NASA finds Tropical Depression Dahlia's center devoid of rainfall

December 4, 2017, NASA's Goddard Space Flight Center
On Dec 4 at 1441 UTC (9:41 a.m. EST), the GPM core satellite analyzed Tropical Depression Dahlia's rainfall and found the circulation center devoid of precipitation. Light rainfall near 0.1 inches per hour was falling east of the center (light blue). Credit: NRL/NASA/JAXA

Tropical Depression Dahlia was weakening into a remnant low pressure area when the Global Precipitation Measurement mission core satellite or GPM analyzed the storm's precipitation. GPM found the center devoid of rainfall and light rainfall to the east of center.

On Dec. 3 at 4 p.m. EST (2100 UTC) the Joint Typhoon Warning Center issued the final bulletin on Dahlia. At that time, Dahlia was still a tropical storm with near 35 knots (40 mph). Dahlia was centered near 16.2 degrees south latitude and 111.9 degrees east longitude. That's about 402 nautical miles north-northwest of Learmonth, Australia. Dahlia was moving to the south at 10 knots (11.5 mph/18.5 kph).

At the time of the last bulletin, infrared satellite imagery showed that the strongest storms were beginning to decouple from the low level circulation center and moving off to the southeast. Early the next day, the storm had become a depression then weakened further to a remnant low pressure area.

On Dec. 4 at 1441 UTC (9:41 a.m. EST), the GPM core satellite passed over Dahlia in the Southern Indian Ocean. Data collected by GPM's Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments were used to show the intensity of precipitation. GPM's radar (DPR ku Band) measured rain falling at 0.1 inches (2.5 mm) per hour to the east of the center of circulation near the of Western Australia. The of circulation had no measureable rainfall.

The Australian Bureau of Meteorology issued Wind Warnings from 10:00 p.m. WST (local time, Western Australia) on Dec. 4, for the period until midnight WST Dec. 5, 2017. A Strong Wind Warning for the following areas: Perth Local Waters, Gascoyne Coast, Geraldton Coast, Perth Coast and Bunbury Geographe Coast

Dahlia was moving into cooler sea surface temperatures and an area of stronger wind shear, both factors that were expected to lead to its dissipation later on Dec. 4.

Explore further: GPM Satellite observes Tropical Cyclone Dahlia and landslide potential

Related Stories

NASA eyes intensifying Tropical Cyclone Frances

April 29, 2017

Two NASA satellites provided forecasters in Australia with visible and rainfall data as Tropical Cyclone Frances strengthened in the western Timor Sea. NASA's Aqua satellite captured a visible image of the storm that showed ...

NASA sees heavy rain in Arabian Sea tropical cyclone

June 29, 2016

Tropical Cyclone 02A in the Arabian Sea east of Oman has been weakening and has become a tropical depression. The Global Precipitation Measurement or GPM mission core satellite analyzed the rainfall in the system.

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

Paleontologists report world's biggest Tyrannosaurus rex

March 22, 2019

University of Alberta paleontologists have just reported the world's biggest Tyrannosaurus rex and the largest dinosaur skeleton ever found in Canada. The 13-metre-long T. rex, nicknamed "Scotty," lived in prehistoric Saskatchewan ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.