Jangmi – Northwestern Pacific Ocean

Aug. 11, 2020 – NASA Finds Jangmi Now an Extra-Tropical Storm

NASA’s Aqua satellite obtained a visible image of Tropical Storm Jangmi after it transitioned into an extra-tropical storm.

Aqua image of Jangmi
NASA’s Aqua satellite provided a visible image to forecasters of extra-tropical storm Jangmi in the Sea of Japan on Aug. 11, 2020. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

The Joint Typhoon Warning Center (JTWC) posted its final bulletin on Tropical Storm Jangmi on Aug. 10 at 11 a.m. EDT (1500 UTC). At that time, it was located near latitude 26.9 degrees north and longitude 130.4 degrees east, about 139 miles northeast of Chinhae, South Korea. Jangmi was speeding to the north-northeast at 29 knots and had maximum sustained winds of 35 knots (40 mph).

On Aug. 11, Jangmi had moved into the Sea of Japan and had become extra-tropical.

 What an Extra-tropical Storm Means

When a storm becomes extra-tropical, it means that a tropical cyclone has lost its “tropical” characteristics. The National Hurricane Center defines “extra-tropical” as a transition that implies both poleward displacement (meaning it moves toward the north or south pole) of the cyclone and the conversion of the cyclone’s primary energy source from the release of latent heat of condensation to baroclinic (the temperature contrast between warm and cold air masses) processes. It is important to note that cyclones can become extratropical and retain winds of hurricane or tropical storm force.

 The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite captured a visible image of extra-tropical storm Jangmi in the Sea of Japan, near the Korea Strait. The Korea Strait is located between South Korea and Japan, connecting the East China Sea, the Yellow Sea and the Sea of Japan. The MODIS image showed that the storm had become somewhat elongated. Satellite imagery was created using NASA’s Worldview product at NASA’s Goddard Space Flight Center in Greenbelt, Md.

On Aug. 11, the Japan Meteorological Agency posted advisories along the prefectures in the Sea of Japan as Jangmi is forecast to move through it in a north-northeasterly direction and weaken. For updated warnings and watches, visit: https://www.jma.go.jp/en/warn/.

About NASA’s Worldview and Aqua Satellite

NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.”

NASA’s Aqua 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.

By Rob Gutro
NASA’s Goddard Space Flight Center

Jangmi – Northwestern Pacific Ocean

Aug. 10, 2020 – NASA Sees Compact Tropical Storm Jangmi Exiting East China Sea

Tropical Storm Jangmi was exiting the East China Sea and moving toward the Sea of Japan when NASA’s Aqua satellite measured the strength of the system.

Aqua image of Jangmi
On Aug. 9 at 10:20 a.m. EDT (1420 UTC) NASA’s Aqua satellite gathered temperature information about Tropical Storm Jangmi’s cloud tops. Aqua found the most powerful thunderstorms (red) around the center where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Credit: NASA/NRL

Jangmi formed as a depression on Aug. 8. At 5 a.m. EDT (0900 UTC), Tropical Depression 05W formed about 377 miles northeast of Manila, Philippines. Locally in the Philippines, the depression was known as Enteng. By 5 a.m. EDT (0900 UTC) on Aug. 9, the depression strengthened into a tropical storm.

On Aug. 9 at 10:20 a.m. EDT (1420 UTC) infrared data from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite provided a look at cloud top temperatures in Tropical Storm Jangmi as it was about to move out of the East China Sea. Strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.

MODIS found the most powerful thunderstorms were around the center of circulation, where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

On Aug. 10, the Joint Typhoon Warning Center noted that animated multispectral satellite imagery showed a partially exposed low-level circulation center with building strong thunderstorms in the northwestern quadrant of the storm.

On Monday, August 10, 2020 at 5 a.m. EDT (0900 UTC), the Joint Typhoon Warning Center (JTWC) noted that Tropical storm Jangmi was located near latitude 34.2 degrees north and longitude 128.7 degrees east, approximately 48 nautical miles south of Chinhae, South Korea. Jangmi was moving at 23 knots (26 mph/43 kph) and had maximum sustained winds of 35 knots gusting to 45 knots (52 mph/ 83 kph).

Jangmi is moving northeast past South Korea and is forecast to move into the Sea of Japan where it is forecast to merge with an approaching mid-latitude elongated area of low pressure (trough) and then become extra-tropical.

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.

By Rob Gutro
NASA’s Goddard Space Flight Center