There's an old saying that you can't fool Mother Nature. She's in control when it comes to the weather, particularly precipitation patterns we depend on for growing our crops and forests.
So last spring, when long-range weather forecasters began reading a massive shift in Pacific Ocean temperatures along the equator, we got nervous even as much of California received significant rainfall. Those sea surface temperatures seem to be the engine driving massive climate systems up and down the coast -- and in fact around much of the globe in the Northern Hemisphere. For example, there's a relationship between the intensity of Atlantic hurricanes and cool water halfway around the world in the Pacific Ocean.
There's no question now. The cold water displaced warm water on a grand scale, and we've gone from El NiÃ±o to La NiÃ±a in four short months. Last winter was relatively dry in the Pacific Northwest. California got drenched with repeated storms. Most recent La NiÃ±a events that extend into the winter bring the exact reverse -- wet in the north, dry in the south.
That's exactly what the National Weather Service predicts for this winter in the outlook issued Aug. 19. The wrinkle this year appears to be an extension of the heavy winter precipitation to far Northwestern California and into almost all of Idaho and a bit of far northern Nevada. In the Northwest, that could set the scene for local flooding and deep mountain snowpacks.
For California, which didn't get its reservoirs refilled by the deluges of 2010 -- the state was coming off three drought years -- it's right back to below-normal precipitation this winter. Mother Nature won't be denied.
The Golden State, a long way from reworking a regional water storage and distribution system that's plagued by environmental lawsuits and a thirsty population, appears headed back into drought.
The other part of our Western water cycles is the seasonal pattern: Rain or snow from November through late March, and little or no precipitation for at least six of the next seven months. Without reservoir storage, a winter snowpack or recharging of groundwater, the reality is inadequate growing season water for all but the most drought-tolerant crops.
If there's a glimmer of hope, it's that the jury is still out among long-range forecasters on how long La NiÃ±a will persist. Most computer models run through last week had the condition remaining strong at least into early 2011. If the cold water in the eastern Pacific moderates, that could bring a bit of normal spring precipitation to California.
Ready or not, Mother Nature is serving up the conditions in which we will operate next year, and those we will cope with this winter.