April 11, 2021 - Tropical Cyclones Odette and Seroja off Western Australia

    Follow @NASA_MODIS

   Odette and Seroja
    Tweet
    Share

   On April 9, 2021, two cyclones jockeyed for position as they raced
   towards the shores of south-western Western Australia. The Moderate
   Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua
   satellite acquired a true-color image of Tropical Cyclone Odette and
   Tropical Cyclone Seroja on that same day.

   At the time the image was captured, Odette was a slightly stronger
   storm and, with its center located to the northwest, it was spinning
   clockwise around Serjoa and both cyclones were affecting the track and
   the strength of each other. This cyclone-style interaction is a rare
   phenomenon known as the Fujiwhara effect. The National Oceanic and
   Atmospheric Administration (NOAA) National Weather Service defines the
   Fujiwhara effect as follows: “When two hurricanes spinning in the same
   direction pass close enough to each other, they begin an intense dance
   around their common center. If one hurricane is a lot stronger than the
   other, the smaller one will orbit it and eventually come crashing into
   its vortex to be absorbed. The storms closer in strength can gravitate
   towards each other until they reach a common point and merge, or merely
   spin each other around for a while before shooting off on their own
   paths. But often, the effect is additive when hurricanes come together,
   and we usually end up with one massive storm instead of two smaller
   ones.”

   By April 10, Tropical Cyclone Odette had spun to the southeast of
   Seroja and merged with it. The enhanced Tropical Cyclone Seroja then
   has intensified as it approached the Western Australia coast. It is
   forecast to make landfall north of Geraldton at about 1200 UTC (8:00
   EDT) on April 11. The Joint Typhoon Warning Center (JTWC) forecast that
   Seroja will carry sustained winds of about 75 mph (120 km/h) and gusts
   of up to 92 mph (148 mph) just before landfall. This wind speed places
   the storm as the equivalent of a Category One storm on the
   Saffir-Simpson Hurricane Wind Scale and as a weak Category Three storm
   on the Australian tropical cyclone intensity scale. It is expected to
   weaken slightly before moving over land.

   Unlike the northwestern coast of Western Australia, the southwestern
   coast rarely experiences cyclones, which means that the region is
   relatively unprepared for severe storms coming onto land. There is
   concern that infrastructure, particularly house structure, has not been
   built to face exceptionally strong wind, high storm surge, and
   torrential rains. Evacuations are in place for many regions along the
   coast as Tropical Cyclone Seroja approaches. The storm is expected to
   weaken quickly once it makes landfall and sweeps across southwestern
   Australia.

   Image Facts
   Satellite:  Aqua
   Date Acquired: 4/9/2021
   Resolutions:  1km (1.9 MB),  500m (5.4 MB),  250m (3.8 MB)
   Bands Used: 1,4,3
   Image Credit: MODIS Land Rapid Response Team, NASA GSFC



https://modis.gsfc.nasa.gov/gallery/individual.php?db_date=2021-04-11
 
