Northern Australia is dealing with two tropical systems today, and both were close enough to be captured on one satellite image. One of them has strengthened enough to be named Tropical Cyclone Lua, while the other is still getting organized and is a tropical low pressure area. The unnamed storm is currently close enough to the coast to generate warnings, while Lua is not.
When NASA's Aqua satellite passed over northern Australia on March 12 at 1711 UTC and March 13 at 0539 UTC it captured the two tropical disturbances close enough to appear on one image. Tropical Cyclone Lau appears on the left side of both days of satellite imagery, while System 96P appears on the right side of the images. Lua is located in the Southern Indian Ocean, while System 96P is in the Southern Pacific Ocean. Both systems seemed to grow closer over the two days and both are affecting coastal areas in northern Australia on March 13.
Aqua captured an infrared image of both storms' cloud top temperatures using the Atmospheric Infrared Sounder (AIRS) instrument. AIRS data showed that the coldest cloud top temperatures were colder than -63F/-52.7C around the center of circulation in both systems.
Tropical cyclone Lua formed off the northern coast of Western Australia. On March 13, it was a minimum tropical storm with maximum sustained winds near 35 knots (~40 mph/~65 kph). It was located about 240 miles west-northwest of Port Hedland, Australia, near 18.4 South and 115.0 East. It was barely moving at 2 knots (~2 mph/~4 kph) to the west-northwest, but is expected to turn to the east-southeast in a day or two. Forecasters at the Joint Typhoon Warning Center expect Lua to meander for a day or two before intensifying before making landfall in the Pilbara region sometime on March 16. There are currently no warnings posted yet for Tropical Storm Lua, but that is likely to change over the next couple of days.
Located to the east of Tropical Storm Lua, and in the Southern Pacific Ocean is System 96P. Although not a tropical storm, System 96P is closer to land and has caused watches and warnings to go up. There is currently a high seas weather warning for "Metarea 10/11" and a Coastal Waters Wind Warning for waters from Cape Don to Kuri Bay.
At 1200 UTC (8 a.m. EST/8:00 p.m. Australia WST) the tropical low known as System 96P was located near 12.9 South and 128.0 East, about 170 nautical miles west of Darwin and 115 nautical miles northwest of Port Keats. It was moving south at 4 knots (4.6 mph/7.4 kph).
AIRS infrared satellite imagery showed that deep convection (rising air that forms the thunderstorms that make up the tropical cyclone) is growing in size around the low-level circulation center. There are also bands of thunderstorms spiraling into the low's center. The Joint Typhoon Warning Center noted weather observations from nearby Troughton Island, located southwest of the center, showed a 10-minute sustained wind speed as high as 20 knots (23 mph/37 kph).
System 96P is in an area of warm sea surface temperatures and is getting organized. Forecasters at the Australian Bureau of Meteorology and Joint Typhoon Warning Center agree that it may become a tropical depression within the next day. The low is expected to curve towards the southeast for a landfall south of Port Keats late on March 14, or early on March 15. Residents from Dundee Beach to Port Keats to Kalamburu should monitor this storm closely and expect heavy rainfall, gusty winds, and rough surf along beaches.
Explore further: NASA sees Tropical Storm 12S - a possible threat to Madagascar