PRISM
Station File
Format Specification
Current as of: 2/12/16
PRISM reads the station data file in a fixed format, which allows for imbedded blanks in the alphanumeric
fields. The format specifications below must be followed faithfully. Stations having one or more illegal
fields are omitted from the analysis. An example station data file is provided with the model distribution
under the "data" directory.
Record 1
iproj (a3) = geographic projection of the station coordinates in this file



GEO = geodetic (latitude/longitude)
ALB = Albers Equal Area
UTM = Universal Transverse Mercator
Note: Other x,y or equal area projections not listed here should be labeled UTM or
ALB. iproj must match the projection of the DEM used in the model application.
Record 2
itype (a4) = file descriptor of user's choosing
Any 3-character alphanumeric string for file identification. Itype is not used by
PRISM, and may be left as a blank record.
Record 3 - N
Monthly station data, one record per station, 12 months and annual per record.
Each record consists of the following columns of data:
id (a8)
station ID string
Station ID is used in various diagnostic lists and outputs. Each station should have
a unique identifying string, but no checking is done by PRISM to ensure this.
lflg1 (a1)
flag for use by ASSAY statistical preprocessor
Lflg1 is an * or blank. Typical value is blank. Values other than * are treated as
blanks. When the ASSAY Operation parameter is set to either "* stn C-V
w/replacement" or "* stn C-V no replacement", setting lflg1 to an * indicates that
the station is to be processed. Those without an * are omitted from the ASSAY
analysis. ASSAY is usually operated in the "All stn C-V w/replacement" mode, in
which lflg1 is ignored.
name (a12)
station name string
Station name is used in various diagnostic lists and outputs. May have imbedded
blanks. Two stations may have the same name, but station IDs should be different.
lev (i5)
station elevation in meters
Elevation of station in meters (see lflg2).
lflg2 (a1)
station elevation flag
*, @, or blank. This flag indicates how the station elevation is to be handled. An *
forces the station elevation to be calculated from the DEM, and the elevation given
by lev (previous variable) is ignored. An @ forces the station elevation to be equal
to lev, and the DEM elevation is ignored. A blank indicates that the selection of lev
or DEM elevation is made by comparing the two values; if the absolute value of the
difference between the two is greater than Max DEM - Stn Elev Diff specified in the
General Section of the control file, then the station elevation is set to lev. If not, the
DEM elevation is used.
PRISM Station Format
-2-
xeast (f12 or i12)
station easting or longitude
Easting (longitude) of station location. When using GEO coordinates, western
hemsiphere longitudes must be given as negative values, unless the Hemisphere
parameter in the General Section of the control file is set to "Western". In this case,
positive values are used. When using GEO coordinates, PRISM checks to ensure
that xeast is between -180 and 180 and xnorth is between -90 and 90. If not, the
station is omitted.
xnorth (f12 or i12)
station northing or latitude
See description above.
p (13f6 or 13i6)
monthly parameter values + annual
Thirteen observed values for the parameter being modeled, typically 12 months
and an annual written as either floating point or integer values. For temperature
and precipitation, several choices of units and scaling factors are available (see
Units of station data in control file General Section). When modeling other
parameters, and the Modeled Parameter is set to "general" (General Section of
control file), observed values must be positive. As a rule, units that give a wide
range of values, say 0 - 5000, give best numerical results from PRISM. Scaled
integer values are often used. The acceptable range of values is 0-9999 mm or its
equivalent for precipitation, 200 - 333 degrees K or its equivalent for temperature,
and 0-9999 for general (unspecified) parameters. Records having values outside
these ranges are omitted from the analysis.
Simplified FORTRAN read of the PRISM station file:
dimension p(13)
double precision xeast,xnorth
character iproj*3, itype*4, id*8, lflg1*1, lflg2*1,
.
name*12
read(1,100) iproj
read(1,101) itype
5
read(1,102,end=99)
id,lflg1,name,lev,lflg2,xeast,xnorth,(p(ii),ii=1,13)
go to 5
99
stop
100
101
102
format(a3)
format(a4)
format(a8,a1,a12,i5,a1,2f12.0,13f6.0)
PRISM Station Format
-3-
First few lines of a PRISM precipitation station data file showing NWS cooperative observations. Station
ID strings are right-justified and have the state code in columns 3 and 4 (02 for Arizona), then the 4-digit
station ID:
GEO
TEST
020060
5
3
020080
3
2
020159
13
20
020287
5
8
020309
5
13
020380
4
12
020498
4
2
020586
8
5
020632
6
8
020670
10
5
020750
13
9
020808
12
17
020855
14
19
...
AGUILA
23
38
AJO
26
50
ALPINE
93
103
ANVIL RANCH
75
63
APACHE POWDE
93
84
ARIVACA 1 E
114
88
ASHURST HAYD
28
37
BAGDAD
38
61
BARTLETT DAM
30
43
BEAVER CREEK
39
51
BETATAKIN
37
42
BLACK RIVER
84
81
BLUE
99
101
660
24
549
25
2454
67
838
45
1125
47
1120
51
499
22
1131
33
503
36
1165
42
2221
29
1841
50
1652
68
-113.1833
21
20
-112.8667
16
17
-109.1333
54
37
-111.3833
26
15
-110.2500
31
14
-111.3167
33
22
-111.2500
19
24
-113.1667
26
34
-111.6333
28
35
-111.7167
34
35
-110.5333
31
30
-109.7667
42
32
-109.1667
61
31
33.9500
243
32.3667
25
217
33.8500
42
537
31.9833
30
331
31.9000
26
373
31.5833
42
448
33.0833
39
268
34.5667
37
379
33.8167
45
366
34.6667
35
388
36.6833
28
311
33.4833
47
490
33.5833
52
555
25
23
29
8
15
15
18
6
32
31
28
17
20
18
19
7
23
16
13
7
26
24
24
8
25
26
33
10
39
39
41
17
37
37
46
14
32
37
45
24
22
23
28
18
37
34
37
16
34
32
29
15
26
PRISM Station Format
-4-