Understanding Precipitation data

Question

I am trying to perform an analysis on weather and car collisions data of New York city. I have downloaded weather data from NOAA. But I am not able to understand the data provided in the precipitation column of the weather dataset. It has a numerical value followed by capital letter. Some of these letters are: A,B,C,G,I,H.

Example: 0.03G, 0.08A, 0.0H

Can anyone please help me understand what these letters mean here. I have provided a picture of this column. Also, the name of the column in the dataset is PRCP.

Answer 1

This seems to be the same data mentioned at http://shallowsky.com/blog/programming/NOAA-weather.html .

In their write up, they also link to NOAA's documentation for the document.

Note that this is what's commonly called an 'ASCII table', in which it is not delimited, but contains a number of fixed-width columns.

As such, the field is not '0.00G' but actually two fields, '0.00' (columns 119 to 123) and 'G' (column 124).

Column 124 is a notation of how the value was measured at the given site:

• A = 1 report of 6-hour precipitation amount.
• B = Summation of 2 reports of 6-hour precipitation amount.
• C = Summation of 3 reports of 6-hour precipitation amount.
• D = Summation of 4 reports of 6-hour precipitation amount.
• E = 1 report of 12-hour precipitation amount.
• F = Summation of 2 reports of 12-hour precipitation amount.
• G = 1 report of 24-hour precipitation amount.
• H = Station reported '0' as the amount for the day (eg, from 6-hour reports), but also reported at least one occurrence of precipitation in hourly observations--this could indicate a trace occurred, but should be considered as incomplete data for the day.
• I = Station did not report any precip data for the day and did not report any occurrences of precipitation in its hourly observations--it's still possible that precip occurred but was not reported.