8.83 inches. That’s the total average precipitation accumulation for the state of California so far for the first four months of this year. Out of the entire climate record, this paltry accumulation is less than that received during any similar period of any year since 1895.
Overall, rainfall totals throughout the state remained below 26 percent of typical levels for this time of year. And with California entering its third year of drought, the state would have to receive an average of 53 inches between now and October, more than 10 inches of rainfall each month, to break the current and very extreme ongoing drought.
(Drought monitor color graphic of California drought as of May 6. Tan = moderate drought. Orange = severe drought. Red = extreme drought. Dark Red = exceptional drought. Image source: Drought Monitor.)
As of late April, the drought had expanded to cover every corner of the state leaving not an inch of this critical agricultural region untouched. Drought continued to intensify, bringing with it water stress, cracked soil, crashing reservoirs and heavy strains to farms, businesses, cities and individuals. By May 6, fully 77 percent of California stifled under severe or extreme drought conditions.
The drought has become so severe that water-strapped cities like Santa Cruz have resorted to the most dire measures, including rationing, to husband dwindling water supplies. Last week, the city, which depends on some of the most vulnerable and thinly-stretched water resources in the state, announced a number of severe fines to water consumers exceeding assigned usage levels. The fines could quickly double, triple, or even quadruple water costs for any non-farm water consumer within the city.
Across the State, various desperate water conservation regimes have been put in place with the Federal Government announcing earlier this year that it would be forced to stop water allocations to farmers in an unprecedented move to stave off further declines in stores.
(US Seasonal Drought Outlook. Image source: CPC.)
Unfortunately, the persistent high pressure blocking pattern off the US West Coast, which has hovered in the same region for more than a year, remains in place even as it continues to deflect rain-bearing storms north toward the Washington and Canadian coasts.
This pattern — arising from a set of abnormal atmospheric conditions including added heating through human-caused warming and a Jet Stream that has the tendency to become stuck more and more often as sea ice erodes — results in a high likelihood that drought will remain or intensify for California and much of the US Southwest throughout this summer.
Climate Prediction Center analysis, shown above, projects that the current California drought will persist or worsen for the entire state through at least July 31rst. If relief does come, it will arrive many months from now. For the most likely chance for a change in the weather doesn’t appear until fall and winter of 2014. And this potential brings with it the risk for a radical switch to yet another damaging climate extreme.
Hoping For El Nino is Like Praying to Godzilla
Yesterday’s report from NOAA indicating a near 80 percent chance of El Nino by the end of this year provided some hope for additional rainfall after what is expected to be a very dry and difficult summer. But given current atmospheric conditions, the El Nino event would have to be in the moderate-to-strong range to both overcome what is a demonically persistent blocking pattern and to deliver enough moisture to make up the severe rainfall deficit. Anything less would be too weak to cure the current drought. But something stronger may well kill the patient.
Unfortunately, there remains a substantial risk that the 2014-2015 El Nino event could be a Godzilla of a thing — a monstrous outburst of the extreme ocean heat storage of the past 16 years that Dr. Kevin Trenberth has warned could well come back to haunt us. A record high ocean heat content that is out there, lurking in the Pacific Ocean even now. And it’s the potential that this heat will hit the surface with a severity rivaling or even exceeding the epic 1998 event that should well be cause for a different kind of concern.
(Ocean heat content through 2013. Image source: Reanalysis of Global Ocean Heat Content.)
In such an instance, the onrush of heavy rains would be less a relief and more a switch from extreme drought to extreme flood. During the 1998 event more than 20 California counties were declared disaster areas due to the sudden deluge. But with human warming amping up the hydrological cycle by more than 6% and with such a large and vicious store of ocean heat waiting to be released, a severe El Nino at this stage might look more like an Arkstorm — an event which could dump many feet of rain over a period of weeks.
On the other hand, if the El Nino fizzles into only a minor event and that massive ocean heat store decides to lay in wait for another year or two or three, California is much more likely to remain locked in a continued multi-year dry pattern. So the best California could hope for is to thread an El Nino needle and receive a just-right moderate to strong El Nino. But with the current climate regime favoring extremes, the possibility for such a just-right occurrence is quite a bit lower than either the Godzilla or the fizzle.
In any case, both added heat and dryness are set to intensify over coming years and decades for California. This ongoing ratcheting is the direct result of human-caused climate change. A result that will either be bad or terrible depending on whether or not we decide to rapidly reduce and eliminate our greenhouse gas emissions.