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Hurricane Season 2010: Tropical Storm Nisha (Southern Pacific Ocean)
01.29.10
 
January 29, 2010

TRMM captured Nisha's rainfall on Jan. 28 at 1947 UTC (2:47 p.m. ET). > View larger image
TRMM captured Nisha's rainfall on Jan. 28 at 1947 UTC (2:47 p.m. ET). The rainfall is occurring from the south to northeast of the storm's center. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour. Red areas are heavy rainfall at almost 2 inches per hour.
Credit: NASA/SSAI, Hal Pierce
Tropical Storm Nisha Being Battered by Wind Shear

Nisha is not expected to maintain its tropical storm status this weekend, because it is being battered by wind shear.

At 10 a.m. ET, January 29, Tropical Storm Nisha was barely hanging onto its status as a tropical storm, with maximum sustained winds near 39 mph (35 knots). It was located 150 nautical miles west-northwest of Rarotonga, near 19.8 South and 161.9 West. It was moving east-northeast near 11 mph.

The Tropical Rainfall Measuring Mission (TRMM) satellite, managed by NASA and the Japanese Space Agency flew over Nisha on January 28 and noticed that most of its rainfall is light to moderate, and spans from the south to the northeastern side of the storm. There were some isolated areas of heavy rainfall where rain was falling at about 2 inches per hour. However, most of the rain was moderate, falling at rates between 20 and 40 millimeters (.78 to 1.57 inches) per hour.

Nisha is in an area of moderate to high vertical wind shear which is battering and weakening the storm. Nisha is forecast to move slowly to the east and dissipate over the latter half of the weekend.

Text credit: Rob Gutro, NASA/Goddard Space Flight Center



January 28, 2010

Nisha has strengthened quickly; many areas within the storm have rainfall rates of over 2 inches per hour (red). > View larger image
At 6:35 a.m. ET January 28, TRMM captured Tropical Storm Nisha's rainfall. The storm has strengthened quickly and there are many areas within the storm that have rainfall rates of over 2 inches per hour (red). The green and yellow areas indicate light to moderate rainfall (.78-1.69 inches per hour).
Credit: NASA/SSAI, Hal Pierce
NASA's TRMM Sees Depression 10P Strengthen into Tropical Storm Nisha

The tenth tropical depression in the Southern Pacific Ocean has strengthened overnight and has been dubbed "Tropical Storm Nisha" and NASA's Tropical Rainfall Measuring Mission has watched the storm's precipitation increase since yesterday.

The Tropical Rainfall Measuring Mission or TRMM satellite is managed by both NASA and the Japanese Space Agency, JAXA. At 11:35 UTC (6:35 a.m. ET) today, January 28, TRMM flew over Nisha and captured an image of the storm's rainfall. The storm has strengthened quickly and there are many areas within the storm that have rainfall rates of over 2 inches per hour. TRMM also noticed that the highest cloud heights on the thunderstorms on the northeast quadrant of the storm are as high as 6 miles (10 kilometers).

The Joint Typhoon Warning Center (JTWC) forecasts for storms in this region. JTWC noted that animated infrared imagery and a microwave image from the TRMM satellite shows that the low has become more organized over the last 12 hours.

At 10 a.m. ET today, January 28, Tropical Storm Nisha had maximum sustained winds near 57 mph (50 knots) with higher gusts. It was located about 450 nautical miles southeast of Pago Pago, American Samoa, near 19.4 South and 164.5 West. It was moving east-southeast near 18 mph (16 knots).

Nisha is expected to move east-southeast and remain over warm waters that will help the storm maintain intensity or strengthen. The sea surface temperatures in the vicinity are warmer than 28 degrees Celsius (82 Fahrenheit).

Nisha has spawned some warnings in the region. A tropical cyclone warning is up for Palmerston Island and the rest of the South Cook Islands. Forecasters note that French Polynesia could be affected by the weekend.

Text credit: Rob Gutro, NASA/Goddard Space Flight Center



January 27, 2010

satellite image of Tropical Depression 10-P > View larger image
NASA's MODIS instrument captured an infrared image of Tropical Depression 10P on January 27 at 12:17 UTC.
Credit: NASA/JWTC
NASA Satellite Sees Tropical Depression 10P Strengthening in So. Pacific

NASA's Aqua satellite is keeping an eye on the tenth tropical depression to form in the southern Pacific Ocean. Tropical Depression 10P has formed overnight and is expected to continue strengthening.

When Aqua passed over Tropical Depression 10P (TD 10P) on January 27 at 12:17 UTC (7:17 a.m. ET) it was located near 15.1 South and 169.7 W, had maximum sustained winds near 39 mph (35 knots) and a minimum central pressure of 996 millibars. That places TD 10P's center about 45 nautical miles west-southwest of Pago Pago, American Samoa.

American Samoa is an unincorporated territory of the United States, located in the South Pacific Ocean, southeast of the sovereign state of Samoa.

TD 10P is moving east-southeast at a speedy 20 mph (18 knots). The Moderate Resolution Imaging Spectradiometer (MODIS) instrument on NASA's Aqua satellite took an infrared image of TD 10P earlier today, January 27, revealing the depression was strengthening quickly. Ground observations from the Ta'u Airport at American Samoa agreed with the 35 maximum sustained wind-speed satellite estimate. Ground observations noted that air pressure has dropped over the last day, to 997.5 millibars, which also indicates a strengthening storm.

Because of low wind shear and warm sea surface temperatures, TD 10P is expected to continue to strengthen.

Over the next several days, TD 10P is forecast to move generally in an easterly direction, and is expected to bring rains and gusty winds to Barotonga, Bora Bora and Tahiti.

Text credit: Rob Gutro, NASA/Goddard Space Flight Center