1951-80 DAILY NORMALS OF TEMPERATURE, 
                      PRECIPITATION AND DEGREE DAYS

                               TD-9641


This data set contains 6 files of daily normals of maximum, minimum, average 
(mean) temperature, heating and cooling degree days, and precipitation for  
National Weather Station and principal climatological stations, adjusted
to the station location in 1980.  The daily values are not simple arith-
metic averages of the observed daily values.  They are interpolated from
the much less variable monthly normals by use of the natural spline
function as described by Greville (1967).  The procedure involves
construction of a cumulative series of the monthly sums with the sum
for each month being assigned to the last of the month.  The cumulative
series is for an 18-month period (Oct, Nov, Dec, Jan-Dec, Jan, Feb, Mar)
so the interpolation function can adequately fit the end points of the 
annual series.  This process is applied independently to all the elements.
No normal values for Feb. 29 are included.  In common practice, the normal
values for Feb. 28 are used for Feb.29 in each leap year.

Data are in station identifier and day sort.



Reference:

Greville, T.N.E., 1967: Spline Functions, Interpolation, and Numerical
Quadrative.  Mathematical Methods of Digital Computers, Vol. 2 (edited
by Ralson, A. and H.S. Wilf). Wiley and Sons, New York.


ELEMENT                                           WIDTH    COLUMNS

STATION IDENTIFIER                                  6      001-006
ELEMENT CODE                                        1      007-007
DAY 1 VALUE                                         3      008-010
     .
     .
     .
DAY 365 VALUE                                       3     1100-1102 


ELEMENT CODE  1 = MAXIMUM TEMPERATURE (DEGREES F)
              2 = MINIMUM TEMPERATURE (DEGREES F)
              3 = MEAN TEMPERATURE (DEGREES F)
              4 = HEATING DEGREE DAYS (BASE 65 F)
              5 = COOLING DEGREE DAYS (BASE 65 F)       
              6 = PRECIPITATION (HUNDREDTHS OF INCHES)

VALUE OF -99 REPRESENTS LESS THAN 1 BUT GREATER THAN 0

ONLY NEGATIVE TEMPERATURES ARE SIGNED TO THE LEFT OF THE MOST SIGNIFICANT
DIGIT.  FIELDS ARE NOT ZERO FILLED TO THE LEFT OF A SIGNIFICANT DIGIT.
THERE IS ONE TERMINAL ZERO FOR A ZERO FIELD.