Dependable Erection

Tuesday, October 23, 2007

Forecast

# Tonight: Partly cloudy skies this evening. A few showers developing late. Low near 70F. Winds S at 10 to 20 mph. Chance of rain 30%.
Tomorrow: Showers and thundershowers likely. Warm. High 82F. Winds S at 5 to 10 mph. Chance of rain 60%. Rainfall near a quarter of an inch.
Tomorrow night: Showers likely and possibly a thunderstorm during the evening, then some lingering showers still possible overnight. Low near 60F. SE winds shifting to NE at 10 to 15 mph. Chance of rain 60%. Rainfall near a half an inch.
Thursday: Cloudy with occasional rain showers. High around 65F. Winds NE at 10 to 20 mph. Chance of rain 50%.

More promising than it's been for quite some time. A couple of days of rain would be plenty helpful, and might save my fall cabbage crop.

UPDATE: If i'm reading the current forecast correctly, we could be in for as much as 4 inches of rain over the next two days. We're at a deficit for the year of about 10 inches, so this will go a long way to helping if it in fact comes to pass. Normal rainfall for the whole month of October is somewhat under 3 inches.

I had a brief conversation in the comments at Kevin's place last week about rainfall and California, among other things. If you look at a precipitation chart for NC, you'll see that historically the Piedmont averages about 45 inches of rain a year, and it's fairly well distributed throughout the year. (Rougly 4" during the wettest summer months, and 2.9" in the dryer fall months.)

Compare to California where most of the rain falls in the mountainous eastern part of the state, and most of that between November and March. Add in the snowmelt releasing large amounts of water in a very short period of time, and you can understand why it's been necessary for California to develop an extensive series of reservoirs and aqueducts to capture pretty much every bit of precipitation that falls in the state and control its movement between the mountains and the ocean. One below normal rainy season and the state is essentially going two years without rain. So the reservoirs, when full, usually have enough water for 3 years or so.

In NC, where we are used to a fairly steady supply of rainwater, our reservoirs usually top out at about 9 months capacity, and they tend to be smaller and local, with no mechanisms in place for diverting water from one part of the state to another. If it turns out that our current drought is an anomaly, and we return to a more historically normal pattern of ranfall over the next year or two, that'll probably be sufficient.

But what if we're looking at something more than that? In the past 5 years this is the second summer where rainfall has been essentially non-existent. If long term weather patterns are changing (and it doesn't really matter for this discussion what the proximate cause of this would be if it is the case) the whole water storage system for NC, and the entire southeast, actually, is going to have to be rethought and re-engineered, as well as the entire philosophy of development in the region. Water may turn out to be a much more limiting resource than energy supplies in the long, and even the near term. One reason why it's so disappointing to read news items like this one, and see that water supplies aren't even on the agenda.

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