Weather Warning

With El Nino conditions peaking across the Pacific, we are seeing a dramatic response with the upper level jet stream lining up storms all the way from Asia on towards the California coast. The result will be a nearly continuous train of storms moving onshore across California…affecting both southern and northern portions of the state. This extended period of precipitation is something that only happens once every few years. Between this weekend thru next week we expect there to be no more than an 18 hour break between each system…with about 5 storms to move onshore over the next 7 days. The strongest winds and heaviest precipitation will be late Monday thru Wednesday. Over the next 7 days total rainfall amounts of 4-8 inches are possible across the valleys with 7-14 inches of rain across the mountains…heaviest across the Western Sierra. Snow amounts of 6-12 feet possible across the mountains…heaviest in the Sierra. We will attempt to break this pattern down below:

Areas of light to moderate rain will develop…with valley areas getting about a half inch of rain or less…with mountains expecting one half to one inch of rain. Snow levels will still be at seasonable levels…4500-5500 ft where 5-10 inches of snow is possible. Winds will be light to moderate out of the SE to SW Saturday…but will begin to strengthen late Sunday to 15-25 mph in the valleys and 25-35 mph ridges.

A strong storm moves onshore early Monday and a second one on Tuesday. Winds will be increasing…southerly 20-30 mph valleys and 30-50 mph across the mountains on Monday…with winds about 10 mph stronger on Tuesday. Rainfall will be heavier and more widespread…with 1-3 inches in the valleys and 3-5 inches across many mountains. Snow levels will slowly fall from 5000 ft down to 2500-3500 ft late Tuesday. Snowfall totals of 25-45 inches possible across many elevations above 5000 ft with 5-15 inches of snow at 3500-4500 ft.

Much colder air moves in with the next strong storm on Wednesday. Strong South winds of 25-40 mph across the valleys and 30-60 mph across the mountains…with localized gusts approaching hurricane strength on upper ridges. Heavy rain everywhere…with 1-2 inches valleys and 2-4 inches mountains. Snow levels falling to between 2000-3000 feet with 20-40 inches of additional snowfall.

Heavy precipitation will become lighter and more showery, but should will be widespread and affect most areas with an additional quarter inch in the valleys and 1-2 inches across the mountains. Snow levels 1000-2000 feet with an additional 10-20 inches of snowfall. Winds will be diminishing…10-20 mph valleys and 20-30 mph mountains.

Brief drying possible next Saturday-Sunday…then the next series of storms expected to move onshore next Mon-Tue with more rain and higher snow levels.