Tag: 33W 2018

November 29, 2018 – NASA’s IMERG Analyzed Tropical Storm Usagi’s Rainfall

When Tropical Cyclone 33W, also known as Usagi strengthened to hurricane intensity as it approached Vietnam from the South China Sea it dropped a lot of rain. Although the storm weakened to tropical storm intensity when coming ashore in Vietnam, it continued to generate a lot of rain, and NASA added up that heavy rainfall.

Very heavy rainfall and damaging winds accompanied tropical storm Usagi when it hit Vietnam’s southern coast. More than 350 mm (14 inches) of rainfall was reported causing widespread flooding around Ho Chi Minh City.

NASA’s Integrated Multi-satellitE Retrievals for GPM (IMERG) data were used to show estimates of rainfall accumulation produced by Usagi as the tropical cyclone moved across the South China Sea into Southeast Asia. An IMERG accumulation analysis created at NASA’s Goddard Space Flight Center in Greenbelt, Maryland encompassed the period from November 19 to 26, 2018.

NASA rainfall analysis encompassed the period from November 19 to 26, 2018 tracked rain dropped by 33W (Usagi) across the South China Sea into Southeast Asia. Tropical Storm Usagi or 33W often dropped more than 240 mm (9.4 inches) of precipitation over southern Vietnam. Rainfall intensity decreased rapidly as the remnants of Usagi moved inland over Cambodia.  Credit: NASA/JAXA, Hal Pierce

Those data indicated that Usagi dropped moderate to heavy rain along its path. The analysis showed that tropical storm Usagi often dropped more than 240 mm (9.4 inches) of precipitation over southern Vietnam. Rainfall intensity decreased rapidly as the remnants of Usagi moved inland over Cambodia.

GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.

By Harold F. Pierce
NASA Goddard Space Flight Center

November 26, 2018 – NASA Sees Tropical Cyclone 33W Dissipating

When NASA-NOAA’s Suomi NPP satellite passed over the Ca Mau Peninsula it captured a visible image of the dissipating former Tropical Cyclone 33W.

The Ca Mau Peninsula is the southernmost area of Vietnam, located between the South China Sea to the east and the Gulf of Thailand on the west.

The Joint Typhoon Warning Center issued its last advisory on 33W known as Usagi, on Sunday, Nov. 25, 2018. On that day, Tropical Storm 33W weakened to a depression after making landfall near Ho Chi Minh City, Vietnam. Maximum sustained winds had weakened to 30 knots (34.5 mph/55.5 kph) and it continued weakening as it moved further inland.

At 2:12 a.m. EDT (0712 UTC) on Nov. 26, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite analyzed Tropical Cyclone 33W’s disorganized remnants dissipating over the Ca Mau Peninsula.

By Rob Gutro
NASA’s Goddard Space Flight Center

November 23, 2018 – NASA Sees Stronger Tropical Cyclone 33W Headed Toward Vietnam

33W was a tropical depression when it crossed the southern and central Philippines. As it moved through the South China Sea over the last two days it strengthened into a tropical storm and was renamed Usagi. On Nov. 23, NASA-NOAA’s Suomi NPP satellite captured a visible image of the stronger storm on approach to Vietnam.

Suomi NPP passed over 33W on Nov. 23 at 1:24 a.m. EDT (0624 UTC) and the VIIRS instrument provided a visible image. The VIIRS image showed 33W had strengthened and its center was surrounded by powerful storms. Bands of thunderstorms wrapped into the low-level center from the southern quadrant.

At 10 a.m. EDT (1500 UTC) Tropical Storm 33W or Usagi was located near 10.4 degrees north latitude and 110.4 degrees east longitude. That’s about 243 nautical miles east of Ho Chi Minh City, Vietnam. 33W was moving west and has maximum sustained winds near 55 knots (63 mph/102 kph).The Joint Typhoon Warning Center or JTWC noted that 33W may intensify slightly before making landfall on a day.

JTWC forecasters expect 33W to make landfall very near Ho Chi Minh City late on Nov. 24, and then progress to the northwest into Cambodia

For updated forecasts and warnings, visit the Vietnam National Centre for Hydro-Meteorological Forecasting (NCHMF): http://www.nchmf.gov.vn

By Rob Gutro 
NASA’s Goddard Space Flight Center

November 21, 2018 – NASA Sees Tropical Depression 33W Enter the Sulu Sea

Tropical Depression 33W moved through the central Philippines and entered the Sulu Sea when NASA-NOAA’s Suomi NPP satellite provided a visible image of the storm.

The Sulu Sea is located west of the central and southern Philippines. The VIIRS instrument aboard the Suomi NPP satellite revealed that 33W’s center was in the Sulu Sea on Nov. 21 as the elongated storm extended over the island of Palawan. The storm appeared stretched out from southwest to northeast, and clouds associated with the depression stretched back into the central and northern Philippines.

At 10 a.m. EST (1500 UTC) the center of Tropical Depression 33W was located near latitude 10.7 degrees north and longitude 119.8 degrees east. That’s 237 nautical miles south of Manila, Philippines. 33W is moving west-southwest. Maximum sustained winds remain at 25 knots (29 mph/46 kph).
Warm sea surface temperatures are helping keep the storm together as it battles moderate vertical wind shear of winds 20 to 25 knots (23 to 29 mph/37 to 46 kph). 33W was moving west toward the South China Sea where the wind shear is expected to ease. 33W is then forecast to strengthen as it crosses the sea and heads toward Vietnam.

By Rob Gutro 
NASA’s Goddard Space Flight Center

November 20, 2018 – NASA Sees Tropical Depression 33W Affecting Philippines

Visible imagery from NASA’s Terra satellite revealed the extent of Tropical Depression 33W showed the tropical low pressure system moving into the central part of the Philippines on Nov. 20.

Tropical Depression 33W (33W), known locally in the Philippines as Tropical Cyclone Samuel has triggered many warnings and watches.

Storm Signal 1 was in effect in three regions of the Philippines.In Luzon, Signal 1 was in effect for Masbate, Ticao Island, Romblon, southern Oriental and southern Occidental Mindoro, northern Palawan including Cuyo Island and the Calamian group of islands. In Visayas, Signal 1 was in effect for Northern Samar, Samar, Eastern Samar, Biliran, Leyte, Southern Leyte, Bohol, Cebu, Siquijor, Negros Oriental and Occidental, Guimaras, Iloilo, Capiz, Aklana and Antique. In Mindanao, Signal 1 was in effect for Surigao del Norte and Sur, Agusan del Norte and Sur, Dinagat Islands, Misamis Oriental and Camiguin

On Nov. 20 a visible image from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite showed a large disorganized storm moving through the central Philippines.

AT 10 a.m. EST (1500 UTC) On Nov. 20, Tropical depression 33W, (Philippines designation Samuel) was located near 10.9 degrees north latitude and 126.3 degrees east longitude, about 381 miles southeast of Manila, Philippines.  33W was moving to the west-northwest and had maximum sustained winds near 25 knots (28.7 mph)

33W will move generally west and cross the south-central Philippines. It is then forecast to move into the South China Sea and strengthen. The system will make a final landfall in central Vietnam and dissipate there.

By Rob Gutro
NASA’s Goddard Space Flight Center

November 19, 2018 – GPM Satellite Sees Light Rain Occurring in Tropical Depression 33W’s Eastern Side

The Global Precipitation Measurement mission or GPM core satellite is providing data on rain rates within Tropical Cyclone 33W as it moves over the Philippines on Nov. 19.

Tropical Depression 33W is about to traverse the south-central Philippines. In the Philippines, 33W is designated “Samuel.”

The GPM satellite passed over the eastern half of Tropical Depression 33W on Nov. 19 at 3:06 a.m. EST (0806 UTC) and measured the rainfall rates. The heaviest rainfall was occurring around the center at a rate of 1.2 inches per hour while light rain was occurring throughout much of the eastern half of the storm. The bulk of the clouds and showers associated with 33W are located in the storm’s western quadrant.

GPM is a joint satellite mission between NASA and the Japan Aerospace Exploration Agency called JAXA.

At 10 a.m. EST (1500 UTC), the center of 33W was located near latitude 9.1 degrees north and longitude 129.7 degrees east. 33W is moving toward the west-northwest and has maximum sustained winds near 30 knots (34.5 mph/55.5 kph)

Philippines storm signal 1 has been placed in effect for Luzon that includes Masbate, and for the Visayas region that includes Samar, Eastern Samar, Biliran, Leyte, Southern Leyte, Bohol, Cebu, Siquijor, Negros Oriental and Occidental. In the Mindanao region, Signal 1 is in effect for Surigao del Norte and Sur, Agusan del Norte and Sur, Dinagat Islands, Misamis Oriental and Camiguin

33W will move west-northwest, later west and into the South China Sea.

By Rob Gutro
NASA’s Goddard Space Flight Center