# Presentation: 785861

## Development of the National Digital Forecast Database Web Display

- Presented by: Marc Saccucci
- NOAA/NWS/Meteorological Development Laboratory
- _http://weather.gov/forecasts/graphical_

*NOAA WebShop 2004*

## > Introduction

- The National Digital Forecast
- 	Database (NDFD) is a mosaic
- 	of official Weather Forecast
- 	Office (WFO) forecasts
- The NDFD became a new experimental public resource on the web in 2003
- Allows users and partners to create a wide range of text, graphic, and image products

## Example NDFD National Forecast Graphic

## > NDFD Web Presence

- Goal to make graphic and data rich page accessible (Section 508 Compliant)
- Challenging due to graphical nature of product and quantity of data to display

## > Scope of NDFD Data

- Approximately 15,000 forecast images updated hourly
- 5 km data resolution
- Many predefined zooms (national, sectors, states)
- Currently includes 9 forecast elements out to 7 days

- Example NDFD Forecast Image

## > NDFD Predefined Regions

- 16 Sectors
- CONUS
- Every state
- Puerto Rico
- Coming soon:
- Alaska
- Hawaii
- Guam

## Part of the Rehabilitation Act of 1973, amended in 1998 to include latest information technology
Created the requirement that Federal Agencies provide electronic information technology accessible to individuals with disabilities
Alternate methods of retrieving information should be made available unless it causes “undue burden”
						 -source: www.section508.gov

- Created the requirement that Federal Agencies provide electronic information technology accessible to individuals with disabilities
- Alternate methods of retrieving information should be made available unless it causes “undue burden”
- 						 -source: www.section508.gov

- > Section 508 Accessibility Overview

## > Accessibility Considerations

- Visual
- Colorblindness
- Blindness
- Mobility
- Cognitive
- Equipment
- Software

## > Accessibility Considerations: Visual

- _Colorblindness_
- Perform color recognition tests
- Modify color curves to eliminate problems where possible
- When colors cannot be modified to perfectly distinguish colors try:
-  Contrast
-  Context

## > Accessibility Considerations: Visual

- Deuteranopia Colorblindness Test (green)

- Image produced by:
- http://www.vischeck.com/vischeck/

## > Accessibility Considerations: Visual

- Protanopia Colorblindness Test (red)

- Image produced by:
- http://www.vischeck.com/vischeck/

## > Accessibility Considerations: Visual

- Tritanopia Colorblindness Test (blue/yellow)

- Image produced by:
- http://www.vischeck.com/vischeck/

## > Accessibility Considerations: Visual

- _Blindness_
- Make pages accessible to screen readers
- “ALT” tags on all images
- Check for <TAB> navigation ease
- Consistent page navigation
- Web page bookmarks to skip top navigation (enter key)
- Provide alternate methods of getting information

## > Accessibility Considerations: Visual

- Dynamic Images
- Problem: “ALT” tags could not describe dynamic data
- NDFD Solutions:
- Probe the data to obtain forecast information
- Pop up alternate text representation of select point forecasts inline
- Include alternate “City Forecasts” in plain HTML

## > Accessibility Considerations: Mobility

- Mobility Impairment Considerations
- Similar to blindness considerations for screen readers
- Do not assume mouse use
- Test <TAB> key page navigation
- Utilize consistent page navigation
- Web page bookmarks to skip top navigation (enter key)
- Provide alternate methods of getting information

## > Accessibility Considerations: Cognitive

- Try to reduce the volume of information
- Supply multiple methods of viewing data
- Users can choose a method that best suits their needs
- Simplify/summarize data where possible

## > Accessibility Considerations: Cognitive

- The NDFD Solution:
- Split the forecast data into 12 hr periods. (Daily View)
- Split the forecast
- 	data into element
- 	groupings
- 	(Weekly View)
- Provided rollover
- 	forecast box at
- 	select cities

## > Accessibility Considerations: Equipment

- Connection Speeds
- Download speeds are important
- Limit image file size
- Provide navigation that allows users to jump to choice page
- Screen Size
- Assume users only have 800X600 resolution

## > Accessibility Considerations: Software

- Avoid use of applets and plugins
- Sparingly use PDF format
- Test pages with multiple browsers
- Considerations before using various software:
- Use if document formatting must be perfectly maintained
- Will slow user navigation down
- Can impact accessibility
- Will users be irritated/burdened by downloading software to view document?

## > NDFD Web: Future Improvements	

- Forecasts at every point (Latitude/Longitude, zip code, street address, etc)
- Significantly improves accessibility to data
- Can provide data in:
- Daily summaries
- Meteograms
- Worded forecasts
- XML
- Now available at _[http://](http://www.nws.noaa.gov/forecasts/xml/)__[www.nws.noaa.gov](http://www.nws.noaa.gov/forecasts/xml/)__[/forecasts/xml/](http://www.nws.noaa.gov/forecasts/xml/)_

## For More Information:

- NDFD Graphical Forecast Page:
- _[http://weather.gov/forecasts/graphical](http://weather.gov/forecasts/graphical)_
- NDFD Information Page:
- _[http://www.nws.noaa.gov/ndfd](http://www.nws.noaa.gov/ndfd)_
- NDFD XML Web Service:
- _[http://www.nws.noaa.gov/forecasts/xml/](http://www.nws.noaa.gov/forecasts/xml/)_
- Personal Email/Phone:
- _[marc.saccucci@noaa.gov](mailto:marc.saccucci@noaa.gov)_
- 301.713-1768 x107