NOAA Atlas 14 Precipitation Frequency Estimates in GIS Compatible Format
This web page provides access to NOAA Atlas 14 precipitation frequency estimates (with upper and lower bounds of the 90% confidence interval) in GIS compatible format. For Volumes 2 and 3, only partial duration series (PDS)-based grids are available for download; annual maximum series (AMS)-based grids can be calculated by applying ratios from Table 4.6.2 from corresponding NOAA Atlas 14 documents. For NOAA Atlas 14 Volume 1, and Volume 4 and above, both, AMS- and PDS-based grids are available for download. Please note that the precipitation frequency estimates for each volume of NOAA Atlas 14 were computed independently using all available data at the time. Some discrepancies between volumes at project boundaries are inevitable and they will generally be more pronounced for rarer frequencies.
DOWNLOAD GIS DATA
To display and interpret the data, two separate files are needed:
Zipped ASCII grids - These files contain the final, spatially interpolated, high-resolution NOAA Atlas 14 precipitation frequency estimates with confidence limits, and are the basis for the PFDS interface results.
Grid metadata file - These files contain information on projection, grid resolution, precipitation units, and other details relevant to data shown in ASCII grid files. Grid metadata files are in the XML format and are automatically downloaded with zipped ASCII grids. The grid metadata files can be also viewed and downloaded separately below.
The files either can be downloaded 1) via pull-down menu, 2) by anonymous ftp or 3) via web browser. Ftp is recommended for multiple-file downloads. To obtain precipitation frequency estimates without downloading files, please visit the PFDS interface.
1) Via pull-down menu:
2) By anonymous ftp:
Action
Type
this
Open
ftp to the server:
ftp hdsc.nws.noaa.gov
Login
as anonymous user:
anonymous
Give
the password (your email id):
myemail@company.com
Switch
to binary mode:
binary
Change
directory:
cd pub/hdsc/data/xx/ (replace "xx" with an abbreviation, abbreviations can be found at the top of the page in parenthesis, i.e. "sw" for Semiarid and California)
Get
one file:
Example: mget orb100yr24ha.zip (this will download the 100-year 24-hour ArcInfo ASCII grid for the Volume 2: Ohio River Basin and Surrounding Areas)
Get several files
Example: mget orb*yr24ha.ver3.zip (The wildcard '*' in this case will get all frequencies for the 24-hour duration)
Quit
ftp:
quit
3) Via web browser:
alternatively you can peruse the ftp directory via a browser.
www.nws.noaa.gov
