Second Only South Atlantic Tropical Storm: 90Q, Moving Away from Brazil

At 0845 UTC (3:45 a.m. ET) today, March 11, Tropical Storm 90Q had maximum sustained winds near 46 mph (40 knots). It was located about 325 miles east of Puerto Alegre, Brazil in the waters of the South Atlantic Ocean near 30.0 South latitude and 45.8 West longitude.

Early today, March 11, the Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA’s Aqua satellite captured an infrared image of 90Q. The infrared image showed some high, cold thunderstorms in the center of the storm, confirming strong convection in the storm.

This infrared image of 90Q from NASA’s Aqua satellite was captured on March 11 at 0341 UTC (Mar. 10 at 10:41 p.m. ET) and shows some high, cold thunderstorms in the center of the storm.

Hubert’s Remnants Still Raining on Southern Madagascar

The infrared image of Hubert captured on March 11 at 1053 UTC (5:53 a.m. ET) and showed some high, cold thunderstorms around the center of the storm, and that the eastern edge of Hubert was still over the Southern Indian Ocean. Hubert is expected to continue moving inland and grow weaker.

At 1 p.m. ET, March 11, heavier rains stretched from the city of Vavtenina southward through the cities of Mahanoro, Nosy Varika, Mananjary and Fianarantsoa. Most of the heaviest rains remained to the east and south of the capital city of Antananarivo.

Residents in southern and central Madagascar can continue to expect some moderate to heavy rainfall from this system over the next couple of days.

90Q: A Curious Short-Lived “Tropical” Cyclone in the Southern Atlantic

Tropical cyclones typically don’t form in the Southern Atlantic because the waters are usually too cool. However, forecasters at the Naval Research Laboratory noted that a low pressure system off the coast of Brazil appeared to have tropical storm-force winds yesterday.

On Wednesday, March 10 at 1400 UTC (9:00 a.m. ET) “System 90Q” was located near 29.8 degrees South latitude and 48.2 degrees West longitude, about 180 miles east of Puerto Alegre, Brazil. The Naval Research Laboratory said on March 10 the system had maximum sustained winds near 39 mph (35 knots) but has weakened today below the tropical storm-force winds threshold.

The Geostationary Operational Environmental Satellite, GOES-12 captured a visible image of System 90Q at 14:45 UTC (9:45 a.m. ET) on March 11, and it appeared as a small circular area of clouds off the Brazilian coast. GOES is operated by the National Oceanic and Atmospheric Administration, and NASA’s GOES Project, located at NASA’s Goddard Space Flight Center, Greenbelt, Md. creates some of the GOES satellite images.

System 90Q continues to move away from the Brazilian coast and is expected to be absorbed in a mid-latitude cold front in the next couple of days.

Low Strengthens Into Hubert, Making Landfall in Madagascar

The low that forecasters were watching for development yesterday, March 9, strengthened into Tropical Storm Hubert, and is already making landfall in eastern Madagascar.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua satellite captured Tropical Storm Hubert’s cold thunderstorm cloud tops on March 10 at 5:11 a.m. ET as the western edge of the storm was already raining on eastern Madagascar. The infrared imagery showed two areas where convection was strong in Hubert: the northeastern and southern quadrants of the storm. It is in those two areas that the highest, coldest thunderstorm tops were revealed by AIRS infrared imagery. Those thunderstorm cloud tops were as cold as -63 Fahrenheit!

Hubert has maximum sustained winds near 39 mph (35 knots) and is moving west-southwest near 6 mph (5 knots). At 10 a.m. ET (1500 UTC) on March 10, Hubert was located about 160 nautical miles southeast of the capital city of Antananarivo, Madagascar near 20.9 South and 48.8 East.

As Hubert continues moving inland over the next two days, forecasts for the capital city and other areas in south central Madagascar will continue to experience periods of moderate to heavy rainfall, and gusty winds.

Animated multispectral satellite imagery showed a loss of central convection as Hubert’s center moves closer to a landfall. Once Hubert’s center is over land, forecasters expect Hubert will quickly fall below tropical storm strength.

Tropical Cyclone Formation Likely Near Madagascar

Forecasters are watching a low pressure area located off the east coast of Madagascar that appears ripe for development in the Southern Indian Ocean. If it becomes a tropical storm, it would be named Hubert.

On March 9 the low, currently named “90S” is located near 20.1 South latitude and 50.8 East longitude is approximately 225 nautical miles east-southeast of the capital city of Antananarivo (which is located 145 miles inland from the east coast). The low’s winds are estimated to be between 28- 34 mph (25 to 30 knots). The system is moving south-southeastward at 5 mph (4 knots). Minimum sea level pressure is estimated to be near 1000 millibars.