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Hurricane Season 2010: Tropical Storm Zelia (South Pacific Ocean)
01.18.11
 
January 18, 2011

NASA's Terra Satellite Saw Tropical Storm Zelia Fizzling Enroute to New Zealand

NASA's Terra satellite captured a visible image of Tropical Storm Zelia heading for New Zealand › View larger image
NASA's Terra satellite captured a visible image of Tropical Storm Zelia heading for New Zealand on January 16 at 7 p.m. EST, and the image showed a strong storm with a visible eye. Credit: NASA MODIS Rapid Response Team
NASA's Terra satellite captured a visible image of a weakening Tropical Storm Zelia heading for New Zealand on January 16 at 7 p.m. EST. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument captured the image from its perch aboard the Terra satellite. The image showed a strong storm with a visible eye which fizzled quickly as a result of wind shear.

On Monday, January 17 at 10am EST (1500 UTC) Tropical Storm Zelia still had maximum sustained winds near 62 mph and was moving southeast toward New Zealand. At that time, it was centered about 495 nautical miles north-northwest of Auckland, New Zealand near 31.4 South and 170.3 East. It was still a tropical cyclone despite cooler water temperatures.

The New Zealand Meteorological Service noted on Monday, January 17 that Tropical Cyclone Zelia was northwest of Norfolk island and moving toward New Zealand. Zelia quickly weakened and became a remnant low, raining on northern New Zealand Tuesday afternoon and evening (local time).

To see weather radar from the New Zealand meteorological services for Auckland, go to: http://www.metservice.com/national/maps-rain-radar/rain-radar/all-nz-rain-last-6-hrs.

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



January 14, 2011

NASA's TRMM Satellite Sees Zelia Born of System 94P

NASA's TRMM satellite captured this image of Tropical Storm Zelia's rainfall on January 14 at 0417 UTC. › View larger image
NASA's TRMM satellite captured this image of Tropical Storm Zelia's rainfall on January 14 at 0417 UTC. The heaviest rainfall (falling at about 2 inches per hour) appears to be on the northwestern and southwestern sides of the storm and appear in red. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour.
Credit: SSAI/NASA, Hal Pierce
The low pressure area known as System 94P on January 13 strengthened into the seventh tropical cyclone of the South Pacific Cyclone season, today becoming Tropical Storm Zelia. NASA's TRMM satellite found heavy rainfall was already occurring in the storm as it was turning away from New Zealand and heading toward New Caledonia.

New Caledonia just dealt with Tropical Storm Vince today, and is expecting to feel winds and rains from Tropical Storm Zelia as it passes to the southwest of the island group this weekend.

The Tropical Rainfall Measuring Mission (TRMM) satellite, managed by NASA and the Japanese Space Agency flew over Tropical Storm Zelia on January 14 at 0417 UTC (Jan. 13 at 11:17 p.m. EST). TRMM noticed that the heaviest rainfall (falling at about 2 inches/50 mm per hour) appeared to be on the northwestern and southwestern sides of the storm.

TRMM images are pretty complicated to create. They're made at NASA's Goddard Space Flight Center in Greenbelt, Md. At Goddard, rain rates in the center of the swath (the satellite's orbit path over the storm) are created from the TRMM Precipitation Radar (PR) instrument. The TRMM PR is the only space borne radar of its kind. The rain rates in the outer portion of the storm are created from a different instrument on the satellite, called the TRMM Microwave Imager (TMI). The rain rates are then overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS). For more information about TRMM, visit: http://www.trmm.gsfc.nasa.gov/.

Infrared satellite imagery shows strong convection (rapidly rising air that condenses and forms the thunderstorms that power the tropical cyclone) consolidating over the western quadrant and near the center. The storm appears well-organized as bands of thunderstorms wrapping around the center were also evident in satellite imagery.

At 1500 UTC (10 a.m. EST/ 2 a.m. on Jan. 15, Pacific/Noumea local time) Tropical Storm Zelia had maximum sustained winds near 55 knots (63 mph/101 km/hr) with higher gusts. Zelia's center was located about 860 nautical miles north of Brisbane, Australia near 13.4 South and 152.3 East. Zelia is moving southeastward near 9 knots (10 mph/~16 km/hr).

The Joint Typhoon Warning Center expects Zelia to continue moving in a general southeastern direction and strengthen into a cyclone before becoming extra-tropical.

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



January 13, 2011

NASA's Aqua Satellite Sees Tropical Potential in System 94P Between Australia, Papau New Guinea

AIRS Infrared image of System 94P showing cloud tops as cold as or colder than -63 Fahrenheit (-53 Celsius). › View larger image
This NASA AIRS Infrared image on January 13, 2011 at 0353 UTC showed some strong convection in the center of System 94P where cloud tops were as cold as or colder than -63 Fahrenheit (-53 Celsius), strong thunderstorms were and areas where heavy rain was likely falling.
Credit: NASA/JPL, Ed Olsen
The last thing that Queensland, Australia needs is more rainfall after the record-breaking flooding that has been occurring there in the last two months. Now, NASA's Aqua satellite has noticed a low pressure area with signs of tropical development in the Coral Sea ( part of the South Pacific Ocean Basin), between Papua New Guinea and Australia's East Coast.

When NASA's Aqua satellite passed over System 94P on January 13, 2011 at 0353 UTC, the Atmospheric Infrared Sounder (AIRS) instrument captured an infrared image of the low's cloud temperatures. The AIRS cloud temperatures revealed some strong convection in the center of System 94P where cloud tops were as cold as or colder than -63 Fahrenheit (-53 Celsius) in strong thunderstorms and areas where heavy rain was likely falling. At that time, however, heavy rainfall was limited to areas over open ocean.

At 1000 UTC on Jan. 13, System 94P was located about 285 miles northeast of Cairns, Australia near 14.0 South and 149.7 East. Maximum sustained winds are reported around 33 mph (55 km/hr), just near tropical depression status. The low is still not a tropical depression, but forecasters at the Joint Typhoon Warning Center give it a good chance to become one. Minimum central pressure is estimated near 1001 millibars.

The JTWC noted that "Animated multispectral imagery Indicated that rapid consolidation and intensification of the low level circulation center over the past 12 hours (to 2200 UTC on Jan. 12). System 94P is also in an area of low wind shear and sea surface temperatures warmer than the 80F threshold needed to help a tropical cyclone develop.

Currently the JWTC is projecting that System 94P will track to the northeast away from eastern Australia over the next couple of days and toward Port Moresby, Papua New Guinea. Forecasters will keep watching to see if System 94P becomes a tropical depression in the next day or two.

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