image: The Tropical Rainfall Measuring Mission satellite captured the rainfall rates of Tropical Storm Nock-ten on July 26. The heaviest rainfall appears in red, falling at almost 2 inches (50 mm) per hour. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour. view more
Credit: NASA/SSAI, Hal Pierce
NASA satellite data has shown that Tropical Storm Nock-ten has been a big rainmaker across the Philippines for the last two days and is now tracking into the South China Sea.
The Tropical Rainfall Measuring Mission (TRMM) satellite data was used to create a 3-D image of Tropical Storm Nock-ten's rainfall and cloud heights as it passed overhead on July 25. Nock-ten had towering convective storms near their centers of circulation that extended to heights above 15km (~9.3 miles) with heavy rainfall, falling at 2 inches (50 mm) per hour.
The 3-D view was made from TRMM's Precipitation Radar (PR) data collected on July 25, 2011 at 1631 UTC (12:31 p.m. EDT). Nock-ten had towering convective storms near the center of circulation that extended to heights above 15 kilometers (~9.3 miles). These tall towers are associated with convective bursts and can be a sign of future strengthening because they indicate areas where energy is being released into the developing tropical storms. Even on July 25, tropical storm Nock-ten was affecting the eastern Philippines.
Warnings are still in effect in the Philippines today, July 27, as Nock-ten makes its exit. The Public storm warning signal #1 is in effect in the Luzon provinces of Aurora, Apayao, Cagayan, Pangasinan, Nueva Ecija, Northern Quezon, Zambales, Pampanga, Tarlac, Bulacan, Bataan, Rizal and Metro Manila. In addition, Public storm warning signal #2 is in effect for the Luzon provinces of Ilocos Norte & Sur, Abra, Kalinga, Isabela, Mt. Province, Ifugao, La Union, Benguet, Nueva Viscaya and Quirino.
According to the Manila Sun Star news, the third day of heavy rains from Nock-ten (locally named Juaning) caused flooding in the northeastern Philippines and is responsible for 24 deaths.
At 1500 UTC (11 a.m. EDT) on July 27 infrared imagery from the Atmospheric Infrared Sounder instrument on NASA's Aqua satellite indicated that Nock-ten's center moved off the coast of western Luzon. Tropical Storm Nock-ten's maximum sustained winds were still near 50 knots (57 mph/92 kmh). It was centered about 170 miles (273 km) north-northwest of Manila, near 17.4 North and 120.4 East. Tropical storm-force winds extend out to 70 miles (112 km) from the center. Nock-ten was moving to the northwest at 14 knots (16 mph/26 kmh), and is making its way out of Luzon and into the South China Sea.
The forecasters at the Joint Typhoon Warning center expect Nock-ten to strengthen and make a second landfall crossing over Hainan Island, China and finally landfalling in Vietnam.