34, "Roy Avis" wrote:
A question ( I'm sure I used to know the answer!)

Should I count the 'rain' recorded by my tipping bucket by melted frost in
my rain totals, or should I note it but delete from totals?
I have had one 'tip' for today and one yesterday (i.e. 0.2mm each)

Hi, Roy,
It should be added to your monthly total and a daily note made that it
was dew or hoar.
Met O practice is to enter XX and the amount,
thus 0.2mm dew/hoar etc would be entered XX02
If rain has fallen, but none in the gauge, enter trace, (Met O form X
in the left hand column)
There are lots of other rules that I will let you know if and when a
problem arises
HTH
Ken
Copley, Teesdale

Question - Melted Hoar Frost/Rime - is it counted in Rainfall Totals?
 

Thanks for your help Ken - I will note it in the Notes column of my Davis
database.

I did some Observing in the Met Office back in the 60's & 70's, but some of
the detail of entering the data has long gone from my memory!
I still have an old RAF Form 2050B Daily Register (January 1964). The hours
I spent checking the entries of the previous shift! Probably all shredded
by now!

Roy Avis
See Bracknell Weather/Webcam updated every minute plus Historical Data link
at: http://homepage.ntlworld.com/roy.avis/WDLive/index.html
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"Ken Cook" wrote in message
...
On 13 Dec, 11:34, "Roy Avis" wrote:
A question ( I'm sure I used to know the answer!)

Should I count the 'rain' recorded by my tipping bucket by melted frost
in
my rain totals, or should I note it but delete from totals?
I have had one 'tip' for today and one yesterday (i.e. 0.2mm each)

Hi, Roy,
It should be added to your monthly total and a daily note made that it
was dew or hoar.
Met O practice is to enter XX and the amount,
thus 0.2mm dew/hoar etc would be entered XX02
If rain has fallen, but none in the gauge, enter trace, (Met O form X
in the left hand column)
There are lots of other rules that I will let you know if and when a
problem arises
HTH
Ken
Copley, Teesdale

Question - Melted Hoar Frost/Rime - is it counted in RainfallTotals?
 

On Dec 13, 11:42 am, Ken Cook wrote:

Hi, Roy,
It should be added to your monthly total and a daily note made that it
was dew or hoar.
Met O practice is to enter XX and the amount,
thus 0.2mm dew/hoar etc would be entered XX02

I wonder if this was the case at St James's Park yesterday - the Met
Office stats page for the Southeast has "St James Park" as the wettest
at 0.2mm:
http://www.metoffice.gov.uk/weather/...t_weather.html

Assuming this is the one in London, I'm pretty sure no rain fell
there, but there was a heavy frost/dew. Any ideas?

Question - Melted Hoar Frost/Rime - is it counted in Rainfall Totals?
 

"Ken Cook" wrote:
On 13 Dec, 11:34, "Roy Avis" wrote:

Should I count the 'rain' recorded by my tipping bucket by melted frost
in
my rain totals, or should I note it but delete from totals?
I have had one 'tip' for today and one yesterday (i.e. 0.2mm each)

It should be added to your monthly total and a daily note made that it
was dew or hoar.
Met O practice is to enter XX and the amount,
thus 0.2mm dew/hoar etc would be entered XX02
If rain has fallen, but none in the gauge, enter trace, (Met O form X
in the left hand column)
There are lots of other rules that I will let you know if and when a
problem arises

But always bear in mind that plastic gauges, especially elevated
ones, catch rather more moisture from hoar/rime/condensation
than a standard metal gauge.

The Eden rain-gauge mantra: if you have an AWS, fantastic, but
always try to have a standard manual rain-gauge too. Because
it's, well, standard.

Philip

Question - Melted Hoar Frost/Rime - is it counted in RainfallTotals?
 

On 13 Dec, 11:58, "Philip Eden" philipATweatherHYPHENukDOTcom wrote:
But always bear in mind that plastic gauges, especially elevated
ones, catch rather more moisture from hoar/rime/condensation
than a standard metal gauge.

The Eden rain-gauge mantra: if you have an AWS, fantastic, but
always try to have a standard manual rain-gauge too. Because
it's, well, standard.

Hi, Philip,
As you say, the AWS catches more condensation. My Davis often tips
0.2mm "dew catch" whereas the Met O copper gauge is normally trace, if
any, and occasionally 0.1mm during thick, wet fog. It rarely amounts
to 0.2mm in 24 hours.
Ken
Copley, Teesdale.

Question - Melted Hoar Frost/Rime - is it counted in Rainfall Totals?
 

Ken Cook wrote:

On 13 Dec, 11:58, "Philip Eden" philipATweatherHYPHENukDOTcom wrote:
But always bear in mind that plastic gauges, especially elevated
ones, catch rather more moisture from hoar/rime/condensation
than a standard metal gauge.

The Eden rain-gauge mantra: if you have an AWS, fantastic, but
always try to have a standard manual rain-gauge too. Because
it's, well, standard.

Hi, Philip,
As you say, the AWS catches more condensation. My Davis often tips
0.2mm "dew catch" whereas the Met O copper gauge is normally trace, if
any, and occasionally 0.1mm during thick, wet fog. It rarely amounts
to 0.2mm in 24 hours.
Ken
Copley, Teesdale.

Unusually, I got 0.2 mm from melted hoar frost in the standard 5"
copper gauge this morning. There was a heavy hoar frost, though.

Norman
--
Norman Lynagh
Chalfont St Giles, Buckinghamshire
85m a.s.l.
(remove "thisbit" twice to e-mail)

Question - Melted Hoar Frost/Rime - is it counted in RainfallTotals?
 

On 13 Dec, 13:17, "Norman" normanthis...@thisbitweather-
consultancy.com wrote:
Unusually, I got 0.2 mm from melted hoar frost in the standard 5"
copper gauge this morning. There was a heavy hoar frost, though.

Similar to you Norman, just shy of 0.2mm in std copper gauge from this
mornings hoar/rime. Once or twice a year I'll record 0.2mm, usually on
a
claggy North Sea day. You don't record this as a rain day do you??
please tell me no, otherwise I've been cocking up for 30 years :(

Ian,

Raunds, East Northants. 63m. amsl. NGR SP9972.

Question - Melted Hoar Frost/Rime - is it counted in RainfallTotals?
 

On 13 Dec, 13:17, "Norman" normanthis...@thisbitweather-
consultancy.com wrote:

Unusually, I got 0.2 mm from melted hoar frost in the standard 5"
copper gauge this morning. There was a heavy hoar frost, though.

Similar to you Norman, I recorded just shy of 0.2mm melted hoar/rime
in a std 5" copper gauge this morning. Happens 2 or 3 times a year.
Please tell me you are not supposed to record this as a rain day if
you do record 0.2mm, otherwise I've been cocking up for 30 yrs!!

Ian,

Raunds, East Northants. 63m amsl. NGR SP9972.

Question - Melted Hoar Frost/Rime - is it counted in Rainfall Totals?
 

Ian wrote:

On 13 Dec, 13:17, "Norman" normanthis...@thisbitweather-
consultancy.com wrote:
Unusually, I got 0.2 mm from melted hoar frost in the standard 5"
copper gauge this morning. There was a heavy hoar frost, though.

Similar to you Norman, just shy of 0.2mm in std copper gauge from this
mornings hoar/rime. Once or twice a year I'll record 0.2mm, usually on
a
claggy North Sea day. You don't record this as a rain day do you??
please tell me no, otherwise I've been cocking up for 30 years :(

Ian,

Raunds, East Northants. 63m. amsl. NGR SP9972.

I think you do but I might be wrong. No doubt someone will be able to
give chapter and verse :-)

--
Norman Lynagh
Chalfont St Giles, Buckinghamshire
85m a.s.l.
(remove "thisbit" twice to e-mail)