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Central California Enters a Drought Period Unprecedented in its Weather History

By: Christopher C. Burt, 10:53 PM GMT on January 15, 2014

Central California Enters a Drought Period Unprecedented in its Weather History

There are few sites in the U.S. (or, for that matter, the world) that have as long an unbroken period of record for precipitation measurements as the city of San Francisco. This official record extends back to November 1849. Today, January 15th, the city has now entered unchartered territory by surpassing 1916-1917 as the driest ‘wet season’ to date on record.

Map of soil moisture conditions across the U.S. as of January 13th. NOAA/NCDC.

Driest Water Years (July 1-June 30) in San Francisco history

As of January 15th, San Francisco has received a seasonal precipitation total of just 2.12”. Here is a list of the top ten driest water years (since 1849-1850) for the city:

Season to date precipitation for selected California cities

Below is a list of seasonal precipitation to date for selected California cities (arranged from north to south) with comparison to normal:

Sierra snow pack issues

The snow pack in the Sierra is currently averaging 15% of normal for this time of the year, the lowest on record. The graphics below illustrate the dire situation:

Satellite images comparing California from a year ago to today. Not only is the snow cover drastically less but also notice how brown the central valley ground cover is relative to the green of January 2013. Images from NOAA.

The graphs above show the water content of the snow pack for the northern Sierra (top), central Sierra (center) and southern Sierra (bottom). As can be seen, the snow pack water content is at its lowest on record for all three districts. Graphs from California Department of Water Resources.

What’s next?

The worst drought on record for California was that of 1975-1977. After two consecutive dry seasons, and with this season on track to become the driest on record, drought conditions could even end up worse than those of 1975-1977.

Some are surprised that an official ‘drought emergency’ has yet to be declared by Governor Brown (although he has indicated that such is likely by February 1st). One of the reasons for this is that “legally, drought means much more than no rain. It means the governor, by making the declaration of a drought emergency, may lift environmental protections that help our [SF] bay-estuary to allow water transfers to other parts of the state. A declaration doesn't create water or money. It may allow the governor to redirect certain funds, typically unspent water bond funds. Those dollars are scarce, however, with the last water bond in 2009…The question before the governor is this: Does it make economic sense to drop environmental protections to move around more water? The governor's Drought Task Force is meeting weekly but so far has made no recommendation.” (This was a quote from an editorial in the San Francisco Chronicle newspaper on January 13th).

A map of the current status of the water levels in the major state reservoirs. As can be seen the situation is worse in the northern two-thirds of the state than in the southern section. California Department of Water Resources.

A major drought in California would have nation-wide implications. California is the number one state in cash farm receipts with 11.3 percent of the U.S. total. The state accounts for 15 percent of national receipts for crops and 7.1 percent of the U.S. revenue for livestock and livestock products. California’s agricultural abundance includes more than 400 commodities. The state produces nearly half of U.S.-grown fruits, nuts and vegetables. Across the nation, U.S. consumers regularly purchase several crops produced solely in California. The state is also the nation's largest agricultural exporter. –REF: California Department of Food and Agriculture

Needless to say, all agricultural crops and livestock are dependent on a reliable and continuous water supply.

Since the rainy season in this part of the country can be extremely variable, many are assuming that the drought is bound to break soon. The area is only at the halfway point in the water season, so not to worry too much yet. However, the forecast models are so dire (for lack of any precipitation until at least February) that one might think they must be erroneous. We shall see what verifies in the weeks ahead.

P.S.-Just In: San Francisco Airport observed its warmest January day on record today, January 15th, with a 73° reading. This beats the previous monthly record of 72° set twice before (on January 13, 2009 and January 24, 1948). Records at the airport location began in 1938. Oakland Airport reached 77° and Monterey hit a stunning 83°, which would be a record for even many summer days.

Christopher C. Burt
Weather Historian

Extreme Weather Drought Precipitation Records

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

I should ask my brother about the drought situation, he lives in San Jose, CA.

Thanks for the new post and updated information. Seems like they're gonna smash that water year record if the wet season doesn't come back soon.
The agricultural production figures are sobering. Don't know what portion of agricultural water comes from snow melt, ongoing precipitation, reservoirs, or well/subsurface water. Certain crops/products may be more water intensive than others. Would be interesting to see how one would optimize water distribution to try to maintain the most agricultural state GDP.

Hopefully the pattern will change, but now is the time for contingency planning, not when produce is turning brown.
The following article is courtesy of oldnewmex, posted on my blog:

Resistance is futile: Inevitable changes to water management in California
There may be some good news for California after February 1st.

The ridge over the West Coast is forecast to build north and retrograde the last week of January. This could open the door for a split flow pattern across the NorthPac which would allow at least some disturbances to slip under the ridge and impact the West Coast.

Unfortunately, though, looking at teleconnective patterns that far ahead it would appear the main target for low tracks via the Pacific the first week of February will be near the Oregon/Washington border, with mainly northern California getting grazed by weakening frontal passages and basically little to nothing for SoCal. A slight deviation from this pattern could bring stormier times to most of California but it just doesn't appear in the cards.
You can't believe it Chris, I have arrived at Bangkok from California and it was warmer in parts of LA than in Bangkok now . I had to remove my sweater in LA and i put it on here. I am quite shocked. ;-)
The snowpack comparison images= Doom.
It's as if we are stuck on October 20: Tinder try brown hills, hazy air, warm days and chilly nights. I still think we'll get a few rain events before the "season" ends, but they'll be band-aid storms at best.
Goes to a previous blog topic but I think it is still of interest.

New all time Australian heat records set this year. From the Extreme temperatures around the world site.

Tambo (Australia) max. 44.5
Windorah (Australia) max. 48
Applethorpe (Australia) max. 37.8
Goondiwindi (Australia) max. 46.4
Surat (Australia) max. 45.7
Quilpie Airport (Australia) max. 47.1
Collarenebri (Australia) max. 48
St George (Australia) max. 47.2
Blackall (Australia) max. 45.7
Roma (Australia) max. 45.8
Mungindi (Australia) max. 48
Walgett (Australia) max. 49.1
Moree (Australia) max. 47.3
Barraba (Australia) max. 44.9
Narrabri (Australia) max. 47.8
Tamworth Airport (Australia) max. 45.1
Glen Innes (Australia) max. 37
Armidale (Australia) max. 37.1
Inverell (Australia) max. 41.9
Guyra (Australia) max. 34.4
Murrurundi (Australia) max. 41.2
Mudgee (Australia) max. 42.5
Coonabarabran (Australia) max. 44
Dunedoo (Australia) max. 45
Taroom (Australia) max. 45.3
Gympie (Australia) max. 42.4
Archerfield (Australia) max. 43.5
Why are they showing 3 Lake graphs with NO DATA! It just looks like the lakes in that region are completely DRY. At least make those graphs a different color when showing their averages, if that is even important against no data values.
To me that is a type of "map lie".

It would almost be more helpful to have an estimated reservoir capacity in days till dry, assuming continued drought consumption rates for the season.
N. California can get heavy precipitation in the spring. I recall at least a few years with very heavy rain in March or April. Even one with heavy rain in May although that is exceedingly rare. This would refill the reservoirs but won't give them the type of steady water supply that they get with a snowpack. We can always hope, but the numbers are not in their favor. I do not want to think about the fire season they will have if something does not happen soon.
There will be quite a few more names added to BaltimoreBrian's list when this week's records are included (although this week in southern Australia has been more notable for consecutive days of heat than for absolute extremes).
weatherhistorian has created a new entry.