Friday, April 22, 2011

The cold spring -- or is it?

Photo: Last year's much earlier spring grass.

I have been bothered a little by the weather lately.

I have a number of projects to get done, but primarily I need to finish some fencing, to satisfy a neighbor who wants our admittedly marauding chickens off her land.

She gets free eggs and free slug control, but apparently is no longer willing to host the birds. We'll keep giving her eggs, of course. There's no reason to make a big deal about our birds. They shouldn't be over there in the first place.

But the weather hasn't cooperated with fencing, or at least it seems that way. The snow lingered late into April and the frozen ground prevented fencing. Now that the ground is thawed, massive rainstorms have moved in each weekend.

I have only two weekend days each week, and usually lose part of those to college work each time, grading or events, so a weekend rainstorm that is poorly timed can use up all my remaining time for farming.

And yes, as an official Yorkshireman I do work in the rain, but light mizzly (misty and drizzly) Yorkshire rain at 50 degrees F is a lot easier to work in than Maine's heavy spring downpours at 38 degrees F.

But at least it's not snowing. Although we did see a little snow in the air yesterday afternoon.

We're also out of hay, and so I'm buying in expensive stuff each week at $45 a round bale. It's beautiful hay, and good feed for the nursing mothers, but sheep waste a lot from any bale. I want to get them on grass as soon as possible, but the grass seems stalled.

So I wanted to know if my apprehension that the spring has been cold and the grass stalled out is actually true, and I also wanted to know if the La Nina conditions that came upon us late last fall were causing it.

I'm an experienced enough scientist by now to know that trying to decide for yourself if current weather is different than normal is fraught with difficulty, because our observational abilities are so poor, and our natural subjectivity intervenes very easily. Luckily, I keep a farm diary online, and so have dated pictures and narrative reports of weather in past years.

As for the ENSO, and in particularly the La Nina cycle, it's a very difficult phenomenon to sort out. Much complexity is involved, and there's no simple, direct connection. I do know for sure, because I've been monitoring, that the jet stream has been making the deep standing waves that are one sign of La Nina conditions. But I didn't know how strong the current La Nina index was.

So let's start with the local data. Here are the relevant farm blog posts from around this time in previous years:

Clearly, by April 25th, 2010, the grass was much further along than it is now.

In 2009, we had a dry spell at the beginning of April, and I distinctly remember this work day on the 12th April because it was so gross. The trees are bare. There was no grass until later in the month.

There isn't a clear photo of the paddocks in April 2008, but this post, on May 12th, 2008, about other signs of spring clearly shows Aimee's tomato plants, a little further along than they are now, a little later in the year. The trees in the background are just greening up, which they should be doing this year too, by May 12th.

So my own data is inconclusive, but if anything tends to make me begin to think that this weather is not particularly different than normal.

The semester is ending a week earlier, the end of the first week in May rather than the end of the second week in May, so that might be the main reason for my perception.

Most likely explanation, this is more like a normal year, while last year was warmer because of the El Nino conditions that prevailed.

As for La Nina, my favorite US science agency, NOAA, says La Nina has weakened, but effects will linger. They provide the following, recently updated discussion:

"La Niña will continue to have global impacts even as the episode weakens through the Northern Hemisphere spring. Expected La Niña impacts during April-June 2011 include suppressed convection over the west-central tropical Pacific Ocean, and enhanced convection over Indonesia. Potential impacts in the United States include an enhanced chance for below-average precipitation across much of the South, while above-average precipitation is favored for the northern Plains. An increased chance of below-average temperatures is predicted across the northern tier of the country (excluding New England). A higher possibility of above-average temperatures is favored for much of the southern half of the contiguous U.S. (see 3-month seasonal outlook released on March 17th, 2011)."

So New England shouldn't be feeling much if anything in the way of La Nina effects at this point, and summer should be about average. Of course, that meandering jet stream, until it calms down, will mean bigger then normal spring storms, and alternating cold and warm periods, but the net result shouldn't hold up spring very much more.

Good. Maybe the grass will start to grow now.

I'd like to see a nice green farm soon, like the one we had this time last year. I have some fence to build and I'm tired of shelling out extra dollars for hay.

And today's supposed to be a nice day, so that's a start.

Now I have to go eat breakfast and give the sheep another expensive bale of hay.

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