September 9, 1999 15 Minute Precipitation Data National Climatic Data Center 151 Patton Ave. Asheville, NC 28801-5001 USA Field numbers are shown with column positions in parenthesis. FIELD 1 (1-6): Station Identification Number This 6-character alphanumeric station identifier is assigned by the National Climatic Data Center. The first two digits refer to a state code (see below). The next four digits refer to the Cooperative Network Index number (value range is 0001-9999). Missing/not assigned = 999999. (1-2): State Code STATE CODE as indicated. Range of value is 01 to 48, 50, 51, 66, 67, and 91. STATE CODE TABLE 01 Alabama 28 New Jersey 02 Arizona 29 New Mexico 03 Arkansas 30 New York 04 California 31 North Carolina 05 Colorado 32 North Dakota 06 Connecticut 33 Ohio 07 Delaware 34 Oklahoma 08 Florida 35 Oregon 09 Georgia 36 Pennsylvania 10 Idaho 37 Rhode Island 11 Illinois 38 South Carolina 12 Indiana 39 South Dakota 13 Iowa 40 Tennessee 14 Kansas 41 Texas 15 Kentucky 42 Utah 16 Louisiana 43 Vermont 17 Maine 44 Virginia 18 Maryland 45 Washington 19 Massachusetts 46 West Virginia 20 Michigan 47 Wisconsin 21 Minnesota 48 Wyoming 22 Mississippi 49 Not Used 23 Missouri 50 Alaska 24 Montana 51 Hawaii 25 Nebraska 66 Puerto Rico 26 Nevada 67 Virgin Islands 27 New Hampshire 91 Pacific Islands Optional Field (8-37): Station Name This 30-character alphanumeric field is displayed if the data selection is for data with Station Name. Spacing for all fields following are adjusted 31 characters. (e.g., Division Number = 39-40). FIELD 2 (8-9): Cooperative Division Number The division number was 00 in this data set until September 1993. The current Cooperative Network Division Number (01 - 10) is recorded in this element, beginning in October 1993. FIELD 3 (11-14): Element Type The type of data element stored in this record. Range of values is listed below. (Includes the daily total) QPCP 15-minute precipitation data. Prior to January 1996 QPCP was the only element in this data set. (Includes the daily total) QGAG This element type was added with the January 1996 data. QGAG indicates that quarter-hour Fischer/Porter gage values and the Daily total are stored. FIELD 4 (16-17): Element Units The units and decimal position of the data value for this record. Range of values is listed below. HI Hundredths of inches. Data stored and observed to the same accuracy. HT Tenths of inches. Data stored to tenths only. FIELD 5 (19-22): Year This is the year of record. Range of values is generally 1971 through current year processed. (A few stations begin earlier.) FIELD 6 (24-25): Month Month of record. Range of values = 01-12. FIELD 7 (27-28): Day Day of record. Range of values = 01-31. Days are right justified zero filled. FIELD 8 (30-33): Time Of Value This contains the ending time of the precipitation in hours and minutes 0015 - 2500. (Example, 15 minute period 0345 is defined as 0331 - 0345.) Midnight = 2400. Hour 2500 will indicate the daily total, and it will be the last value. Hour is in the 2 left digits, and minutes are in the 2 right digits. Local Standard Time in use. FIELD 9 (35-40): Data Value The actual 15-minute precipitation data value. The data value portion is the five-digit integer with a leading algebraic sign. The sign is blank to indicate positive and the minus to indicate negative is never used in this data set. Units and decimal position, if appropriate, are indicated in the Element Units field described in Field 4. Range = 000000-099999. 000000 will be used only on the first day 15 minute time period of each month unless there is precipitation, a begin missing, a begin delete or a begin accumulation is indicated. On other days during the month with no precipitation, no entry will be made. 099999 indicates that the data value is unknown. FIELD 10 (42): Flag1 The Data Measurement Flag. Flag1 Table (Measurement Flag) a Begin accumulation. A value of 99999 accompanies this flag. It indicates that the accumulation has begun sometime during the 15 minute period. A End accumulation (amount is associated with this flag). It indicates the accumulation has ended sometime during the 15 minute period. Accumulated period indicates that the precipitation amount is correct, but only the inexact beginning and ending times are known. A data value of 99999 occurring on the last day and hour of a month indicates the accumulation continues into the next month (see Flag 1 ",") , The "," flag is used at the beginning of a data month when an accumulation is in progress from the previous month. A data value of 99999 always accompanies this flag. This flag is used prior to 1984. { Begin deleted period during the 15 minute period (inclusive). The original data were received, but were unreadable or clearly recognized as noise. A value of 99999 accompanies this flag. Primarily used since 1984. Also used in Alaska for 1976-1978. } End deleted period during the 15 minute period (inclusive). The original data were received, but were unreadable or clearly recognized as noise. A value of 99999 accompanies this flag. Primarily used since 1984. Also used in Alaska for 1976-1978. [ Begin missing period during the 15 minute period (inclusive). A value of 99999 accompanies this flag. ] End missing period during the 15 minute period (inclusive). A value of 99999 accompanies this flag. Prior to 1984, if precipitation occurred during the last 15 minutes of the missing period, the ending missing value appears with a non-zero value (example 00021]). Beginning in 1984, the beginning and ending 15 minute period of the missing period are recorded as 99999[ and 99999], respectively. A missing flag indicates that the data were not received. This flag appears on the first and last day of each month for which data were not received or not processed by NCDC. E Evaporation may have occurred. Data may or may not be reliable. This flag was used during the period 1984-1993. g Only used for day 1, hour 0015 when precipitation is zero. M Missing data. No data available for this period. b (blank) no Flag needed. FLAG1 Table (Data Measurement Flag for Daily Total Data Values) I Incomplete or Inexact daily total occurring only with hour 2500. Value is not a true 24-hour amount. One or more periods are missing and/or an accumulated amount has begun but not ended during the daily period. P A daily total excludes erroneous values (those flagged q, Q, {, or }. A "P" flag will also be present when an accumulation has ended (but not begun) during the daily period. b (blank) no Flag needed. !!!!!!!!!!!!!!!!!!!!!N O T I C E !!!!!!!!!!!!!!!!!!!!! EFFECTIVE WITH THE JANUARY 1996 DATA, THE FLAG1 ELEMENT(ABOVE) IS DEFINED AS FOLLOWS: a Begin accumulation. A value of 99999 accompanies this flag. A End accumulation (amount is associated with this flag). , The "," flag is used at the beginning of a data month when an accumulation is in progress. This enables a data month to be examined as a singularly context consistent entity. (suggested by the National Weather Service, Office of Hydrology). The post 1983 processing system does not provide for accumulations to span data months. The "," flag is intended to correct erroneous flag sequences in the historical data. [ Begin missing period during the hour (inclusive) ] End missing period during the hour (inclusive) { Begin deleted period during the hour (inclusive). } End deleted period during the hour (inclusive) Note... the ] and the [ and the } and the { will be placed on monthly boundaries when the period covered crosses a monthly boundary. In this way, a given months data will "stand on its own two feet". g Accompanies the Zero "day one" value. T Indicates a "trace" amount. Data value will be zero. "T" flags appear on NWS First Order data only. I Incomplete data. Daily totals only. M Missing data. No data available for this period. GAGE data flags. Beginning January 1996, the data contains the archive of the original gage translation data. These data are in units of gage weight. The element is QGAG (counterpart of QPCP). The measurement flags are: FLAG1 (measurement) a begin accumulation (indicates measurement periods overlapped) A End accumulation. [ Begin Missing ] End Missing { Begin Delete ] End Delete S gage reset FIELD 11 (44): FLAG2 The Data Quality Flag. FLAG2 Table (Data Quality Flag) X Used for data prior to 1996 as part of a 1997 data rehabilitation effort. Indicates value failed an extreme value test; data are to be used with caution. Extremes tests were: 1)If the value was not an accumulated precipitation total, the value failed the one-hour statewide 100 year return period precipitation. 2)If the value was an accumulated precipitation total, the value failed the 24-hour statewide extreme precipitation total. Z Used since January 1996. Indicates probable amounts as a result of melting frozen precipitation. When assigned to a daily total, it indicates some or all of the total contains values assigned a flag of Z. This flag may be used to identify those sites that are deficient in how the snow shields are employed. R Used since January 1996. Indicates data values are suspect with regard to the times or period of occurrence. When assigned to a daily total, it indicates data with suspect "times" are included in the daily amount. Q Used since January 1996. A single erroneous datum (value will be present.) Lowest data resolution is hourly. This data value is excluded from the daily total. q Used since January 1996. An hourly value excludes one or more 15 minute periods. Lowest data resolution is 15 minutes. A Accumulated period and amount. An accumulated period indicates that the precipitation amount is correct, but the exact beginning and ending times are only known to the extent that the precipitation occurred sometime within the accumulation period. The begin accumulation period 'data value' in Field 010 will always be 099999. The examples below do not represent the actual data format. They are used to illustrate the use of data measurement FLAG1. !!!!!!!!!!!!!!!!!!!!!N O T I C E !!!!!!!!!!!!!!!!!!!!! EFFECTIVE WITH THE JANUARY 1996 DATA, THE FLAG1 ELEMENT(ABOVE) IS DEFINED AS FOLLOWS: Z Indicates probable amounts as a result of melting frozen precipitation. When assigned to a daily total, it indicates some or all of the total contains values assigned a flag of Z. This flag may be used to identify those sites that are deficient in how the snow shields are employed. R Indicates data values are suspect with regard to the times or period of occurrence. When assigned to a daily total, it indicates data with suspect "times" are included in the daily amount. B A single missing datum. Q A single erroneous datum (value will be present). P A daily total excludes erroneous value(s) (flagged Q). D Deleted Flag. Beginning and ending of a deleted period. A deleted value indicates that the original data were received, but were unreadable or clearly recognized as noise. Example 1: 01 0015099999Ab 01 2500 099999Ib 02 1345000080Ab 02 2500 000080Ib. (Precipitation on the 1st day of month began accumulating at 0015 hours. At 2500 hours (daily total) was listed as incomplete (I). On day 02, the accumulation period ended at 1345 hours at which .80 inch of precipitation was measured. The daily total on day 02 was listed as incomplete due to the accumulation period from day 01 to day 02.) Example 2: 01 0630099999Ab 01 221500140Ab. Accumulation of 1.40 inches of precipitation was recorded from 0630 hours to 2215 hours on day 01. NOTICE: The data prior to January 1996 will have a blank followed by 99999D to indicate a deleted time period. The data from January 1996 to current will have a delete denoted by 099999D. GAGE data flags. Beginning January 1996, the data contains the archive of the original gage translation data. These data are in units of gage weight. The element is QGAG (counterpart of QPCP). The data quality flags are: FLAG 2 (Quality) Q Questionable value. Data not used. P Punch mechanism failure, missing punch assumed. Assumed punch value being used. V Evaporation likely. Gage value has dropped. Data are being used. FLAG EXAMPLES This precipitation accumulation occurs from 1st month, day 02 to 2nd month, day 04. Month Day Hour Data Value 01 0002 0500 000030bb 1115 099999Ab (Accumulation begins) 2500 000030Ib (Daily total incomplete) 02 0001 0100 099999Ab (Accumulation continues) 2500 099999Ib (Daily total) 0004 0845 000390Ab (3.90 inches) 2500 000390Ib (Daily total incomplete) This precipitation accumulation occurs for 1 month only. 01 0001 0015 099999Ab (Accumulation begins) 2500 099999Ib (Daily total incomplete) 0031 2400 000320Ab (3.20 inches) 2500 000320Ib (Daily total incomplete) This example includes several types of flags through month 01 and 02. 01 0001 0015 000008bb (.08 inches) 1145 099999Ab (Accumulation begins) 2500 000008Ib (Daily total incomplete) 02 0001 0015 099999Ab (Accumulation continues) 1430 000340Ab (Accumulation ends) 1545 099999Db (Deleted period begins) 2500 000340Ib (Daily total incomplete) 02 0028 1330 099999Db (Deleted period ended) 1600 099999Mb (Missing data) 2300 099999Mb (Missing data) 2500 099999Ib (Daily total incomplete) This example represents no chart or data record were received at NCDC for month 01 and 02. 01 0001 0015 099999Mb (Missing data) 2500 099999Mb 0031 2400 099999Mb 2500 099999Mb 02 0001 0015 099999Mb 2500 099999Mb 0028 2400 099999Mb 2500 099999Mb NOTE: blank = b 17. Summary: This digital file was originally maintained on the 15-Minute Fischer-Porter Data (TD-9927) file. This digital file contained the period of record from May 1971 through December 1983. Data before 1984 were converted from existing digital files (TD-9927) to the element structure format. These (historical) data were processed through a gross value check only. Beginning January 1984 the 15-minute precipitation data were processed through a completely revised system which produces the element structure data base file. This system was further enhanced beginning with the January 1996 data month. The new interactive quality control system introduced many added features. Data are subjected to new computer editing procedures reducing the manual handling of the data.