Frequently Asked Questions

Some basic questions and answers about Upweather:

What resolution are the images?

The satellite photos have approximately 4 kilometer resolution. This is the highest resolution imagery that is available 24 hours a day.

The resolution shown for the forecast model is approximately 0.5°.

How can I get smoother animation?

Upweather may take a while to warm up. If you want to see something more clearly, swipe backward and forward in time. Each time you swipe, the image will get a little better. The faster your internet connection, the faster the animation improves. The network activity indicator will be spinning in the lower left corner when images are still being downloaded.

Where do the satellite photos come from?

Satellite imagery is based on the 11 micron infrared channels from the GOES-EAST and GOES-WEST satellites.

How up to date are the satellite photos?

Upweather fetches new satellite imagery every half hour or so. In the best case, that image reaches Upweather in about ten minutes. So the latest satellite image is usually between ten and forty-five minutes old..

Where does the forecast come from?

The GFS forecast model is updated every six hours by NOAA. Meteorologists rely on many different computer models in making their forecasts: the GFS is one of the most important of these.

What times are available?

Satellite imagery is available for the previous seven days. Forecast imagery extends seven days into the future.

What area is covered?

The available area is between the central Pacific to the central Atlantic, and from the Equator to the Arctic Circle. That's from 0° to 66°N and 180° to 27°W.

Can you do a larger area?

Maybe! Unfortunately we don't have access to global satellite imagery, but there are other areas that could be added with enough demand.

Sometimes I see glitches in the satellite imagery. What's up with that?

Depending on the position of the earth and sun, the satellites may not operate perfectly. This can lead to missing data in the image.

Sometimes I see strange edges when animating satellite imagery. What's up with that?

The images from the two different satellites don't always line up perfectly. Upweather takes some liberties in combining images from as long as a half hour apart. We also try to smooth over missing areas in the satellite image.

Why is the forecast blockier than the satellite images?

Predicting the weather is hard for computers too! The 0.5°×0.5° forecast has about a twentieth of the resolution of the 4km satellite images. Even at this lower resolution, each run of the GFS model takes several hours of supercomputing at NCEP, the National Centers for Environmental Prediction.