NASA's Integrate Multi-satellitE Retrievals for GPM (IMERG) product followed the path of Hurricane Isaias as it coursed through the Caribbean.
On August 2, 2020, the NASA/JAXA Global Precipitation Measurement (GPM) satellite passed over Isaias as it crossed into the central Bahamas, revealing deep hot towers.
At this point, southwesterly wind shear and the interaction with the land caused Isaias to weaken from a Category 1 hurricane down to a tropical storm.
GPM shows that the rain was almost entirely northeast of Isaias' center with very little rain on the western side of the storm.
This highly asymmetric structure reflects both the effects of wind shear and Isaias' lack of intensity.
After regaining hurricane intensity over the Gulf Stream, Hurricane Isaias made landfall on the south coast of North Carolina on August 3 at 11:10 pm EDT near Ocean Isle Beach.
On August 4, GPM caught Tropical Storm Isaias about 5 hours after landfall, with the center of circulation over northeastern North Carolina.
GPM observed a large rain shield extending to New England and the Canadian border along a coastal front.
Parts of the Bahamas received over 30 centimeters (~1 foot) of rainfall during Isaias' passage, while some areas in the U.S. East Coast received over 7.5 centimeters (~3 inches) by dawn of August 4, on the way to 8 inches or more.