Development of the National Digital Forecast Database Web Display

1
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
2
gt 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

3
Example NDFD National Forecast Graphic
4
gt 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

5
gt 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
6
gt NDFD Predefined Regions

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

7
gt Section 508 Accessibility Overview

• 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

8
gt Accessibility Considerations

• Visual
• Colorblindness
• Blindness
• Mobility
• Cognitive
• Equipment
• Software

9
gt 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

10
gt Accessibility Considerations Visual

• Deuteranopia Colorblindness Test (green)

Image produced by http//www.vischeck.com/vischec
k/
11
gt Accessibility Considerations Visual

• Protanopia Colorblindness Test (red)

Image produced by http//www.vischeck.com/vischec
k/
12
gt Accessibility Considerations Visual

• Tritanopia Colorblindness Test (blue/yellow)

Image produced by http//www.vischeck.com/vischec
k/
13
gt Accessibility Considerations Visual

• Blindness
• Make pages accessible to screen readers
• ALT tags on all images
• Check for ltTABgt navigation ease
• Consistent page navigation
• Web page bookmarks to skip top navigation (enter
  key)
• Provide alternate methods of getting information

14
gt 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

15
gt Accessibility Considerations Mobility

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

16
gt 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

17
gt 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

18
gt 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

19
gt 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?

20
gt 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//www.nws.noaa.gov/forecasts
  /xml/

21
For More Information

• NDFD Graphical Forecast Page
• http//weather.gov/forecasts/graphical
• NDFD Information Page
• http//www.nws.noaa.gov/ndfd
• NDFD XML Web Service
• http//www.nws.noaa.gov/forecasts/xml/
• Personal Email/Phone
• marc.saccucci_at_noaa.gov
• 301.713-1768 x107