Northern California, Oregon to be Hit With Heavy Rain and Flooding Into Saturday
By By Meghan Mussoline, AccuWeather Meteorologist
February 08, 2015, 2:27:20 AM EST
Heavy rain will inundate coastal Oregon and northern California into early next week, threatening serious flash flooding, mudslides and travel delays and cancellations.
A Pineapple Express will help to fuel the heavy rain as the first of two major storms plows into the Pacific coast through Saturday.
"A Pineapple Express is a continuous surge of tropical moisture extending from near Hawaii all the way into a West Coast storm," AccuWeather.com Senior Meteorologist Bernie Rayno said.
This pattern can significantly enhance rainfall and threats such as flooding. Recent burn scar areas in California will be especially vulnerable to flooding and debris flows, since rain water cannot penetrate scorched ground.
Widespread rainfall amounts of 2-3 inches are expected in western Oregon and northern California, including in the Bay Area. In far northern California, amounts will exceed 6 inches in some communities through Saturday.
Lengthy flight delays and cancellations are possible at San Francisco International Airport due to low clouds and excessive rainfall associated with the storm.
Motorists may face travel problems on the ground as rain mixes with oil buildup on roadways to create slick conditions.
During Saturday into Saturday night, the rain will taper to showers. However, runoff will continue to cause small streams to run high.
A second storm will arrive along the West Coast Sunday into Monday, unleashing another round of heavy rain and most likely another dose of flash flooding, mudslides and travel disruptions.
The rounds of rain follow after an extremely dry January for many locations.
"This is the first significant rain [for Northern California] since the middle of December," AccuWeather. Western Weather Expert Ken Clark said.
January 2015 went down in the record books as the driest January on record for San Francisco with no rain recorded.
Downtown San Francisco 1st ever January w/no measurable precip in 165 years. #cawx
— NWSBayArea (@NWSBayArea) January 31, 2015
The second longest period of dry weather on record has ended at 43 days in San Francisco as of 9 a.m. PST on Friday. The longest period with no measurable rain on record was 60 days spanning Nov. 17, 1876, to Jan. 15, 1877. Records at San Francisco date back to 1849.
Meanwhile, mountain snowpack is an important resource for filling reservoirs and water supply for drought-stricken California. It is crucial to look at snowpack when analyzing the potential impact of storms on the ongoing drought. However, mountain snow is not likely with the upcoming storms, Clark said.
"Snow levels, because of the warm subtropical flow, will be very high, above 8,000 feet most of the time," Clark said. "Therefore, while the rains are welcomed, though too much in some places is not good either, these storms will be no help in putting down a snowpack."
Keep checking back with AccuWeather.com for updates on the Pineapple Express setting up and any potentially life-threatening flooding that may result.
Comments that don't add to the conversation may be automatically or manually removed by Facebook or AccuWeather. Profanity, personal attacks, and spam will not be tolerated.
More Weather News
Weather News - July 21, 2019, 3:19:52 PM EDT
The heat wave gripping a wide swath of the United States will soon end, but not before severe thunderstorms and flooding downpours threaten communities.
Weather News - July 21, 2019, 5:27:10 PM EDT
Heat has already been blamed for the deaths of three people late last week, as well as more than 100 residents evacuating a senior center in New Jersey after air conditioning failed. More lives are in jeopardy with excessive heat warnings and advisories stretching from eastern Kansas and Oklahoma to Maine and South Carolina on Sunday.
Weather News - July 21, 2019, 11:10:06 AM EDT
AccuWeather meteorologists are monitoring the southwestern Atlantic Ocean for potential gradual tropical development later this week.
Kerala to face rounds of flooding downpours into early week; More than 10 million affected by flooding in India's northeast
Weather News - July 21, 2019, 10:41:44 AM EDT
As flooding continues to affect parts of northeast India, downpours will focus on Kerala in the coming days and bring a new threat for flooding.
Weather News - July 21, 2019, 10:57:05 AM EDT
Danas continues to bring downpours across South Korea and Japan.
Weather News - July 21, 2019, 9:37:53 AM EDT
Less than one month after a historic heat wave gripped more than half of Europe, another far-reaching heat wave will affect parts of the continent this week.
Weather News - July 21, 2019, 9:26:21 AM EDT
Golfers were met with rainfall and gusty winds during the first round of The Open, but the worst weather of the tournament will plague the final round.
Weather News - July 21, 2019, 9:16:02 AM EDT
Millions of Americans remain under excessive heat warnings from the Eastern Seaboard to the central Plains, where AccuWeather RealFeel® Temperatures will once again dangerously soar past the century mark.