Gelena (Southern Indian Ocean)

Feb. 14, 2019 – NASA’s Aqua Satellite Finds Winds Battering Tropical Cyclone Gelena

Tropical Cyclone Gelena is being battered by outside winds, and that’s weakening the storm. Visible imagery from NASA’s Aqua satellite revealed the bulk of clouds in Tropical Cyclone Gelena were pushed away from the center.

Aqua image of Gelena
On Feb. 14, 2019 at 2:45 a.m. EDT (0745 UTC) the MODIS instrument aboard NASA’s Aqua satellite captured a visible light image of Tropical Cyclone Gelena being battered by wind shear in the Southern Indian Ocean. Credit: NASA/NRL

On Feb. 14, 2019 at 2:45 a.m. EDT (0745 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite captured a visible image of Tropical Cyclone Gelena in the Southern Indian Ocean. The image showed Gelena’s clear low level center of circulation, and the bulk of the tropical cyclone’s clouds pushed south of the center. That’s because of strong northerly wind shear.

In general, wind shear is a measure of how the speed and direction of winds change with altitude. Wind shear can tear a tropical cyclone apart or weaken it.

On Feb 14 at 10 a.m. EDT (1500 UTC), Gelena’s maximum sustained winds were near 40 knots (46 mph/74 kph). It was centered near 28.6 degrees south latitude and 86.6 east longitude. Tropical Cyclone Gelena is approximately 1,474 nautical miles south-southeast of Diego Garcia, and has tracked east-southeastward.

The Joint Typhoon Warning Center expects Gelena to dissipate in 24 hours as it continues to face strong vertical wind shear and moves into increasingly cooler sea surface temperatures.

By Rob Gutro
NASA’s Goddard Space Flight Center

Oma (Southern Pacific Ocean)

Feb. 14, 2019 – NASA’s Aqua Satellite Eyes Tropical Cyclone Oma Near Vanuatu

Visible imagery from NASA’s Aqua satellite revealed the center of Tropical Cyclone Oma was just northwest of the island of Vanuatu in the South Pacific Ocean.

Aqua image of Oma
On Feb. 14, 2019, the MODIS instrument aboard NASA’s Aqua satellite captured a visible light image of Tropical Cyclone Oma in the Southern Pacific Ocean. Oma’s center is northwest of Vanuatu. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

Vanuatu consists of roughly 80 islands that stretch about 808 miles (1,300 kilometers).

The Vanuatu Meteorology and Geo-Hazards Department (VMGD) issued Tropical Cyclone Warning Number 18 for the Torba, Sanma, Penama and Malampa Provinces. Those provinces can expect heavy rainfall and flash flooding over low lying areas and areas close to the river banks. In addition, coastal flooding will continue.

The Vanuatu National Disaster Management Office (NDMO) noted that a red alert remains in force for Torba, Sanma, Penama and Malampa provinces, while yellow alert is in effect for the Shefa province.

On Feb. 14, 2019, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite captured a visible image of Tropical Cyclone Oma. The image showed Oma’s center northwest of Vanuatu. The image revealed a large area of bands of powerful thunderstorms wrapping into the low level circulation center, with most convection (rising air that forms the clouds and thunderstorms that make up the tropical cyclone) displaced to the north of the low-level center.

The VMGD noted “At 2:00 a.m. local time (Vanuatu) on Feb. 15 (9 a.m. EDT on Feb 14), Tropical Cyclone Oma was located at 16.0 degrees south and 164.7 degrees east. This is about 240 kilometers (149 miles) west southwest of Santo and 370 kilometers (230 miles) southwest of Banks. Tropical Cyclone Oma has moved in a south southwesterly direction at 16 kph (10 mph/9 knots). The central pressure of the system is estimated at 984hPa. Sustained winds close to the center are estimated at 95 kph (59 mph/50 knots). Gale force winds of 75 kph (46 mph/40 knots) will continue to affect Torba, Sanma, Penama and Malampa Provinces tonight.”

The Joint Typhoon Warning Center expects Oma to continue to move away from Vanuatu in a southwesterly direction.

For updated forecasts for Vanuatu, visit: https://www.vmgd.gov.vu

By Rob Gutro
NASA’s Goddard Space Flight Center

Gelena (Southern Indian Ocean)

Feb. 13, 2019 – NASA Finds Tropical Cyclone Gelena in the Middle of the Southern Indian Ocean

Visible imagery from NASA’s Terra satellite showed a weaker Tropical Storm Gelena far from land areas, and in the middle of the Southern Indian Ocean.

Terra image of Gelena
On Feb. 13, 2019 the MODIS instrument aboard NASA’s Terra satellite provided a visible image of Tropical Cyclone Gelena in the Southern Indian Ocean that showed bands of thunderstorms spiraling into the center. Credit: NASA Worldview, EARTH Observing System Data and Information System (EOSDIS).

On Feb. 13, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite provided a visible image of Gelena. The image showed bands of thunderstorms spiraling into a cloud-filled, but defined low level circulation with the bulk of its associated convection and clouds pushed eastward from westerly winds.

At 10 a.m. EDT (1500 UTC) on Feb. 13, the Joint Typhoon Warning Center or JTWC noted that Oma had maximum sustained winds near 55 knots (63 mph/102 kph). It was centered near 26.0 degrees north latitude and 79.2 degrees east longitude. That’s 1,193 nautical miles east-southeast of Port Louis, Mauritius. Omi was moving east-southeast.

JTWC has forecast Gelena to continue moving southeastward and weakening to dissipation in two days.

By  Rob Gutro
NASA’s Goddard Space Flight Center

Oma (Southern Pacific Ocean)

Feb. 13, 2019 – Tropical Cyclone Oma Threatens Vanuatu, Seen by NASA-NOAA’s Suomi NPP Satellite

Tropical Cyclone Oma continued to move southeast in the Southern Pacific Ocean, and continue affecting Vanuatu. NASA-NOAA’s Suomi NPP satellite provided a visible image of the storm.

Suomi NPP image of Oma
NASA-NOAA’s Suomi NPP satellite passed over the Southern Pacific Ocean and captured a visible image of Tropical Cyclone Oma on Feb. 13 as it approached Vanuatu. Credit: NASA Worldview, EARTH Observing System Data and Information System (EOSDIS).

Suomi NPP passed over Oma on Feb. 13 and the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument provided a visible image of the storm. The VIIRS image showed a circular center of thunderstorms with a large, wide band of thunderstorms wrapping into the center from the northwest. That’s because the storm is experiencing easterly winds that are pushing clouds west and away from the center. The image also showed the southeastern quadrant already over Espiritu Santu, Vanuatu.

The Joint Typhoon Warning Center (JTWC) noted on Feb. 13 at 4 a.m. EDT (0900 UTC) that Oma was near 14.6 degrees south latitude and 165.2 east longitude, about 262 nautical miles northwest of Port Vila, Vanuatu. Maximum sustained winds were near 45 knots (52 mph/83 kph). Oma was moving to the west-southwest.

On Feb. 13, Tropical Cyclone Warning Number 9 was issued by the Vanuatu Meteorology and Geo-Hazards Department (VMGD), in Port Vila, Vanuatu for Torba, Sanma and Malampa provinces. Gale force winds are expected to affect those provinces today, Feb. 13. VMGD’s warning noted “Heavy rainfalls and flash flooding over low lying areas and areas close to the river banks, including coastal flooding will continue to affect Torba, Sanma and Malampa provinces tonight. Seas will be very rough to phenomenal with heavy and phenomenal swells expected.”

Forecasters at the Joint Typhoon Warning Center noted that Oma is expected to strengthen over the next day as it begins curving to the south. By February 15, as Oma takes more of a southwesterly turn and heads away from Vanuatu and toward northern New Caledonia, increasing wind shear and movement over cooler waters will weaken the storm.

For updated local forecasts from VMGD, visit: https://www.vmgd.gov.vu/

By Rob Gutro 
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Oma (Southern Pacific Ocean)

Feb. 12, 2019 – NASA’s Aqua Satellite Catches Development of Tropical Cyclone Oma

NASA’s Aqua satellite passed over the Southern Pacific Ocean and captured a visible image of Tropical Cyclone Oma. Oma formed northwest of Vanuatu.

Aqua image of Oma
On Feb. 12 at 0305 UTC (Feb 11 at 10:05 p.m. EDT) the MODIS instrument aboard NASA’s Aqua satellite captured a visible image of newly formed Tropical Cyclone Oma in the Southern Pacific Ocean. Oma was located northwest of Vanuatu. Credit: NASA/NRL

On Feb. 12 at 0305 UTC (Feb 11 at 10:05 p.m. EDT) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite provided a visible image of Tropical Cyclone Oma. Satellite imagery showed Oma’s center between the Solomon Islands to the northwest and Vanuatu to the southeast. The bulk of Oma’s clouds were west of the center of circulation.

At 10 a.m. EDT (1500 UTC) the center of Oma was located near latitude 13.8 degrees south and longitude 165.6 degrees east. That’s about 289 nautical miles northwest of Port Vila, Vanuatu. Oma was moving to the east. Maximum sustained winds were near 45 knots (52 mph/83 kph) and Oma is forecast to strengthen slightly over the next two days before weakening.

The Vanuatu Meteorology & Geo-Hazard Department (VMGD) noted “Damaging gale force winds of 75 kph (40 knots) are expected to affect Torba and Sanma today and for the next 12 to 24 hours.” In addition damaging gale force winds and very rough seas with heavy swells will affect Torba and Sanma. VMGD also noted “Heavy rainfall and flash flooding over low lying areas and areas close to river banks, including coastal flooding will continue to affect these provinces. The marine strong wind warning and a high seas warning is current for northern and central waters.”

For updated forecasts from the Vanuatu Meteorology & Geo-Hazard Department, visit: https://www.vmgd.gov.vu/

By Rob Gutro
NASA’s Goddard Space Flight Center

Gelena (Southern Indian Ocean)

Feb. 12, 2019 – NASA-NOAA Satellite Finds Tropical Cyclone Gelena Sheared

Wind shear can push tropical cyclones apart and satellite imagery from NASA-NOAA’s Suomi NPP satellite revealed that is what is happening to Tropical Cyclone Gelena in the Southern Indian Ocean.

Suomi NPP image of Gelena
On Feb. 12 at 4:18 a.m. EDT (0918 UTC) the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of Tropical Cyclone Gelena moving through the Southern Indian Ocean. Credit: NASA/NOAA/NRL

In general, wind shear is a measure of how the speed and direction of winds change with altitude. Winds at different levels of the atmosphere pushed against the cylindrical circulation center and skewed it, weakening the rotation.

On Feb. 12 at 4:18 a.m. EDT (0918 UTC) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of Tropical Cyclone Gelena moving through the Southern Indian Ocean. The Joint Typhoon Warning Center noted that: “Animated multispectral satellite imagery shows a system with a mostly exposed low level circulation and its associated convection sheared eastward.”  The clouds are being pushed eastward by strong westerly winds.

On Feb. 12 at 10 a.m. EDT (1500 UTC) Gelena’s maximum sustained winds were near 50 knots (57 mph/92 kph) and weakening. Gelena was located approximately 961 nautical miles east-southeast of Port Louis, Mauritius. The tropical storm is moving to the east-southeast. Because Gelena is expected to move over cooler sea surface temperatures and the wind shear is expected to persist, the storm is forecast to dissipate in two days.

By Rob Gutro
NASA’s Goddard Space Flight Center

Neil (Southern Pacific Ocean)

Feb. 11, 2019 – NASA Catches the 1-Day Life of Tropical Cyclone Neil

Tropical Cyclone Neil had a short life in the Southwestern Pacific Ocean. It developed on February 9 and dissipated on February 10. NASA’s Aqua satellite captured an image of the storm that developed even while battling wind shear.

Aqua image of Neil
This visible image of short-lived Tropical Cyclone Neil was taken from NASA’s Aqua satellite on Feb. 9. The image shows that northwesterly vertical wind shear was affecting the storm and pushing the bulk of clouds to the southeastern quadrant. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

Neil developed around 4 p.m. EDT (2100 UTC) on February 9 about 302 nautical miles west-southwest of Niue with maximum sustained winds near 35 knots (40 mph/65 kph). Niue is a small island nation in the South Pacific Ocean. According to the official website of Niue tourism, Niue is one of the smallest countries and one of the largest raised coral atolls on Earth.

On Feb. 10, Tropical cyclone no longer qualified as a tropical cyclone. At 4 a.m. EDT (0900 UTC) Neil was dissipating near 24.0 degrees south latitude and 173.9 east longitude, about 369 miles southwest of Niue. Neil’s maximum sustained winds had already dropped to 30 knots (34.5 mph/55.5 kph) and continued weakening.

A visible image of short-lived Tropical Cyclone Neil was taken from NASA’s Aqua satellite on Feb. 9. The image showed that northwesterly vertical wind shear was affecting the storm and pushing the bulk of clouds to the southeastern quadrant.

In general, wind shear is a measure of how the speed and direction of winds change with altitude. In order to understand how it affects a tropical cyclone or hurricane, think of a tropical cyclone as a vertical rotating cylinder. The different levels of rotating winds in the center of Tropical cyclones need to be stacked on top each other for the storm to strengthen. If there are outside winds pushing against the cylinder near the top, it affects the balance of the entire cylinder and that’s what happens when vertical wind shear pushes against a storm. It pushes the center and weakens (or wobbles) the rotation of the entire cylinder (storm).

On Feb. 9, the  Joint Typhoon Warning Center noted that the final warning was issued on Neil .

By Rob Gutro
NASA’s Goddard Space Flight Center

Gelena (Southern Indian Ocean)

Feb. 11, 2018 – NASA’s Aqua Satellite Shows Winds Shear Affecting Tropical Cyclone Gelena

Visible imagery from NASA’s Aqua satellite revealed the effects of wind shear on Tropical Cyclone Gelena in the Southern Indian Ocean. The storm weakened to a tropical storm.

MODIS image of Gelena
On Feb. 11, 2019, the MODIS instrument aboard NASA’s Aqua satellite captured a visible light image of Tropical Cyclone Gelena in the Southern Indian Ocean. Wind shear pushed the bulk of clouds and storms east of the center. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

On Feb. 11, 2019, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite captured a visible image of Tropical Cyclone Gelena. Westerly wind shear pushed the bulk of clouds and storms east of the center. Wind shear is a measure of how the speed and direction of winds change with altitude.

At 10 a.m. EDT (1500 UTC) on Feb. 11, Gelena was located near 24.6 degrees south latitude and 70.3 east longitude, approximately 745 nautical miles east-southeast of Port Louis, Mauritius. Gelena was moving to the southeast. Maximum sustained winds were near 55 knots (63 mph/102 kph).

Forecasters at the Joint Typhoon Warning Center expect Gelena to dissipate in three days, by February 14.

By Rob Gutro
NASA’s Goddard Space Flight Center

Gelena (Southern Indian Ocean)

Feb. 8, 2019 – NASA’s Aqua Satellite Finds Tropical Cyclone Gelena’s Strongest Side

NASA’s Aqua satellite passed over the Southern Indian Ocean and captured an infrared image of Tropical Cyclone Gelena that revealed strongest storms were northwest of the eye.

Satellite image of storm Gelena
At 5:05 a.m. EST (1005 UTC) on Feb. 8, the MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Tropical Cyclone Gelena. Strongest thunderstorms were in the northwestern quadrant of the storm, where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62 Celsius) and appear in yellow in this false colored image. Credit: NASA/NRL

On Feb. 8, a tropical cyclone warning class 2 is in force at Mauritius and Rodrigues.

At 5:05 a.m. EST (1005 UTC) on Feb. 8 the MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Tropical Cyclone Gelena. Infrared data provides temperature information. MODIS found coldest cloud top temperatures as cold as minus 80 degrees Fahrenheit (minus 62 Celsius) in storms in the northwestern quadrant, outside of the eye. NASA research has shown that cloud tops with temperatures that cold were high in the troposphere and have the ability to generate heavy rain.

At 10 a.m. EDT (1500 UTC), the center of Tropical Cyclone Gelena was located near latitude 15.7 degrees south and longitude 55.3 degrees east. That’s about 288 nautical miles north-northwest of Port Louis, Mauritius. Maximum sustained winds were near 105 knots (121 mph/194.5 kph) and strengthening.

The Joint Typhoon Warning Center noted that Gelena will strengthen to 130 knots (149.6 /241 kph) within 24 hours. Although a weakening trend will then begin, Gelena is forecast to have winds of about 120 knots (138 mph/222 kph) upon closest approach to Rodrigues on Feb. 9.

Rob Gutro
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Funani (Southern Indian Ocean)

Feb. 8, 2019 – NASA Looks at Tropical Cyclone Funani’s Rainfall Rates

Tropical Cyclone Funani continued tracking southeast through the Southern Indian Ocean on Feb. 7, 2019. When the GPM satellite passed overhead, it revealed that Funani’s strongest rains wrapped around the center and extended northwest.

The Global Precipitation Measurement mission, or GPM, core satellite passed over Tropical Cyclone Funani on Feb. 8. GPM found the heaviest rainfall around the center and a fragmented band of thunderstorms northwest of center. In both areas rain was falling at a rate between 10 and 13 mm (0.4 and 0.5 inches) per hour. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.

satellite image of Funani rainfall
The GPM core satellite passed over Tropical Cyclone Funani on Feb. 8, 2019. GPM found the heaviest rainfall (red) was around the center and a fragmented band of thunderstorms northwest of center. In both areas rain was falling at a rate between 10 and 13 mm (0.4 and 0.5 inches) per hour. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS), JAXA
Link to high-res image: https://go.nasa.gov/2Sg1ASi

At 10 a.m. EST (1500 UTC), the center of Funani was located near latitude 24.4 degrees south and longitude 71.2 degrees west. That’s about 813 nautical miles east-southeast of Port Louis, Mauritius. Maximum sustained winds were near 105 knots (121 mph/195 kph).

Forecasters at the Joint Typhoon Warning Center expect Funani will continue to move southeast. The storm will gradually weaken before becoming extra-tropical after a day or so.

Rob Gutro
NASA’s Goddard Space Flight Center, Greenbelt, Md.