Wyoming Average Monthly or Annual Precipitation, 1961-90

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Frequently-anticipated questions:


What does this data set describe?

    Title: Wyoming Average Monthly or Annual Precipitation, 1961-90
    Abstract:
    This ftp site contains vector and polygon coverages of average monthly and annual precipitation for the climatological period 1961-90. Parameter-elevation Regressions on Independent Slopes Model (PRISM) derived raster data is the underlying data set from which the polygons and vectors were created. PRISM is an analytical model that uses point data and a digital elevation model (DEM) to generate gridded estimates of annual, monthly and event-based climatic parameters. Detailed descriptions of the PRISM raster data can be found with the accompanying raster data sets. For further information, the online PRISM homepage can be found at <URL:http://www.ocs.orst.edu/prism/prism_new.html>.

  1. How should this data set be cited?

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

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -111.0568923905
    East_Bounding_Coordinate: -104.0520553588
    North_Bounding_Coordinate: 45.00590515136
    South_Bounding_Coordinate: 40.99474716186

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 19610101
    Ending_Date: 31-Dec-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: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • Label point (342)
      • String
      • GT-polygon composed of chains

    2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.02083333. Longitudes are given to the nearest 0.02083333. Latitude and longitude values are specified in Decimal Degrees.

      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 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.

  7. How does the data set describe geographic features?

    RANGE
    Polygons representing an area with a fixed value of precipitation. The precipitation value is stored as the item RANGE in the attribute table. (Source: Oregon Climate Service PRISM Project)

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    AREA

    PERIMETER

    PRECIP_

    PRECIP_ID

    RANGE

    LEGEND

    CONTOUR
    Contours representing lines of equal precipitation. The precipitation value is stored as the item CONTOUR in the attribute table. (Source: Oregon Climate Service PRISM Project)

    precipitation polygons
    average precipitation polygons (Source: Daly, C., R.P. Neilson, and D.L. Phillips, 1994: A Statistical-Topographic Model for Mapping Climatological Precipitation over Mountainous Terrain. J. Appl. Meteor., 33,140-158.)

    Range of values
    Minimum:0
    Maximum:600
    Units:inches
    Resolution:2 inches

    precipitation contours
    average precipitation contours (Source: Daly, C., R.P. Neilson, and D.L. Phillips, 1994: A Statistical-Topographic Model for Mapping Climatological Precipitation over Mountainous Terrain. J. Appl. Meteor., 33,140-158.)

    Range of values
    Minimum:0
    Maximum:600
    Units:inches
    Resolution:2 inches


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  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


Why was the data set created?

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


How was the data set created?

  1. From what previous works were the data drawn?

    CLIM81 (source 1 of 4)
    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 4)
    Natural Resources Conservation Service, 1991, Cooperative Snow Survey Data of Federal - State - Private Cooperative Snow Surveys: Cooperative Snow Survey Data of Federal - State - Private Cooperative Snow Surveys Annual issue for Western US states, Natural Resources Conservation Service, Water and Climate Center, Portland, OR, USA.

    Source_Contribution:

    LOCAL (source 3 of 4)
    , Unpublished material, Local Precipitation monitoring networks.

    Type_of_Source_Media: digital files
    Source_Contribution:

    DEM (source 4 of 4)
    Agency, Defense Mapping , 1985, 1:250,000-scale Digital Elevation Models (DEM) also known as 1-Degree DEM's: U.S. Geological Survey, Washington, DC.

    Online Links:

    Type_of_Source_Media: digital files
    Source_Contribution:
    Terrain surface input to PRISM model for estimation of precipitaion between known points.

  2. How were the data generated, processed, and modified?

    Date: Apr-1998 (process 1 of 4)
    Filter raster data from a resolution of 4 km to 2 km using a Gaussian filter

    Date: Apr-1998 (process 2 of 4)
    Contour 2 km raster data

    Date: Apr-1998 (process 3 of 4)
    Convert adjacent contour lines to areas or polygons using custom software

    Date: 1905 (process 4 of 4)
    Metadata imported.

    This shapefile was reprojected and clipped to the Snake/Salt River Basin Boundary as part of the Wyoming Water Plan

  3. What similar or related data should the user be aware of?


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?

    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?

    Polygon and chain-node topology present. Checks were made to ensure that no two adjacent polygons are labeled with the same precipitation value. A manual spot check was made of peaks, depressions, and islands.


How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: n/a, no restrictions apply
Use_Constraints:
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.

  1. Who distributes the data set? (Distributor 1 of 1)

    Oregon Climate Service
    316 Strand Agricultural Hall
    Corvallis, OR 97331
    USA

    (541) 737-5705 (voice)
    (541) 737-5710 (FAX)
    oregon@oce.orst.edu

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

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    This ftp site was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or misuse

  4. How can I download or order the data?

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

    Geographic data are intended for use in a Geographic Information System


Who wrote the metadata?

Dates:
Last modified: 23-Apr-1998

Metadata author:
Tye Parzybok
Strand Ag Hall 326, Oregon Climate Service, Oregon State University
Corvallis, OR 97331-2209
USA

(541) 737-5705 (voice)
(541) 737-5710 (FAX)
parzy@oce.orst.edu

Metadata standard:
FGDC Content Standards for Digital Geospatial (FGDC-STD-001-1998)

Metadata extensions used:


Generated by mp version 2.7.33 on Wed May 19 08:45:39 2004