Experimental Tropo Forecast
The beacon's tropo forecast turns NOAA's global weather model into a chance of ducting on 2 meters, 70 centimeters, and 23 centimeters, like a rain forecast. The chances were calibrated against a year of weather-balloon soundings at Oakland, San Diego, Quillayute, Lihue, and Hilo, and they check out: when the forecast says 80 percent or more, balloons found a duct over 90 percent of the time.
| Region | How well it works |
|---|---|
| California coast | Strong: clearly separates good days from bad |
| Pacific Northwest coast | Moderate: useful, especially on 70 cm |
| Hawaii | Ducts are nearly always present there, so the forecast adds little |
The model can say how likely ducting is, but not reliably at what height; the balloon soundings in the beacon's TROPO section give heights. For wide-area and multi-day views, see the Hepburn tropo maps and F5LEN.
The current forecast and the beacon's own model maps appear below.
Current forecast
Bay Area coast: ducting expected on 2 meters and up, 85 percent. Southern California coast: ducting expected on 70 centimeters, 90 percent; ducting likely on 2 meters, 60 percent. Pacific Northwest coast, peaking around 3 AM: ducting expected on 70 centimeters, 80 percent; a slight chance of ducting on 2 meters, 25 percent. Nothing toward Hawaii.
From the report of Monday, October 5, 2026, 1:00 AM PDT (0800 UTC)
