Tag: 27S 2020

May 26, 2020 – NASA Catches the Extra-Tropical Ending of Mangga

By Sunday, May 24, Tropical Cyclone Mangga had already transitioned to an extra-tropical storm and was affecting the southwestern coast of Australia.

When a storm becomes extra-tropical, it means that a tropical cyclone has lost its “tropical” characteristics. The National Hurricane Center defines “extra-tropical” as a transition that implies both poleward displacement (meaning it moves toward the north or south pole) of the cyclone and the conversion of the cyclone’s primary energy source from the release of latent heat of condensation to baroclinic (the temperature contrast between warm and cold air masses) processes. It is important to note that cyclones can become extra-tropical and retain winds of hurricane or tropical storm force.

The Australian Bureau of Meteorology issued Severe Weather Warnings in Western Australia on Sunday as the extra-tropical system tracked in a southeasterly direction.

The final warning for Mangga came on May 23 at 5 pm EDT (2100 UTC), when it was located near latitude 21.6 south and longitude 104.7 east, about 525 nautical miles west of Learmonth, Australia. Mangga was moving southeast at a speedy 44 knots (51 mph/81 kph) and had maximum sustained winds of 35 knots (40 mph/65 kph).

NASA’s Aqua satellite provided a visible look at the extra-tropical low-pressure area along the southwestern coast of Western Australia on May 24. The center of circulation was difficult to pinpoint in the visible image, captured by the Moderate Resolution Imaging Spectroradiometer, an instrument that flies aboard Aqua.

On May 24, the Australian Bureau of Meteorology’s Severe Weather Warning called for “Damaging, locally destructive winds and abnormally high tides for people in Central West, Lower West, South West, South Coastal, South East Coastal, Great Southern, Central Wheat Belt and parts of Gascoyne and Goldfields districts.”

The extra-tropical low-pressure area passed over the southwestern part of the state on Monday, May 25 as it continued to weaken and move back over open waters of the Indian Ocean.

By Rob Gutro
NASA Goddard Space Flight Center

May 22, 2020 – NASA Examines Tropical Storm Mangga in Infrared Light

NASA’s Aqua satellite used infrared light to provide forecasters with a look at the temperatures of the cloud tops in Tropical Storm Mangga.

Mangga, formerly known as 27S, is moving through the Southern Indian Ocean. Mangga was approaching the Cocos (Keeling) Islands, where a tropical cyclone warning was in effect on May 22.

NASA’s Aqua satellite used infrared light to analyze the strength of storms in Mangga. Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.  On May 22 at 3:10 a.m. EST (0710 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite gathered temperature information about Tropical Storm Mangga’s cloud tops. MODIS found one area of powerful thunderstorms where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

Cloud tops of storms surrounding that area were warmer, indicating those storms were weaker and fragmented.

At 5 a.m. EDT (0900 UTC) on May 22, Tropical Storm Mangga was located near latitude 11.1 degrees south and longitude 94.2 degrees east, about 1,324 nautical miles west-northwest of Learmonth, Western Australia. Mangga was moving to southeast and had maximum sustained winds near 35 knots (40 mph/65 kph).

Mangga is forecast to strengthen to 45 knots (52 mph/83 kph), but become extra-tropical before making landfall in southwestern Australia on Sunday, May 24, between Perth and Learmonth.

Typhoons and hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

By Rob Gutro
NASA Goddard Space Flight Center

May 21, 2020 – NASA-NOAA Satellite Catches Development of Tropical Storm 27S

NASA-NOAA’s Suomi NPP satellite passed over the Southern Indian Ocean and provided forecasters with a visible image of newly formed Tropical Storm 27S.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of Tropical Cyclone 27S that revealed a large, weakly-defined low-level circulation center with flaring thunderstorms building over the western side of the storm.

The Australian Bureau of Meteorology issued a tropical cyclone watch for the Cocos (Keeling) Islands.

At 0900 UTC (5 a.m. EDT) TropicalCyclone 27S was located near latitude 9.1 degrees south and longitude 92.2 degrees east, about 1,489 nautical miles west-northwest of Learmonth, Australia. 27S was moving to the south-southeast and had maximum sustained winds near 35 knots (40 mph/65 kph).

The Joint Typhoon Warning Center (JTWC) expects 27S will move southeast, past the Cocos Islands. The system is forecast to strengthen to 55 knots, and then become extra-tropical before making landfall in southwestern Australia. 27S is forecast to make landfall in Western Australia between Perth and Learmonth, on Sunday, May 24.

Tropical cyclones/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

For updated forecasts from the ABM, visit:  http://www.bom.gov.au

By Rob Gutro 
NASA Goddard Space Flight Center