Nav: Home

NASA sees heavy rain in Gaston as it fights wind shear

August 25, 2016

Gaston was a hurricane when the Global Precipitation Measurement mission or GPM core satellite passed overhead and found heavy rain occurring in the storm. GPM imagery also showed that wind shear was stretching the storm out and making it appear elongated from space.

Gaston became the 3rd hurricane of the season early this morning, Aug. 25 (just after midnight EDT) as the storm was moving northwestward into the Central Atlantic about midway between the Leeward Islands and the Cape Verde Islands before weakening back into a tropical storm less than 12 hours later.

Gaston is continuing to battle relatively strong environmental wind shear brought about by an upper-level low pressure center positioned to the west of Gaston. Winds flowing counter-clockwise around the upper low are blowing from the southwest while Gaston is moving northwest. These opposing winds are causing Gaston to become tilted and make it difficult for the storm to consolidate the energy being released through condensation in embedded thunderstorm updrafts.

GPM captured an image of Gaston early this morning at 1:46 a.m. EDT (5:46 UTC) soon after the storm became a hurricane. When GPM passed over the storm, the National Hurricane Center (NHC) reported that Gaston had maximum sustained winds of 75 mph, making it a minimal hurricane. GPM is a joint mission between NASA and the Japanese space agency JAXA.

At NASA's Goddard Space Flight Center in Greenbelt, Maryland, rain rates derived from the GPM GMI (over the outer part of the storm) and DPR (the inner part of the storm) were overlaid on enhanced infrared data from NOAA's GOES-East satellite to show the location of the heaviest rainfall within the entire storm. The composite image showed Gaston was not circular, but very asymmetric. Heavy rain with rates of around 50 millimeters per hour (~2 inches/hr) were occurring near the center and most of the rain was located north and east of the low-level center of circulation, which reflects the effects of the southwesterly wind shear noted by NHC. These two opposing forces will determine Gaston's intensity over the coming days.

At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Gaston was located near latitude 20.4 North, longitude 44.4 West. Gaston is moving toward the northwest near 17 mph (28 kph), and this general motion is expected to continue through Friday, Aug. 26. A turn toward the west-northwest and a decrease in forward speed are expected on Saturday, Aug. 27.

Maximum sustained winds have decreased to near 70 mph (110 kph) with higher gusts, and some additional weakening is possible today. The estimated minimum central pressure is 992 millibars.

Initially, Gaston should continue to feel the adverse effects of the wind shear; however, NHC is forecasting the shear to weaken after a day or so and for Gaston to become a hurricane once again as it moves over increasingly warmer waters.

Gaston is expected to continue moving generally to the northwest over the next several days but remain east of Bermuda before turning back to the northeast.
-end-


NASA/Goddard Space Flight Center

Related Hurricane Articles:

Hurricane resilience in the Bahamas
A new Stanford-led study provides information on how to invest in natural coastal ecosystems that the Bahamian government, community leaders and development banks are applying in post-disaster recovery and future storm preparation in the Bahamas.
NASA finds a weaker hurricane Juliette
Hurricane Juliette has been weakening and NASA-NOAA's Suomi NPP satellite provided a look at the strength of storms within.
NASA sees Dorian become a hurricane
NASA's Terra satellite passed over the northwestern Atlantic Ocean as Dorian reached hurricane status during the afternoon of August 28, 2019.
Landslides triggered by Hurricane Maria
Hurricane Maria hit the island of Puerto Rico on 20 September 2017 and triggered more than 40,000 landslides in at least three-fourths of Puerto Rico's 78 municipalities.
NASA sees Atlantic's Leslie become a hurricane
NASA's Aqua satellite captured an infrared image of Hurricane Leslie that revealed strong storms circled the center.
NASA sees Walaka becoming a powerful Hurricane
The Global Precipitation Measurement mission or GPM core satellite passed over the Central Pacific Hurricane Center and analyzed Walaka's rainfall and cloud structure as it was strengthening into a hurricane.
NASA finds a weaker Hurricane Olivia
Infrared data from NASA's Terra satellite revealed that the area of coldest cloud topped thunderstorms has dropped from the previous day, indicating weaker uplift and less-strong storms
NASA looks at heavy rainmaker in Hurricane Lane
Cloud top temperatures provide scientists with an understanding of the power of a tropical cyclone.
Hector weakens but remains Category 4 Hurricane
Hurricane Hector has weakened slightly but still remains a robust Category Four storm at present.
UA forecast: Below-average hurricane activity
The UA hurricane forecasting model, which has proved to be extremely accurate over the years, is calling for fewer hurricanes in the Atlantic this year on the heels of a devastating 2017.
More Hurricane News and Hurricane Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.