Generating NOAA Rainfall
This topic describes how to use the NOAA ATLAS 14 Rainfall Generator to generate a new storm by downloading the relevant data from the NOAA's Precipitation Frequency Data Server (PFDS), and then to import the downloaded data to the applicable NOAA design rainfall event in the Rainfall Generator dialog.
This topic also describes how to edit, import and delete an existing storm.
Generating a new storm
To generate a new storm using data downloaded from the NOAA's Precipitation Frequency Data Server (PFDS):
- Ensure that a NOAA design rainfall event has been created.
- Click the NOAA ATLAS 14 Rainfall Generator button in the Rainfall Generator dialog. The NOAA ATLAS 14 Rainfall Generator is displayed.
On the generator's Main page:
- Ensure that the Current folder shows the location of the folder where you want the downloaded zip file to be stored. You can use the Browse button ( ) to locate the relevant folder.
- Either click the Generate a new storm button or select the New option from the File menu. This displays the Rainfall data page where you can specify the rainfall parameters for the storm data.
On the Rainfall data page:
- Specify the location which denotes the centroid for the storm data to be downloaded by either clicking on a location on the map or by specifying the required location in the Latitude and Longitude fields.
Note that if you select the location on the map, the Latitude and Longitude fields are automatically populated with the coordinates for the selected location.
- If required, change any of the default settings in the Precipitation type, Data type, Timeseries type, Unit and Method fields.
- Click Continue. The relevant rainfall data is downloaded from the NOAA's Precipitation Frequency Data Server, and the Temporal distribution page is displayed where you can specify the temporal distribution parameters for the storm data.
On the Temporal distribution page:
- If you set the Method for temporal distribution to NOAA ATLAS 14 on the Rainfall data page, ensure that the applicable Distribution area is selected, and remove any checks from the Quartile and Percent of occurrence boxes for which data is not to be generated. Note that least one Quartile and Percent of occurrence box must be checked.
- If you set the Method for temporal distribution to NRCS Regional on the Rainfall data page, select the appropriate Region and Distribution type for the storm data.
- If you set the Method for temporal distribution to Huff Distribution or Bulletin 75 on the Rainfall data page, select the appropriate Catchment area for the storm data.
- Click Continue. The relevant temporal distribution data is downloaded from the NOAA's Precipitation Frequency Data Server, and the Event page is displayed.
On the Event page:
- Change the file name for this storm, which is displayed in the Name field, if required. By default, the format for the name is Storm #000 - <date>. You can change this name but you cannot use a name that is already used for another storm file located in the current folder.
- If you set the Method for temporal distribution to Alternating Block on the Rainfall data page, specify the appropriate Time series interval and select the relevant Time to peak for the storm data. The time series interval must be an integer that is divisible by 5. No decimals are allowed.
- Ensure that at least one box is checked in the Duration and ARI fields and remove any checks for the durations and ARIs for which you do not want storm data generated.
- Change the Multiplying factor if required.
- Save or import the storm data:
If you want to save the storm but do not want to import the data to a rainfall event:
- Click Save Storm to save the storm. The Main page is now displayed with the name of the newly saved storm displayed in the Current folder box.
If you want to save the storm and import the data to the NOAA rainfall event (in the Rainfall Generator dialog), then:
- Click Save Storm to save the storm. The Main page is now displayed with the name of the newly saved storm displayed in the Current folder box.
- Ensure that the name of the newly created storm is highlighted in the Current folder box.
- Click Import on the Main page. The NOAA ATLAS 14 Rainfall Generator is closed, the applicable files are unzipped and the name of each of the generated storms is displayed in the Storm grid in the Rainfall Generator dialog.
If you only want to import the storm data to the NOAA rainfall event (in the Rainfall Generator dialog), without saving the storm, then:
- Click Import in the Event page. The NOAA ATLAS 14 Rainfall Generator is closed, the applicable files are unzipped and the name of each of the generated storms is displayed in the Storm grid in the Rainfall Generator dialog.
- Close the NOAA ATLAS 14 Rainfall Generator, if not already closed, by selecting the Exit option from the File menu.
Editing a storm
As a storm file can be used in different NOAA design rainfall events, you cannot save any changes to the file being edited. A new file, with a new filename will automatically be generated. You can change the automatically generated name but you cannot use the same name as an existing file in the current folder.
To edit an existing storm:
- Open a NOAA design rainfall event.
- Click the NOAA ATLAS 14 Rainfall Generator button in the Rainfall Generator dialog. The NOAA ATLAS 14 Rainfall Generator is displayed.
- Select the name of storm you want to edit from the list of relevant storm files in the Current folder box on the Main page. If the storm you want to edit is not displayed, use the Browse button ( ) to locate the relevant folder, and then select the required storm.
- Click Edit and the Rainfall data page is displayed.
- If you want to change any of the rainfall parameters currently defined for the storm, edit the fields displayed in the Rainfall data page as required.
- Click Continue. The relevant rainfall data is downloaded from the NOAA's Precipitation Frequency Data Server, and the Temporal distribution page is displayed.
- If you want to change any of the temporal distribution parameters currently defined for the storm, edit the fields displayed in the Temporal distribution page as required.
- Click Continue. The relevant temporal distribution data is downloaded from the NOAA's Precipitation Frequency Data Server, and the Event page is displayed.
- If you want to change any of the storm parameters currently defined for the storm, edit the fields displayed in the Event page as required.
Note: A new name for the storm data file is automatically generated. You can change this name but you cannot use a name that is already used for another storm file located in the current folder.
- Save or import the storm data:
If you want to save the storm but do not want to import the data to a rainfall event:
- Click Save Storm to save the edited storm. The Main page is now displayed with the name of the newly saved storm displayed in the Current folder box.
If you want to save the storm and import the data to the rainfall event (in the Rainfall Generator dialog):
- Click Save Storm to save the edited storm. The Main page is now displayed with the name of the edited storm displayed in the Current folder box.
- Ensure that the name of the edited storm is highlighted in the Current folder box.
- Click Import on the Main page. The NOAA ATLAS 14 Rainfall Generator is closed, the applicable files are unzipped and the name of each of the generated storm is displayed in the Storm grid in the Rainfall Generator dialog.
If you only want to import the storm data to the rainfall event (in the Rainfall Generator dialog), without saving the storm, then:
- Click Import. The NOAA ATLAS 14 Rainfall Generator is closed, the applicable files are unzipped and the name of each of the generated storms is displayed in the Storm grid in the Rainfall Generator dialog.
- Close the NOAA ATLAS 14 Rainfall Generator, if not already closed, by selecting the Exit option from the File menu.
Importing a storm
To import existing, downloaded storm data to a design rainfall event:
- Click the NOAA ATLAS 14 Rainfall Generator button in the Rainfall Generator dialog. The NOAA ATLAS 14 Rainfall Generator is displayed.
- Select the name of file, which contains the downloaded data to be imported, from the list of relevant storm files in the Current folder box on the Main page. If the file you want to import is not displayed, use the Browse button () to locate the relevant folder, and then select the relevant storm file.
- Click Import. The NOAA ATLAS 14 Rainfall Generator is closed, the applicable files are unzipped and the name of each of the generated storms is displayed in the Storm grid in the Rainfall Generator dialog.
Deleting a storm
To delete existing, downloaded storm data:
- Click the NOAA ATLAS 14 Rainfall Generator button in the Rainfall Generator dialog. The NOAA ATLAS 14 Rainfall Generator is displayed.
- Select the name of file you want to delete from the list of relevant storm files in the Current folder box on the Main page. If the storm you want to delete is not displayed, use the Browse button ( ) to locate the relevant folder, and then select the relevant one.
- Click Delete, and a message is displayed checking that you do want to delete the storm file.
- Click Yes, and the selected zip file, containing the downloaded storm data, is deleted and its name is removed from the Current folder box.
- Select the Exit option from the File menu to close the NOAA ATLAS 14 Rainfall Generator.