inconsistent precipitation data

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  • Updated 2 years ago
Hi,I'm looking into daily totals for historical snow data and am finding wildly different values for various types Wunderground queries (API and non API). I am interested in any large city and chose New York for this example. I searched and found several other forum conversations implying the same kind of inconsistencies but most did not have robust explanations and none show the data like what I have below. Thanks in advance.

First off, there was a snowstorm occurring in NYC on Feb 5th-8th, 1967.

1. If I do a query from the wunderground site

Actual Precipitation is shown as 0.09, snow as 0.00
And for the other days:
Feb 5th shows 0 precip, 0 snow
Feb 7th shows 0.34 precip, 0 snow
Feb 8th shows 0 precip, 0 snow

That doesn't seem to show a storm.

AND the Feb 7th page actually shows the record as being set in 1967 with 12.50 inches of snow. 

2. Additionally, if I do a similar query to get the monthly data in csv form, those numbers do not match the ones above.

3. If I do the API query, it looks a little bit better. This shows the day's summary for precipm as 8.64 which I believe is 8.64 inches. If anyone can confirm what units those are, I'd appreciate it.

The values for other days are:
5th: 0.0 
6th: 2.29 
7th: 8.64 
8th: 0 

The 8.64 is lower than the 12.50 shown as the record on the web query, but I could understand that difference from two different stations perhaps. (KNYC vs. whatever the API uses for the "New_York_City" query.

In summary, 3 different queries return 3 wildly different sets of values. I haven't been able to find what units precipm is in. I really just need daily snowfall totals that are at least somewhat correct.

I started trying the monthly queries because I would prefer to use those rather than the querying the API for every day for the last 50 years. But the main issue is that none of these values seem to correspond and now I don't trust this data and/or my methods.

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Posted 2 years ago

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