(as of December 20, 2021)
The USGS automatic Operational Aftershock forecasts are initiated on the following schedule and are issued 10 minutes later. Forecasts using the Generic parameters for the region are initiated 10 miinutes, 30 minutes, 50 minutes, and 2 hours after the mainshock occurs. Thus, the first forecast is issued 20 minutes following the mainshock.
After those times a Bayesian combination of Generic and Sequence Specific productivity parameters are used. During the first day, those forecasts are initiated at 4 hours, 6 hours, 12 hours, and 18 hours after the mainshock occurs. Further forecasts are initiated daily at days 1 to 14, every three days for days 16 to 28, every 7 days for days 35 to 357, and a final forecast is issued at day 365.
Manual forecasts may be issued for additional updates, when changing forecast parameters such as the magnitude of completeness, or when switching to include sequence specific decay parameters. In the latter case, the Sequence Specific parameters are used without a Bayesian combination. The current model type and basic parameters are found in the Model tab of the forecast. All parameters are shown in the download file which is in json format.
The full list of times when forecasts are initiated is (* denotes a Generic forecast):
10 minutes* 30 minutes* 50 minutes* 2 hours* 4 hours 6 hours 12 hours 18 hours 1 day 2 days 3 days 4 days 5 days 6 days 7 days 8 days 9 days 10 days 11 days 12 days 13 days 14 days 16 days 19 days 22 days 25 days 28 days 35 days 42 days 49 days 56 days 63 days 70 days 77 days 84 days 91 days 98 days 105 days 112 days 119 days 126 days 133 days 140 days 147 days 154 days 161 days 168 days 175 days 182 days 189 days 196 days 203 days 210 days 217 days 224 days 231 days 238 days 245 days 252 days 259 days 266 days 273 days 280 days 287 days 294 days 301 days 308 days 315 days 322 days 329 days 336 days 343 days 350 days 357 days 365 days