Should dew be recorded as rainfall

gpercival · **Posted:** Wed Apr 10, 2013 8:39 am

I have just made some modifications to my rain gauge increasing the resolution from 0.5mm to 0.1mm. I have tested and seem to record accuratly.

My problem is that for the last two morings I have recorded 0.1mm of dew. Should dew be recorded as rainfall? If not what do others do about this problem?

Geoff

http://www.rhumbline.com.au/weather

nitrx · **Posted:** Wed Apr 10, 2013 8:51 am

According to the KNMI (Royal Dutch Meterotical Institute free translated) dew is percepation also snow hail etcetra Dew is measured as percipation and recorded as rain , I think the confusion comes from the word 'rain'.

steve · **Posted:** Wed Apr 10, 2013 8:51 am

In the UK at least, it counts to the total. For manual recording, if the observer knows that the precipitation was caused by dew, this is noted in the return.

mcrossley · **Posted:** Wed Apr 10, 2013 9:07 am

I also had a 0.1mm gauge which recorded dew. Cumulus counts this towards the total (a very minor contribution!), but made sure the 'rain day' threshold in Cumulus was set to 0.2mm so it was not counted as a rainy day if only 0.1mm was accumulated.

logjam · **Posted:** Wed Apr 10, 2013 1:12 pm

mcrossley wrote:

I also had a 0.1mm gauge which recorded dew. Cumulus counts this towards the total (a very minor contribution!), but made sure the 'rain day' threshold in Cumulus was set to 0.2mm so it was not counted as a rainy day if only 0.1mm was accumulated.

That's a very good idea. I assume that is RainDayThreshold in Cumulus.ini. Mine is set to -1. :?:

Is it a matter of changing it to 0.2 or is it located elsewhere ?

steve · **Posted:** Wed Apr 10, 2013 1:22 pm

There isn't a config screen for it, so you can only changing it by stopping Cumulus and editing cumulus.ini. But note that the default value of -1 corresponds to 0.2mm anyway.

gpercival · **Posted:** Wed Apr 10, 2013 8:28 pm

Thanks everyone, especially Mark. Your suggestion solves my problem.

Geoff

	It is currently Wed Jun 19, 2013 5:55 am
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Should dew be recorded as rainfall

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