NASA's Global Precipitation Measurement (GPM) mission in combination with other satellites have been gathering data on abundant amounts of rainfall which wreaked havoc across the Pacific Northwest over the last couple of days.
The heavy rainstorms are caused by the "Pineapple Express", hose of tropical moisture originating from the Western Pacific Ocean.
NASA's IMERG measured rainfall from December 2 to 9, 2015 and found that many areas from northern California through the state of Washington had rainfall totals greater than 160 mm (6.3 inches). Over open waters of the Pacific Ocean some rainfall totals reached over 310 mm (12.2 inches). Image credit: NASA/JAXA/SSAI, Hal Pierce
"Riding a pumped up jet stream, a convoy of wet storms have pummeled and drenched the Pacific Northwest for the past week. Following a couple of years of regional drought, all this rain and mountain snow has whiplashed many Washington and Oregon communities from extremely dry conditions into flooding and even landslides. Once again, the old adage, 'Great droughts end in great floods' comes to mind," said Bill Patzert, climatologist at NASA's Jet Propulsion Laboratory in Pasadena, California.
The relatively narrow, moisture-rich rains and snow, coming from the tropics are known as atmospheric rivers. These storm types supply up to 50% of the water supplies for the US West Coast states. According to Patzert, these storms can be fast and furious, and highly damaging.
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NASA's Integrated Multi-satellite Retrievals for GPM (IMERG) measured the precipitation amount in the period between December 2 and 9, 2015. According to the data, many areas from northern California to the state of Washington measured total amounts of rainfall over 160 mm (6.3 inches) while 310 mm (12.2 inches) was observed over the open waters of the Pacific Ocean.
The storms had caused major flooding across Portland, Oregon on December 8 and more strong winds and heavy rainfalls have been battering the flood-stricken areas since. So far, at least 2 deaths have been reported.
Jay Inslee, the Governor of Washington has declared a state of emergency on December 9 after "days of hazardous weather with landslides closing major highways, high winds knocking out power to thousands, and rainfall causing wide-spread flooding of roadways, homes and property."
More thunderstorms and strong downpours have been forecast for the Pacific Northwest for the next week. This will increase the risk of flash floods and landslides. The National Weather Service (NWS) has issued a warning for tides and combined storm surge to run 2 feet above the predicted values. The rivers will be running high which will increase the flooding potential on the tidally influenced reaches and estuaries of the coastal rivers.
Featured image: NASA's IMERG measured rainfall from December 2 to 9, 2015 and found that many areas from northern California through the state of Washington had rainfall totals greater than 160 mm (6.3 inches). Over open waters of the Pacific Ocean some rainfall totals reached over 310 mm (12.2 inches). Image credit: NASA/JAXA/SSAI, Hal Pierce