Tag: Josephine 2020

Aug. 17, 2020 – NASA Sees Former Tropical Storm Josephine Open into a Trough

Tropical Storm Josephine weakened on Aug. 16 in the North Atlantic Ocean and satellite imagery showed the storm had become elongated and stretched out into a trough of low pressure a couple of hundred miles north of Puerto Rico.

Early on Sunday, Aug. 16, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite provided infrared temperatures of the storm’s cloud tops and revealed the storm had become more disorganized over the last day. Coldest cloud top temperatures were near minus 70 degrees Fahrenheit and were displaced from the center. At the time, the National Hurricane Center said, “Josephine’s low-level center has raced out over 100 nautical miles to the west of a remnant area of deep convection, which itself is shrinking and becoming more disorganized.”

Later in the day, at 1:30 p.m. EDT, the MODIS instrument aboard NASA’s Terra satellite provided a visible image of Josephine as it was degenerating into a trough (elongated area) of low pressure about 175 miles (280 km) north of San Juan, Puerto Rico. The MODIS image showed a low-level swirl that became less defined later in the day. Wind data on the afternoon of Aug. 16 indicated Josephine had degenerated into a trough of low pressure.

Josephine’s Final Advisory

The NHC posted its final advisory on Josephine on Sunday, Aug. 16 at 5 p.m. EDT (2100 UTC). At that time, the remnants of Josephine were located near latitude 20.9 degrees north and longitude 65.8 degrees west. The remnants were moving toward the west-northwest near 12 mph (19 kph), and is expected to turn toward the northwest.

Maximum sustained winds are near 35 mph (55 kph) with higher gusts. The maximum winds associated with the remnants are forecast to continue to decrease over the next day or two. The remnants are forecast to recurve toward the north and northeast Tuesday and Tuesday night.

About NASA’s Worldview and Terra Satellite

NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.” One of the satellites providing data is NASA’s Terra Satellite. Terra is one in a fleet of NASA satellites that provide data for hurricane research.

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, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 14, 2020 – NASA Finds Wind Shear Affecting Tropical Storm Josephine

NASA-NOAA’s Suomi NPP satellite provided forecasters with a visible image of Tropical Storm Josephine east of the Lesser Antilles island chain. Suomi NPP revealed that Josephine was being affected by wind shear.

The Lesser Antilles is a group of islands that form the boundary of the western Atlantic Ocean and the Caribbean Sea (to the west). They are a long, partly volcanic island arc stretching between the Greater Antilles to the north-west and South America.

On Aug. 13, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP revealed southwesterly wind shear was pushing the bulk of clouds and precipitation to the northeast of the center, giving the storm an elongated appearance.

Vertical wind shear, that is, winds outside of a tropical cyclone at different heights in the atmosphere (the troposphere), pushes against a tropical cyclone and tears it apart.

On Aug. 14, National Hurricane Center hurricane forecaster Jack Beven noted that wind shear was continuing. Beven said, “Morning visible satellite imagery indicates that the center of Josephine is located to the south or southwest of the strongest area of convection, likely due to the onset of southwesterly vertical wind shear.”

Tropical Storm Josephine on Aug. 14

At 11 a.m. EDT (1500 UTC) on Aug. 14, the center of Tropical Storm Josephine was located near latitude 16.1 degrees north and longitude 54.7 degrees west. The storm was centered 575 miles (920 km) east-southeast of the southern Leeward Islands.

Josephine is moving toward the west-northwest near 16 mph (26 kph), and this general motion is expected to continue for the next couple of days. The estimated minimum central pressure was 1006 millibars. Maximum sustained winds were near 40 mph (65 km/h) with higher gusts. Some strengthening is possible during the next 24 hours. After that time, Josephine is expected to encounter upper-level winds that will not be conducive for strengthening.

Josephine is expected to turn toward the northwest late this weekend or early next week. On the forecast track, the center of Josephine is expected to pass to the northeast of the Leeward Islands over the weekend.

 NASA Researches Tropical Cyclones

Hurricanes/tropical cyclones 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 more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.

For updated forecasts. visit: www.nhc.noaa.gov

By Rob Gutro 
NASA’s Goddard Space Flight Center

Aug. 13, 2020 – NASA-NOAA Satellite Nighttime Imagery Reveals Development of Tropical Storm Josephine

The tenth named tropical cyclone of the Atlantic Ocean hurricane season was named today, Aug. 13, after NASA-NOAA’s Suomi NPP satellite provided a nighttime image of the storm.

Tropical Storm Josephine developed from Tropical Depression 11. Over the last two days, Tropical Depression 11 has been moving through the Central Atlantic Ocean and was slow to organize. Satellite imagery indicated the depression became more organized and reached tropical storm strength on Aug. 13.

Another Record-Breaker for the Season

Josephine is the earliest tenth tropical storm of record in the Atlantic, with the next earliest tenth storm being Tropical Storm Jose on August 22, 2005.

NASA’s Night-Time View  

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a nighttime image of Josephine on Aug. 13 at 2 a.m. EDT (0500 UTC). The imagery showed that Josephine had strong thunderstorms surrounding its center of circulation and fragmented thunderstorms wrapping into the low-level center from the northern quadrant. The image was created using the NASA Worldview application.

The National Hurricane Center (NHC) noted, “Satellite imagery shows that the convective pattern associated with Josephine has become a little better organized since the last advisory (at 5 a.m. EDT), with a ragged central convective feature and a weak band in the northern semicircle.”

Josephine’s Formation Advisory

At 11 a.m. EDT (1500 UTC) on Aug. 13, NHC announced the formation of Tropical Storm Josephine. At that time, the center was located near latitude 13.7 degrees north and longitude 49.2 degrees west. Josephine was located about 975 miles (1,565 km) east-southeast of the Northern Leeward Islands.

Josephine was moving toward the west-northwest near 15 mph (24 kph), and this general motion is expected to continue for the next few days followed by a turn toward the northwest late this weekend or early next week. The estimated minimum central pressure is 1005 millibars.

Recent satellite wind data indicate that maximum sustained winds have increased to near 45 mph (75 kph) with higher gusts.  Some additional strengthening is forecast during the next 48 hours.

NHC cautions that interests in the Leeward Islands should monitor the progress of this system.

About NASA’s EOSDIS Worldview

NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.”

NASA Researches Earth from Space

For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.

For updated forecasts, visit: www.nhc.noaa.gov

By Rob Gutro 
NASA’s Goddard Space Flight Center