Owen (South Pacific Ocean)

December 10, 2018 – NASA-NOAA Satellite Sees Tropical Cyclone Owen’s Remnants Reorganizing

The remnants of Tropical Cyclone have been lingering in the Southern Pacific Ocean for days. On Dec. 10, the storm finally appeared more organized on satellite imagery providing forecasters with a strong indication that it may be reborn as a tropical cyclone. NASA-NOAA’s Suomi NPP satellite passed over the Gulf of Carpentaria and saw the storm.

Suomi NPP image of Owen
On Dec. 10, 2018 the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of the remnants of Tropical Cyclone Owen in the Gulf of Carpentaria, just west of Queensland. Credit: NASA/NRL

On Dec. 10 at 0100 UTC (Dec. 9 at 8 p.m. EST), Owen’s remnants were located near 16.1 degrees south latitude and 144.6 degrees east longitude, approximately 282 nautical miles east-northeast of Mornington Island, Australia, and just west of the northern tip of Queensland.

On Dec. 10 at 0410 UTC (Dec. 9 at 11:10 p.m. EST, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite analyzed the remnants. VIIRS revealed a consolidating low level circulation center with deep convection building over the center.

The Joint Typhoon Warning Center noted: “Sea surface temperatures in the Gulf of Carpentaria are conducive for future tropical cyclone development. Multiple [computer forecast] models indicate development over the next 24-36 hours with a westward trajectory.”

By Rob Gutro
NASA’s Goddard Space Flight Center

Owen (Southern Pacific Ocean)

December 04, 2018 – NASA-NOAA Satellite Finds Owen Fading in the Coral Sea

Tropical Cyclone Owen appeared disorganized on satellite imagery as it moved through the Coral Sea in the Southern Pacific Ocean. Imagery from the Suomi NPP satellite showed that Owen was being stretched out and had weakened from wind shear.

Suomi NPP image of Owen
On Dec.4, the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of Tropical Storm Owen in the Coral Sea, South Pacific Ocean. Owen was southwest of Vanuatu. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

In general, wind shear is a measure of how the speed and direction of winds change with altitude. Winds at different levels of the atmosphere pushed against the cylindrical circulation center and skewed it, weakening the rotation. As a result of the wind shear, Owen weakened from a tropical storm to a tropical depression on Dec. 4.

Early on Dec. 4 the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite analyzed Owen, and showed a disorganized storm with little thunderstorm development. The bulk of the clouds and showers were pushed east of the center of circulation from wind shear.

On Dec. 4 at 10 a.m. EDT (1500 UTC) Owen’s maximum sustained winds had dropped to 34.5 mph (30 knots/55.5 kph). It was located approximately 519 nautical miles east of Cairns, Australia. Owen was moving westward.

Although it is a depression, the Joint Typhoon Warning Center noted that there is a chance the storm may re-strengthen after two days when the wind shear is expected to relax. Forecasters are keeping an eye on Owen.

By Rob Gutro
NASA’s Goddard Space Flight Center

Owen (Southern Pacific Ocean)

December 03, 2018 – NASA Catches Newborn Tropical Cyclone Owen’s Rainfall, Observed By GPM Satellite

Tropical Cyclone Owen formed in the Southern Pacific Ocean’s Coral Sea southwest of the Solomon Islands when the GPM core observatory satellite passed above and analyzed its rainfall.

GPM image of Owen
On December 2, 2018 at 9:50 a.m. EST (1450 UTC) the GPM core satellite showed that tropical cyclone Owen was producing heavy downpours. GPM’s GMI indicated that heaviest rainfall was occurring near the low level center of circulation and in feeder bands that were wrapping around Owen’s eastern side. GMI showed that storms in that area were dropping rain at a rate of over 53 mm (2.1 inches) per hour. Credit: NASA/JAXA, Hal Pierce

On December 2, 2018 at 9:50 a.m. EST (1450 UTC) data collected by GPM’s Microwave Imager (GMI) and GPM’s Dual-Frequency Precipitation Radar (DPR) instruments aboard the Global Precipitation Measuring Mission or GPM core satellite showed that tropical cyclone Owen was producing heavy downpours.  GPM’s GMI indicated that heaviest rainfall was occurring near the low level center of circulation and in feeder bands that were wrapping around Owen’s eastern side. GPM’s GMI provided the best coverage of rainfall in the center of the tropical cyclone. GMI showed that storms in that area were dropping rain at a rate of over 53 mm (2.1 inches) per hour. GPM’s radar (DPR Ku Band) probed storms on Owen’s eastern side. DPR indicated that a few of these intense storms, far from Owen’s center, were dropping rain at a rate of over 94 mm (3.7 inches) per hour.


On December 2, 2018 at 9:50 a.m. EST (1450 UTC)  the GPM core satellite showed that tropical cyclone Owen was producing heavy downpours.  GPM’s GMI indicated that heaviest rainfall was occurring near the low level center of circulation and in feeder bands that were wrapping around Owen’s eastern side.  A few powerful storms there were reaching heights above 15 km (9.3km).   GMI showed that storms in that area were dropping rain at a rate of over 53 mm (2.1 inches) per hour. Credit: NASA/JAXA, Hal Pierce

A 3-D animation created with the data showed a simulated flyby above tropical cyclone Owen. GPM’s radar (DPR Ku Band) probes into a feeder band on the eastern side of tropical cyclone Owen showed that a few powerful storms there were reaching heights above 15 km (9.3km).   DPR’s Ku Band radar enables accurate three dimensional measurements of precipitation within a 152 mile (245 km) wide swath. The heights of precipitation over a larger area were estimated by blending measurements from

GPM’s radar (DPR Ku band) with heights based on the Himawari-8 satellite’s infrared temperatures.

On Dec. 3 at 10 a.m. EST (1500 UTC) Tropical cyclone Owen was located near 15.7 degrees south latitude and 155.8 degrees east longitude. That’s 579 miles east of Cairns, Australia. Owen is moving to the east-southeast and has maximum sustained winds 50 knots (57 mph/92.6 kph)

Owen is forecast to move southeast, later west. The storm will strengthen slightly before weakening as it turns west. Owen will dissipate after two days.

By Harold F. Pierce / Rob Gutro
NASA Goddard Space Flight Center