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California Hopes for a Wet Winter

By: Christopher C. Burt, 8:41 PM GMT on October 12, 2015

California Hopes for a Wet Winter

The hype is on for a big El Nino-fueled rainy season this coming winter and spring in California. The latest data indicates that the developing (already in progress) El Nino event should become just as strong (perhaps even stronger) than the record setters of 1982-1983 and 1997-1998. Here’s a look at how those seasons panned out for the state precipitation-wise and where precipitation totals for this year and season now stand.

Precipitation in California as of mid-October 2015

This calendar year and precipitation season (which began on July 1st) has consisted of two different regional narratives. The first has been a much wetter than normal start to the season for southern California. In fact, for San Diego precipitation has been at near record levels since the beginning of the rainy season on July 1st.



Accumulated precipitation curves for San Diego since the beginning of the rainy season July 1st. Two record-breaking rain events (in part due to moisture entrained from dissipated tropical storms) has propelled San Diego’s July 1st to date (Oct. 12th) precipitation up to 3.37”, just shy of the record amount of 3.76” set during the same time period in 1939 (another year that saw tropical storm-related precipitation soak the city). Rainfall is now normal for the calendar year in the city thanks to this summer’s storms. Graph from NOW data.

Los Angels has also seen much above normal rainfall since July 1st with a 3.22” total compared to a normal of just .46” for the period. Meanwhile, precipitation has been running much below normal for central and northern California, both for the calendar year and the season to date. In fact, for San Francisco, it has so far been the driest calendar year on record as of October 12th with a paltry 3.25” of rainfall since January 1st, drier than Las Vegas or Phoenix and falling short of the previous driest year-to-date experienced just two years ago when 3.94” had accumulated as of October 12, 2013. 2013 went on to become the city’s driest calendar year on record with an annual total of just 5.59”.



Accumulated precipitation curves for San Francisco since January 1st. The label at the bottom of this NOW graphic is wrong. 2015 has seen just 3.25” of precipitation since January 1st whereas 2013 saw 3.94” accumulate by this same time that year. Since the current rainy season began on July 1st, San Francisco has picked up .20” of drizzle and rainfall compared to a normal of .50” by this date (Oct. 12th).

Below are two tables of how the current precipitation season stands (July 1st to date top table) and how the calendar year has fared (January 1st to date bottom table). I’ll be the first to admit that these figures are not too meaningful since the rainy season normally doesn’t get underway until November, so just a FYI.





California Precipitation During the Big El Nino Seasons of 1982-83 and 1997-98

Should the current El Nino season result in precipitation amounts similar to those of the seasons of 1982-83 and 1997-98 California may expect some record amounts of rain to fall. Some of the sites that saw all-time record seasonal precipitation occur in 1982-83 and 1997-98 are listed below with their respective precipitation POR’s:

Season of 1982-83 all-time seasonal records set

FRESNO: 23.57” (POR 1881-)

SACRAMENTO: 37.49” (POR 1850-)

Season of 1997-98 all-time seasonal records set

BAKERSFIELD: 14.66” (POR 1889-)

FORT BRAGG: 79.13” (POR 1901-)

MONTEREY: 47.12” (POR 1847-)

MT. SHASTA CITY: 75.89” (POR 1889-formerly known as Sisson)

SANTA BARBARA: 46.99” (POR 1864-)

SANTA MARIA: 32.56” (POR 1885-)

Neither season resulted in seasonal precipitation records for the state’s major cities of Los Angeles, San Diego, or San Francisco, but nevertheless were very wet. Los Angeles (downtown site) picked up 31.25” in 1982-83 and 31.01” in 1997-98. Normal is 14.93” and the record was 38.18” set in 1883-84. San Diego received 18.26” in 1982-83 and 17.78” in 1997-98. Normal is 10.33” and the record was 25.97” in 1883-84. San Francisco (downtown site) picked up 38.17” in 1982-83 and 47.22” in 1997-98. Normal is 23.65” and the record was 49.27” in 1861-62. The 1997-98 season was the city’s 2nd wettest on record.

In both of the earlier cases cited above, the heaviest of the precipitation that fell occurred in January and February. February 1998 was particularly anomalous ranking as the wettest February on record for the state as a whole (average state-wide precipitation being 11.50”). All-time monthly precipitation records (for any month) were set at Los Angles (20.51”) and Monterey (14.26”) and it was the wettest February on record for many other sites (including San Francisco with 14.89”). Below is a chart of the distribution of the rainfall month-by-month for San Francisco in both 1982-83 and 1997-98:



Monthly precipitation in San Francisco during the El Nino events of 1982-83 and 1997-98 compared to average for such. Graphic courtesy of the San Francisco Chronicle based on data supplied by Jan Null at Golden Gate Weather Services.

Of course, there is no guarantee that this coming winter will turn out as wet as those of 1982-83 and 1997-98 and other factors aside from El Nino will play an important role. It should be noted, of course, that even if record or near-record precipitation such as that in the previous two cases does occur it is unlikely to end the current drought affecting the state. Of critical importance is how much of the precipitation falls as snow in the Sierra Nevada. If the storms are warm and the rain falls in just a series of intense storms much of the benefit will be lost to run-off into the Pacific Ocean.

The best source for keeping track of how this year’s El Nino will impact California is Daniel Swain’s California Weather Blog.

Christopher C. Burt
Weather Historian

Extreme Weather El Nino Precipitation Records Drought

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Keep hoping...
Thank you Doctor.
I'm a big fan of history, so I really enjoy your Blog! Thanks.
I hope for allot of snow and rain, we need it in the valley!
SFO will probably recover with more late fall and winter precipitation.
El Niño Brings Risk Of Flash Flooding, Debris Flows Near Wildfire Scars - capradio.org
(For the full article click the link above. Below is an excerpt.)
A strong El Niño is forecast to bring a wetter-than-normal winter to much of California.

But, the ocean warming condition can also create high intensity rainfall events that cause mudslides, flash floods and debris flows in areas recently scarred by wildfires.

And those hazards aren’t just a risk for Southern California.

"Even in Northern California we are going to see an increased risk," says Meteorologist Michelle Mead with the National Weather Service in Sacramento.

....(snip)
The question remains whether this winter will bring lots of snow or warm storms with high snow levels a la pineapple express.
Quoting 6. BaltimoreBrian:

The question remains whether this winter will bring lots of snow or warm storms with high snow levels a la pineapple express.


Likely the second scenario.
But high level snowfalls would anyway help the moribund glaciers, which are a very important source of water.
Quoting 6. BaltimoreBrian:

The question remains whether this winter will bring lots of snow or warm storms with high snow levels a la pineapple express.
Yeah, the wrong kind of "snow" (liquid) goes toward filling the man made reservoirs in the rainy season that ends in spring. It's the right kind of snow that creates the natural reservoir of snow pack whose melt keeps the high sierra trees alive and maintains man made reservoir levels over the hot dry summer and into fall.
Will it actually happen this time? For the last couple of years there have been El Nino conditions setting up according to NOAA, then failing due to the so-called RRR (ridiculously resilient ridge) in the Pacific.
Quoting 9. C4r0l3:

Will it actually happen this time? For the last couple of years there have been El Nino conditions setting up according to NOAA, then failing due to the so-called RRR (ridiculously resilient ridge) in the Pacific.
See what
Dr. Jeff Masters' WunderBlog : Blob Watch: The Latest on the Northeast Pacific’s Unusual Warmth | Weather Underground
has to say about it.
California stormin' on such an autumn's day.



Generally what time of year is your prediction for the El Niño Raina to begin?
The El Niño strength is not in doubt. However, it will be dueling with a now established powerful phenomenon, the persistent wavy (meridional) Northern hemisphere jet stream paths evidently caused due to Arctic warming/amplification (per Jennifer Francis, RutgersU). This durable year-after-year phenomenon is responsible for extreme weather hemisphere-wide, including the California drought and wild Eastern winters. So the big question becomes how the El Niño may interact with the arguably new normal Arctic-warming based jet stream path alterations. Will the El Niño dominate or will it merely somewhat modify the existing new jet stream path scenario? The El Niño will likely lead to record high global average temperatures and extreme weather somewhere, but in light of the dueling phenomena notion, history may be no guide.
The following article has very useful information for people living anywhere that it rains in the United States.

Map: El Niño: Should you buy flood insurance to protect your home? (FAQ) | 89.3 KPCC
(For the full article click the link above. Below are excerpts.)
Floods don't normally rank among the top concerns of California homeowners, especially during these four years of historic drought. But many are reconsidering, given that forecasters are confidently predicting an El Niño storm system to hit this winter that would be among the most powerful on record.

Since the beginning of September, Farmer's Insurance has seen a 152 percent increase in flood insurance sales in California versus the same period last year, according to Jeff Hinesly, the National Flood Insurance Program Director for Farmers Insurance Group. Nationwide sales have been flat.

....(snip)

Insurance brokers say customers are often confused about flood coverage, thinking that it is included in their existing homeowners or renters policy (it almost never is) or that if they are not in a FEMA-designated high-risk flood zone, they don't need insurance (they still could be at risk). To help, we've putting together some frequently asked questions.

....(snip)
Emphasis added by me.

The following article targets a specific region.
Flood Zones in Southern California | scpr.org
El Nino rains forecast to reach far into Northern California, where they're most needed - LA Times
(For the full article click the link above. Below are excerpts.)
....(snip)

The new forecast is particularly significant because it shows the increased rain reaching far into Northern California to the mountain ranges and system of reservoirs that provide the state with huge amounts of its water. Earlier forecasts showed El Niño providing rain mainly to Southern California.

....(snip)

This prompted officials, who had generally been reluctant to predict El Niño's effect on the drought, to say they expect the rains will ease the drought conditions but won't end them.

“If the wettest year were to occur, we still wouldn't erase the deficit that's built up in the last four years,” said hydrologist Alan Haynes for the National Oceanic and Atmospheric Administration.

....(snip)

Diamond Valley Lake is Southern California's largest reservoir — built two decades ago to provide the region with more reliable water storage and bolster its emergency supplies. It draws much of its supply from the far reaches of Northern California.

In the last several years, the lake has been rapidly shrinking, falling to levels so low that the boat launch ramp doesn't even reach the water's edge. Officials fear prolonged drought conditions could eventually plunge the lake to emergency reserve levels — the amount needed to protect Southern California's water supply after an earthquake or other natural disaster.

But a single year of heavy El Niño rains is unlikely to fill up Diamond Valley Lake to full capacity, said Bob Muir, spokesman for the Metropolitan Water District of Southern California, which built the reservoir. So many wells and reservoirs farther north are so dry, it's hard to say how much Southern California would get.

“The big reservoirs — Oroville, Shasta and the many hundreds of small reservoirs up and down the state, as well as the groundwater basins — it just takes a long time to fill all that stuff up. It's never happened in one winter,” said Bill Patzert, climatologist for NASA's Jet Propulsion Laboratory in La Cañada Flintridge.

On a conference call with reporters Thursday, scientists said the amount of precipitation California's Sierra Nevada has lost in the four-year drought has been 2.5 to 3 times the average annual precipitation.

....(snip)

Even if El Niño turns out to bring heavy rains to California this winter, it could prove disappointing.

Ideally, precipitation would fall in Northern California's mountains as mostly snow, so it can be kept frozen for many months and refill reservoirs at a slow, gentle pace as it melts in the spring and summer.

But in recent years, abnormally hot winters have brought precipitation that has come down there as mostly rain — a big problem because too much rain all at once, even in a drought, will force dam officials to flush out excess water to ensure dams don't overflow and have enough capacity to keep incoming floodwaters from destroying cities downstream. Scientists say they don't know if the northern mountains will see more snow or more rain.

The other big problem is the intensity of this four-year drought. It will almost certainly take years to catch up and will require years of consistent above-average rains to get there.

....(snip)
thanks for the info http://alobien.info/ http://www.francisco-bustos.com/
thanks for the info http://alobien.info/ http://www.francisco-bustos.com/
See Jan Null's excellent analysis of California monthly precipitation during strong and super strong El Nino events:

http://ggweather.com/enso/monthly/

Thanks for that I'm looking through the analysis now!
If memory serves me during the 1990's drought, Monterey's reservoirs were at 5% until the "March Miracle" in 1991 filled them in one month. Drought has shaped and will continue to shape California's history so we need to prepare for it.
Re: comparisons to 1987-1992 drought:

In fact, the effects on California will be far greater today than during previous droughts, says drought veteran Felicia Marcus. Chair of California’s Water Resources Control Board, Marcus was with at Los Angeles Department of Public Works during the drought in the late 1980s and early ‘90s. “It’s a much harsher and crowded and less-resilient situation than we had back then,” she says.

“It’s also worse precipitation-wise,” she adds. The Sierra snowpack, source of three-quarters of the state’s water supply, is nearly nil today, meaning there’s no runoff on the way for low reservoirs. “We’re just in a worse situation all around.”
From the weather blog: ``One of the most striking take-aways is that the December precipitation was BELOW AVERAGE throughout most of California during both "Strong" and "Very Strong" events.''

Born and raised here, I always thought that was true. (Relatively) lots of rain in December --> less rain Jan/Feb.
Reposting this from the flagship blog's comment section thinking about the comparison with California. One might say there is no comparison, and in a lot of ways I would agree, but mining the aquifers is a repeating theme around the world.

After looking at the picture of Mukalla above (barren desert), I was curious about the fresh water sources in Yemen. From the article "Water supply and sanitation in Yemen" in Wikipedia:
Yemen's groundwater is the main source of water in the country but the water tables have dropped severely leaving the country without a viable source of water. For example, in Sana'a, the water table was 30 meters below surface in the 1970s but had dropped to 1200 meters below surface by 2012. The groundwater has not been regulated by Yemen's governments.[5] Even before the revolution, Yemen's water situation had been described as increasingly dire by experts who worried that Yemen would be the "first country to run out of water".[6] Agriculture in Yemen takes up about 90% of water in Yemen even though it only generates 6% of GDP - however a large portion of Yemenis are dependent on small-scale subsistence agriculture. Half of agricultural water in Yemen is used to grow khat, a narcotic that most Yemenis chew. This means that in such a water-scarce country as Yemen, where half the population is food-insecure, 45% of the water withdrawn from the ever-depleting aquifers is used to grow a crop that feeds nobody.[5]
The only thing that counts is the snowpack in the Sierra. LA, and to a lesser extent, San Diego and San Francisco, draws its water from reservoirs fed by snowmelt. Another below normal snow year will be a disaster for California and northern Nevada.
If You Think the Water Crisis Can't Get Worse, Wait Until the Aquifers Are Drained

A new report from Stanford University ["Groundwater: Ignore It, and It Might Go Away"] says that nearly 60 percent of the state's water needs are now met by groundwater, up from 40 percent in years when normal amounts of rain and snow fall."

Even if El Nino brings bountiful snowpack, and I hope it does, the situation is not sustainable. Something has to give eventually.
Thanks 'bappit for this.

You are spot on. The REAL long-term issue for California agriculture is the critical aquifers situation. This problem will not be solved by just a few wet years.


Quoting 27. bappit:

If You Think the Water Crisis Can't Get Worse, Wait Until the Aquifers Are Drained

A new report from Stanford University ["Groundwater: Ignore It, and It Might Go Away"] says that nearly 60 percent of the state's water needs are now met by groundwater, up from 40 percent in years when normal amounts of rain and snow fall."

Even if El Nino brings bountiful snowpack, and I hope it does, the situation is not sustainable. Something has to give eventually.
So tell me where the Farmers Almanac has been wrong, other then it cant predict silly lows or highs it has always been spot on! Past two years it said California would get little precipitation which happened. 3 years ago it said heavy rain which we got. This year it says heavy rain and colder then normal. It has never been wrong!!
California has always been spotty rainfall wise short of upper northern areas. What has changed is the insane amount of people that suck up what comes, this is the fact. Southern California never gets water and has stole it from every avenue it can since it became something, another fact.
Quoting 27. bappit:

If You Think the Water Crisis Can't Get Worse, Wait Until the Aquifers Are Drained

A new report from Stanford University ["Groundwater: Ignore It, and It Might Go Away"] says that nearly 60 percent of the state's water needs are now met by groundwater, up from 40 percent in years when normal amounts of rain and snow fall."

Even if El Nino brings bountiful snowpack, and I hope it does, the situation is not sustainable. Something has to give eventually.

Do you know whats up from years past? It is the population!
weatherhistorian has created a new entry.
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