1

    U.S.HOURLY SURFACE OBSERVATIONS (TDF14)


         THIS DATA FOR U.S. SURFACE STATIONS WAS RECIEVED FROM
    ASHEVILLE IN TDF14 FORMAT.  THE HOURLY (OR THREE-HOURLY) SURFACE
    OBSERVATIONS ARE AVAILABLE FOR 177 KEY LOCATIONS IN FIFTY STATES
    AND SOME U.S. MILITARY STATIONS OVERSEAS, AND GENERALLY START IN
    1948 AND GO THROUGH 1983.  THE DATA IS SIMILAR TO AIRWAYS CODE (AS
    OPPOSED TO SYNOPTIC CODE) AND CONTAINS MOST STANDARD WEATHER VARI-
    ABLES, EXCEPT PRECIPITATION AMOUNT; DATA FOR STATIONS NOT INCLUDED
    IN THIS DATASET MAY BE OBTAINED FROM N.C.D.C.
         IN TDF14, EACH LOGICAL RECORD HAS 6 HOURLY OBSERVATIONS (ALL
    FROM THE SAME STATION) IN TIME SERIES ORDER.  THE FORMAT ALLOWS
    SPACE FOR EACH SUCCESSIVE HOUR, WHETHER OBSERVATIONS WERE RECORDED
    HOURLY OR THREE-HOURLY; UNUSED HOURLY OBSERVATIONS ARE LEFT BLANK
    AFTER THE HOUR FIELD.  OF THE 495 8-BIT BYTES IN A LOGICAL RECORD,
    THE FIRST 15 BYTES WERE USED OFR HEADING INFORMATION, WITH THE RE-
    MAINING 480 BYTES DIVIDED INTO SIX GROUPS OF 80 BYTES, ONE FOR EACH
    HOURLY OBSERVATION.
         THE DATA WAS PUT INTO A BINARY PACKED FORMAT WHERE ALL OF THE
    DATA FOR ONE DAY (LOCAL TIME) IS TOGETHER IN ONE LOGICAL RPTOUT RE-
    CORD.  MISSING OBSERVATIONS HAVE BEEN DELETED TO SAVE TAPE SPACE AND
    AVOID NEEDLESS CHECKING OF MISSING CODES.  A DAY THAT IS PRESENT WILL
    HAVE 1 TO 24 OBSERVATIONS, DEPENDING ON THE FREQUENCY OF REPORTING.
         THE BINARY RECORD FOR A DAY HAS 128 BITS OF GENERAL STATION IN-
    FORMATION (NOT ALL BITS USED).  LATITUDE, LONGITUDE, ELEVATION, TIME
    ZONE AND NUMBER OF OBSERVATIONS IN THE RECORD WERE ADDED TO THE STA-
    TION INFORMATION PRESENT IN THE TDF14 HEADING.  THERE ARE 256 BITS
    OF DATA FOR EACH HOURLY OBSERVATION PRESENT.  THE FORMAT OF A DAILY
    REPORTS FOLLOWS, OUTLINING THE HEADING BITS AND DATA BITS; TABLES
    FROM THE TDF14 FORMAT TEXT MUST BE USED TO GET DETAILED MEANINGS OF
    THE VARIABLES.  TIME IS LOCAL STANDARD TIME.

    DEFINITIONS:

         INVALID        VALUE DECODED FROM TDF14 FORMAT CONTAINED
                        CHARACTER(S) INDICATING THE DATA FIELD
                        COULD NOT BE DIGITIZED BY ASHEVILLE

         OUT OF RANGE   VALUE DECODED FROM TDF14 FORMAT WAS NOT IN
                        RANGE OF PERMISSIBLE DATA VALUES FOR THE
                        DATA FIELD

         BAD CHARACTER  VALUE DECODED FROM TDF14 FORMAT CONTAINED A
                        CHARACTER NOT IN THE TDF14 CHARACTER SET

         MISSING        VALUE DECODED FROM TDF14 FORMAT CONTAINED
                        CHARACTER(S) INDICATING THE DATA FIELD WAS
                        NOT RECORDED

         THE NCAR BLOCKING ROUTINE RPTOUT PACKS LOGICAL RECORDS INTO
    LARGER PHYSICAL RECORDS.  THE FIRST WORD OF EACH PHYSICAL RECORD
    CONTAINS THE NUMBER OF WORDS (N) IN THE PHYSICAL RECORD.  WORD N
    IS A CHECKSUM (ADD WITH END-AROUND CARRY) OF WORDS 1 THROUTH N-1.
    THE LOGICAL RECORDS FOLLOW.  IN A LOGICAL RECORD, THE FIRST 12
    BITS ARE USED BY RPTOUT FOR THE NUMBER OF 64-BIT WORDS IN THE LO-
    GICAL RECORD, AND THE NEXT 4 BITS UNUSED, FOR A TOTAL OF 16 BITS.
    THEN, THE DATA FOLLOWS.
1

                                                                     2
    HEADER:
                   TDF14      TDF14             BINARY            NO.
    FIELD         FIELD NO.   VALUE             VALUE            OF BITS
    ********************************************************************
    RPTOUT             *                                            12

    RPTOUT(UNUSED)     *                                             4

    UNUSED             *                                             3

    TAPE DECK        001      1400 TO 1499      0 TO 99              7
    NUMBER                    INVALID           124
                              OUT OF RANGE      125
                              BAD CHARACTER     126
                              MISSING           127

    STATION          002      0 TO 99999        0 TO 99999          17
    NUMBER                    INVALID           131068
                              OUT OF RANGE      131069
                              BAD CHARACTER     131070
                              MISSING           131071

    YEAR             003      0 TO 99           0 TO 253             8
                              (YEAR-1900)       (YEAR-1800)
                              BAD CHARACTER     254
                              MISSING           255

    MONTH            004      1 TO 12           1 TO 12              4
                              OUT OF RANGE      13
                              BAD CHARACTER     14
                              MISSING           15

    DAY              005      1 TO 31           1 TO 31              6
                              INVALID           60
                              OUT OF RANGE      61
                              BAD CHARACTER     62
                              MISSING           63

    LATITUDE           *      LATITUDE IS GIVEN IN HUNDREDTHS OF    15
                              DEGREES PLUS 9000, I.E., 0 IS 90S,
                              9000 IS 0S, 16000 IS 70N, ETC.

                              90S TO 90N        0 TO 18000
                              MISSING           32767

    LONGITUDE          *      LONGITUDE IS GIVEN IN HUNDREDTHS OF   16
                              DEGREES EAST, I.E., 0 IS 0E, 18000
                              IS 180E, 27000 IS 90W, ETC.

                              0E TO 360E        0 TO 36000
                              MISSING           65535


1

    HEADER CONT'D.                                                   3

                   TDF14      TDF14             BINARY            NO.
    FIELD         FIELD NO.   VALUE             VALUE            OF BITS
    ********************************************************************
    ELEVATION          *      ELEVATION IS GIVEN IN METERS+1000     14

                              -1000 TO 9000     0 TO 10000
                              MISSING           16383

    TIME ZONE FLAG     *      TIME IS LOCAL STANDARD TIME. FLAG IS   5
                              NUMBER OF HOURS EAST OR WEST OF
     (see note at end)        GREENWICH.
                              5=EST, 6=CST, 7=MST, 8=PST, ETC.
			      RANGE IS 0 TO 12.

    NO. OF OBSERVATIONS *                       1 TO 24              5
    IN THIS RECORD                              (there are a few
						 zero counts)
    UNUSED BITS         *                                           12
1

    DATA                                                             4

                   TDF14      TDF14             BINARY            NO.
  # FIELD         FIELD NO.   VALUE             VALUE            OF BITS
 ** ********************************************************************
  1.HOUR             101      0 TO 23           0 TO 23              5
    (LOCAL STANDARD           INVALID           28
     TIME)                    OUT OF RANGE      29
                              BAD CHARACTER     30
                              MISSING           31

  2.CEILING          102(I)   1,2,3,-,&, ,A     1,2,3,4,5,6,7        3
    HEIGHT                    OTHER CHARACTER   0
    INDICATOR

  3.CEILING          102      0 TO 999          0 TO 999            10
    HEIGHT                    INVALID           1020
                              OUT OF RANGE      1021
                              BAD CHARACTER     1022
                              MISSING           1023

  4.VISIBILITY       103(I)   0 TO 5            0 TO 5               4
    INDICATOR                 M                 6
                              INVALID           12
                              OUT OF RANGE      13
                              BAD CHARACTER     14
                              MISSING           15

  5.HORIZONTAL       103      0 TO 999          0 TO 999            10
    VISIBILITY                INVALID           1020
                              OUT OF RANGE      1021
                              BAD CHARACTER     1022
                              MISSING           1023

  6.WIND DIRECTION     *      0=36PT FIELD VALUE MISSING, 16PT       2
    FLAG                        FIELD VALUE USED (AFTER 1/1/63)
                              1=VALUE IS DERIVED FROM 16 PT FIELD
                                (BEFORE 1/1/63)
                              2=VALUE IS FROM 36 PT FIELD AND
                                AGREES WITH 16 PT FIELD GIVEN
                              3=VALUE IS FROM 36 PT FIELD AND
                                DISAGREES WITH 16 PT FIELD GIVEN

  7.WIND DIRECTION   137 OR   0 TO 36           0 TO 360             9
    (SEE APPENDIX A) 104      INVALID           508
                              OUT OF RANGE      509
                              BAD CHARACTER     510
                              MISSING           511


  8.WIND SPEED       105      0 TO 199          0 TO 199             8
                              INVALID           252
                              OUT OF RANGE      253
                              BAD CHATRACTER    254
                              MISSING           255
1

    DATA CONT'D.                                                     5

                   TDF14      TDF14             BINARY            NO.
  # FIELD         FIELD NO.   VALUE             VALUE            OF BITS
 ** ********************************************************************
  9.DRY BULB  AIR    106      -130 TO 140       70 TO 340            9
    TEMPERATURE               (DEGREES F)       (DEGREES F+200)
                              INVALID           508
                              OUT OF RANGE      509
                              BAD CHARACTER     510
                              MISSING           511

 10.WET BULB         107      (SAME AS TDF14 FIELD 106)              9
    TEMPERATURE

 11.DEW POINT        108      (SAME AS TDF14 FIELD 106)              9
    TEMPERATURE

 12.RELATIVE         109(I)   &,(BLANK)         0,1                  2
    HUMIDITY                  OTHER CHARACTER   3
    INDICATOR

 13.RELATIVE         109      0 TO 100          0 TO 100             7
    HUMIDITY                  (PERCENT)         (PERCENT)
                              INVALID           124
                              OUT OF RANGE      125
                              BAD CHARACTER     126
                              MISSING           127

 14.SEA LEVEL        110      09000 TO 10900    0 TO 1999           11
    PRESSURE                  (.1 MBS)          (.1 MBS-9000)
                              INVALID           2044
                              OUT OF RANGE      2045
                              BAD CHARACTER     2046
                              MISSING           2047

 15.STATION          111      0 TO 3999         0 TO 3999           12
    PRESSURE                  (.01 HG)          (.01 HG)
                              INVALID           4092
                              OUT OF RANGE      4093
                              BAD CHARACTER     4094
                              MISSING           4095

 16.SKY CONDITION    112(I)   -                 0                    2
    INDICATOR                 (BLANK)           1
                              OTHER CHARACTER   3

 17.SKY CONDITION    112      0 TO 9            0 TO 9               4
     1ST DIGIT                -                 10
                              INVALID           12
                              OUT OF RANGE      13
                              BAD CHARACTER     14
                              MISSING           15

1

    DATA CONT'D.                                                     6

                   TDF14      TDF14             BINARY            NO.
  # FIELD         FIELD NO.   VALUE             VALUE            OF BITS
 ** ********************************************************************
 18.SKY CONDITION    112      (SAME AS TDF14 FIELD 112, 1ST DIGIT)   4
     2ND DIGIT

 19.SKY CONDITION    112      (SAME AS TDF14 FIELD 112, 1ST DIGIT)   4
     3RD DIGIT

 20.SKY CONDITION    112      (SAME AS TDF14 FIELD 112, 1ST DIGIT)   4
     4TH DIGIT

 21.TOTAL SKY        113      0 TO 9            0 TO 9               4
    COVER                     -                 10
                              INVALID           12
                              OUT OF RANGE      13
                              BAD CHARACTER     14
                              MISSING           15

 22.TOTAL OPAQUE     114      (SAME AS TDF14 FIELD 113)              4
    SKY COVER

 23.LOWEST CLOUD     115      0 TO 9            0 TO 9               4
    AMOUNT                    -                 10
                              INVALID           12
                              OUT OF RANGE      13
                              BAD CHARACTER     14
                              MISSING           15

 24.LOWEST CLOUD     116      0 TO 9            0 TO 9               5
    TYPE                      -                 10
                              K,M,N,O,P,R       11 TO 16
                              INVALID           28
                              OUT OF RANGE      29
                              BAD CHARACTER     30
                              MISSING           31

 25.LOWEST CLOUD     117      0 TO 999          0 TO 999            10
    HEIGHT OF BASE            ---               1000
                              INVALID           1020
                              OUT OF RANGE      1021
                              BAD CHARACTER     1022
                              MISSING           1023

 26.SECOND CLOUD     118      (SAME AS TDF14 FIELD 115)              4
    AMOUNT

 27.SECOND CLOUD     119      (SAME AS TDF14 FIELD 116)              5
    TYPE

 28.SECOND CLOUD     120      (SAME AS TDF14 FIELD 117)             10
    HEIGHT OF BASE

1

    DATA CONT'D.                                                     7

                   TDF14      TDF14             BINARY            NO.
  # FIELD         FIELD NO.   VALUE             VALUE            OF BITS
 ** ********************************************************************
 29.SUM OF AMOUNT    121      0 TO 9            0 TO 9               4
    OF FIRST TWO              -                 10
    CLOUD LAYERS              OTHER CHARACTER   14
                              MISSING           15

 30.THIRD  CLOUD     122      (SAME AS TDF14 FIELD 115)              4
    AMOUNT

 31.THIRD  CLOUD     123      (SAME AS TDF14 FIELD 116)              5
    TYPE

 32.THIRD  CLOUD     124      (SAME AS TDF14 FIELD 117)             10
    HEIGHT OF BASE

 33.SUM OF AMOUNT    125      (SAME AS TDF14 FIELD 121)              4
    OF FIRST THREE
    CLOUD LAYERS

 34.FOURTH CLOUD     126      (SAME AS TDF14 FIELD 115)              4
    AMOUNT

 35.FOURTH CLOUD     127      (SAME AS TDF14 FIELD 116)              5
    TYPE

 36.FOURTH CLOUD     128      (SAME AS TDF14 FIELD 117)             10
    HEIGHT OF BASE

 37.OCCURRENCE OF    129      0 TO 9            0 TO 9               4
    THUNDERSTORMS,ETC.        INVALID           12
                              OUT OF RANGE      13
                              BAD CHARACTER     14
                              MISSING           15

 38.OCCURRENCE OF    130      (SAME AS TDF14 FIELD 129)              4
    RAIN,ETC.

 39.OCCURRENCE OF    131      (SAME AS TDF14 FIELD 129)              4
    RAIN SQUALLS,ETC.

 40.OCCURRENCE OF    132      (SAME AS TDF14 FIELD 129)              4
    SNOW PELLETS,ETC.

 41.OCCURRENCE OF    133      (SAME AS TDF14 FIELD 129)              4
    SNOW SHOWERS,ETC.

 42.OCCURRENCE OF    134      (SAME AS TDF14 FIELD 129)              4
    SLEET,ETC.

1

    DATA CONT'D.                                                     8

                   TDF14      TDF14             BINARY            NO.
  # FIELD         FIELD NO.   VALUE             VALUE            OF BITS
 ** ********************************************************************
 43.OCCURRENCE OF    135      (SAME AS TDF14 FIELD 129)              4
    FOG,ETC.

 44.OCCURRENCE OF    136      (SAME AS TDF14 FIELD 129)              4
    SMOKE,ETC.

    UNUSED BITS       -                                              4

1

    ORDER OF BITS ON OUTPUT FOR HEADER:                              9
                                                    SKIP        TAKE
                                     TDF14          NUMBER      NUMBER
    FIELD NAME                    FIELD NUMBER      OF BITS     OF BITS
    *******************************************************************
    RPTOUT OVERHEAD                     -                0        16
    UNUSED                              -               16         3
    TAPE DECK NUMBER                   001              19         7
    STATION NUMBER                     002              26        17
    YEAR                               003              43         8
    MONTH                              004              51         4
    DAY                                005              55         6
    LATITUDE                            -               61        15
    LONGITUDE                           -               76        16
    ELEVATION                           -               92        14
    TIME ZONE FLAG                      -              106         5
    NUMBER OF OBSERVATIONS IN RECORD    -              111         5
    UNUSED BITS                         -              116        12
                                                               --------
    TOTAL NUMBER OF BITS IN HEADER                               128
1

    ORDER OF BITS ON OUTPUT FOR DATA:                               10
                                                      SKIP(*)   TAKE
    FIELD                              TDF14          NUMBER    NUMBER
  # NAME                            FIELD NUMBER      OF BITS   OF BITS
 ** *********************************************************************
  1 HOUR                               101               0         5
  2 CEILING HEIGHT INDICATOR           102(I)            5         3
  3 CEILING HEIGHT                     102               8        10
  4 HORIZ. VISIBILITY INDICATOR        103(I)           18         4
  5 HORIZ. VISIBILITY                  103              22        10
  6 WIND DIRECTION FLAG                 -               32         2
  7 WIND DIRECTION                  137 OR 104          34         9
  8 WIND SPEED                         105              43         8
  9 DRY BULB TEMPERATURE               106              51         9
  0 WET BULB TEMPERATURE               107              60         9
 11 DEW POINT TEMPERATURE              108              69         9
 12 RELATIVE HUMIDITY INDICATOR        109(I)           78         2
 13 RELATIVE HUMIDITY                  109              80         7
 14 SEA LEVEL PRESSURE                 110              87        11
 15 STATION PRESSURE                   111              98        12
 16 SKY CONDITION INDICATOR            112(I)          110         2
 17 SKY CONDITION  1ST                 112             112         4
 18 SKY CONDITION  2ND                 112             116         4
 19 SKY CONDITION  3RD                 112             120         4
 20 SKY CONDITION  4TH                 112             124         4
 21 TOTAL SKY COVER                    113             128         4
 22 TOTAL OPAQUE SKY COVER             114             132         4
 23 LOWEST CLOUD AMOUNT                115             136         4
 24 LOWEST CLOUD TYPE                  116             140         5
 25 LOWEST CLOUD BASE HGT.             117             145        10
 26 SECOND CLOUD AMOUNT                118             155         4
 27 SECOND CLOUD TYPE                  119             159         5
 28 SECOND CLOUD BASE HGT.             120             164        10
 29 SUM 1ST TWO CLOUD LAYER AMOUNTS    121             174         4
 30 THIRD  CLOUD AMOUNT                122             178         4
 31 THIRD  CLOUD TYPE                  123             182         5
 32 THIRD  CLOUD BASE HGT.             124             187        10
 33 SUM 1ST THREE CLOUD LAYER AMOUNTS  125             197         4
 34 FOURTH CLOUD AMOUNT                126             201         4
 35 FOURTH CLOUD TYPE                  127             205         5
 36 FOURTH CLOUD BASE HGT.             128             210        10
 37 OCCURRENCE OF THUNDERSTORMS, ETC.  129             220         4
 38 OCCURRENCE OF RAIN, ETC.           130             224         4
 39 OCCURRENCE OF RAIN SQUALLS, ETC.   131             228         4
 40 OCCURRENCE OF SNOW PELLETS, ETC.   132             232         4
 41 OCCURRENCE OF SNOW SHOWERS, ETC.   133             236         4
 42 OCCURRENCE OF SLEET, ETC.          134             240         4
 43 OCCURRENCE OF FOG, ETC.            135             244         4
 44 OCCURRENCE OF SMOKE, ETC.          136             248         4
    UNUSED BITS                         -              252         4
                                                                ----
    TOTAL NUMBER OF BITS FOR EACH OBSERVATION                    256

 (*) I.E., THE NUMBER OF BITS SKIPPED FROM BEGINNING OF THE OBSERVATION

1

                                                                    11
    APPENDIX A
    METHOD OF WIND DIRECTION CALCULATION

    WIND DIRECTION WAS RECORDED BY TWO METHODS IN TDF14, DEPENDING ON
    THE DATE OF THE OBSERVATION.  PRIOR TO JANUARY 1, 1963, WIND DIR-
    ECTION WAS CODED IN A 16PT WBAN CODE INTO TDF14 FIELD NUMBER 104.
    AFTER THIS DATE, THE WIND DIRECTION WAS RECORDED AS TENS OF DEGREES,
    PUT IN FIELD 137, AND THE APPROPRIATE WBAN CODE PUT IN FIELD 104.

    WHEN ONLY A 16PT CODE WAS AVAILABLE, THE BINARY VALUE USED WAS THE
    NEAREST WHOLE DEGREE IN THE MIDDLE OF THE RANGE FOR THAT ENTRY.
    IF A 36PT CODE WAS AVAILABLE, THE BINARY VALUE WAS CALCULATED AS
    THE FIELD VALUE TIMES 10.
    16PT     RANGE     VALUE USED
    -----------------------------
    11      349-011       360
    12      012-033       023
    22      034-056       045
    32      057-078       067
    33      079-101       090
    34      102-123       113
    44      124-146       135
    54      147-168       157
    55      169-191       180
    56      192-213       203
    66      214-236       225
    76      237-258       247
    77      259-281       270
    78      282-303       293
    88      304-326       315
    18      327-348       337
    00       CALM         000


    TIME ZONE FLAG

	To convert local standard time to Greenwich:

		For longitudes greater than 180.00E add time zone value
		to local hour and subtract 24 if result is greater than
		or equal to 24; adjust year/month/day accordingly.

		For longitudes less than 180.00E subtract time zone value
		from local hour and add 24 if result is less than
		zero; adjust year/month/day accordingly.