Tag: 18P 2020

Wasi (Formerly 18P) – Southern Pacific Ocean

Feb. 24, 2020 – NASA’s Aqua Satellite Finds Tropical Cyclone Wasi’s Remnants

Tropical Cyclone 18P briefly strengthened into a tropical storm in the Southern Pacific Ocean and quickly faded.

On Feb. 22 at 4 a.m. EST (0900 UTC), 18P became Tropical Cyclone Wasi with maximum sustained winds near 55 knots (63 mph/102 kph), the peak of its strength. At that time, Wasi triggered a tropical cyclone and gale warning for Niue. A tropical storm warning was also posted for Tutuila, Aunuu and Manua Islands in American Samoa.

On Feb. 24, 2020 at 0125 UTC (Feb. 23 at 8:50 p.m. EST), the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite provided a visible image of the remnants clouds of Wasi in the Southern Pacific Ocean. Credit: NASA/NRL

By Feb. 23 at 10 a.m. EST (1500 UTC), the Joint Typhoon Warning Center posted its final warning on Wasi. At that time, Wasi was located near 17.2 degrees south latitude and 171.0 degrees west longitude, about 130 nautical miles north-northwest of Niue. Maximum sustained winds had dropped to 25 knots (29 mph/46 kph), below tropical cyclone strength.

On Feb. 24, 2020 at 0125 UTC (Feb. 23 at 8:50 p.m. EST), the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite provided a visible image of the remnants clouds of Wasi in the Southern Pacific Ocean.

NASA’s Aqua satellite is one in a fleet of NASA satellites that provide data for hurricane research.

Tropical cyclones are the most powerful weather event on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

Rob Gutro
NASA’s Goddard Space Flight Center, Greenbelt, Md.

18P – Southern Pacific Ocean

Feb. 21, 2020 – NASA Sees Tropical Cyclone 18P Form Near American Samoa

The low-pressure area that has been lingering west-northwest of American Samoa for several days has organized into a tropical depression. NASA’s Terra satellite passed over the Southern Pacific Ocean and provided forecasters with a visible image of Tropical Depression 18P.

Terra image of 18P
On Feb. 21, 2020, the MODIS instrument that flies aboard NASA’s Terra satellite provided a visible image of newly developed Tropical Depression 18P in the Southern Pacific Ocean. Credit: NASA Worldview

On Feb.21, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite provided a visible image of 18P that showed an improved cyclonic circulation along the southern end of a line of deep convection and thunderstorms that extends north-to-south.

At 10 a.m. EST (1500 UTC) on Feb. 21, the Joint Typhoon Warning Center said Tropical Cyclone 18P had maximum sustained winds near 30 knots (34.5 mph/55.5 kph). It was located near latitude 12.9 degrees south and longitude 174.8 degrees west, about 280 nautical miles west-northwest of Pago Pago, American Samoa. 18P is moving to the east-southeast.

The tropical cyclone is forecast to intensify to a tropical storm reaching maximum sustained winds to 45 knots as it passes near American Samoa on Feb. 22. In three days, vertical wind shear is expected to kick in which will cause the storm to dissipate quickly.

In addition to Tropical Cyclone 18P, Tropical Storm Vicky has developed to the southeast of American Samoa. Together, these systems have generated several warnings and watches. On Feb. 21, the National Weather Service (NWS) in Pago Pago has continued the Flash Flood Watch for all of American Samoa through Saturday, Feb. 22. The NWS forecast page stated, “The active monsoon trough remains across the area with several hybrid lows developing northwest and moving swiftly across the islands through the week. A flash flood watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation.”

NASA’s Terra satellite is one in a fleet of NASA satellites that provide data for hurricane research.

Tropical cyclones/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

For updated forecasts from NWS, Pago Pago, visit: https://www.weather.gov/ppg/?lang=english

By Rob Gutro
NASA’s Goddard Space Flight Center