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Hurricane Season 2010: Tropical Storm Vania (South Pacific Ocean)
01.12.11
 
January 12, 2011

NASA's TRMM Satellite Sees Heavy Rain and Towering Thunderstorms in Tropical Storm Vania

TRMM captured the rainfall rates of Tropical Storm Vania on January 12 › View larger image
TRMM captured the rainfall rates of Tropical Storm Vania on January 12 at 1246 UTC. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour. The heaviest rains were falling in the northeastern quadrant of the storm (Red) and indicate rainfall at about 2 inches per hour. Credit: NASA/SSA
The low pressure area that NASA has been watching previously known as System 93P strengthened into the fifth tropical depression of the South Pacific Hurricane season late yesterday. This morning System 93P strengthened even more and became a tropical storm. NASA's TRMM Satellite flew over Tropical Storm Vania saw the heavy rainfall and towering thunderstorms within.

The Tropical Rainfall Measuring Mission (TRMM) satellite captured the thunderstorm heights and rainfall rates in Tropical Storm Vania on January 12 at 1246 UTC (7:46 a.m. EST). TRMM noticed that some of the thunderstorms reached more than 9 miles (~15 kilometers) high, indicating strong uplift and a heavy rainmakers. TRMM also noticed that the heaviest rains were falling in the northeastern quadrant of the storm and indicate rainfall at about 2 inches per hour. Other quadrants of the storm were generating moderate rainfall rates between .78 to 1.57 inches per hour. TRMM is managed by NASA and the Japanese Space Agency, JAXA.

Warnings are posted for Vanuatu and New Caledonia. The Vanuatu warnings include: A Red Alert for the Erromango and Tanna Islands, a Yellow Alert for Shefa and the rest of Tafea Province and a Blue Alert for Penama and Malampa province. The New Caledonian warnings include the Loyauté and Grand Terre.

At 0900 UTC (4 a.m. EST) on January 12, Tropical Storm Vania had maximum sustained winds near 52 mph (23 km/hr). It was located about 250 miles northeast of Noumea, New Caledonia near 19.1 South and168.5 East. Vania was moving very slowly to the south-southwest at 2 mph (~3 km/hr). It was generating seas as high as 12 feet (3.6 meters). Tropical Storm Vania is slowly moving toward Vanuatu but is forecast to move southwest and pass over or near New Caledonia. As Vania continues to move further south, it is expected to encounter wind shear and weaken.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD


January 11, 2011

NASA Infrared imagery sees System 93P Strengthening, Vanuatu Warnings Up

System 93P› View larger image
When NASA's Aqua satellite passed over System 93P on January 11 at 02:34 UTC, most of the coldest, highest cloud tops and strongest thunderstorms (purple) were still east of the island nation. New Zealand is on the bottom right of the image. Credit: NASA JPL, Ed Olsen
NASA's Aqua satellite flew over the low pressure area known as System 93P in the Southern Pacific Ocean early today and saw rainfall already occurring over Vanuatu. Warnings are already up for portions of Vanuatu.

Vanuatu is an island nation located in the South Pacific Ocean. Vanuatu Meteorological Service issued a Yellow Alert for Shefa and Tafea. A Blue Alert is in force for Malampa and Penama as the local forecast calls for rain and thunderstorm over the group of islands today and some rain will be heavy at times. Flooding expected over low lying areas and river banks, and gusty winds are expected.

When NASA's Aqua satellite passed over System 93P on January 11 at 02:34 UTC (Jan. 10 at 9:34 p.m. EST) the Atmospheric Infrared Sounder (AIRS) instrument captured an infrared image of the storm's cloud temperatures. Cloud temperatures are a key in determining storm strength. The higher the cloud tops, the stronger the convection and the stronger the thunderstorms are that power a tropical cyclone. AIRS data showed that most of the coldest, highest cloud tops and strongest thunderstorms were still east of the island nation at that time. The coldest cloud tops were as cold as or colder than -63 degrees Fahrenheit (-53 Celsius).

By 0600 UTC (1 a.m. EST) on January 11, the center of System 93P (also called Tropical Disturbance 03F in Fiji) was about 125 miles east-southeast of Port Vila, Vanuatu near 18.9 South and 170.0 East. It was moving west-southwestward at 5 mph and had maximum sustained winds near 33 mph.

Infrared and multispectral satellite imagery show that convection (rapidly rising air that forms the thunderstorms that make up a tropical cyclone) have strengthened over the low level circulation center. The Joint Typhoon Warning Center, the organization that forecasts tropical cyclones in that region, noted that there is a good chance that System 93P would become a tropical depression in the next 24 hours. For local weather updates in Vanuatu, visit: http://www.meteo.gov.vu/.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD


NASA's Aqua Satellite Sees System 93P Fire up in the South Pacific

This MODIS infrared image provided appearances of circular motion, but didn't show a well-organized storm. › View larger image
When NASA's Aqua satellite passed over System 93P on Jan. 10 at 1419 UTC (9:19 a.m. EST) its maximum sustained winds were near 28 mph. The infrared image provided an appearances of circular motion, but didn't show a well-organized storm. Areas that are brighter white are areas of stronger convection.
Credit: NRL/JTWC/NASA
A low pressure system that has a fair chance of becoming the world's next tropical cyclone has developed in the South Pacific, and NASA's Aqua satellite captured in infrared image of the storm.

System 93P, which is also designated in the Fiji Islands as "03F" for third tropical disturbance formed in the South Pacific Ocean. On Monday, January 10, 2011 at 0600 UTC (1 a.m. EST), it was located about 115 miles east-northeast of Port Vila, Vanuatu near 16.9 South and 170.0 East.

Vanuatu is an island nation located in the South Pacific Ocean about 1,090 miles (1,750 kilometers) east of northern Australia, and 301 miles (500 kilometers) northeast of New Caledonia and west of Fiji.

When NASA's Aqua satellite passed over System 93P on Jan. 10 at 1419 UTC (9:19 a.m. EST), it had maximum sustained winds near 28 mph and a minimum central pressure of 998 millibars. The infrared image provided an appearances of a circular motion, but didn't show a well-organized storm.

Animated multi-spectral imagery showed that convection in System 93P is strengthening and consolidating over the low level circulation center. According to the Joint Typhoon Warning Center, the weather station at Bauerfield efate, Vanuatu, is reporting that pressure has fallen three millibars over the last 24 hours, which indicates the low is strengthening.

Currently the deepest convection and strongest thunderstorms remain confined to the northern side of the system. Sea surface temperatures are currently near 84 degrees Fahrenheit (29 Celsius) and any temperature near 80 F or higher can power a tropical cyclone and help it develop. Wind shear remains light, so there's a fair chance that this system could become a tropical depression in the next 24 hours.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD