Start Here: Using SKC Weather

Start with a question, rather than the most colorful map. Are you checking where rain is occurring now, exploring tomorrow’s storm evolution, or comparing the range of possibilities later in the week? Each SKC Weather tool answers a different part of that question.

Choose the right starting point

• MRMS radar: examine recently observed radar echoes. Check the latest frame time before calling an image current.
• RRFS: explore forecast reflectivity and other available high-resolution guidance. These are predictions, not a continuation of observed radar.
• Ensemble maps: compare probability, mean, anomaly and spaghetti products across GEFS, ECMWF EPS and AIFS ENS.
• Point plumes: examine member forecasts through time near a selected location.

Read three labels before interpreting a map

The initialization identifies the model run. The forecast hour is time after that initialization. The valid time is when the forecast applies. An illustrative 00Z run at F024 is valid at 00Z the following day. UTC, also written Z, is not necessarily your local time.

For precipitation, also read the accumulation window. A 12-hour amount ending at F024 describes F012–F024; it is not the entire total since initialization. Compare like periods when switching products or models.

A practical first visit

1. Open GEFS and select a precipitation threshold relevant to your question.
2. Check its units, accumulation period, run and valid time.
3. Step forward, then play the loop to follow the pattern. Pause before reading a specific frame.
4. Compare a plume for your location, remembering that a grid forecast is not an exact forecast for your property.
5. Compare another available model and an official forecast before making a decision.

Free and Premium

No sign-in is required for GEFS maps and precipitation plumes, RRFS, MRMS, or EPS/AIFS guidance through F024. Premium adds later EPS/AIFS guidance, GEFS temperature plumes, EPS/AIFS precipitation and temperature plumes, and ensemble Present. A Free account does not unlock Premium. Compare membership options.

If something looks old or empty

Read the run and latest available hour. Publication follows upstream delivery and processing, so a newer cycle may still be filling in. Refresh available hours where offered; do not treat a missing image as a zero probability. If the problem persists, send support the page, product, run, valid time and device.