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.

System 97W’s “Castle Wall” Breached, and Opened Up to Dissipation

TRMM’s analysis of rainfall within System 97W on Dec. 3 showed a very limited area of moderate rainfall. The yellow and green areas indicate rainfall between .78 to 1.57 inches per hour.

The “walls” of System 97W have been breached, and residents in the Western Pacific Ocean no longer have a tropical cyclone to worry about today. The Joint Typhoon Warning Center cancelled their “formation alert” for System 97W. System 97W is following in Nida’s footsteps and is headed for dissipation. Nida has now officially dissipated.

Tropical cyclone’s center of circulation like a castle wall. Once it is breached, anything from the outside can enter and take over or destroy whatever is inside.

Infrared satellite image showing Hurricane Felicia’s cold clouds and thunderstorms Still from GOES Project movie of Hurricane Felicia’s track through the Eastern Pacific Ocean NASA satellite imagery has helped forecasters see that Hurricane Felicia is running into cooler waters and increasing wind shear, two things have taken her strength down a peg or two. Felicia will continue to weaken further over the weekend as she heads to Hawaii where landfall isn’t expected until late Monday or early Tuesday. By Friday, Aug. 7 at 11 a.m. EDT (5 p.m. Hawaiian Time), Felicia had weakened from a Category four hurricane on the Suffer-Simpson scale to a Category two hurricane with sustained winds near 100 mph. Additional weakening is expected over the weekend, and forecasters at the National Hurricane Center are forecasting that by Monday, Aug. 10 Felicia will be a tropical storm.

Felicia is moving west-northwest near 13 mph and will turn toward the west over the weekend. Her minimum central pressure continues rising and is currently 973 mill bars. Rising air pressure means a weakening storm, and that’s good news for the big island of Hawaii.

Over the weekend as Felicia continues her track toward Hawaii, she’s running into cooler waters that will continue sapping her strength. Hurricanes need warm waters of at least 80 degrees Fahrenheit to maintain strength. In addition, vertical wind shear (winds that can weaken and tear a storm apart) will increase from the west.

AIRS captured an infrared image of Hurricane Felicia tracking through the Eastern Pacific Ocean on August 7 at 6:59 a.m. EDT showing a tight circular shape, indicating she’s still a powerful hurricane. AIRS provides visible, infrared and microwave images of tropical storms. Infrared imagery shows the temperature of the cloud tops which gives a hint about the power of the thunderstorms in a tropical cyclone. The colder the clouds are, the higher they are, and the more powerful the thunderstorms are that make up the cyclone.

NASA also creates imagery from a satellite operated by the National Oceanic and Atmospheric Administration and created a movie of Hurricane Felicia’s track through the Eastern Pacific Ocean. Images from Aug. 5 through Aug. 7 from the Geostationary Operational Environmental Satellite (GOES-11) were put together as a movie.

NASA’s GOES Project, located at NASA’s Goddard Space Flight Center, Greenbelt, Md. created the movie that clearly shows Felicia as a powerful Category Four hurricane with a very visible eye. Interests in the Hawaii should monitor Felicia’s progress closely over the weekend.