                       OCTOBER 08, 1999   

                     MONTHLY SURFACE DATA
                       (PRIMARILY U.S.)

                 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): COOPERATIVE STATION NUMBER

This 6-character alphanumeric station identifier is assigned by the
National Climatic Data Center.  The first two digits refer to a state
code (value range is 01-91; reference Table "A").  The next four
digits refer to the Cooperative Network Index number (value range
is 0001-9999).  Missing/not assigned = 999999.


FIELD 2   (8-12): WBAN STATION NUMBER

This 5-character alphanumeric station identifier is assigned by the
National Climatic Data Center.  It originally referred to Weather Bureau,
Army, and Navy (WBAN) stations which mailed weather observational forms to
NCDC.  These stations normally have more detailed data available than strictly
cooperative stations, so stations with WBAN numbers will usually have
additional data elements.


Optional Field (14 - 43):  STATION NAME

This 30-character alphanumberic 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 = 45-46).


FIELD 3  (14-15): DIVISION NUMBER

These two digits refer to the Cooperative Network Division Number (value range
is 01-10; 99 = missing Division Number; reference Table "B").

 
Field 4  (17-20):  ELEMENT TYPE

The type of data element stored in this record.  Range is listed
below.  (Metric units were used by most of the Caribbean
countries except Puerto Rico and the Virgin Islands.)
 
          CLDD Monthly cooling degree days - base 65 deg. F.  (1980
               onward.)
 
          DP01 Number days with greater than or equal to 0.1 inch 
		   precipitation.  (1954 onward.)
 
          DP03 Number days with greater than or equal to 3.0 millimeters
               precipitation.  (Metric stations only.)
 
          DP05 Number days with greater than or equal to 0.5 inch 
		   precipitation.  (1951 onward.)
 
          DPOH Number days with greater than or equal to 0.01 inch 
		   precipitation.  (Only before 1954.)
 
          DPOQ Number days with greater than or equal to 0.25 inch 
		   precipitation.  (Only before 1951.)
 
          DP10 Number days with greater than or equal to 1.0 inch 
		   precipitation.
 
          DP25 Number days with greater than or equal to 25.0 millimeters 
		   precipitation.  (Metric stations only.)
 
          DP50 Number days with less than or equal to 50.0 millimeters 
		   precipitation.  (Metric stations only.)
 
          DPNP Departure from normal monthly precipitation.
 
          DPNT Departure from normal monthly temperature.
 
          DSNW Number days with snow depth greater than or equal to 1 inch.
 
          DT00 Number days with minimum temperature less than or equal
	         to 0 deg. F.
 
          DT15 Number days with maximum temperature less than or equal 
		   to 15 deg. C.  (Metric stations only.)
 
          DT30 Number days with maximum temperature greater than or equal 
		   to 30 deg. C.  (Metric stations only.)
 
          DT32 Number days with minimum temperature less than or equal 
		   to 32 deg. F.
 
          DT60 Number days with minimum temperature less than or equal 
		   to 59 deg. F.  (Puerto Rico and Virgin Islands only.)
 
          DT70 Number days with maximum temperature greater than or equal 
		   to 70 deg. F.  (Alaska only.)
 
          DT90 Number days with maximum temperature greater than or equal 
               to 90 deg. F.
 
          DX15 Number days with maximum temperature less than or equal 
		   to 15 deg. C.  (Metric stations only.)
 
          DX32 Number days with maximum temperature less than or equal 
               to 32 deg. F.
 
          DX60 Number days with maximum temperature less than or equal 
               to 59 deg. F.  (Puerto Rico and Virgin Islands only.)
 
          EMXP Extreme maximum daily precipitation in the month.
               (Contains the day of occurrence in the DAY field.)
 
          EMNT Extreme minimum temperature for the month.
               (Contains the day of occurrence in the DAY field.)
 
          EMXT Extreme maximum temperature for the month.
               (Contains the day of occurrence in the DAY field.)
 
          FRZD Freeze Data
 
          Freeze data contains the dates of the last spring (01
          January through 30 June) and the first fall occurrences
          (01 July through 31 December) for five thresholds of
          temperature (16, 20, 24, 28, and 32 deg. F).  The MONTH
          and DAY fields contain the date of occurrence.  The
          DATA-VALUE field contains the sign and actual temperature.
 
          Example:  The first threshold position that represents
                    the last occurrence of a temperature less
                    than or equal to 16 deg. F in the spring will 
                    appear as 020700016 (February 7th, temperature
                    was 16 deg. F.) (Reference Table C)
 
          HTDD Monthly heating degree days - base 65 deg. F.  (July
               1950 onward.)
 
          MMNP Monthly mean minimum temperature of evaporation
               pan water.
 
          MMNT Monthly mean minimum temperature.
 
          MMXP Monthly mean maximum temperature of evaporation
               pan water.
 
          MMXT Monthly mean maximum temperature.
 
          MNTM Monthly mean temperature.
 
          MXSD Maximum snow depth during the month.  (Contains
               the day of occurrence in the DAY field.)
 
          TEVP Total monthly evaporation.
 
          TPCP Total monthly precipitation.
 
          TSNW Total monthly snowfall.
 
          TWND Total monthly wind movement (in miles) over
               evaporation pan.
 
 
                            SOIL DATA
 
          Soil records are from 1982 forward.  The last two
          digits on soil element names represent codes for soil
          cover and soil depth.  Example: "MN11" represents the
          element name for mean monthly soil temperature of grass
          cover at 2 inches and/or 5 cm.  There is no distinction
          whether the depth reading is read in inches or
          centimeters.  See  "Known Uncorrected
          Problems" section before using soil records.
          When using soil data you must examine the FLAG-1 and
          FLAG-2 fields.  FLAG-1 field contains flags to
          determine if temperature at observation time was taken
          in the morning or the evening (AM or PM).  FLAG-2 field
          determines if the observation taken is a subplot within
          the primary plot.
 
          MNyz      Monthly mean minimum soil temperature.
 
          HNyz      Highest minimum soil temperature for the
                    month.
 
          LNyz      Lowest minimum soil temperature for the
                    month.
 
          MOyz      Monthly mean soil temperature at observation
                    time.
 
          HOyz      Highest soil temperature at observation time.
 
          LOyz      Lowest soil temperature at observation time.
 
          MXyz      Monthly mean maximum soil temperature.
 
          HXyz      Highest maximum soil temperature for the
                    month.
 
          LXyz      Lowest maximum soil temperature for the
                    month.
 
          CODE (y = Code for soil cover)
               (z = Code for soil depth)
               (Reference TABLE D.)
 

Field 5  (22-23):  ELEMENT UNIT

The units and decimal position of the data value for this record.
(Reference TABLE E - Range of values.)
 
 
Field 6  (25-28):  YEAR

This is the year of record.  Range = 1831-present.
 

Field 7  (30-30):  AM-PM

(Soil temperatures only.)  Indicator used to determine if the
soil temperature at observation time was taken in the morning or
the evening. (Reference TABLE F.)
 
 
Field 8  (32-32):  SUB-PLOT

(Soil temperatures only.)  Indicator used to determine if the
observation is for a primary plot or a plot within a primary plot
(subplot) (Reference TABLE G).


Field 9  (34-35): MONTH

Month of element value.  Range = 1-13.  13 => annual value.
 

Field 10 (37-38): DAY

Day of element value, if applicable.  Range = 00-31.  00 => elements
are monthly means or number of days of occurrences of precipitation
and/or temperatures within specified limits as listed in the
ELEMENT TYPE field.
 
 
Field 11 (40-45): DATA-VALUE

Actual data value.  The first position of this field is the
"sign" of the meteorological data value.  This position contains
either a blank or a minus sign (never a plus sign).  The remaining
positions of this field contain a five-digit integer.  Units and
decimal position are indicated by the ELEMENT UNITS field.


Field 12 (47-47): FLAG-1

Data Measurement Flag.
 
          A    Accumulated amount.  This value is a total that
               may include data from a previous month or months
               (TPCP).
 
          B    Adjusted Total.  Monthly value totals based on
               proportional available data across the entire
               month.  (CLDD, HTDD, TEVP, TWND)
 
          E    An estimated monthly or annual total.
 
          I    Monthly means or totals based on incomplete time
               series.  1 to 9 days are missing.  (DSNW, MMNT,
               MMXP, MMXT, MNTM, TPCP, TSNW)
 
          M    "M" is used to indicate data element missing.
 
          S    Precipitation for the amount is continuing to be
               accumulated.  Total will be included in a
               subsequent value (TPCP).
 
               Example:  Days 1-20 had 1.35 inches of
               precipitation, then a period of accumulation
               began.  The element TPCP would then be 00135S and
               the total accumulated amount value appears in a
               subsequent monthly value.
 
               If TPCP = "99999" there was no precipitation
               measured during the month.  Flag 1 is set to "S"
               and the total accumulated amount appears in a
               subsequent monthly value.
 
          T    Trace of precipitation, snowfall, or snowdepth.
               The precipitation data value will = "00000".
               (EMXP, MXSD, TPCP, TSNW)
 
          +    The phenomena in question occurred on several
               days.  The date in the DAY field is the last day
               of occurrence.
 
     (blank)   No report when data value = "99999".
 

Field 13 (49-49): FLAG-2

Data Quality FLAG.  FLAG-2 is only used if FLAG-1 contains "T".
Freeze data is the only exception. 
 
          A    Accumulated amount.
          E    Estimated value.
          +    Value occurred on more than 1 day - last date of
               occurrence is used.


FIELDS 9-13 are then repeated for each month of the year, beginning with
01 in the MONTH field, and ending with 13 in the MONTH field.  So, the data
for MONTH 02 will occupy columns 51-66, MONTH 03 = 68-83, etc.

 
Known Uncorrected Problems:

     There are sporadic instances of duplicate data records,
     in which an element (e.g., TPCP) for a year has two data
     records instead of one.  In these cases, one of the data
     records will contain mostly missing values, while the 2nd
     data record will have the remainder of the data.  You can
     combine the 2 records to obtain the most complete data for
     the affected year.
      
     The historical data were converted from existing digital
     files and structured into the element structure format.
     These data were processed through a gross value check and
     not the current edit system.  It is NCDC's goal to bring
     these historical files up to the same level of quality as
     those from 1982 onward as resources become available.
 
     Soil data were added in January 1982 with approximately 250
     stations reporting soil data.  Soil data before 1982 are
     available in TD9639.  In January 1987, the 1982 and 1983
     soil data were removed due to poor data quality.
 
     There may be a few cases in which precipitation and
     temperature are in metric units but are not labeled as such
     in the "Element Units" field.  This seems to be limited to
     data from the early 1960's from the U.S. Virgin Islands and
     Puerto Rico.
 

                             TABLES


                      *******Table A*******

  State Code Table
 
          01 Alabama          43 Vermont
          02 Arizona          44 Virginia
          03 Arkansas         45 Washington
          04 California       46 West Virginia
          05 Colorado         47 Wisconsin
          06 Connecticut      48 Wyoming
          07 Delaware         49 Not Used
          08 Florida          50 Alaska
          09 Georgia          51 Hawaii
          10 Idaho            60 Bahamas
          11 Illinois         61 Turks & Caicos Islands
          12 Indiana          62 Cuba
          13 Iowa             63 Jamaica
          14 Kansas           64 Haiti
          15 Kentucky         65 Dominican Republic
          16 Louisiana        66 Puerto Rico
          17 Maine            67 Virgin Islands
          18 Maryland         68 Netherlands Antilles, North
          19 Massachusetts    69 Antigua, Leeward Islands
          20 Michigan         70 Guadeloupe
          21 Minnesota        71 Martinique
          22 Mississippi      72 Grenada, Windward Islands
          23 Missouri         73 Tobago
          24 Montana          74 Trinidad
          25 Nebraska         75 Netherlands Antilles, South
          26 Nevada           76 British Guiana
          27 New Hampshire    77 Surinam
          28 New Jersey       78 Venezuela
          29 New Mexico       79 Colombia
          30 New York         80 French Guiana
          31 North Carolina   81 British Honduras
          32 North Dakota     82 Costa Rica
          33 Ohio             83 El Salvador
          34 Oklahoma         84 Guatemala
          35 Oregon           85 Honduras
          36 Pennsylvania     86 Nicaragua
          37 Rhode Island     87 Panama Canal Zone
          38 South Carolina   88 Mexico
          39 South Dakota     90 Barbados
          40 Tennessee        91 Pacific Islands
          41 Texas            96 Canada
          42 Utah
 
     NOTE:  STATE NUMBER     PERIOD OF RECORD
                 60             1960-1967
            61-65, 68-88        1960-1964 (overall)



                      *******TABLE B*******

  Division Table

               HAWAII (51)
 
          ISLAND    DIVISION
 
          Kauai        01
          Oahu         02
          Molokai      03
          Lanai        04
          Maui         05
          Hawaii       06
 
          Hawaii's division numbers were changed during the
          initial conversion of this file.  Divisions within
          islands no longer exist; however, division numbers now
          represent each island.
 
               PACIFIC (91)
 
          DIVISION
 
          02 - East of 180th Meridian - Phoenix Islands, Line
               Islands, and American Samoa
          03 - Western Pacific Islands, North of 12N.
          04 - Caroline and Marshall Islands



                      *******TABLE C*******

 
  FREEZE DATA TABLE
 
          Threshold         Meaning
          Position
 
               1          Temp less than or equal to 16 deg. F  Last occurrence in the
               2          Temp less than or equal to 20 deg. F  spring.
               3          Temp less than or equal to 24 deg. F
               4          Temp less than or equal to 28 deg. F
               5          Temp less than or equal to 32 deg. F
               6          Temp less than or equal to 16 deg. F  First occurrence in the
               7          Temp less than or equal to 20 deg. F  fall.
               8          Temp less than or equal to 24 deg. F
               9          Temp less than or equal to 28 deg. F
              10          Temp less than or equal to 32 deg. F
 
          For no occurrences: MONTH     = 99
                              DAY       = 99
                              DATA-VALUE = -99999
                              FLAG-1     = M
                              FLAG-2     = +



                      *******TABLE D*******

  SOIL DATA TABLE

          y = 1 Grass           CODE     Depth      Depth
              2 Fallow          (z=)    (inches)     (cm)
              3 Bare ground
              4 Brome grass       1         2          5
              5 Sod               2         4         10
              6 Straw mulch       3         8         20
              7 Grass muck        4        20         50
              8 Bare muck         5        40        100
              0 Unknown           0      unknown



                      *******TABLE E*******

  ELEMENTS TABLE

          C    Whole deg. C (right justified)
          D    Whole Fahrenheit degree days (right justified)
          F    Whole deg. F (right justified)
          HI   Hundredths of inches
          I    Whole inches (right justified)
          M    Whole miles (right justified)
          MH   Miles per hour
          MM   Millimeters
          NA   No units applicable (non-dimensional)
          TC   Tenths of deg. C
          TF   Tenths of deg. F
          TI   Tenths of inches
          TM   Tenths of millimeters
          1    Soils - deg. F, soil depth in inches and 100ths
          2    Soils - deg. C, soil depth in whole centimeters
          3    Soils - deg. C, soil depth in inches and 100ths
          4    Soils - deg. F, soil depth in whole centimeters
          5    Soils - If the soil station closed during the
               current month, the "5" indicates the station has
               closed.  At the end of the current processing
               year, the "5" will not appear in the annual TD3220
               file.



                      *******TABLE F*******

  SOIL OBSERVATION FLAG TABLE

          A = Temperature reading at AM
          P = Temperature reading at PM
          9 = Not applicable



                      *******TABLE G********

  SUB-PLOT FLAG TABLE

          0 = Station plot only
          1 = 1st subplot
          2 = 2nd subplot
          3 = 3rd subplot
          4 = 4th subplot
          8 = 8th subplot
          9 = Not applicable
 


