Precipitation for Idaho; Average Monthly and Annual (1961-90) (Raster)

Frequently-asked questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. Where did the data come from?
  2. What changes have been made?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
  6. Is there some other way to get the data?
  7. What hardware or software do I need in order to use the data set?
• Who wrote the metadata?

These data are spatially gridded precipitation of average monthly and annual precipitation for the climatological period 1961-90.  Distribution of the point measurements to a spatial grid was accomplished using the PRISM model, developed by Chris Daly of PRISM Services/Oregon State University. Care should be taken in estimating precipitation values at any single point on the map. Precipitation estimated for each grid cell is an average over the entire area of that cell; thus, point precipitation can be estimated at a spatial precision no better than half the resolution of a cell. For example, the Oregon precipitation data was distributed at a resolution of approximately 4km. Therefore, point precipitation can be estimated at a spatial precision no better than 2km. However, the overall distribution of precipitation features is thought to be accurate. For further information, the online PRISM homepage can be found at http://www.ocs.orst.edu/prism/prism_new.html>.

There are many methods of interpolating precipitation from monitoring stations to grid points. Some provide estimates of acceptable accuracy in flat terrain, but few have been able to adequately explain the extreme, complex variations in precipitation that occur in mountainous regions.  Significant progress in this area has been achieved through the development of PRISM (Parameter-elevation Regressions on Independent Slopes Model). PRISM is an analytical model that uses point data and a digital elevation model (DEM) to generate gridded estimates of monthly and annual precipitation (as well as other climatic parameters). PRISM is well suited to regions with mountainous terrain, because it incorporates a
conceptual framework that addresses the spatial scale and pattern of orographic precipitation.

1. How should this data set be cited?
   
   
   University of Idaho Library , Oregon Climate Service, 19991122, Precipitation for Idaho; Average Monthly and Annual (1961-90) (Raster): University of Idaho Library, Moscow, Idaho.
   
   
   Online links:

   • http://www.insideidaho.org/data/statewide/ocs/imap/ppt_id_ocs/ppt_id_ocs/metadata.xml

   
   
2. What geographic area does the data set cover?
   
   
   Bounding coordinates:

   West: -117.54391667

   East: -110.62758314

   North: 49.00517911

   South: 41.93336634
   
   
3. What does it look like?
   
   
   http://www.insideidaho.org/data/statewide/ocs/atlas/ppt_id_ocs.gif (GIF)

   Mean annual precipitation
   
   
   
   
4. Does the data set describe conditions during a particular time period?
   
   
   Beginning date: 1961

   Ending date: 1990
   Currentness reference:

   Climatological period from which the point observations were taken.

   
   
5. What is the general form of this data set?
   
   
   Geospatial data presentation form: map
   
   
6. How does the data set represent geographic features?
   
   
   1. How are geographic features stored in the data set?
      
      
      This is a Raster data set. It contains the following raster data types:

      • Dimensions 199 x 128 x 1, type Grid Cell
      
      
   2. What coordinate system is used to represent geographic features?
      
      
      The map projection used is Transverse Mercator.

      
      

      Projection parameters:

      Transverse Mercator

      Scale factor at central meridian: 0.999600

      Longitude of central meridian: -114.000000

      Latitude of projection origin: 42.000000

      False easting: 500000.000000

      False northing: 100000.000000

      
      

      Planar coordinates are encoded using Row and Column.

      Abscissae (x-coordinates) are specified to the nearest 3951.765262.

      Ordinates (y-coordinates) are specified to the nearest 3951.765262.

      Planar coordinates are specified in meters.

      
      

      The horizontal datum used is North American Datum of 1927.

      The ellipsoid used is Clarke 1866.

      The semi-major axis of the ellipsoid used is 6378206.

      The flattening of the ellipsoid used is 1/294.9786982.

      
      
7. How does the data set describe geographic features?
   
   
   ppt_id_prism.vat

   Attribute table of ppt_id_prism (Source: Oregon Climate Service)

   
   

   ObjectID

   Internal feature number. (Source: ESRI)
                     

   
   

   Sequential unique whole numbers that are automatically generated.

   
   

   Value

   Internal feature number for GRIDs (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	1
   Maximum:	12234

   
   

   Count

   Number of GRID cells of a VALUE (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	1
   Maximum:	2

   
   

   Ppt_01

   Mean precipitation for January (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	868
   Maximum:	37735
   Units:	mm*100

   
   

   Ppt_02

   Mean precipitation for February (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	600
   Maximum:	30289
   Units:	mm*100

   
   

   Ppt_03

   Mean precipitation for March (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	544
   Maximum:	29003
   Units:	mm*100

   
   

   Ppt_04

   Mean precipitation for April (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	1124
   Maximum:	19335
   Units:	mm*100

   
   

   Ppt_05

   Mean precipitation for May (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	1550
   Maximum:	18778
   Units:	mm*100

   
   

   Ppt_06

   Mean precipitation for June (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	1734
   Maximum:	19607
   Units:	mm*100

   
   

   Ppt_07

   Mean precipitation for July (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	409
   Maximum:	14453
   Units:	mm*100

   
   

   Ppt_08

   Mean precipitation for August (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	702
   Maximum:	13110
   Units:	mm*100

   
   

   Ppt_09

   Mean precipitation for September (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	1071
   Maximum:	13321
   Units:	mm*100

   
   

   Ppt_10

   Mean precipitation for October (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	879
   Maximum:	15757
   Units:	mm*100

   
   

   Ppt_11

   Mean precipitation for November (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	1215
   Maximum:	39919
   Units:	mm*100

   
   

   Ppt_12

   Mean precipitation for December (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	1151
   Maximum:	39041
   Units:	mm*100

   
   

   Ppt_14

   Mean annual precipitation (Source: Oregon Climate Service)
                     

   
   

   Range of values
   Minimum:	17151
   Maximum:	268752
   Units:	mm*100

   
   
   Entity and attribute overview:

   Monthly and annual precipitation

   
   

   Entity and attribute detail citation:

   None

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   
   
   • University of Idaho Library
   • Oregon Climate Service
   
   
2. Who also contributed to the data set?
   
   
3. To whom should users address questions about the data?
   
   
   Oregon Climate Service at Oregon State University

   Strand Ag Hall 326,
   
   Oregon Climate Service,
   Oregon State University
   

   Corvallis, OR 97331-2209

   USA

   
   

   541-737-5705 (voice)

   541-737-5710 (FAX)

   oregon@oce.orst.edu

Display and/or analyses requiring spatially distributed monthly or annual precipitation for the climatological period 1961-90.

1. Where did the data come from?
   
   
   CLIM81 (source 1 of 5)

   
   

   National Climatic Data Center (NCDC), 1991, U.S. National 1961-1990 Climate Normals, Climatography of the United States No. 81.: National Climatic Data Center (NCDC), Asheville, NC, USA.

   
   

   Type of source media: digital files

   Source contribution:

   Location and values of known average monthly and annual precipitation.

   
   
   SNOTEL (SNOwpack TELemetry) (source 2 of 5)

   
   

   National Resource Conservation Service, 1991, Cooperative Snow Survey Data of Federal-State-Private Cooperative Snow Surveys.: Cooperative Snow Survey Data of Federal-State-Private Cooperative Snow SurveysAnnual issue for Western US states, Natural Resources Conservation Service, Water and Climate Center, Portland, OR, USA.

   
   

   Type of source media: digital files, paper reports, online

   Source contribution:

   Location and values of known average monthly and annual precipitation.

   
   
   LOCAL (source 3 of 5)

   
   

   Natural Resources Conservation Service, Water and Climate Center, Unpublished Material, Local precipitation monitoring networks.

   
   

   Type of source media: digital

   Source contribution:

   Location and values of known average monthly and annual precipitation.

   
   
   DEM (source 4 of 5)

   
   

   Defense Mapping Agency, 1985, 1:250,000-scale Digital Elevation Models (DEM) also known as 1-Degree DEMs: U.S. Geological Survey, Washington, DC.

   
   

   Online links:

   • http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/ndcdb.html

   
   

   Type of source media: digital tape media

   Source contribution:

   Terrain surface input to PRISM model for estimation of precipitation between known points.

   
   
   PPT_OCS (source 5 of 5)

   
   

   Chris Daly of Oregon State University and George Taylor of the Oregon Climate Service at Oregon State University, 199804, Idaho Average Monthly or Annual Precipitation, 1961-90: Water and Climate Center of the Natural Resources Conservation Service, Portland, Oregon, USA.

   
   

   Online links:

   • http://www.ocs.orst.edu/pub/maps/Precipitation/Total/States/ID/id_rast_meta.html

   
   

   Type of source media: online

   Source contribution:

   13 Gridded ASCII files
   
   Latitude_Resolution: .04166666666
   Longitude_Resolution: .04166666666
   Geographic_Coordinate_Units: Decimal degrees
   Geodetic_Model:
   Horizontal_Datum_Name: World Geodetic Spheroid 1972 (WGS 1972)
   Ellipsoid_Name: WGS72
   Semi-major_Axis: 6378135.0
   Denominator_of_Flattening_Ratio: 298.26
   

   
   
2. What changes have been made?
   
   
   Date: 199804 (change 1 of 2)

   It is beyond the scope of this metadata to document the processes involved in generating spatially gridded precipitation using the PRISM model. However, the processes are documented in numerous conference proceedings and journal articles. The references can be found online at http://www.ocs.orst.edu/prism/prism_new.html.

   
   

   Person responsible for change:
   

   Oregon Climate Service at Oregon State University

   Strand Ag Hall 326,
   
   Oregon Climate Service,
   Oregon State University
   

   Corvallis, OR 97331-2209

   USA

   
   

   541-737-5705 (voice)

   541-737-5710 (FAX)

   oregon@oce.orst.edu

   
   

   Data sources used in this process:

   • CLIM81
   • SNOTEL (SNOwpack TELemetry)
   • LOCAL
   • DEM

   
   
   Date: 19991122 (change 2 of 2)

   These data were acquired from the PRISM web site (http://www.ocs.orst.edu/prism/prism_new.html) for use on the INSIDE Project.
   
   Specifically, the Monthly and Annual Precipitation gridded ASCII files with ARC/INFO headers (thirteen files) were downloaded from the PRISM web site.  The ASCII data were converted to ARC/INFO grids using ASCIIGRID (nearest neighbor; default cell size).  The thirteen grids were then projected to IDTM using the following method:
   
   The most accurate way to convert between WGS84 or WGS72 and NAD27is the following:
   
   1.) PROJECT the dataset from "DATUM WGS84" to "DATUM NAR_C" (uses three parameter method).
   
   2.) Use PROJECTDEFINE to update the datum to "DATUM NAD83".
   
   3.) PROJECT from "DATUM NAD83" to "DATUM NAD27" (uses NADCON method).
   
   This two step method takes advantage of the fact that the most accurate way to convert between NAD83 and NAD27 is the NADCON method.
   
   The thirteen grids were combined into one grid coverage.
   
   This metadata file was created in SMMS using metadata downloaded with the gridded ASCII files.
   

   
   

   Person responsible for change:
   

   Lily Wai

   University of Idaho Library

   Head of Government Documents

   University of Idaho Library

   Moscow, ID 83844-2350

   USA

   
   

   208-885-6344 (voice)

   208-885-6817 (FAX)

   lwai@uidaho.edu

   Hours of Service: 9:00 am - 5:00 pm, Monday - Friday

   
   

   Data sources used in this process:

   • PPT_OCS

   
   

1. How well have the observations been checked?
   
   
2. How accurate are the geographic locations?
   
   

   Accuracy of this data set is based on the original specification of the Defense Mapping Agency (DMA) 1 degree digital elevation models (DEM). The stated accuracy of the original DEMs are 130 m circular error with 90% probability.

   
   
3. How accurate are the heights or depths?
   
   
4. Where are the gaps in the data? What is missing?
   
   

   Point estimates of precipitation originated from the following sources: National Weather Service Cooperative (COOP) stations, 2) Natural Resources Conservation Service (NRCS) SNOTEL, 3) local networks. All COOP station data were subjected to quality control checks by the National Climatic Data Center (NCDC).

   
   
5. How consistent are the relationships among the observations, including topology?
   
   

   All data were based on the same averaging period (1961-1990). Similar quality assurance procedures were used with all input data sets.

   
   

Acknowledgement of the following agencies in products derived from these data: Natural Resources Conservation Service (NRCS) Water and Climate Center, NRCS National Cartography and Geospatial Center (NCGC), PRISM Model, and the Oregon Climate Service at Oregon State University.

Who distributes the data set?


Lily Wai
University of Idaho Library
Head of Government Documents
University of Idaho Library
Moscow, ID 83844-2350
USA


208-885-6344 (voice)
208-885-6817 (FAX)
lwai@uidaho.edu
Hours of Service: 9:00 am - 5:00 pm, Monday - Friday


What's the catalog number I need to order this data set?


Downloadable Data


What legal disclaimers am I supposed to read?


Although these data have been processed successfully on a computer system at the University of Idaho Library, no warranty, expressed or implied, is made regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty.


How can I download or order the data?


• Availability in digital form:




Data format:	A directory containg the Arc/Info Grid coverage is compressed. in format TGZ (version 1.2.4 (gzip)) tar and gzip Size: 0.758
Network links:	http://www.insideidaho.org/data/statewide/ocs/archive/ppt_id_ocs.tgz



• Cost to order the data: None



Is there some other way to get the data?


What hardware or software do I need in order to use the data set?

University of Idaho Library