FORMAT FOR THE MDL U.S. AND CANADIAN SURFACE HOURLY DATA FOR 1976 THRU 1996 The MDL U.S. and Canadian Surface Hourly Data (ds472.0) is archived in an ascii format. In 1997, MDL changed the original format of the data as well as the output fields. To accomodate the new format and fields, DSS changed its ascii format of the data in 1997. Below is the description of the OLD format for the data archived for 1976 thru 1996 In most MDL/TDL documentation, this is often referred to as MOS1974.

NOTE:This format description is for the Reanalysis version of the data. The only difference between this version and the ascii version are the byte ranges of the fields.


Missing Values : If a field is missing, then the entire fields width is set to 9's. For example, if temperature is missing, the value is 999. If sea level pressure is missing, the value would be 99999, which, after dividing by 10, would become 9999.9.

byte range	Field Width	Implied Decimal Places	Parameters In Both Formats	Units	Name
35 - 36	2	0	Y		Year
37 - 38	2	0	Y		Month
39 - 40	2	0	Y		Day
41 - 42	2	0	Y		Hour
43 - 46	4	0	Y		Station ID
47 - 51	5	2	Y	degrees	LATITUDE
52 - 57	6	2	Y	degrees	LONGITUDE
58 - 60	3	0	Y		OBSERVATION TIME
61 - 61	1	0	Y	oktas	CLOUD AMOUNT 1
62 - 64	3	0	Y	100's of feet	CLOUD HEIGHT 1
65 - 65	1	0	Y	oktas	CLOUD AMOUNT 2
66 - 68	3	0	Y	100's of feet	CLOUD HEIGHT 2
69 - 69	1	0	Y	oktas	CLOUD AMOUNT 3
70 - 72	3	0	Y	100's of feet	CLOUD HEIGHT 3
73 - 74	2	0		tenths	OPAQUE SKY COVER
75 - 75	1	0		coded	OBSTRUCTION TO VISION
76 - 78	3	0		100's of feet	CEILING
79 - 79	1	0		coded	TOTAL SKY COVER
80 - 49	4	2	Y	miles	VISIBILITY
84 - 51	2	0	Y	coded	WEATHER
86 - 54	3	0	Y	degrees F	DEW POINT
89 - 57	3	0	Y	degrees	WIND DIRECTION
92 - 94	3	0	Y	knots	WIND SPEED
95 - 99	5	1	Z	knots	U-WIND COMPONENT
100 - 104	5	1	Z	knots	V-WIND COMPONENT
105 - 107	3	0	Y	degrees F	TEMPERATURE
108 - 112	5	3	Y	inches hours and hundredths	6-HR PRECIP. AMOUNT DAILY SUNSHINE AMOUNT
113 - 115	3	0	Z	degrees F	MAX OR MIN TEMP
116 - 120	5	3	Z	inches	12-HR PRECIP AMOUNT
121 - 121	1	0		coded	SEVERE WEATHER
122 - 123	2	0	Y	coded	SNOW DEPTH
124 - 128	5	2	Y	inches	6-HR SNOWFALL AMOUNT
129 - 131	3	0	Y	knots	WIND GUST SPEED
132 - 136	5	1		millibars	STATION PRESSURE
137 - 141	5	1	Y	millibars	SEA LEVEL PRESSURE

The byte ranges noted above are for the reanalysis version of the data

NOTE : Definition of Symbols for Parameters in both Formats :
        Y = Parameter is in both formats
        Z = a similar Parameter exists in the other format
  blank = Neither the parameter nor anything similar exists in the other format