Apr. 7th, 2015 07:08 am
ljgeoff: (Default)
We've got a El Nino brewing for the northern hemisphere autumn, which usually brings warmer and dry conditions to the Midwest. Again, as last year, no one really knows how these El Nino conditions will play out -- the jet stream is just too weird, and loss of arctic ice and polar land snow cover is throwing everything off. For me, for now, I might cut down on the tomato plants this year because watering them with city water is just too expensive. Here are some pics:

April 1, 2014

March 31, 2015

With no relief in sight for California, we're looking at a price hike in food costs. Maybe I'll plant those tomatoes anyway.
ljgeoff: (Default)
Are you ready for Sandy?

I'm sure most of the east coast folk have heard plenty, but here's a clip from Climate Central:

During the past 24 hours, the models have come into better agreement about how Sandy will interact with several unusual weather features. Those converging events include a large dip in the jet stream into the eastern U.S., a powerful subtropical jet stream moving across the southern U.S., a massive area of high pressure that will be parked over northeastern Canada and southwestern Greenland, and a storm in the Central Atlantic. These features may help steer Sandy right into the Mid-Atlantic or New England.


The high pressure area near Greenland, in particular, may act as a block (it's technically known as as a “blocking high”), which may help prevent Sandy from moving out into the open ocean. While it is not unusual to have a high pressure area in that location, its intensity is striking for this time of year. As Jason Samenow of the Capital Weather Gang wrote, the North Atlantic Oscillation, which helps measure this blocking flow, "is forecast to be three standard deviations from the average — meaning this is an exceptional situation." (my emphasis)

Recent studies have shown that blocking patterns have appeared with greater frequency and intensity in recent years, which some scientists think may be related to the loss of Arctic sea ice as a result of global warming. The 2012 sea ice melt season, which just ended one month ago, was extreme, with sea ice extent, volume, and other measures all hitting record lows. The loss of sea ice opens up large expanses of open water, which absorbs more of the incoming solar radiation and adds heat and moisture to the atmosphere, thereby helping to alter weather patterns. Exactly how weather patterns are changing as a result, however, is a subject of active research.

This is what James Hansen was writing about in Storms of My Grandchildren. And the Greenland Block isn't the only odd thing going on in the weather.

We had been heading toward a weak El Niño. Now that is fading. And that's very unusual, says Mike Halpert, deputy director of NOAA's Climate Prediction Center, "We really haven't seen it before. When we reach a certain threshold by August or September, we always proceed into El Nino," said Halpert. "It is incredibly unique in 60 years of data, which is a relatively small sample size."

The forecast for the coming winter season is up in the air. What Jeff Masters from Wunderground says in his blog:

I'm often asked by friends and neighbors what my forecast for the coming winter is, but I usually shrug and ask them to catch some woolly bear caterpillars for me so I can count their stripes and make a random forecast. Making an accurate winter forecast is very difficult, as there is too much that we don't know. I've learned to expect the unexpected and unprecedented from our weather over the past two years, so perhaps the most unexpected thing would be a very average winter for temperatures. The one portion of the winter forecast that does have a high probability of being correct, though, is the forecast of dry conditions over Texas and surrounding states. Extreme droughts tend to be self-reinforcing, by creating high pressure zones around them that tend to deflect rain-bearing low pressures systems. The unpredictable AO doesn't affect weather patterns that much over Texas, so we can expect that the fairly predictable drying La Niña influence will dominate Texas' weather this winter.

new lows

Aug. 2nd, 2012 10:08 pm
ljgeoff: (Default)
graph - arctic sea ice extent )

Neven has a good graphic up on the Arctic Sea Ice Blog.

I'm trying to picture what it will be like when we have a worse year next year; hotter, drier/wetter and more crops failing. And another year. And another. I wonder how long we can keep going.

Lake Mead is below projections, currently at 1,116 ft, which is 113 ft below full pool of 1,229 ft. This is not it's lowest level; it's lowest level was in Oct of '10. It will be interesting to see what happens there over the next couple of months.

The Ogallala Aquifer had an annual rate of ground water decline of approximately 1.4 feet per year from 1969 to 1979 to just over 0.5 feet per year from 1989 to 1999. (report) Last year it declined 2.56 ft. -- the third largest single year decline that has been measured.

Here's the current drought picture of the US:

I'm hoping that with the coming El Nino, we'll have some relief. But I keep thinking of that .89 °C per decade estimate. I can't get my head around it.


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