On March 17, 2008, HPC made significant changes to the look of the short range forecast web pages.   These changes were made for primarily two reasons:

• To introduce two new graphics, a 6-hour forecast of fronts, pressure centers and precipitation valid at 06Z or 18Z of the issuance day and a 60-hour forecast of fronts and pressure centers.
• Make the pages more user-friendly, particularly by allowing easier navigation through the forecast periods and providing the valid day and time of the forecast.

How to use the new web page

 

The user interface can be broken up into three main sections.  At the top is a tab bar (displayed below) with the three image types HPC creates: color, black and white, and the forecast graphic with the terrain/satellite background. Clicking on an option in the tab bar will take you to a page displaying a sequence of forecasts of the selected image type.   Note that "color" images were previously referred to as "color on white" and the images with the "terrain/satellite" background were referred to as "full color".

 

Below the tabs is a horizontal menu bar containing a series of days and "Z" (UTC) times. (See below for an example.) These refer to the valid day and time of the forecast.

There are two ways to use this bar to access a forecast. Moving the mouse over a given time (such as Friday 00Z) will quickly display in the main window the forecast valid for that day and time. Clicking on a given time will open a page displaying a larger version of the particular forecast as well as options (above the image) to change image types or move backward or forward through the forecast cycle.

In addition, you will see a "Loop" option on the far right side of this bar. Moving the mouse over this option will display in the main window an animation of the latest forecast. View an example of this animation. If you click on Loop, a Java applet, similar to many others on our site, will load a loop of the latest forecast. Unlike the simple animation, controls are available on this page to start/stop the loop or change the animation speed, as well as zoom into a region.  In addition, you have the option of toggling on/off the precipitation and/or fronts/pressures.  In October, 2008, a label was added to the upper right-hand side of the applet which provides a quick reference to the forecast valid time of each frame (which can be very helpful while in zoom mode).