Throw those rain cheater on and slip into those mud boots if you ’re in California , because it ’s going to be a muddy , windy , showery few days . A atmospheric condition phenomenon call an “ atmospheric river ” is snake itsway throughthe fortunate   state .

An atmospheric river is a slender , ephemeral newspaper column of condensed water vapour from the tropics locate up in the atmosphere   –   “ like a river in the sky , ” accord to the National Oceanic and Atmospheric Administration ( NOAA ) . When the “ river ” makes it to land , it ’s normally in the var. of big rain or snowfall .

This current event   is also experience as a “ Pineapple Express ” because the moisture originated near Hawaii and travel to the Western US . Typically , atmospherical rivers are around 1,600 kilometers ( 1,000 miles ) long and 400 - 600 kilometre ( 250 to 375 miles ) widely . They can   hold   water vapor 7.5 - 15 times the average water stream at the mouth of the Mississippi river .

While this sounds end of the world and sombreness , it ’s not all bad news . As long as everyone is good during the result , the rainfall can ply much - necessitate H2O and snowpack to orbit like the Sierra .

“ Not all atmospherical river stimulate hurt ; most are weak system that often allow for good rain or Charles Percy Snow that is all important to the water supply , ” notesNOAA . “ Atmospheric river are a cardinal characteristic in the global H2O bicycle and are closely tied to both water supply and flood risk of infection – peculiarly in the western United States . ”

Like most weather phenomena , it ’s a double - edged sword . The atmospheric river can provide weewee to neighborhood where it ’s needed but it could also be life story and result in injuries , as find a dyad twenty-four hours ago when rider on aflightfrom Southern California to Seattle were hit with severe turbulence due to the storm and were coerce to make an emergency landing .

Just this month , a newfangled scale to categorize atmospheric rivers was created by researchers at UC San Diego in theBulletin of the American Meteorological Society . They have assigned these weather events on a Category 1 to Category 5 plate , from “ weak ” to “ surpassing ” respectively . The criteria is based on the amount of water supply vaporization and its duration in a single location .

This violent storm is   a Category 3 , grant toCBS San Francisco . This deems it a “ potent ” consequence with a Libra of beneficial and hazardous termination . An example the scientist provide of a old family 3 outcome was the   atmospheric river   on October 14 , 2016 , that lasted for 36 hours and produce 5 - 10 inches of rain . In skillful newsworthiness , it helped replenish reservoirs after a drought . In not so well news program , it caused some rivers to arise too much .

It should also be noted that atmospherical rivers “ move with the atmospheric condition and are present somewhere on Earth at any move over time , ” fit in to NOAA .

For this outcome , the National Weather Service report impact of pelting and malarky , with a region   in the San Bernardino Mountains receive an incredible 9.4 column inch over 48 hr . Thousands in Northern California lose power and   floodlight warnings are in effect for many realm .

In other words , stay safe out there .