Saturday, December 10, 2016

Rain Days

California weather fans will recall all the excitement over El Nino last year.  Would it bring desperately needed rain?  If so, to what parts of the state?  Precedents were all over the place.

This year: no El Nino, nobody cares.  Or at least cared to speculate.

But here on the North Coast (far northern CA), we've had more rain since October than in this period last year--in fact, more than twice as much.  Due to a very rainy October and a pretty rainy November, we've had 19 inches of rain from Oct. 1 to today (December 9.)  We got a touch over 9 inches last year in the same period.  October 2016 alone was the second highest on record.  By late November our reservoir was full and we were officially out of drought.

Last year we did end up with some El Nino rain later in the winter.  But even though we're a tad behind last December, it's raining now and there's rain in the forecast for the next week.  We've been spared the worst effects of the winter storms that have hit harder to our north and east, but we're getting the rain.

So what gives?  We're not looking gift rain in the mouth, but this isn't a reversion to normal patterns either.  October was early for that much rain, and the Oct. & November totals likewise.  Statistically and experientially, December and January are the big rain months.  Average for Oct.& Nov. together is 7.8, exceeded this year by more than 10 inches. But those months this year were also several inches over the combined Dec.-Jan. average.

We've had surprises in recent years--a month of rain every day followed by a bone dry winter month--but it does look like a wet winter.  And if this month and next are high we're looking at mixed blessings--including possible flooding.

So if it's not El Nino and not a reversion to normal?  It could just be weather variation. Or (or more likely, plus)...the climate crisis.   New climate crisis models show the likelihood of more high rainfall storms--a 400% increase in big storms with 70% more rain--but these are more likely on the Atlantic coast and in the Gulf states.

Still, we're having warmer temps year round now, and with the preponderance of evidence, you'd be foolish not to consider climate crisis causes for climate changes.  It is this uncertainty in specific places and times that makes some planning difficult.  But it seems likely we're at the leading edge of lasting changes. We just don't yet know exactly what some of those changes are going to be here.

Fortunately, this is California, and we can still talk about the climate crisis, and address it's causes and effects.

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