How often are warnings updated by JTWC?
North Pacific tropical cyclone warnings are routinely updated every six hours. Indian Ocean and South Pacific tropical cyclone warnings are routinely updated every twelve hours. The REMARKS section of each warning bulletin lists the times when the next warnings are scheduled. When JTWC issues the final warning for a tropical cyclone, no additional warnings are issued unless the cyclone regenerates. Back to top Q: When are warnings available? A: JTWC products are transmitted not later than 3 hours past the synoptic hour from which a warning has been created. As the synoptic hours are 00Z, 06Z, 12Z, and 18Z, warnings will be available by 03Z, 09Z, 15Z, or 21Z. Back to top Q: What is the shaded area around the forecast track on your warning graphic? A: The shaded area around the forecast track is called the “area of uncertainty.” The area of uncertainty is calculated by adding the JTWC 5-year running mean forecast track error to the forecast 35 knot wind radii at each forecast time. Since
