Tropical Storm Marcus forms off the northwest coast of Australia. Marcus forms in an area of tropical convection stretched across the tropical West Pacific possibly part of a weak Madden Julian oscillation signature.
As Tropical Storm Marcus moves away from the northwest coast of Australia intensification will occur possibly faster than forecast. Currently, Marcus is expected to reach hurricane intensity within 30 hours and major category 3 tropical cyclone intensity in 60 hours (Fig. 1). A category 4 system is projected within 72 hours. Marcus turns due south during the strengthening. In the extended-range operational models weaken Marcus as the system approaches southwestern Australia next weekend.
Climate Impact caveat forecast: Strengthening occurs more rapidly. Marcus may lose strength west of Australia as waters begin cool significantly.
Fig. 1: 5-day forecast track for Tropical Storm Marcus indicates intensification to a category 4 tropical cyclone upon a south turn within 72 hours.