NOAA/National Centers for Environmental Information
NOAA's Weather and Climate Toolkit

Top of Page I ordered NEXRAD data from the HAS but the Viewer/Exporter cannot find it?

The destination location of the data orders may have changed. Please verify that you have the most recent version of the Weather and Climate Toolkit.

Top of Page I get a connection error when I enter my HAS number into the Viewer

This could be a firewall ftp configuration issue. The data can also be accessed by http by entering the following under the "Custom" tab under the "NEXRAD Data Selector":

where the x's are the HAS number assigned to your order.

Top of Page My GeoTIFFs look all black and/or white in ArcGIS?

ArcGIS seems to not handle 32-bit GeoTIFFs correctly, when using the 'Stretched' symbology. Try changing to a 'Classified' symbology with many classification breaks.

Top of Page Problems running on MacOSX versions prior to 10.7.3 (Lion)

Mac Operating Systems at versions prior to 10.7.3 (Lion) are unable to upgrade to Java 7. The Weather and Climate Toolkit, as of version 3.7, requires Java 7. The last stable release supported on Java 6 and Mac Operating Systems prior to 10.7.3 (Lion) is version 3.6.7 [download]. Please refer to the 'New Features' document for information on differences between versions. Please refer to the Oracle Java on Mac Documentation for more information on this topic.

Top of Page Problems with the data valus in 'Native NetCDF' export format for NEXRAD Level-II data

A 'Radial' NetCDF structure is used when exporting NEXRAD Level-II data to the 'Native NetCDF' format. This structure uses an 'unsigned byte' instead of the typical 'signed byte'. Before applying the scale_factor and add_offset, the byte values need to be read as unsigned bytes, with a range of 0-255. These files were written as NetCDF 3, which doesn't support the unsigned byte type directly, so an attribute is used to indicate that the user should convert from signed to unsigned after reading the data. Here are some matlab examples that might help: and

NetCDF Types:

Example metadata:
    byte Reflectivity_HI(scanR_HI=4, radialR_HI=720, gateR_HI=1832);
      :units = "dBz";
      :long_name = "Reflectivity_HI";
      :missing_value = 0B; // byte
      :signal_below_threshold = 0B; // byte
      :scale_factor = 0.5f; // float
      :add_offset = -33.0f; // float
      :_Unsigned = "true";
      :SNR_threshold = 16S; // short
      :range_folding_threshold = 50S; // short
      :_CoordinateAxes = "timeR_HI elevationR_HI azimuthR_HI distanceR_HI";
      :scale_factor_metadata = 0.5f; // float
      :add_offset_metadata = -33.0f; // float
      :range_folded_value_packed = 1B; // byte
      :range_folded_value = -32.5; // double
The user reported that after doing the signed-to-unsigned conversion, then remove the missing value (0), and applying scale_factor and add_offset, the range of values was correct:

Now i have this situation (case Reflectivity_HI(1,:,:) of the dataset that i have already sent you): 1) after signed->unsigned conversion range is [0 189] 2) after filling/missing value procedure range is [12 189] 3) after scaling/offsetting range is [-27 61.5], because scale is 0.5 and offset is -33.0

Top of Page How do I add Desktop Shortcuts or a Start Menu entry (Desktop Integration)?

Below are 4 different options for desktop integration:
  • Right-click on the 'Launch the BETA/STABLE Version x.x.x Weather and Climate Toolkit' link and save link (JNLP file) to your computer. This JNLP file (NOAA_Weather_and_Climate_Toolkit.jnlp) is all that is needed to launch the application.
  • Update this for the standalone app.

Top of Page How do I Uninstall this application?

Since the Weather and Climate Toolkit does not use a system installer, simply delete the folder that exists after downloading the file from NCEI, and delete any shortcuts created to the wct.exe program.

Top of Page General Errors and Cache Cleanup

Most of the time, errors with Java Web Start can be resolved by relaunching from the Installation Page. If errors persist, then make sure your version of Java is the most up-to-date. After these steps, a full deletion of the Web Start cache seems to clear up any remaining problems.

The errors occur when downloading, verifying or launching the application and include messages such as:

'NullPointerException' and 'found unsigned entry in resource'.

To clean up the cache, select 'Run' from the 'Start' menu and type (without quotes) "javaws -viewer". On Mac or Linux, type "javaws -viewer" from the terminal command prompt. Now from the Cache Viewer, remove all applications that are 'NOAA Weather and Climate Toolkit' or 'BETA NOAA Weather and Climate Toolkit'. Now select 'Resources' from the 'Show:' menu on the upper left and remove ALL resources. Close the Cache Viewer and Java Control Panel and retry launching the Weather and Climate Toolkit (WCT) from

If the above method doesn't work and you are still seeing errors when downloading the WCT, the cache may be manually deleted. On Windows XP, navigate to the folder C:\Documents and Settings\''\Application Data\Sun\Java\Deployment\cache . On other operating systems, the cache location can be obtained by viewing the 'Settings' for Temporary Internet Files from the Java Control Panel. (WARNING: The following will delete ALL cached applications and resources in Java Web Start) Now delete the folder '6.0'. If you are unable to delete the folder, you may need to close any open applications that use Java Web Start.