Hurricane Season 2008: Nicholas (Indian Ocean)
Feb. 21, 2008
Active Cyclones in the South Indian Ocean
With tropical cyclone season near its peak in the South Indian Ocean, two
were recently active in the region: Nicholas a one-time Category 1 cyclone that
made landfall in far Western Australia and Ivan a powerful Category 4 cyclone
devastated parts of Madagascar. The Tropical Rainfall Measuring Mission
(known as TRMM) was placed into service in November of 1997. From its low-earth
orbit, TRMM can provide valuable images and information on tropical cyclones
the Tropics using a combination of passive microwave and active radar sensors.
The first image shows Cyclone Nicholas as it was moving to the southwest
to the west coast of Australia at 17:17 UTC 17 February (2:17 am 18 February
Australian WDT) 2008. The image shows the horizontal pattern of rain intensity
within the storm. Rain rates in the center swath are from the TRMM
Radar (PR), the first precipitation radar in space, while rain rates in the
swath are from the TRMM Microwave Imager (TMI).
The rain rates are overlaid on
infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS). Nicholas'
field is asymmetric, which is characteristic of a less intense storm. There is,
however, good banding (or curvature) in the rain bands, which is indicative of a
developed circulation. At the time of this image, Nicholas was a Category 1
with maximum sustained winds estimated at 70 knots (81 mph) by the Joint Typhoon
Warning Center. After this image was taken, the system turned south and came
ashore near Coral Bay on Australia's remote northwest coast. No damage or
were reported due to the storm.
The second image shows cyclone Ivan, a much more powerful storm, as it was
down on the island of Madagascar. The image was taken at 06:21 UTC (9:21 am
time) on February 16th. A large, well-defined eye is apparent, and the storm is
much more symmetric than was evident with Nicholas. At the time of this image,
was a Category 3 storm with maximum sustained winds estimated at 100 knots (115
It would make landfall the next morning (local time) on the east coast of
killing 11. The hardest hit area was the island of Sainte Marie (the small
located just off the main coastline) where 9 people died.
The last image was taken simultaneously with the previous and shows a 3D picture
of Ivan courtesy of the TRMM PR. A ring of taller towers (highlighted in red)
reveals areas of deep convection (e.g., thunderstorms) that are associated with
the eyewall. The western eyewall is the most prominent in this image. Other
of deep convection are associated with outer rainbands. The South Indian Ocean
typically has 17 tropical cyclones in an average year. So far, there have been
9 tropical systems in the South Indian Ocean this year.
TRMM is a joint mission between NASA and the Japanese space agency JAXA.
Steve Lang, NASA's Goddard Space Flight Center/Science Systems and Applications Incorporated
Feb. 20, 2008
Nicholas Fading Near Far Western Australian Coast
Tropical Cyclone Nicholas is fading near the western Australian coast, and the Joint Typhoon Warning Center (JTWC) has just issued their final advisory on it.
On Feb. 20 at 1500 UTC (10:00 a.m. EST), Nicholas was near 25.9 degrees south latitude and 114.3 degrees east longitude. It's approximately 205 nautical miles south of Learmonth, Australia. Over the past 6 hours, Nicholas has tracked south-southeastward at 12 knots (13 mph). The storm has maximum sustained winds near 25 knots (29 mph).
The JWTC noted that "The system continues to weaken due to land interaction and moderate vertical wind shear. Based upon satellite intensity estimates, as well as synoptic observations, the storm is now below warning criteria." The remnants are expected to continue to track generally in a southerly direction over the next 12 hours. The low-level remnant circulation will remain near the western Australian coast as it tracks southward, but regeneration is not expected because of cooler sea surface temperatures and wind shear (winds that tear a storm apart).
This visible image of Nicholas was created on Feb 20 at 5:41 UTC (12:41 a.m. EST) by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. Nicholas is visible as the swirl of clouds on the left side of the image, and Australia is the green landmass to the right of the storm.
Rob Gutro, NASA's Goddard Space Flight Center
Feb. 15, 2008
Cyclone Nicholas Headed for Landfall in Western Australia
Tropical Cyclone Nicholas is forecast to make landfall in Western Australia over the weekend of Feb. 16.
On Feb. 15, Nicholas was in the southern Indian Ocean, with maximum sustained winds near 70 knots and higher gusts. Nicholas was moving west-southwest near 6 knots (6 mph). At 1200 UTC (7:00 a.m. EST), Nicholas was near 16.4 degrees south latitude, and 118.8 degrees east longitude, or 440 miles northeast of Learmonth, Australia. Satellite imagery indicates that Nicholas is a well-developed storm.
Forecasters expect Nicholas' track to shift to the southwest, and it is expected to make landfall 100 miles west of Port Hedland, on Feb. 17.
Cyclone Nicholas is visible as the circular purple and blue area to the northwest of Australia (top left) in this infrared image. The image was created by data from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite on Feb. 15 at 5:23 UTC (12:53 a.m. EST).
This AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of Nicholas. The infrared signal does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the Earth, revealing warmer temperatures (red).
Rob Gutro, NASA's Goddard Space Flight Center