A 1 in 10 year storm event is expected to hit Northern California this weekend. Rainfall totals could easily be twice the average precipitation for January.
An atmospheric river will take aim with heavy precipitation, high snow levels and soils that are already saturated from recent storms. Precipitation starts Saturday, but the brunt of the storm will be Sunday & Monday. Forecasters say this will exceed stream and river flood levels last seen in 2005.
Snowfall ahead of the storm will be significant, then likely melt with the second warmer event Sunday:
Rainfall amounts over the weekend are likely to be heavy in the Sierra Nevada Foothills and higher mountain areas.
This is going to be some of the more significant flooding we’ve seen in the past decade. Areas may flood that haven’t seen impacts for several years.
According to Dr. Ryan Maue:
If this isn’t the end of the California drought then it’s the beginning of the end of the end. 7-day NCEP WPC liquid equivalent precip:
Unfortunately, California’s outdated reservoir system will likely not capture but a fraction of that water for later use.
From the NWS Sacramento Forecast Discussion:
Deep atmospheric moisture becomes focused over the Northern California Sunday resulting in periods of moderate to heavy rain with snow levels
above 8000 feet. Flood watch in place to cover potential flooding of urban areas, small streams and creeks, and unregulated rivers in the foothills and West Slopes of the Sierra Nevada, such as the Cosumnes. Heaviest precipitation appears to be focused over southern portions of the Sacramento Valley and Northern San Joaquin Valley, Motherlode, and Sierra Nevada Sunday into Sunday night. Models point to a second atmospheric river setting up over the area Tuesday into Wednesday with more significant precip. Have expanded the Flood Watch to include this.
Heavy precip looks to continue along the Motherlode and West Slopes of the Sierra Nevada Monday morning with lighter precip elsewhere across the CWA. Storm QPF Saturday through Monday ranges from 2 to 6 inches in the Central Valley, 3 to 8 inches in the foothills and Coastal/Shasta mountains, and 7 to 14 inches for the Western Plumas mountains and Sierra Nevada. Precipitation amounts this high have not been seen since the storms of December 2005 and could surpass the average monthly total for many areas.
Colder air pushes into the area Monday with lowering snow levels.
Wet pattern continues into the extended period as the next land- falling moisture plume moves into Norcal on Tue, to be followed by another plume on Thu. Precipitation lingers on Wed as Norcal will be in between weather systems (TPW plumes). Slight ridging ahead of the approacing Eastern Pacific trough is expected to shift the precip Northward onto the Northern CA coast with orographic effects prevailing over the Sierra on Tue. WAA ahead and associated with the moisture plume is expected to raise snow levels Tue/Tue nite. Then, a dip in snow levels Tue nite into Wed as the precip begins to diminish. Modest fluctuations in snow levels expected with a more modest moisture plume on Thu. With that said, snow levels are expected to remain below pass levels so this will be a couple of snowier weather systems with greater snow impacts, but less runoff. However, with rivers and streams still elevated from previous rains, additional rainfall over the foothills and Valley will continue the potential for flooding.
In 1861, following 20 years of drought, California had 6 weeks of flooding rain. Los Angeles got 66″ of rain.
The whole article is interesting, fascinating:
“In 1861, farmers and ranchers were praying for rain after two exceptionally dry decades. In December their prayers were answered with a vengeance, as a series of monstrous Pacific storms slammed—one after another—into the West coast of North America, from Mexico to Canada. The storms produced the most violent flooding residents had ever seen, before or since.
“Sixty-six inches of rain fell in Los Angeles that year, more than four times the normal annual amount, causing rivers to surge over their banks, spreading muddy water for miles across the arid landscape. Large brown lakes formed on the normally dry plains between Los Angeles and the Pacific Ocean, even covering vast areas of the Mojave Desert. In and around Anaheim, , flooding of the Santa Ana River created an inland sea four feet deep, stretching up to four miles from the river and lasting four weeks.”
https://www.scientificamerican.com/article/atmospheric-rivers-california-megaflood-lessons-from-forgotten-catastrophe/
It was worse than that inland. Try a description of an inland sea 300 miles long by 20 miles wide around Sacramento. The legislature had to be relocated to San Francisco for over a year. In some places people were living on the second floor of homes going in and out of the windows as needed. A map I saw suggests that you might have been able to reach the Bay Area by boat.
The Sacramento River is navigable from the SF Bay to Sacramento.
And the story goes that Leland Stanford had to row a boat to his own inauguration in Sacramento.
One of my tasks at the civil engineering firm was to update the “Old Timer’s Rainfall Chart” maintained by R.B. Lewis. The flood you mention was in the notations as having rained for 60 consecutive days in Ventura. The Ventura River flowed from bank to bank which now includes the heavily populated North Ventura Avenue. The old mission aqueduct was destroyed in the flood. The drought conditions today are very similar to that prior to the winter of 1861. With “Moonbeam’s” policy towards destroying a century’s worth of flood control measures, anything close to 1861 would be an unthinkable disaster.
The worst in my lifetime was the storm of 1943(?) and that of 1969.
So Moonbeam gets Federal money (debt) for flooding, drought, earthquakes, and cracked ice in Antarctica. You would think they could afford safety inspections of warehouses in his former neighborhood.
With the California state landmass covering as many latitudinal degrees and elevations as it does, there should be little wonder as to its wide diversity of weather events.
I live in the middle of Calaveras County and have had a Davis weather station for 13 years. The average yearly rainfall over that time is 30.80″. The wettest year was 2005/2006 with 41.25″. So far this season I have 24.34″ or 79% of an average year. (The rainfall year is July 1 – June 30.) Looks like this week we’ll easily blow through 100%. It seems unlikely that we won’t exceed 2005/2006. Next stop is the 200+% received in the 1982/83 season.
Ahhh, Calaveras County, one of the best places on the planet. Murphys, Arnold, Big Trees, jumping frogs, Etc. Not to mention some of the best wineries (& wines) in the world. Ironstone is my favorite. But I’m OT. So, back to the subject at hand. I remember that winter of 82/83 clearly as we got stuck up in the mountains for a week due to a Pineapple Express dropping about 4 feet snow on us in a day or so. And as I’m sure Chuck will remember, after that winter, CA had a drought, at least in name. Than kind of average till the big slosh in 95. For a good review, go to: http://www.thestormking.com/Weather/Sierra_Snowfall/sierra_snowfall.html
Living here near Sacramento, CA, I’m unimpressed by the hysterical, hyperbolic descriptions of the storms in the local radio news. Yes, we occasionally get heavy rain. My back yard floods in every big rainstorm, but since I dug a trench through my side yard in 1986, I haven’t needed to worry much about actual flooding affecting the house.
It’s much like the children’s song about the Itsy Bitsy Spider who repeatedly built his web in the downspout; if you live near the Sacramento, American or Cosumnes Rivers, you probably should elevate your house to prevent flooding. Otherwise, you’ll be OK.
Hint. They are fake news.
As I recall, almost everyone’s winter forecast called for a relatively dry and warm winter for the Pacific Northwest and California. It has been anything but that so far. Isn’t this unusually wet for an ENSO Neutral winter? I am thinking the culprit is the unexpected colder than average temperatures in the North Pacific, but I am unsure how that works? Any thoughts out there?
The track of Pacific low pressure systems is farther South than last year. The winds are scooping up moisture from the lower latitudes.
Yes, but why? The track and frequency of the storms is more typical of strong El Nino years. It’s almost as if the ‘Arctic’ has moved south, into Siberia and the north Pacific, creating a similar temperatures gradient over the rest of the Pacific to a strong El Nino Winter. On the other side of the continent, the persistent forecast of a negative Arctic Oscillation (AO) and the resultant blocking over Greenland and the Canadian Maritimes, hasn’t happened yet, although the models keep trying to predict it.
Clarke a rex block has formed with a high in Alaska and a low off the left coast. Rex blocks tend to be stationary once set up and so this pattern should stick around …. until its gone 😉
California Extreme Precipitation Symposium
http://cepsym.org/proceedings.php
Irony abounds. “There’s no way ought!” of the California drought.
http://www.dailybreeze.com/environment-and-nature/20150825/california-climate-researchers-sound-the-alarm-at-symposium-theres-no-way-out
So warming climate will bring more extreme precipitation, and more extreme and persistent droughts. Got it.
“Unfortunately, California’s outdated reservoir system will likely not capture but a fraction of that water for later use.”
Perhaps the most important reservoir in the system is the “Frozen Reservoir” which is the snowpack above 8000 feet. It takes a very warm storm indeed to clobber the highest elevations. The good news is that the warm phase of this next system will only last a couple of days, so only a fraction of the heavy accumulation up top we got earlier this week will be washed away. The dangerous runoff should mostly be from lower the slopes.
Forecast 5 day NCEP precipitation total for Central Sierra- 16″
Forecast 7 day NCEP precipitation total for Central Sierra- 27″
These are usually pretty accurate.
Why can’t we go back to the much more pleasing term Pineapple Express?
Not all atmospheric rivers are Pineapple Expresses. The one earlier this week had considerable cold air fed into it from a low centered near Alaska. The classic P.E. is almost entirely warm air from near Hawaii, and produces rain at unusually high elevations. Even the event predicted for this weekend will not be warm enough to rain much above 8000 feet ASL (considered the base of the the snow pack) in the Sierra Nevada.
What the hell makes a 1 in 10 year event newsworthy?
This is a total waste of time, effort, newsprint, and electrons.
Could some one get a life?
I spent a lot of time in the ’80s and ’90s and ’00s trying to convince the egomaniacs in Sac that if they REALLY wanted to help the citizens, they would build some dams and a lot of reservoirs.
Currently, some totally unimportant fish are more important that the people. The politicians attacked the farmers for their water usage (see dead areas of the Central Valley), but have NEVER done anything about industry. Their idea of solving the water problem is to only shower once a week and don’t flush a toilet unit the smell it too much. Even during the “every 5-10 year mega-drought,” Hollywood was pretty much untouched–they had their megalawns and pools.
I am so glad not to live in CA any more.
California:
It rains, and they tell you “due to high rain levels, there is large increase in brush and high fire danger in the forests.” Next year, due to lower rain levels, “due to extreme dry brush, there is high fire danger in the forests.”
They NEVER clean out the brush, they just close public lands.
This has been an every year occurrence since at least the ’60s.
Every year, it is extreme danger.
Wasn’t Von Braun’s motto: I aim for the stars and hit London?
http://www.breitbart.com/california/2014/04/07/california-water-storage-drought-mcclintock/
I think the main reason the California Reservoir system won’t catch too much of this rainfall is not because it is outdated, but rather because it is already at 97% of it’s average storage capacity. It seems California defines drought politically, not practically. Until every region gets every inch of rain we “lost,” they will keep us in “drought” to exercise maximum control. The fact is, the drought broke last year. http://cdec.water.ca.gov/cgi-progs/reservoirs/RES
I always though “drought” was a reflection of soil moisture content, not how much water is in reservoirs. After all, reservoirs can be drained intentionally, for whatever reason, even when the watershed and region are enjoying normal meteorological conditions, and local flora are not suffering from dry conditions. The Dust Bowl was not a drought because reservoirs were empty, it was because crops were failing and billions of tons of topsoil were blowing away, for many years.
You missed “on steroids”!
This is really a matter of weather and not climate change. I expect that this weather event will finally fill our reservoirs here in California. Last year we had above average rainfall but it was not enough to fill our reservoirs. But I am still saving what I can of water flowing from my roof for later use in watering my garden. We all have to do our part in this time of drought.
It is Jerry Brown’s fault. The last time he was Governor we had a severe drought followed by flood. I am not going to vote for him again in 2050 for his third term.
I’m here in the Mother Lode at 1,200′ between Sac-Town and Tahoe and so far the mega rain hasn’t shown.
About a tenth of an inch of rain since Friday AM. Little less than a 3rd of an inch a bit north, east of Rattlesnake Bar.
Good site for checking recent rainfall amounts in this area:
http://www.foresthillweather.com/24_Precip.php
Here you go Anthony, this link provides the latest GFS direct grid interpolated data dump for a specified airport. I ran it for KOVE.
http://wxweb.meteostar.com/sample/sample.shtml?text=KOVE
The 12Z run for 2017 Jan 7 shows 9.76″ out to 180 hours and another 4.9″ for 180-384 hours.
That’s a total of 14.66″ out to 384 hours. Looks like serious flooding. Take care.
Watch the USGS Yuba River gauge near Marysville here:
https://waterdata.usgs.gov/nwis/uv/?site_no=11421000&agency_cd=USGS
“Unfortunately, California’s outdated reservoir system will likely not capture but a fraction of that water for later use.”
This is almost gross negligence IMO.
What idiots we have running this state.
These storms reveal the influence of sea temperatures on our terrestrial temperature data sets. This is a case of the dog wagging the tail.
The flood potential for California in this winter is now back full steam. Look at this new stream of 43kg/m2 TPW flow that just started up over night to add to the already high moisture level which will enter through California and Southern Oregon. …https://earth.nullschool.net/#current/wind/surface/level/overlay=total_precipitable_water/orthographic=-122.69,28.10,497/loc=-131.966,24.258
The Truckee River in Reno is an hour or so from official flood stage at 11.0 feet on the gauge. I just drove by and looked before dark, it’s an angry river, with lots of large dead fall tree trunks racing by.
https://waterdata.usgs.gov/nwis/uv?10348000
The Truckee River in Reno crested at only ~1.3 feet over flood stage. And this morning fresh snow in the adjacent foothills. Looking at the snowpack figures for the Tahoe Basin, just before this warm storm and flooding, the Tahoe Basin stood at 134% normal snow water equivalent (SWE) for the date, and this morning it’s still 131%. Apparently the snow level didn’t rise as high as predicted (some observers had feared 10,000 feet) and the flooding in Reno was not as severe as feared. Also, the Sierra just north of Tahoe and Reno was at 138% SWE before this storm, and is now at 158%. My fear was that much of our snowpack would be washed away, but apparently much of the rain was retained in the snowpack, and fresh snow fell early this morning as colder air invaded the atmospheric river. We got lucky.
http://www.wcc.nrcs.usda.gov/ftpref/data/water/wcs/gis/maps/west_swepctnormal_update.pdf
Dams? Levees? Reservoirs?
Too bad that CA never clears out dead brush or trees and just lets it build up.
This is the unprecedented once every 10 years storm that signals the end of whatever civilization CA thinks they have.
To Mr. Watts : whatever happened to your weather forcast?
[To what weather forecast(s) do you refer???? .mod]
Seen ‘the pinapple express’ first-time on TV on the continent;
same time we had snow and ice on roads and rooftops.
Nonetheless best 2017 !