image: On Sept. 17 at 10:30 a.m. EDT (1430 UTC) the MODIS instrument that flies aboard NASA's Aqua satellite revealed a large area of the most powerful thunderstorms (yellow) were around Noul's center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). Those storms were over the central Vietnam coast and extended over the South China Sea. Strong storms (red) with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded the center and were generating large amounts of rain. view more
Credit: Credit: NASA/NRL
Powerful storms with heavy rainmaking capabilities appeared over the coast of central Vietnam in NASA provided infrared imagery on Sept. 17.
NASA's Infrared Data Reveals Heavy Rainmakers
Tropical cyclones are made up of hundreds of thunderstorms, and infrared data can show where the strongest storms are located. That is because infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures.
On Sept. 17 at 10:30 a.m. EDT (1430 UTC), the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite revealed a large area of the most powerful thunderstorms (yellow) were around Noul's center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). Those storms were mostly in the western quadrant of the storm and over the central Vietnam coast and they extended over the South China Sea. Strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded the center and were generating large amounts of rain.
Noul was encountering some northeasterly vertical wind shear. That is, outside winds blowing from the northeast and pushing the bulk of clouds and precipitation toward the southwest of the center of circulation.
National Centre for Hydro-Meteorological Forecasting (NCHMF) is a governmental organization belonging Vietnam Meteorological Hydrological Administration (VMHA). NCHMF has authority to issue forecasting/warning information for weather, climate, hydrology, water resource, marine weather (i.e. hydrometeorology) and provide hydrometeorology services. NHCMF has issued coastal warnings for central Vietnam. Those warnings can be found on their website: https://nchmf.gov.vn/KttvsiteE/en-US/2/index.html.
Noul's Status on Sept. 17
At 11 a.m. EDT (1500 UTC), Noul had maximum sustained winds near 45 knots. It was located over the coastline of central Vietnam, near latitude 15.9 degrees north and longitude 110.9 degrees east, about 191 nautical miles east of Da Nang, Vietnam. Noul was moving to the west and is forecast to move across Laos and Thailand over the next couple of days as it weakens due to interaction with land.
NASA Researches Earth from Space
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By Rob Gutro
NASA's Goddard Space Flight Center