Upon making landfall on the southeastern U.S. coast on September 14, 2018, <a href="https://en.wikipedia.org/wiki/Hurricane_Florence" class="extiw" title="en:Hurricane Florence">Hurricane Florence</a> brought strong winds and torrential rains that flooded roads, houses, and rivers to historic levels and left hundreds of thousands of people without power. NASA data and researchers observed and analyzed the event, providing a steady stream of information to the Federal Emergency Management Agency (FEMA) and the National Guard to help assess the hurricane's impact.
<p>Elizabethtown and Swansboro, North Carolina, received the highest recorded rainfall totals in the region—surpassing 33 inches (83 centimeters)— from September 13 to 18, <a rel="nofollow" class="external text" href="https://www.wpc.ncep.noaa.gov/discussions/nfdscc4.html">according to the National Weather Service</a>. Trent River, about 40 miles (60 kilometers) northwest of Swanson, swelled to levels exceeding previous records. At least 28 cities and towns in North Carolina received at least 20 inches of rain. Flooded roads isolated some areas such as Wilmington, where officials were planning to airlift food and water into the city.
</p><p>The image above shows soil moisture in the region on September 11, 2018, before the arrival of Hurricane Florence. The data for that map come from the <a rel="nofollow" class="external text" href="https://smap.jpl.nasa.gov/">Soil Moisture Active Passive</a> (SMAP) satellite, which uses a radiometer to measure soil moisture in the top 5 centimeters of the ground.
</p><p>Heavier rainfall occurred on the right/north side of the hurricane track, similar to past hurricanes. As hurricanes in the northern hemisphere spin counterclockwise, winds on the right side tend to be stronger and can increase evaporation from the surface, particularly over the ocean.
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“But it's probably more important that the stream of air being pulled up the right side is coming from the tropics, which tend to have more moisture that feeds the precipitation,” said George Huffman, a research meteorologist at NASA’s Goddard Space Flight Center. “As you get close to landfall, the left side starts getting fed by air from the land, which is almost always drier.”
NASA Earth Observatory images by Joshua Stevens and Lauren Dauphin, using soil moisture data courtesy of JPL and the SMAP Science Team, IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC, and modified Copernicus Sentinel data (2018), processed by ESA and analyzed by the NASA-JPL/Caltech ARIA team. Story by Kasha Patel.
2018-09-11
<a rel="nofollow" class="external free" href="https://earthobservatory.nasa.gov/images/92775/florence-inundates-the-carolinas">https://earthobservatory.nasa.gov/images/92775/florence-inundates-the-carolinas</a>