- TC Charlotte reached Cat 3 strength early Tuesday
- Wastage of TC, expected on Wednesday, to be determined
- The potential for swelling is limited near Exmouth in the middle of the week.
- Forecast track still in development, check local weather warnings
Forecast related to this outlook: Australia North Coast | Coral Coast | Perth | SW
About a year ago, a powerful tropical cyclone named Seroja made landfall near Calabari, WA. This left chaos in its wake and triggered a very unusual late autumn and early winter for all of WA’s NW coasts.
Today, Tropical Cyclone Charlotte hovers over the waters of the Indian Ocean. It is forecast to hit 90 knots of sustained winds in open water about 400 nautical miles northwest of Exmouth, Charlotte. It should strengthen to an extreme Category 3 cyclone in the early hours today, then downgrade quickly to a southwest track on Wednesday.
As we approach Seryozha’s one-year anniversary, Charlotte’s initial forecast track may look alarming. By comparing the two, we can uncover some clear contrasts in cyclone strength and formation, which make the two particularly distinct scenarios at this time.
While both Charlotte and Seroja pass through severe cyclone strength over the same area over the eastern Indian Ocean (-19S, 110E), Seroja was already underway for five days. Seroza arrived as Cat 2 from the south coast of Timor, became temporarily extinct, and was ready for a second round by the time it moved NW of Exmouth. The storm came with a buildup of speed, heavy moisture and latent heat.
The other major difference is concurrent tropical cyclone activity. Simply put, TC Seryozha was part of a double-up. As it approached NW WA, it also contacted TC Odette, who had formed separately in the same area. As Seroza approached WA, it and Odette’s remains underwent a phenomenon known as the Fujiwara effect—a type of dance during which the two systems circled around a mid-point. Seryozha’s dance with Odette intensifies it again and is pushed back ashore, resulting in destruction at Calbari.
Current TC Charlotte is not likely to feed off any other tropical storms in the system. Without an immediate past cyclone in the vicinity, a dramatic cyclone upgrade or assistance is not likely to occur in any major tropical season. Charlotte’s charts do not show any other TC expected at this time.
By the time Charlotte moves south of the 20S parallel, It is likely to weaken severely due to cold water for two to three days. At the same time, a stable high pressure system established south of Charlotte will buffer the storm’s southerly motion and keep it on a slow downgrading trend. The East-TC Charlotte interaction will lead to an increase in ESE winds in SW WA, while a mid-level trough is forecast to deepen over the middle coast. We expect a Sea Wind Warning to appear over many areas of WA in the mid to later part of the week, however, no Cyclone Activity Land Warning has been issued at this time.
We will continue to monitor TC Charlotte and watch the storm’s behavior throughout the week. Stay tuned here for updates and premium forecasts.