Forecast Index (3-hourly)
Forecast Index (1-hourly)
Forecast Index (1-hourly)
Forecast Image

What is this page?

This page is for viewing maps of current 2-day and 7-day weather forecasts. The cool thing is that you can animate the maps.

That's wonderful. How do I use it?

Step 1 — Select Region

Several model domain subsets are available. These include World, Northern Hemisphere, Southern Hemisphere, North America, and Europe, among others. Forecasts on this page come from different models of varying resolution. The source model is listed beside each entry in the Region pulldown menu. A brief synopsis follows:

GFS = Global Forecast System Model (0.25°x0.25°). This is the chief U.S. NCEP/NOAA operational model used for weather forecasting.

NAM = North American Mesoscale Model (Alaska 4 km; CONUS 5 km).

HRRR = High Resolution Rapid Refresh (CONUS 3 km).

WRF-GFS = Weather Research and Forecasting (WRF) model downscale of GFS output (16-25 km). These WRF-GFS simulations are run here at UMaine/CCI.

Check out the Available Datasets page for more information about the models.

Step 2 — Select Parameter

Temperature, precipitation, wind speed, etc. Most parameters are available for every forecast region. Exceptions include temperature anomaly (GFS only), Jetstream Wind speed (GFS and WRF-GFS only), Ground Level Ozone (United States NAM only), and Snow Cover (WRF-GFS only).

Some of these options show only a single parameter; others show one parameter with an overlay of 10-meter wind speed vectors; Precipitation and Clouds shows precipitation (partitioned into rain, mixed, and snow), cloud cover (column average of low, medium, and high-level clouds), and snowdepth.

Step 3 — View the Forecast

Either select an image frame from the Forecast Index, or run an animation using the Playback controls. Arrow and stop icons are pretty ubiquitous, but you might puzzle over the "-" and "+". These two buttons control the playback speed. Click "-" to slow down, and "+" to speed up the animation as it plays.

We like detailed graphics, and therefore the forecast image files on this page are somewhat large, typically 200-500 Kb. Multiply by 60 frames (i.e., for GFS) and you have 12-30 Mb animations. Not a big deal for high bandwidth users. Most home DSL and cable modem connections should be plenty fast. Low bandwith users may need patience if attempting to animate.

In any case, for animations first use a slow playback speed to load all images within a forecast sequence. Then, once the forecast loop has completed once, press "+" to speed up the show.