Featured Images

Text Size

Hurricane Season 2010: Cyclone Giri (Northern Indian Ocean)
10.25.10
 
October 25, 2010

Infrared NASA Satellite Imagery Shows the Power of Cyclone Giri

NASA's Aqua satellite captured this infrared image of the storm's cold cloud tops; even the eye is visible. › View larger image
NASA's Aqua satellite passed over Giri on Friday, Oct. 22 at 06:53 UTC (2:53 a.m. EDT) and captured this infrared image of the storm's cold cloud tops. Giri's coldest cloud tops are seen in purple. Even the eye is visible in this image.
Image Credit: NASA/JPL, Ed Olsen
Cyclone Giri rapidly intensified last week before it slammed into the coast of Myanmar, and infrared satellite imagery from NASA's Aqua satellite conveyed its strength.

Infrared imagery from NASA's Atmospheric Infrared Sounder (AIRS) indicated Giri's cloud tops had grown very cold, very quickly on Oct. 22 at 0653 UTC (2:53 a.m. EDT) indicating higher thunderstorm heights and a strengthening in the storm. High thunderstorm cloud tops indicate a strong storm. When the thunderstorm cloud heights start dropping, they become less cold, and the thunderstorms are less powerful. Cloud-top temperatures are important because they tell forecasters how high thunderstorms are, and the higher the thunderstorm, the colder the cloud tops and the more powerful the thunderstorms.

When AIRS captured the infrared image of Giri, the eye of the cyclone was clearly visible and still off-shore. The AIRS image also showed that at that time (0653 UTC) the strongest thunderstorms were still mostly over the Bay of Bengal and had not yet moved over land.

Cyclone Giri made landfall in near Hunters Bay, Myanmar on Friday, Oct. 22 with maximum sustained winds near 155 mph, the top end of a Category Four Cyclone on the Saffir-Simpson Scale. Some newspaper reports indicate that at least 27 people were killed and more were missing. A couple of thousand homes were also reported damaged from Giri. Giri has since dissipated inland.

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



October 22, 2010

Cat 4 Cyclone Giri Hits Burma, NASA Satellite Sees Heavy Rainfall

This TRMM image shows moderate to heavy rain showers were surrounding Cyclone Giri's partially-formed eye. › View larger image
This TRMM rainfall rate image captured on October 21 at 1534 UTC (11:34 a.m. EDT) shows moderate to heavy rain showers were surrounding Cyclone Giri's partially-formed eye. Red indicates heavy rainfall at more than 2 inches per hour. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour.
Image Credit: NASA/SSAI, Hal Pierce
Tropical Storm 04B grew quickly into powerful Cyclone Giri and was making landfall in Burma today as a powerful Category Four Cyclone on the Saffir-Simpson scale. NASA's TRMM satellite noticed that the storm contained some heavy rainfall in addition to the powerful winds.

Giri is the second tropical cyclone of 2010 to form in the Bay of Bengal and was seen by the Tropical Rainfall Measuring Mission (TRMM) satellite. Cyclone Giri was seen clearly by the TRMM satellite twice on Oct. 21. The first good view was at 1534 UTC (11:34 a.m. EDT) when TRMM data showed a very well organized storm with heavy rainfall south of Giri's partially formed eye. The heaviest rainfall was falling at about 2 inches per hour, south of Giri's eye. The rainfall analysis was done at NASA's Goddard Space Flight Center, Greenbelt, Md.

The second TRMM orbit at 2347 UTC (7:47 p.m. EDT) captured Giri's rainfall when the wind speeds had increased to 85 knots (98 mph) making it a category two tropical cyclone on the Saffir-Simpson scale. The second TRMM image showed that Giri had developed a closed eye surrounded by powerful thunderstorms dropping heavy rainfall. Cyclone Giri then intensified to a category four tropical cyclone with wind speeds estimated at 125 knots (~144mph) before striking Burma's west coast in the middle of the morning.

On Oct. 22 at 1500 UTC (11 a.m. EDT) Cyclone Giri had maximum sustained winds near 135 knots (155 mph) and was weakening as it continued to move inland. Giri's center was about 180 nautical miles south-southeast of Chittagong, Bangladesh near 20.1 North and 93.7 East. It was moving north-northeast at 10 mph.

Satellite data also indicated that as Giri was making landfall, that it had a well-defined eye about 20 nautical miles wide. High waves, coastal erosion, severe winds of Category four hurricane force and very heavy rainfall are all being experienced along coastal areas of Hunters Bay and Combermere Bay. As Giri moves inland over the rugged terrain of Myanmar it will rapidly weaken and drop large amounts of rain.

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



October 21, 2010

NASA Infrared Satellite Instrument Catches Fourth Depression Form in Indian Ocean

The coldest temperatures appear in purple and are as cold as or colder than -65 Fahrenheit (-53 C). › View larger image
NASA's Atmospheric Infrared Sounder (AIRS) instrument captured an image of Tropical Depression 04B's cloud top temperatures on Oct. 20 at 18:35 UTC (2:35 p.m. EDT). The coldest temperatures appear in purple (over the Bay of Bengal) and are as cold as or colder than -65 Fahrenheit (-53 C).
Image Credit: NASA/JPL, Ed Olsen
Tropical Depression 04B formed in the Northern Indian Ocean and has quickly strengthened into a tropical storm today. The AIRS instrument on NASA's Aqua satellite captured an image of Tropical Storm 04B's cloud top temperatures as it was forming yesterday.

NASA's Aqua satellite's Atmospheric Infrared Sounder (AIRS) instrument captured an image of then Tropical Depression 04B's cloud top temperatures on Oct. 20 at 18:35 UTC (2:35 p.m. EDT) and saw they had grown colder and higher than they were earlier in the day. Colder cloud tops indicate stronger convection that created those higher, stronger thunderstorms. Cloud top temperatures were as cold as or colder than -65 degrees Fahrenheit (-53 Celsius). Tropical Depression 04B remained over the eastern Bay of Bengal at the time of the image, and the heavy precipitation was all occurring over the open waters.

At 0900 UTC (5 a.m. EDT) on Oct. 21, Tropical Storm 04B had maximum sustained winds near 45 knots (49 mph). It was located about 295 nautical miles south of Chittagong, Bangladesh, near 17.6 North and 91.9 East. It is moving northeast at 3 mph. It is in warm waters and the wind shear is light, so it is expected to strengthen quickly into a Cyclone.

It is expected to make landfall in Burma tomorrow, October 22, so preparations need to be made quickly.

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