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Data Library

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Finding Data

Tutorial

Questions and Answers

Function Documentation

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NOAA NCDC GDCN dataset

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help

The GDCN data can be found here.

COUNTRY CODES
The country code key is located here.

DATA MEASUREMENT FLAG (DMFlag)

	-	No data measurement information (Tx,Tn,Pr)
65	-	Accumulated precipitation value (Pr)
67	-	Begin or continuing precipitation accumulation (Pr)
69	-	Estimated value provided by source (Pr)
72	-	Accumulated precipitation indicated by source, however no accumulated precipitation value was provided (Pr)
74	-	Source provided accumulated precipitation value, however no information on accumulation period was provided(Pr)
84	-	Trace accumulation reported by source (Pr)

QUALITY CONTROL FLAG (QCFlag)

	-	No quality control information (Tx,Tn,Pr)
70	-	Failed source quality control (Tx,Tn,Pr)
83	-	Suspect value identified by source (Tx,Tn,Pr)
88	-	Exceeds known world daily extreme for that particular element (Krause and Flood, 1997) (Tx,Tn,Pr)
79	-	Temperature value is greater than or equal to 6.0 bi-weight standard deviations from the period bi-weight mean (Tx,Tn)
5	-	Temperature value is greater than or equal to 5.0 and less than 6.0 bi-weight standard deviations from the period bi-weight mean (Tx,Tn)
4	-	Temperature value is greater than or equal to 4.0 and less than 5.0 bi-weight standard deviations from the period bi-weight mean (Tx,Tn)
3	-	Temperature value is greater than or equal to 3.0 and less than 4.0 bi-weight standard deviations from the period bi-weight mean (Tx,Tn)
75	-	Streak value (value occurs 10 or more days in a row). Note 0.0 mm precipitation values are excluded. (Tx,Tn,Pr)
69	-	Extreme precipitation value ( >= 90th percentile of all observations within that month for the period on record). (Pr)
73	-	Internal consistency error, minimum temperature value greater than same day maximum temperature value (Tx,Tn)

It is possible that one or more quality control flags may apply to a single datum. Therefore, the
above listed flags are listed in order of precedence. Thus, if a value is suspect (e.g., flag=83)
and also an outlier (e.g., flag=79), then the suspect flag will be set for that datum.

Note: A list of stations with potentially inconsistent accumulated precipitation observing practices can be found here. More information can be found on page 14 of the official documentation.

Note: A portion of the stations were given new ids to facilitate their entry into the Data Library. A list of these stations, along with their original and new ids, can be found here.

Full documentation for this dataset can be obtained from NCDC.