Oma (Southern Pacific Ocean)

Feb. 21, 2019 – NASA Takes an Infrared Analysis of Tropical Cyclone Oma

An infrared look by NASA’s Aqua satellite revealed where the strongest storms were located within the Southern Pacific Ocean’s Tropical Cyclone Oma.

Aqua image of Oma
On Feb. 20 at 9:53 p.m. EDT (0253 UTC, Feb. 21) the AIRS instrument aboard NASA’s Aqua satellite analyzed cloud top temperatures of Tropical Cyclone Oma in infrared light. AIRS found cloud top temperatures of strongest thunderstorms were as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Credit: NASA JPL/Heidar Thrastarson

On Feb. 20 at 9:53 p.m. EDT (0253 UTC on Feb. 21) the Atmospheric Infrared Sounder or AIRS instrument aboard NASA’s Aqua satellite analyzed cloud top temperatures of Tropical Cyclone Oma in infrared light. AIRS found cloud top temperatures of strongest thunderstorms as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius) circling the center. Cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain. Cloud top temperatures over the bands of thunderstorms feeding into the low-level center have warmed. That’s indicative of a weakening storm. The higher in the atmosphere, the colder the cloud top. When cloud tops warm, it means the uplift of air that pushes them, has weakened.

On Feb. 21 at 10 a.m. EST (1500 UTC), the center of Tropical Cyclone Oma was located near latitude 24.1 degrees south and longitude 159.7 degrees east. That’s about 418 nautical miles east-northeast of Brisbane, Australia. Oma was moving to the south. Maximum sustained winds were near 45 knots (52 mph/83 kph).

The Joint Typhoon Warning Center expects Oma to become slow moving and dissipate after two or three days because of increasing wind shear and movement over cooler sea surface temperatures.

By Rob Gutro
NASA’s Goddard Space Flight Center

Wutip (was 02W – Northwestern Pacific Ocean)

Feb. 20, 2019 – NASA Finds Tropical Cyclone Wutip Organizing

Tropical Depression 02W has organized and strengthened into a tropical storm.

Suomi NPP image of Wutip
On Feb. 20, 2019, the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of Tropical Cyclone Wutip in the Northwestern Pacific Ocean. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

NASA-NOAA’s Suomi NPP satellite captured a visible image of the storm that showed bands of thunderstorms wrapping into a more organized center of circulation. 02W has been renamed Wutip.

On Feb. 20, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite provided a visible image of Tropical Cyclone Wutip.  VIIRS revealed that bands of thunderstorms were wrapping into the low-level center of circulation.

The National Weather Service in Tiyan, Guam noted that a Typhoon Warning remains in effect for Satawal in Yap State and for Puluwat in Chuuk State. A Tropical Storm Warning remains in effect for Fananu, Ulul, Lukunor, Losap and Chuuk in Chuuk State.

A Typhoon Watch remains in effect for Faraulep in Yap State. Residents of the Marianas should carefully monitor the progress of Tropical Storm Wutip.

At 10 a.m. EDT (1500 UTC) on Feb. 20 (1 a.m. CHST on Feb. 21) the center of Tropical Storm Wutip was located near Latitude 5.5 degrees North and Longitude 152.0 degrees East. Wutip is moving west at 13 mph. It is expected to make a slight turn toward the west-northwest with little change in forward speed over the next 24 hours. Maximum sustained winds have increased to 65 mph. Tropical storm force winds extend outward from the center up to 185 miles to the southwest and up to 150 miles elsewhere.

Wutip is forecast to intensify through Saturday possibly becoming a typhoon later today.

Wutip is forecast to pass southwest of Chuuk and Fananu and move toward Guam.

For updated forecasts, visit: https://www.prh.noaa.gov/guam/cyclone.php

By Rob Gutro
NASA’s Goddard Space Flight Center

Oma (Southern Pacific Ocean)

Feb. 20, 2019 – NASA-NOAA Satellite Looks at Large-Eyed Tropical Cyclone Oma

Tropical Cyclone Oma is a large hurricane with a big eye. The storm appeared well-organized on satellite imagery as it moved through the Southern Pacific Ocean.

Suomi NPP image of Oma
On Feb. 20, 2019, the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of Tropical Cyclone Oma west of New Caledonia in the Southern Pacific Ocean. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

On Feb.20, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite provided a visible image of Tropical Cyclone Oma.  VIIRS revealed a large eye surrounded by powerful thunderstorms. The JTWC noted that the system is struggling to intensify due to the large size of the eye.

The VIIRS image also showed a long band of thunderstorms wrapping into Oma’s low level center from the southern quadrant, giving the impression of a long tail. Oma is located west of New Caledonia and east of Queensland, Australia.

JTWC stated that “Animated enhanced infrared satellite imagery depicts a decaying system with limited deep convective banding over the western semicircle [and a] microwave image depicts convective banding wrapping around a broad, defined low-level circulation center.”

At 10 a.m. EDT (1500 UTC) the Joint Typhoon Warning Center or JTWC noted that Oma’s center was located near 22.1 degrees south latitude and 160.6 east longitude, that’s approximately 545 nautical miles northeast of Brisbane, Australia. Oma has tracked south-southwestward. Oma is forecast to turn to the west-northwest on Feb. 24 and pass near Cato Island.

By Rob Gutro
NASA’s Goddard Space Flight Center

02W (Northwestern Pacific Ocean)

Feb. 19, 2019 – A NASA Infrared Look at Tropical Depression 02W, Warnings Posted

Tropical Depression 02W formed in the Northwestern Pacific Ocean on February 19 and the National Weather Service in Guam has issued warnings for Pohnpei, Chuuk and Yap States. NASA’s Aqua satellite found three strongest storms around the depression’s center when it passed overhead.

Aqua image of 02W
At 10:40 a.m. EDT (1540 UTC) on Feb. 19, the MODIS instrument aboard NASA’s Aqua satellite looked at Tropical Depression Two in infrared light. MODIS found coldest cloud tops (light green) had temperatures near minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) in several areas of the depression. Credit: NASA/NRL

Infrared satellite data of Tropical Depression Two (02W) was captured on Feb. 19 at 10:40 a.m. EDT (1540 UTC) from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite. MODIS data revealed several areas in the depression where cloud top temperatures as cold as minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius). Several of those storms appeared in a fragmented band of thunderstorms wrapping into the center from the northern quadrant.  Storms with temperatures that cold are indicative of strong storms and have been shown to have the capability to generate heavy rainfall.

The National Weather Service in Tiyan, Guam noted that a Tropical Storm Warning remains in effect for Nukuoro in Pohnpei State and Lukunor, Losap and Chuuk in Chuuk State. A Tropical Storm Watch remains in effect for Fananu, Puluwat and Ulul in Chuuk State and Satawal in Yap State. Residents of the Marianas should carefully monitor the progress of Tropical Depression Two.

At 1 a.m. CHST on Feb. 20 (10 a.m. EDT/1500 UTC on Feb. 19) the center of 02W was located near Latitude 4.4 degrees North and Longitude 156.4 degrees East. 02W is moving west at 15 mph. It is expected to make a slight turn toward the west-northwest with a slight decrease in forward speed over the next 24 hours. Maximum sustained winds remain at 35 mph (56 kph).

02W is forecast to intensify through Thursday possibly becoming a tropical storm later today.

For updated forecasts, visit: https://www.prh.noaa.gov/guam/cyclone.php

By Rob Gutro
NASA’s Goddard Space Flight Center

Oma (Southern Pacific Ocean)

Feb. 19, 2019 – NASA-NOAA Satellite Sees Powerful Tropical Cyclone Oma Affecting New Caledonia

Tropical Cyclone Oma appeared well-organized on satellite imagery as it moved through the Southern Pacific Ocean, just northwest of New Caledonia.

Suomi NPP Image of Oma
On Feb. 19, 2019, the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of Tropical Cyclone Oma near New Caledonia in the Southern Pacific Ocean. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

On February 19, New Caledonia posted a tropical cyclone alert level 2 for the communities of Belep, Hienghene, Kaala-Gomen, Koumac, Ouegoa, Ouebo and Poum.  New Caledonia is a French territory that consists of dozens of islands in the South Pacific Ocean. It ls located about 750 miles (1,210 km) east of Australia.

On Feb.19, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite provided a visible image of Tropical Cyclone Oma that revealed an eye surrounded by powerful thunderstorms. Oma’s southeastern quadrant covered New Caledonia. The northern tip of the island was close to Oma’s eyewall.

At 10 a.m. EDT (1500 UTC) Oma’s maximum sustained winds were near 75 knots (86 mph/139 kph). Oma’s eye was located approximately 246 nautical miles west-northwest of Noumea, New Caledonia, near 20.6 degrees south latitude and 162.0 east longitude. Oma was moving to the south.

Oma is moving south and the Joint Typhoon Warning Center forecast calls for the storm to strengthen to 85 knots (98 mph/157 kph). The storm will then become extra-tropical as it turns southeast

By Rob Gutro
NASA’s Goddard Space Flight Center

Gelena (Southern Indian Ocean)

Feb. 15, 2019 – NASA Catches Tropical Cyclone Gelena’s Post-Tropical Transition

Tropical cyclones can become post-tropical before they dissipate, meaning they can become sub-tropical, extra-tropical or a remnant low pressure area.  As Tropical Cyclone Gelena transitioned into a subtropical storm, NASA’s Aqua satellite provided a visible image of the storm.

Aqua image of Gelena
On Feb 15 at 10 p.m. EDT (Feb. 16 at 0300 UTC), the MODIS instrument aboard NASA’s Aqua satellite provided a visible image of Gelena that showed the storm had transitioned into a post-tropical cyclone. Credit: NASA/NRL

On Feb 15 at 10 p.m. EDT (Feb. 16 at 0300 UTC), the Joint Typhoon Warning Center or JTWC noted that Gelena had already become subtropical. JTWC issued their final warning on Gelena. At that time, the storm had maximum sustained winds near 40 knots (46 mph/74 kph). It was centered near 29.8 degrees south latitude and 89.3 degrees east longitude. That’s 1,426 nautical miles east-southeast of Learmonth, Australia. Gelena was moving east-southeast.

What is a Post-tropical Storm? 

A Post-Tropical Storm is a generic term for a former tropical cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Former tropical cyclones that have become fully extratropical, subtropical, or remnant lows, are three classes of post-tropical cyclones. In any case, they no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. However, post-tropical cyclones can continue carrying heavy rains and high winds.

What is a Sub-tropical Storm?

 According to the National Oceanic and Atmospheric Administration, a sub-tropical storm is a low-pressure system that is not associated with a frontal system and has characteristics of both tropical and extratropical cyclones. Like tropical cyclones, they are non-frontal that originate over tropical or subtropical waters, and have a closed surface wind circulation about a well-defined center.

Unlike tropical cyclones, subtropical cyclones derive a significant proportion of their energy from baroclinic sources (atmospheric pressure), and are generally cold-core in the upper troposphere, often being associated with an upper-level low pressure area or an elongated area or trough of low pressure.

In comparison to tropical cyclones, these systems generally have a radius of maximum winds occurring relatively far from the center (usually greater than 60 nautical miles), and are generally less symmetric.

What is an Extra-tropical Storm?

Often, a tropical cyclone will transform into an extra-tropical cyclone as it recurves toward the poles (north or south, depending on the hemisphere the storm is located in). An extra-tropical cyclone is a storm system that primarily gets its energy from the horizontal temperature contrasts that exist in the atmosphere.

Tropical cyclones have their strongest winds near the earth’s surface, while extra-tropical cyclones have their strongest winds near the tropopause – about 8 miles (12 km) up. Tropical cyclones, in contrast, typically have little to no temperature differences across the storm at the surface and their winds are derived from the release of energy due to cloud/rain formation from the warm moist air of the tropics.

Visible NASA Imagery Shows the Transition

Visible imagery from NASA’s Aqua satellite revealed Gelena’s subtropical transition.

At 3:25 a.m. EDT (0825 UTC) on Feb. 15, 2019, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite provided a visible image of subtropical storm Gelena in the Southern Indian Ocean.  The MODIS image showed Gelena had a closed surface wind circulation about a well-defined center, but the storm has become asymmetric (as subtropical storms do).

The Joint Typhoon Warning Center noted “animated multispectral satellite imagery shows cloud tops continuing to warm and convective structure continuing to unravel. [Another satellite] image showed remnant convective bands [of thunderstorms] sheared (pushed by winds) to the south and wrapping into an elongated partially exposed low level circulation center.”

Gelena is expected to continue moving through the Southern Indian Ocean over the next day until it dissipates.

By Rob Gutro
NASA’s Goddard Space Flight Center

Oma (Southern Pacific Ocean)

Feb. 15, 2019 – NASA Tracks Tropical Cyclone Oma as Warnings Remain for Vanuatu

Tropical Cyclone Oma continued to stay just west of Vanuatu in the Southern Pacific Ocean as NASA-NOAA’s Suomi NPP satellite passed overhead and captured an image of the tropical storm.

Suomj 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. 15 when it was passing west of Vanuatu. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

Tropical Cyclone Warning Number 26 was issued by the Vanuatu Meteorology and Geo-Hazards Department (VMGD), Port Vila at 3:05 a.m. VUT (local time) Saturday, February 16, 2019 (11 a.m. EDT, Feb. 15) for the Torba, Sanma and Malampa Provinces. The VMGD noted that: “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 remain very rough to phenomenal with heavy and phenomenal swells over the affected areas.”

Suomi NPP passed over Oma on Feb. 15 and the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument provided a visible image of the storm. The VIIRS image showed a large area of thunderstorms wrapping into the center. Most of the convection (rising air that condenses and forms clouds and thunderstorms that make up a tropical cyclone) is north of the center. Oma was passing to the west of Vanuatu.

VMDG reported at 2 a.m. local time on Feb. 16 (10 a.m. EDT on Feb. 15), “Tropical Cyclone Oma was located at 15.5 degrees south and 164.3 degrees east. That is about 260 kilometers (161 miles) west southwest of Santo and 345 kilometers (214 miles) west northwest of Malekula. Expected sustained winds close to the center are estimated at 102 kph (63 mph/55 knots). Damaging gale force winds of 75 kph (46 mph/40 knots) with gusts up to 102 kph (63 mph/55 knots) will continue to affect the Torba, Sanma and Malampa provinces for the next 12 to 24 hours.”

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

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

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