- In the "SELECT" section, select the desired length of the
animation (default is highlighted in gray).
- Select the interval between images (default is
- Press the "Build Animation" button.
The interval between images partly determines the total number
of images in the animation and hence both the downloading time
and the extent to which the image changes from one image to the
next. For example, an animation length of 2 days with an
interval between images of 12 hours will generate an animation
with 5 images in it, covering a 48-hour period ending with the
latest available image and with 12 hours between images.
Missing images are listed and then automatically skipped.
To step through animations frame-by-frame, first press the
"Stop" button ("*"), then press the "Next" button ("|>")
repeatedly to advance frames one at a time. Similarly, press the
"Back" button ("|<") to step backward one frame at a time.
To restart the animation after stopping it, press the "Restart"
The WWWeb server (virga.sfsu.edu) receives data to construct a
sea-level composite weather maps every 6 hours, within 2 hours after
the map analysis time (from the 00Z and 12Z North American model
[NAM] runs) or within 4 hours (from the 00Z, 06Z, 12Z, and 18Z
Global Forecast System [GFS] model runs). The WWWeb server receives
data to construct 500 mb and 300 mb composite weather maps every
12 hours, for the same models.
To update an animation to add any newly created map(s)
(which also drops the oldest one from the animation), simply press the
"Build Animation" button again.
- If the animation does not seem to be working correctly, check
your computer's date/time--the animation depends on its
simpley "scripting" is enabled. (In Microsoft's Internet
Explorer, try looking in the "Web Browser" section of Preferences,
under "Web Content" or "Advanced".)
- If you resize the browser window you might need to press the
Reload button or choose Reload from the View menu.
WWWeb Site Navigation:
In your browser, hit the "Back" or left-arrow ("<==") button to
return to the jet stream analysis animation page from which you just
came. Alternatively, select one of these links:
Animations of Composite Weather Maps:
or go to the Composite Weather Maps