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Hurricane Season 2012: Tropical Cyclone Giovanna (Southern Indian Ocean)
02.22.12
 
In February 2012, the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this natural-color image of the sediment-choked Onibe River on February 19, 2012. › View larger image
In February 2012, the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this natural-color image of the sediment-choked Onibe River on February 19, 2012. The river appears muddy brown throughout this landscape, and delivers a thick plume of sediment to the Indian Ocean.
Credit: NASA Earth Observatory/Jesse Allen/Robert Simmon/NASA EO-1 team
Thick Sediment in Madagascar’s Onibe River After Cyclone Giovanna

In February 2012, the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this natural-color image of the sediment-choked Onibe River on February 19, 2012. The river appears muddy brown throughout this landscape, and delivers a thick plume of sediment to the Indian Ocean.

The Onibe River arises in the highlands of Madagascar’s interior and empties into the ocean just north of the coastal town of Mahavelona (also known as Foulpointe). The river lies along the track Giovanna followed when it came ashore. Giovanna’s heavy rains spurred equally heavy runoff into the Onibe River. This image was created at NASA's Goddard Space Flight Center in Greenbelt, Md. for NASA's Earth Observatory, by Jesse Allen and Robert Simmon, using EO-1 ALI data provided courtesy of the NASA EO-1 team.

In eastern Madagascar, rivers are typically short and fast-moving, thanks to the area’s stark relief. Madagascar’s highest mountain, for example, is 2,876 meters (9,436 feet) above sea level yet lies just 120 kilometers (75 miles) from the coast. The steep slopes lead to significant erosion, but even compared to the island’s usual runoff rates, the Onibe carried a heavy load of mud and debris in the wake of Giovanna. An ALI image of the same area on February 6 showed virtually no sediment plume at the mouth of the river.

Cyclones rank among the most frequent natural hazards for Madagascar. After coming ashore in mid-February, Tropical Cyclone Giovanna blew westward over the island, traveled southward through the Mozambique Channel, then curved back to the east, skirting Madagascar’s southern shore.

Text Credit: Michon Scott
NASA Earth Observatory
NASA's Goddard Space Flight Center



Feb. 21, 2012

TRMM captured the rainfall in fading Tropical Cyclone Giovanna on February 20, 2012 at 0653 UTC. › View larger image
The TRMM satellite captured the rainfall in fading Tropical Cyclone Giovanna on February 20, 2012 at 0653 UTC (1:53 a.m. EST). TRMM data showed that Giovanna had light to moderate rainfall is depicted in blue and green was falling at a rate between .78 to 1.57 inches (20 to 40 mm) per hour. There were no areas of heavy rainfall.
Credit: SSAI/NASA, Hal Pierce
NASA's TRMM Satellite Sees Deadly Cyclone Giovanna Finally Fading

Tropical Cyclone Giovanna is being torn apart in the Southern Indian Ocean on February 21 after taking lives in Madagascar. NASA's TRMM satellite noticed fading rainfall as the system was being battered by strong wind shear.

The Tropical Rainfall Measuring Mission (TRMM) satellite captured the rainfall in fading Tropical Cyclone Giovanna on February 20, 2012 at 0653 UTC (1:53 a.m. EST). TRMM data showed Giovanna had light to moderate rain falling at a rate between .78 to 1.57 inches (20 to 40 mm) per hour. There were no areas of heavy rainfall.

Giovanna had killed at least 23 people and left about 190,000 homeless in the last week, according to news sources.

The last update on Tropical Cyclone Giovanna as issued on February 21 at 0300 UTC (Feb. 20, 10 a.m. EST). The center was located at 23.4 South and 52.6 East, about 410 miles southeast of Antananarivo, Madagascar. Its maximum sustained winds were down to 30 knots (34.5 mph/55.5 kph) and it was moving to the north-northwest near 7 knots (8 mph/13 kph).

Cyclone Giovanna is expected to dissipate east of Madagascar, over the next two days as a result of strong wind shear.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.



Feb. 17, 2012

On infrared imagery from the NASA AIRS instrument, some thunderstorms from northeast to southeast of the center of Cyclone Giovanna were strong (purple) on imagery captured on February 17, 2012 at 1023 UTC (5:23 a.m. EST). › View larger image
On infrared imagery from the NASA AIRS instrument, some thunderstorms from northeast to southeast of the center of Cyclone Giovanna were strong (purple) on imagery captured on February 17, 2012 at 1023 UTC (5:23 a.m. EST).
Credit: NASA JPL, Ed Olsen

Cyclone Giovanna's rainfall from February 8-15, 2012, the highest rainfall totals of over 250mm (~10 inches) fell in the coastal area east of Madagascar's capitol of Antananarivo. In that area people were flooded out of their homes and deaths have been reported.  White symbols show the times and loc › View larger image
Cyclone Giovanna's rainfall from February 8-15, 2012, the highest rainfall totals of over 250mm (~10 inches) fell in the coastal area east of Madagascar's capitol of Antananarivo. In that area people were flooded out of their homes and deaths have been reported. White symbols show the times and locations of tropical cyclone Giovanna as it passed over Madagascar. Credit: SSAI/NASA, Hal Pierce
Rain-Soaked Madagascar Again Threatened by Cyclone Giovanna

Rainfall data from NASA's TRMM satellite revealed that parts of Madagascar's east coast received over a foot (30 cm) of rainfall from Cyclone Giovanna's passage, and new satellite data shows Cyclone Giovanna re-strengthening and turning back toward southeastern Madagascar.

The Tropical Rainfall Measuring Mission (TRMM) satellite, managed by both NASA and the Japanese Space Agency obtains rainfall rate data from space and acts like a flying rain gauge. That data is analyzed to determine how much rain falls from certain events. In a Multi-satellite Precipitation Analysis (TMPA) done at the NASA Goddard Space Flight Center in Greenbelt, Md. on Cyclone Giovanna's rainfall from February 8-15, 2012, the highest rainfall totals of over 250mm (~10 inches) fell in the coastal area east of Madagascar's capitol of Antananarivo. In that area people were flooded out of their homes and deaths have been reported.

Giovanna then tracked across central Madagascar and entered the Mozambique Channel where the warm waters re-energized the storm.

On February 17, 2012, NASA's Aqua satellite flew over Cyclone Giovanna. On infrared imagery from the Atmospheric Infrared Sounder (AIRS) instrument, bands of thunderstorms from northeast to southeast of the center of Cyclone Giovanna appeared strong in an image captured at 1023 UTC (5:23 a.m. EST).

Five hours later at 1500 UTC (10 a.m. EST), Giovanna's maximum sustained winds were near 55 knots (63.3 mph/102 kph). The center of circulation was about 445 nautical miles (512 miles/824 km) south-southwest of Antananarivo, Madagascar, near 25.8 South and 43.2 East. It was moving southeastward at 2 knots (2.3 mph/3.7 kph).

The forecasters at the Joint Typhoon Warning Center expect Giovanna to track over southern Madagascar over the weekend of February 18 and 19 with gusty winds and heavy rainfall. Giovanna is expected to then dissipate over the southeastern part of the island by February 20.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.





This color-coded map shows the rain associated with Giovanna from February 8 to 14, 2012. › View larger image
This color-coded map shows the rain associated with Giovanna from February 8 to 14, 2012.
Credit: NASA Earth Observatory image by Jesse Allen, using near-real-time data provided courtesy of TRMM Science Data and Information System at Goddard Space Flight Center.
NASA Rainfall Map Shows Flooding Rainfall from Cyclone Giovanna

When Tropical Cyclone Giovanna came ashore in eastern Madagascar, the well-organized storm not only brought high winds, but also heavy precipitation. Flooding affected multiple neighborhoods in the capital city of Antananarivo and surrounding areas. As of February 15, 2012, the death toll stood at 16.

This color-coded map shows the rain associated with Giovanna from February 8 to 14, 2012. The heaviest rainfall—more than 350 millimeters or nearly 14 inches—appears in dark blue. The lightest rainfall—less than 50 millimeters or 2 inches—appears in light green. Trace amounts of precipitation appear in pale yellow. The heaviest rainfall occurs east of Madagascar, but almost equally heavy rainfall occurs along the island’s east coast.

Superimposed on the rainfall is Giovanna’s storm track, with darker shades of red corresponding with a greater storm strength. Before making landfall, Giovanna strengthened to a Category 4 storm. Storm strength dissipated over the island and the Mozambique Channel. Forecasts from the U.S. Navy’s Joint Typhoon Warning Center called for Giovanna to re-strengthen somewhat west of Madagascar, but the storm was not expected to match its prior wind speeds.

This image is based on data from the Multisatellite Precipitation Analysis produced at NASA’s Goddard Space Flight Center, which estimates rainfall by combining measurements from many satellites and calibrating them using rainfall measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite.

Text Credit: Michon Scott
NASA Earth Observatory
NASA's Goddard Space Flight Center, Greenbelt, Md.



Feb. 16, 2012

NASA's Aqua satellite passed over Tropical Storm Giovanna on February 16 at 11:23 UTC (6:23 a.m. EST) as it was moving south in the Mozambique Channel. › View larger image
NASA's Aqua satellite passed over Tropical Storm Giovanna on February 16 at 11:23 UTC (6:23 a.m. EST) as it was moving south in the Mozambique Channel. Thunderstorms west of the center still appeared strong, and had high cloud tops. Cloud top temperatures were high enough to reach the -63F/-52.7C (purple) threshold, indicating powerful storms.
Credit: NASA JPL, Ed Olsen
NASA Sees Cyclone Giovanna Moving Through the Mozambique Channel

Infrared NASA satellite imagery showed Cyclone Giovanna moving south through the Mozambique Channel on Thursday, February 16, 2012. Infrared data showed that Giovanna was regaining strength in the warm waters of the Channel, and the strongest thunderstorms were west of the storm's center.

NASA's Aqua satellite passed over Tropical Storm Giovanna on February 16 at 11:23 UTC (6:23 a.m. EST) as it was moving south in the Mozambique Channel. Thunderstorms west of the center still appeared strong, and had high cloud tops. Cloud top temperatures were high enough to reach the -63F/-52.7C threshold, indicating powerful storms. Those strong thunderstorms appeared to be mostly over water and not affecting southwestern Madagascar although Giovanna appeared to be hugging the coastline.

On Thursday, February 16, 2012 at 0000 UTC (Feb. 7 p.m. EST) Giovanna's maximum sustained winds had increased to 50 knots. Giovanna was centered about 450 nautical miles east of Maputo, Mozambique near 24.5 South and 40.7 East. It was moving south-southwest at 4 knots.

Giovanna is moving along the western edge of a ridge (elongated area) of high pressure located to the storm's east. Giovanna is expected to move slowly to the west and cross the Mozambique Channel. Over the next day as Giovanna is crossing the channel toward Mozambique wind shear is expected to increase, according to forecasters at the Joint Typhoon Warning Center, and that will again weaken the storm. Interests along coastal Mozambique should monitor the progress of Cyclone Giovanna.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.



Feb. 15, 2012

MODIS captured a visible image of Cyclone Giovanna at 10:45 UTC (5:45 a.m. EST) on February 15, 2012. › View larger image
MODIS captured a visible image of Cyclone Giovanna in the Mozambique Channel at 10:45 UTC (5:45 a.m. EST) on February 15, 2012. The image showed the convection had diminished greatly in the northwestern quadrant of the storm.
Credit: NASA Goddard MODIS Rapid Response Team
NASA Sees Cyclone Giovanna Enter the Mozambique Channel

Cyclone Giovanna crossed over the island of Madagascar leaving flooding and damages in its wake and has now entered the Mozambique Channel. NASA's Aqua satellite captured an image that showed a ragged eye still exists, and the storm is regaining strength in the warm Channel waters.

Once Giovanna traversed the island nation of Madagascar and entered the Mozambique Channel, the body of water between Madagascar and Mozambique on the African mainland, NASA's Aqua satellite passed overhead and captured a visible image with the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument.

MODIS captured the image at 10:45 UTC (5:45 a.m. EST) on February 15. The image showed that convection (rising air that forms the thunderstorms that make up the storm) had diminished greatly in the northwestern quadrant of the storm,. The MODIS image also showed that thunderstorms were now building around the rest of the tropical storm as a result ove moving into the warm waters of the Mozambique Channel. Sea surface temperatures of at least 80 Fahrenheit (26.6 Celsius) are needed to maintain a tropical cyclone, and temperatures in the Channel are as warm as ~88 Fahrenheit (31 Celsius).

On February 15, 2012 at 0300 UTC (Feb. 14 at 10 p.m. EST), Tropical Storm Giovanna's maximum sustained winds were near 40 knots (46 mph/74 kph). Tropical Cyclone Giovanna's center was located approximately 250 nautical miles west-southwest of Antananarivo, Madagascar, near 20.8 South and 42.4 East. It is moving to the west-southwest at 13 knots (15 mph/24 kph).

BBC News reports that at least two people died from storm related incidents, and the town Vatomandry, south of where Giovanna made landfall in east-central Madagascar, has experienced a lot of damage. BBC News reports that at least 60 percent of homes in the town were damaged or destroyed. Trees, phone and power lines have been downed, especially in eastern areas, as recovery efforts continue.

The Joint Typhoon Warning Center uses satellite data and forecast computer models to create forecasts. The current forecast for Giovanna now takes it on a westerly track toward Mozambique by the week's end. The forecast also indicates that wind shear will increase, which will prevent the storm from strengthening further. Residents along the southeastern coast of Mozambique should monitor the path of this tropical storm.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.



Feb. 14, 2012

On February 14, 2012 at 07:15 UTC, MODIS captured this visible image of Cyclone Giovanna › View larger image
On February 14, 2012 at 07:15 UTC (10:15 a.m. local time - Madagascar/3:15 a.m. EST), the MODIS instrument on NASA's Terra Satellite captured this visible image of Cyclone Giovanna almost directly in the center of the island of Madagascar.
Credit: NASA Goddard MODIS Rapid Response Team
This 3-D image from TRMM satellite data from Feb. 12, 2012 shows the structure of Giovanna's double eye wall. › View larger image
This 3-D image was created from TRMM satellite data from Feb. 12, 2012. Looking from the east, it shows the structure of Giovanna's double eye wall. The tallest storm towers reaching to heights of almost 15km (~9.3 miles) were on Giovanna's eastern side. The storm towers in Giovanna's center were reaching to about 11km (~6.8 miles).
Credit: SSAI/NASA, Hal Pierce
Th3 TRMM pass on February 11 at 1200 UTC, showed that an eyewall replacement was occurring at that time. › View larger image
When the TRMM satellite flew over Giovanna on February 11 at 1200 UTC, it was rapidly becoming more powerful. On the 11th, Giovanna had intensified to a category 3 tropical cyclone on the Saffir-Simpson scale with wind speeds estimated at 100 knots (~115 mph). That TRMM pass showed that an eyewall replacement was occurring at that time. A small ring of strong convective storms was located around the center of the center eye and other powerful storms were seen in the replacement eye further out from Giovanna's center.
Credit: SSAI/NASA, Hal Pierce
NASA Sees Deadly Cyclone Giovanna Over the Center of Madagascar

Cyclone Giovanna made landfall in eastern Madagascar very early on February 14 and continues tracking in a southwestern direction toward the Mozambique Channel. NASA's Aqua satellite captured an image when Giovanna's center was close to the capital city of Antananarivo, and NASA's TRMM satellite saw powerful towering thunderstorms around its center before it made landfall.

According to BBC News, Giovanna made landfall near the eastern port city of Toamasina with winds gusting to 120 mph (194km). Giovanna brought heavy rain, and its strong winds flattened trees. Storm surges continue to pound coastal areas as Giovanna tracks over the fourth-largest island in the world. Rainfall totals are expected between 10 and 20 inches (250 to 500 mm), and may trigger landslides in higher elevations.

On February 14, 2012 at 07:15 UTC (10:15 a.m. local time - Madagascar/3:15 a.m. EST), the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra Satellite captured a visible image of Cyclone Giovanna almost directly in the center of the island of Madagascar. Giovanna had weakened as a result of its interaction with land, and its eye had "closed."

Five hours later on Feb. 14, around 1200 UTC (7 a.m. EST), Giovanna was still tracking over land and weakened significantly to a minimal tropical storm. Maximum sustained winds were near 35 knots (40.2 mph/65 kph) and it was located about 100 nautical miles west of Antananarivo, Madagascar, near 19.6 South and 44.7 East. Giovanna is moving west at 14 knots (16.1 mph/26 kph).

The capitol city of Antananarivo reported a maximum wind speed of 32 knots (10-minute average) (~37 mph/~59 kph) with higher gusts.

As Giovanna approached Madagascar on February 13, another NASA satellite called the Tropical Rainfall Measuring Mission satellite (TRMM) had a fairly good early morning view if it. At 0333 UTC on Feb. 13, rainfall rates were obtained from TRMM Microwave Imager (TMI) and were overlaid on a visible/infrared image from TRMM's Visible and InfraRed Scanner (VIRS) instrument at NASA's Goddard Space Flight Center in Greenbelt, Md. At that time, Giovanna was an intensifying category 4 tropical cyclone with wind speeds estimated at over 125 knots (~144 mph).

Tropical cyclone Giovanna was located in the Indian Ocean east-northeast of Madagascar when it was classified as a tropical storm on February 9, 2012. When the TRMM satellite flew over Giovanna on February 11 at 1200 UTC, it was rapidly becoming more powerful. On the 11th, Giovanna had intensified to a category 3 tropical cyclone on the Saffir-Simpson scale with wind speeds estimated at 100 knots (~115 mph). That TRMM pass showed that an eyewall replacement was occurring at that time. A small ring of strong convective storms was located around the center of the center eye and other powerful storms were seen in the replacement eye further out from Giovanna's center.

The data from the TRMM Precipitation Radar (PR) data were also used to create a 3-D image of the storm. This image, looking from east, shows the structure of Giovanna's double eye wall. TRMM PR data shows that the tallest storm towers reaching to heights of almost 15km (~9.3 miles) were on Giovanna's eastern side. The storm towers in Giovanna's center were reaching to about 11km (~6.8 miles).

Giovanna is now expected to move into the Mozambique Channel where the warm waters will allow it to quickly reorganize. Forecast models take the storm to the center of the channel and then curve it back to the southeast over the next couple of days.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.







Feb. 13, 2012

MODIS captured this visible image of Tropical Cyclone Giovanna on Feb. 13, 2012 at 06:35 UTC › View larger image
The MODIS instrument on NASA's Terra satellite captured this visible image of Tropical Cyclone Giovanna on Feb. 13, 2012 at 06:35 UTC as it approaches a landfall in east-central Madagascar.
Credit: NASA Goddard MODIS Rapid Response Team
These two infrared images show the progression and intensification of Cyclone Giovanna on Feb. 11 and 12 › View larger image
These two infrared images from the AIRS instrument on NASA's Aqua satellite show the progression and intensification of Cyclone Giovanna on Feb. 11 and 12, both captured around 1000 UTC (5 a.m. EST). The image on Feb. 12 shows that an eye has clearly developed as Giovanna strengthened. Purple indicates highest, strongest thunderstorms with heavy rainfall.
Credit: NASA/JPL, Ed Olsen
Dangerous Tropical Cyclone Giovanna to Make Landfall in Madagascar

NASA satellites have been providing visible, infrared, microwave and radar data on Cyclone Giovanna to forecasters at the Joint Typhoon Warning Center as the storm is poised for landfall in east-central Madagascar. Cyclone Giovanna was a category four storm upon its approach to Madagascar and may cause severe damage.

Tropical cyclone Giovanna is forecast to make landfall in east-central Madagascar around midnight local time (Indian/Antananarivo time) on Tuesday, February 14, 2012 (7 p.m. EST/U.S.). NASA's Terra satellite passed over Giovanna early on February 13 and captured in image of the storm that showed the storm has a 30-nautical-mile (34.5 miles/55.5 km) wide eye and remains a powerful cyclone.

Two infrared images from the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite showed the progression and intensification of Cyclone Giovanna on Feb. 11 and 12, as Aqua passed over on both days around 1000 UTC (5 a.m. EST). The image on February 12 showed that an eye had clearly developed as Giovanna strengthened. Cloud top temperatures also dropped, indicating the thunderstorm cloud tops were higher in the troposphere, and their thunderstorms were stronger.

On February 13, at 1500 UTC (10 a.m. EST/6 p.m. local time Madagascar), Cyclone Giovanna had maximum sustained winds of 125 knots (144 mph/231.5 kph). That makes Giovanna a Category Four hurricane/cyclone.

A Category four storm has sustained winds 131-155 mph, 114-135 knots, or 210-249 km/hr. The National Hurricane Center reports that this kind of a cyclone/hurricane will cause "catastrophic damage" to occur.

According to NOAA, a category four cyclone causes catastrophic damage: "Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Long-term water shortages will increase human suffering. Most of the area will be uninhabitable for weeks or months."

On February 13 at 1500 UTC (6 p.m. local time, Madagascar/10 a.m. EST), Cyclone Giovanna was located approximately 250 nautical miles east of Antananarivo, Madagascar, near 18.8 South and 50.8 East. It was moving to the west-southwestward at 12 knots (14 mph/ 22 kph). At that time the western edge of Giovanna was already affecting eastern Madagascar with gusty winds, rough surf and rainfall. Rainfall and winds will increase.

Giovanna is forecast to make landfall over the central eastern coast of Madagascar shortly before 0300 UTC on February 14 (6 a.m. local time, Madagascar/10 p.m. EST, U.S.), and then weaken as it moves across the island. It is expected to move into Mozambique Channel and may re-intensify.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.



Feb. 10, 2012

MODIS captured this image of Tropical Cyclone Giovanna at 06:00 UTC (1 a.m. EST) on February 10, 2012. › View larger image
The MODIS instrument on NASA's Terra satellite captured this image at 06:00 UTC (1 a.m. EST) on February 10, 2012, as Tropical Cyclone Giovanna moved through the Southern Indian Ocean. Although the visible image did not reveal an eye, infrared data did see the beginning of an eye. The thunderstorms around the center of circulation are higher than the surrounding clouds, and cast shadow on the lower surrounding clouds in this image.
Credit: NASA Goddard MODIS Rapid Response Team
NASA Sees Giovanna Reach Cyclone Strength, Threaten Madagascar

Tropical Storm 12S built up steam and became a cyclone on February 10, 2012 as NASA's Terra satellite passed overhead. Residents of east-central Madagascar should prepare for this cyclone to make landfall by February 13 according to forecasters.

Now named Cyclone Giovanna, this storm has reached Category One status on the Saffir-Simpson Hurricane/Cyclone scale with maximum sustained winds near 65 knots (~75 mph/120.4 kph) on February 10, 2012. It was located about 480 nautical miles (552 miles/889 km) northeast of La Reunion island, near 15.8 South and 61.2 East. It was moving to the west-southwest near 8 knots (9mph/15 kph).

\When NASA's Terra satellite passed over Cyclone Giovanna, the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard, captured a visible image at 06:00 UTC (1 a.m. EST) on February 10, 2012. Although the visible image did not reveal an eye, infrared data from the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA's Aqua satellite did see the beginning of an eye. In the visible image, the thunderstorms around the center of circulation appeared higher than the surrounding clouds, and cast shadow on the lower surrounding clouds.

Forecasters at the Joint Typhoon Warning Center (JTWC) are still forecasting a landfall in east-central Madagascar. Residents of Madagascar need to prepare for the storm's arrival and expect heavy, flooding rainfall, very rough surf conditions and Cyclone-force winds.

On February 10 at 0900 UTC (4 a.m. EST) the JTWC forecast stated: "Due to the favorable environment, Giovanna is forecast to strengthen to a peak of 110 knots (~127 mph/~204 kph) within the next 36 hours." The system is expected to weaken significantly as it tracks across Madagascar; however, re-development is expected in the Mozambique Channel after 120 hours."

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.



Feb. 9, 2012

AIRS captured this infrared image of Tropical Storm 12S on February 9, 2012 at 09:41 UTC (4:41 a.m. EST). › View larger image
The AIRS instrument on NASA's Aqua satellite captured this infrared image of Tropical Storm 12S on February 9, 2012 at 09:41 UTC (4:41 a.m. EST). The strongest thunderstorms and heaviest rainfall are close to the center of circulation and in bands of thunderstorms to the south of the center, (purple) where cloud top temperatures are below -63 F (-52.7C).
Credit: NASA/JPL, Ed Olsen
NASA Sees Tropical Storm 12S as a Threat to Madagascar

The twelfth tropical depression formed in the Southern Indian Ocean today and quickly became a tropical storm, dubbed Tropical Storm 12S. NASA's Aqua satellite passed over the storm and captured infrared data that revealed a quickly developing tropical cyclone with powerful thunderstorms around its center of circulation.

Forecasters at the Joint Typhoon Warning Center expect a landfall in Madagascar in several days.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite captured an infrared image of Tropical Storm 12S on February 9, 2012 at 09:41 UTC (4:41 a.m. EST) south of Diego Garcia. Forecasters at the Joint Typhoon Warning Center noted that the system has consolidated quickly with improved convective banding (of thunderstorms) wrapping into the center. The strongest thunderstorms and heaviest rainfall are close to the well-defined center of circulation and in bands of thunderstorms to the south of the center, where cloud top temperatures are below -63 F (-52.7C).

On February 9 at 1500 UTC (10 a.m. EST), Tropical Storm 12S (TS12S) had maximum sustained winds near 35 knots (40 mph/~65 kph). It was located 690 nautical miles (794 miles/1,278 km) northeast of La Reunion Island near 14.1 South latitude and 65.1 East longitude. It was moving to the west near 9 knots (10.3 mph/16.7 kph) toward Madagascar. The forecasters at the Joint Typhoon Warning Center expect TS12S to strengthen as it moves west because of warm sea surface temperatures and light wind shear. Landfall at cyclone strength is expected in east central Madagascar sometime on February 13.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.