System 95B-Northern Indian Ocean

The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite passed over System 95B from its orbit in space and captured an infrared image of the low pressure area on April 29 at 07:53 UTC. Infrared imagery acts like taking the temperature of the system's clouds - and there were some high, very cold clouds that indicated powerful convection and strong thunderstorms in the center. Some cloud top temperatures were as cold as or colder than -63F/-52C. Infrared imagery indicated that there was scattered convection around all sides of the low-level center, and even some curved banding of thunderstorms.

On April 29, System 95B was located about 420 nautical miles east-northeast of Colombo, Sri Lanka near 9.5 North and 96.5 East. System 95B is drifting and currently has estimated sustained surface winds between 15 and 20 knots. Despite the waters in the Bay of Bengal being warm enough to sustain the development of a tropical cyclone, there is a westerly wind field present.

System 91L-Atlantic Ocean

System 91L sparked the interest of forecasters because it had a small chance to develop into a subtropical or tropical storm last week. Now that chance is zero. On Saturday, April 23, 2011, the showers associated with System 91L diminished. At that time, the low was centered about 360 miles north of San Juan, Puerto Rico. Wind shear had taken its toll on the low and weakened it . As a result, the National Hurricane Center issued their final notice about the system on Saturday.

Currently there are no tropical cyclones expected elsewhere in the Atlantic Ocean, and the official hurricane season doesn't start until June 1.

NASA's TRMM Satellite Estimates Australia's Cyclone Season Rainfall

NASA's TRMM satellite measures rainfall from space and data from it was used to create a map of total cyclone rainfall. The TRMM satellite is managed by both NASA and the Japanese Space Agency, JAXA.

At NASA's Goddard Space Flight Center in Greenbelt, Md. data from the Tropical Rainfall Measuring Mission (TRMM) satellite was used to create the cyclone rain maps. TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA), data were used in an analysis to show rainfall contributed by tropical cyclones that have affected Australia in 2011. Hal Pierce of the NASA TRMM team created the image and included the tracks of tropical cyclones on the image.

"The largest tropical cyclone rainfall contribution was over the coast of northwestern Australia with estimated totals of over 600 millimeters (~23.6 inches)," Pierce said. "Cyclones Bianca, Carlos, Twenty, Errol and their remnants were close enough to the northwestern coast of Australia to add to these rainfall totals."

Tropical Low #1 -Atlantic

Hurricane season doesn't start in the Northern Atlantic Ocean until June 1, but a low pressure system in doesn't seem to want to follow the calendar. There's a low pressure area with a small chance for development north-northeast of Puerto Rico, and the GOES-13 satellite captured a visible image of the storm.

The National Hurricane Center (NHC) issued a Special Tropical Weather Outlook today, April 20, that noted the low pressure area was located about 460 miles northeast of San Juan, Puerto Rico at 3:35 p.m. EDT. The NHC noted that slow development is possible over next couple of days. The low is moving west -northwest at 10mph.

The image was created using satellite imagery was captured on April 20 at 17:45 UTC (1:45 p.m. EDT) from the Geostationary Operational Environmental Satellite (GOES-13). Although it is not easy to pick out the center of circulation in the image, it is located to the west of the largest area of clouds.

Tropical Storm Errol

NASA's Aqua Satellite Sees Weaker Tropical Depression Errol Crossing West Timor

NASA's Aqua satellite captured an infrared image of Tropical Depression Errol's warming cloud temperatures as it was crossing the southern tip of West Timor today. West Timor is the western and Indonesian portion of the island of Timor. To the east lies the Timor Sea, to the west is the Southern Indian Ocean.

The Atmospheric Infrared Sounder (AIRS) instrument aboard NASA's Aqua satellite captured an infrared image on April 18 at 04:53 UTC (12:53 a.m. EDT) that showed very little strong convection (rapidly rising air that forms thunderstorms) remained in Errol. The strongest areas of convection had cloud-top temperatures as cold as -63F/-52C. However, AIRS data shows that much of the cloud top temperatures in the depression have since warmed. 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. Warming cloud top temperatures mean lower cloud heights and indicate that the storm is growing weaker. It means that there's not as much power to lift the air up to create the thunderstorms that power it.

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Tropical Storm Errol-Southern Indian Ocean

The low pressure area formerly known as System 92S has strengthened overnight and developed into Tropical Storm Errol today, April 15. Infrared imagery from NASA's Aqua satellite showed strong thunderstorms near Errol's center, but they remained off-shore from Western Australia's northern coast.

An infrared image on April 14 at 0517 UTC from NASA's Atmospheric Infrared Sounder (AIRS) instrument shows that Tropical Storm Errol's strongest thunderstorms with the coldest, highest cloud tops were off-shore from the northern coast of Western Australia. Those thunderstorms had cloud-top temperatures as cold as or colder than -63 F/-52C and brought heavy rainfall. Multispectral satellite imagery also showed a well-defined center of circulation in Errol, and bands of thunderstorms wrapping around its souther and western edges.

Tropical Storm Errol has sustained winds of 40 knots with higher gusts, and is kicking up rough surf along the northern coast of Western Australia today. Errol's center was about 270 miles (434 km) west of Darwin, Australia near 13.1 South latitude and 126.3 East longitude. Errol is currently drifting south-southwestward at 2 knots (2 mph/~4 km) but is expected to start moving to the west-northwest as a result of a strengthening ridge of high pressure building up over Western Australia.

System 92S-Southern Indian Ocean

Visible imagery from NASA's Aqua satellite showed strong convection around the center of developing tropical low 92S that lies north of the Western Australia coastline. System 92S is still in the Timor Sea today. Early this morning (EDT), April 14, it was about 315 miles west of Darwin, Australia. The southern extent of the low pressure area's clouds, however, already stretch over land in Western Australia. The center of System 92S' circulation at 06:30 UTC was near 13.0 South latitude and 125.5 East longitude. The system appears to be consolidating and there is strong convection near the center of circulation. By 8 p.m. WST Australia local time System 92S' center was near 12.5S and 126.3E. That is 127 miles north of Kalumburu. Although it moved from this morning, System 92S is now nearly stationary.

The Australian Bureau of Meteorology has issued a Strong Wind Warning from Kuri Bay to Wyndham for the next 24 to 36 hours. That warning area can expect east-southeasterly wind between 20 and 30 knots with higher gusts and squalls. Seas are expected to be 6 to 10 feet. The Moderate Resolution Imaging Spectroradiometer instrument that flies aboard NASA's Aqua satellite captured a visible image of System 92S on 0519 UTC on April 13. In the imagery there was area near the center that appears to have texture and shadows. That area is one of higher, more powerful thunderstorms, and is still over open waters of the Timor Sea.

Tropical Storm 97W - Northwest Pacific Ocean

Infrared data from NASA's Aqua satellite has seen potential in a developing tropical low pressure system near Brunei. Brunei is located on the north coast of the island of Borneo, in Southeast Asia. Apart from its coastline with the South China Sea, it is completely surrounded by the state of Sarawak, Malaysia.

The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite captured an infrared image of the tropical low pressure area called "System 97W" on April 6 at 0611 UTC (2:11 a.m. EDT). Infrared data basically takes the temperature of atmospheric, land or oceanic objects. The infrared data revealed the coldest temperatures were in thunderstorm cloud tops around the center of System 97W's circulation. Those cloud tops were as cold as or colder than -63 degrees Fahrenheit (-52 Celsius) indicating strong convection (rapidly rising air that forms the thunderstorms that power a tropical cyclone). That's an indication that the storm is getting stronger. There is also a banding of thunderstorms around the low-level center of circulation.

AIRS data also showed that the sea surface temperatures were above 80F (26.7 C), which is the threshold for maintaining a tropical cyclone, so the water remains a power source for intensification. At 0600 UTC on April 6, 2011, System 97W was about 170 miles west-northwest of Brunei near 6.2 North and 112.4 East. Maximum sustained surface winds are estimated at 15 to 20 knots. Minimum sea level pressure is estimated to be near 1008 millibars.

Tropical Storm 2W -Northwest Pacific Ocean

The second tropical depression of the Northwestern Pacific Ocean season has formed, just as the first depression has dissipated. NASA's Aqua satellite captured an infrared image of the depression and observed some strong thunderstorms within, and the storm has already caused warnings to be posted.

On April 5, 2011, Tropical Depression 2W formed about 270 miles (434 km) NW of Anderson Air Force Base, Guam, near 16.1 South and 141.1 East. It was moving east-northeast near 19 knots and had maximum sustained winds near 30 knots. The Northern Marianas are expected to feel the effects of the depression as it continues to move in that direction. A tropical storm warning is in force for Agriahan, Pagan and Alamagan Islands in the Northern Mariana Islands.

The Atmospheric Infrared Sounder instrument on NASA's Aqua satellite captured an infrared image of Tropical Depression 2W on April 5 at 0353 UTC. It showed cold, high, strong thunderstorms around the center of circulation with heavy rainfall west of the Northern Marianas islands.

Tropical Depression 1W-Northwest Pacific Ocean

Tropical Depression 1W formed on April 2 and was dissipating by April 4 a couple of hundred miles east southeast of Vietnam and NASA's Aqua satellite captured its brief life. The Northwestern Pacific Ocean basin can experience tropical cyclones almost all year 'round, except that activity is usually minimal in February and March. So, the first tropical cyclone of the new "season" didn't take long to form after the end of March. The Northwestern Pacific includes all of the area north of the equator and west of the International Date Line, including the South China Sea. The Atmospheric Infrared Sounder instrument that flies aboard NASA's Aqua satellite passed over Tropical Depression 1W on April 2 when it was born, and then again on April 3rd, when it faded. That was a short life for the first tropical depression of the Pacific Northwest's hurricane season, but only the beginning.

AIRS data on April second at 05:41 UTC showed a cluster of strong thunderstorms surrounding the weak center of circulation of TD1W. Some of those thunderstorms were dropping heavy rainfall and had very high cloud tops, so high they were as cold as -63 Fahrenheit/-52 Celsius. On April 2, TD1W was located about 280 miles east-southeast of Ho Chi Minh, Vietnam near 9.3 North latitude and 111.2 East longitude. It was moving very slowly at 1 knot to the west and maximum sustained winds were near 25 knots. By April 3 at 0900 UTC it had continued moving slowly, only at a rate of 2 knots westward and was then 315 miles (506 km) east-southeast of Ho Chi Minh, Vietnam near 9.1 North and 111.7 East. It still had maximum sustained winds near 25 knots, but wind shear was battering the system.

On April 4 NASA's Aqua satellite passed overhead once again and noticed that TD1W had become much more disorganized and spread out. By the fourth, TD1W had also moved more than 45 miles farther away from Vietnam and into the South China Sea. Strong convection appeared scattered and disorganized on AIRS' infrared imagery and not around the center of circulation.

Tropical Depression that influences weather, sea conditions spotted near sabah

A tropical depression that influences weather and sea conditions has been spotted near Kota Kinabalu, Sabah. The Meteorological Department of Malaysia said the tropical depression was located approximately 482km West-Northwest of Kudat, Sabah and 527km North-Northwest of Miri, Sarawak. The tropical depression is expected to track southeastwards at 4kmph. The department issued a heavy rain and thunderstorms advisory and warning on strong winds and rough seas. Intermittent rain occasionally heavy and windy conditions are expected over Sabah, Divisions of Interior (Kuala Penyu, Beaufort Districts), West Coast (Papar, Penampang, Kota Kinabalu, Tuaran, Kota Belud Districts) and Kudat Kudat, Kota Marudu, Pitas Districts) and Labuan from today and is expected to continue until Wednesday (April 6).

This condition may result in floods over low-lying areas and along river banks. Strong North/Northeasterly winds from 60kmph with waves reaching 5.5 metres occurring over the waters off Condore, Reef North and Layang-layang are expected to continue until Thursday (April 7). The condition is dangerous to all coastal and shipping activities, including workers on oil platforms said the statement.

Tropical Depression 91S-South Pacific

NASA's Tropical Rainfall Measuring Mission satellite spotted light to moderate rainfall in the system as continues tracking southwest and bringing rains and winds to the northern coast of Western Australia this weekend. System 91S was located in the Timor Sea, west-southwest of Darwin, Australia and was moving in a west-southwesterly direction. System 91S is forecast to continue traveling in that direction and its center is expected to remain at sea over the next several days as it heads toward the Southern Indian Ocean.

As it continues to track along coastal areas of the Northern Territory and Western Australia, cyclone warnings are in effect. A Cyclone Warning is in effect for Western Australian coastal and island areas from Kuri Bay to the Western Australia/Northern Territory border, including Kalumburu and Wyndham. In addition, a cyclone watch is in effect from Kuri Bay to Cape Leveque, not including Derby. The TRMM satellite, operated by both NASA and the Japanese Space Agency, passed over the system at 1451 UTC on April 1. The U.S. Navy and Naval Research Laboratory's Monterey Marine Meteorology Division, Calif. overlaid TRMM rainfall rate imagery on top of Japan's METSAT-2 infrared imagery to provide a complete picture of the low pressure areas cloud extent and rainfall rates. TRMM's precipitation radar instrument measured rainfall rates close to 1 inch (25 mm) per hour.

NASA Satellites Eyeing 4 Tropical Systems Around the World For Possible Development

NASA satellites are all keeping an eye on for possible development. They are Systems 90S, 91S and 99S in the Southern Pacific, and System 93B in the Northern Indian Ocean. Despite a poor chance for development in all of them, one has triggered warnings in northern Australia because of its proximity to land. NASA and the Japanese Space Agency manage the Tropical Rainfall Measuring Mission or TRMM satellite and TRMM passed over two of those four systems today. TRMM captured light to moderate rainfall in the low pressure area called “System 90S” on March 30 at 01:49 UTC. Rainfall rates were between 5 and 20 millimeters (0.2 and 0.8 inches) per hour within the storm. System 90S is located 500 miles north-northwest of Port Hedland, Australia, near 12.0 South latitude and 116.0 East longitude.

Infrared satellite imagery from the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s Aqua satellite revealed that the low has consolidated during the morning hours, while the Advanced Microwave Scanning Radiometer-E instrument showed deep convection on the north and south sides of the center of circulation. Despite these developments atmospheric dynamics are not currently favorable, so the Joint Typhoon Warning Center currently gives this low a poor chance for development. The second tropical low pressure area NASA satellites are watching is also 500 miles away from land, and that’s System 99S. System 99S is 500 miles north of the Cocos Islands today, near 9.8 South and 99.4 East. The TRMM satellite measured rainfall rates between 5 and 20 millimeters (0.2 and 0.8 inches) per hour within the System 99S early today. The AIRS infrared imagery captured from NASA’s Aqua satellite shows that areas of deep convection exist on all sides of the low pressure center, but it’s not uniform. Vertical wind shear is currently light and sea surface temperatures are warm enough to support development, however, the chance that it will develop into a tropical storm in the next 24 hours is poor. As the week progresses, perhaps the chance will improve with the environmental conditions.

The third tropical low pressure area isn’t a tropical storm but it has triggered a watch for Australia’s Northern Territories. Because of System 91S’ location, about 200 miles northeast of Darwin, Australia (near 10.0 South and 133.1 East), a tropical cyclone Watch has been issued for the coastal communities between Cape Hotham, Port Keats, including Darwin and the Tiwi Islands. The Tiwi Islands include Melville and Bathurst Islands and are part of Australia’s Northern Territory, 25 miles (40 km) north of Darwin where the Arafura Sea joins the Timor Sea. In addition, a Strong Wind Warning has been issued from Milingimbi to Troughton Island.