how to calculate precipRate?

  • 1
  • Question
  • Updated 4 months ago
Hello!

I would like to send to my PWS to the Rain "precipRate" value. My station is not support weather underground directly so i need to "shape" it before send it. (I use Node-RED to the conversation and sendig with REST API call, via HTML)

I able to calculate the "precipTotal" value successfully ( i send it the today rain value and reset this value every midnight)

But the precipRate is harder... if i understand correctly i need to send a value that contain that if the raining is continue the following hour, what will be the rain mm at end of the hour.

But what is the sampling rate? (difference between two measuring?) So need some help understand the "rules" of this value.

My rain meter is only count the rain value infinitely (or null it if i replace the battery) so i need to calculate it pure softwarely.
Photo of Vamp

Vamp

  • 1 Post
  • 0 Reply Likes

Posted 4 months ago

  • 1
Photo of Tim Roche

Tim Roche, Official Rep

  • 356 Posts
  • 53 Reply Likes
Hi Vamp.

This is a great question, and one we don't have a hard and fast rule for.  Since stations all report differently you'll want to find a sampling interval that will provide good information for all conditions, from small amounts per hour to large.  We are working on a revision to our upload specification documentation, and we'll try to come up with a good answer for you here.
Photo of Paul Hutch

Paul Hutch

  • 21 Posts
  • 7 Reply Likes
I just worked on this issue recently. 

From the official document: https://support.weather.com/s/article/PWS-Upload-Protocol?language=en_US
rainin - [rain inches over the past hour)] -- the accumulated rainfall in the past 60 min
My easy, but memory intensive, solution is to just keep all the rainfall readings for the past hour.

When a new reading arrives I delete the oldest reading, add the new reading, then sum the readings to get  rainfall in the past hour.

(Edited)