So far this year, Seattle has seen nearly 6.5 “of rain. With an additional 2-4 inches forecast, the city could receive approximately 25% of its annual rainfall by Jan. 15 from the atmospheric river that irrigates the region.
“This wet start could push Seattle to its wettest start of the year. The previous wettest period from January 1 to 15 occurred in January 1956, when it fell nearly 7 inches in the first half of the month,” said the meteorologist. CNN Pedram Javakheri.
Atmospheric rivers are long, narrow areas in the atmosphere – like rivers in the sky – that transport water vapor, according to the National Oceanic and Atmospheric Administration.
Check the forecast in the counterand
There is also a lot of heat in the middle levels of the atmosphere during this particular atmospheric river event. This will raise snow levels above 6,000 feet in much of the Cascades, with rain falling below that level.
“This will further exacerbate fears of flooding as torrential rain falls on heavy snow. The threat of rapid melting, increased runoff and downstream floods is something that everyone in Western Oregon and Washington should be vigilant about,” Javaheri said.
Higher altitudes in Washington can see 2 inches to 4 inches of rain over the next 24 hours, increasing the risk of floods and landslides.
During this time, rainfall at lower elevations should be between 1 and 2 inches.
In Portland, Oregon, the National Weather Service forecasts up to 7 inches of rain in higher ground and up to 2 inches for the lowlands by Wednesday morning. There is also a strong wind warning.
Wind warnings extend across the Oregon coast, where gusts can reach 75 mph. This raises concerns about fallen trees, power outages and possible dangers across the state 5
The effects of record forest fires are also increasing flood threats to Oregon. According to the Oregon Department of Forestry, more than 1 million acres have been burned. These incineration residues make the threat of flooding even greater due to the charred land without vegetation to absorb rainwater. This increases the possibility of floods and landslides due to the loose terrain.
The phenomenon of weather that causes all this rain is called an atmospheric river. In essence, they are rivers with moisture high in the atmosphere. They transfer abundant moisture from the tropics and release it to other areas in the form of rain or snow.
According to NOAA: “These steam columns move over time, carrying an amount of water vapor approximately equivalent to the average flow of water at the mouth of the Mississippi River.”
Not all atmospheric rivers are bad. Many times they bring very useful rain in areas that need it. Many areas along the west coast will receive 30% -50% of their annual rainfall after just a few such events.
This particular atmospheric river has a 2,700-mile range with bull’s eyes to the northwest. This is equivalent to the distance from Seattle to Miami while a crow flies, and the moisture it carries can include January 2021 in the record books.
Hurricane hunters head to the West Coast
This atmospheric river event is so significant that hurricane hunters will fly through it, releasing buoys.
“To really understand how significant the atmospheric event of the river is, you need to get closer to it. “Hurricane hunters fly inside them and collect valuable data that forecasters then use to determine how a particular atmospheric river will affect the Pacific coast,” said CNN meteorologist Alison Cinchar.
This is their second flight of the season and something they do regularly.
“Hurricane hunters began flying in atmospheric rivers for the first time in February 2016 and have since sent 6-12 flights every January to March since. In itself, it is not uncommon for them to fly this event, although it is a popular misconception that once the winds of hurricane season die, so does their role, ”Javaheri said.