Saturday, September 25, 2010

Happy Equilux

Yep. "Equilux". Even though it sounds like a brand of vacuum cleaner, or perhaps an advanced light bulb, it isn't.

An equilux is the day on which there's exactly (or almost exactly) 12 hours between sunrise and sunset. Equilux's occur once in the Spring (a few days before the Vernal Equinox), and once in the Fall (a few days after the Autumnal Equinox).

The exact dates of the equilux vary by latitude; for Hood River, the autumnal equilux is today. There are a number of online sunrise/sunset calculators. Probably the most official one is at the US Navy site, but the one here is quicker.

Up until recently (yesterday), I thought that the "12 hour equal day/night" thing happened exactly on the Spring and Fall equinoxes. After all, equinox means "equal night". But apparently, that's a blatant lie passed down through the ages by gullible people (me). In conclusion, all is not as it seems, buyer beware, caveat emptor, and so forth.

Furthermore, while the equilux is an actual date, an equinox isn't. It's a moment in time. Specifically,
the moment at which the center of the Sun’s disk crosses the celestial equator, which is the projection of the Earth’s equator out into space;
all explained in more detail here.

Meanwhile, speaking of projections out into space...

Friday, September 10, 2010

August 2010 Revisited

Compared to historical averages, August in Hood River was pretty much like July in Hood River. Warmer than long term averages, but cooler than recent years. It was drier than average, with (surprisingly) average August wind speeds.

At my weather station, the average temperature of 68.9° was warmer than long term averages (1897 to present) of 66.6°, but cooler than more recent (2000-2009)
averages of 70.0°. I'm surprised by my station's average temp for August, as it seemed cooler than that. Tom's Westside station, which is only a few miles away, was 1.3° degrees cooler than mine for the month. However, Nick's Underwood station's average was only 0.2° cooler than mine, so who knows. Darn micro-climates around here...

There was a 5 day "heat wave" starting on the 13th, peaking at 101° on the 16th, and a very brief hot spell on the 24/25th, with a high of 97.
The high heat index for the month was 98°, and the low wind chill was 46°.

Rain finally arrived on August 30th and 31st, breaking a 71 day dry spell. See the two previous posts for all the lurid details.

The 24 hour avg wind speed was 4.4 mph, which was exactly average for August at my station. Like the temperature average for the month, this average wind speed doesn't jive with what I expected the numbers to show, as it seemed pretty darn windy in August. However, other personal weather stations around the area showed even a lower 24 hour average wind speed, so I guess mine is valid. I think that maybe it was just that the wind hardly ever let up throughout the month, but didn't make for higher 24 hour averages. In any event, July and August were great months in the Gorge for wind sports enthusiasts!

There was 1 official local weather record set in August. On the 6th, the "high low" temperature of 67° surpassed the old record of 66° (2000).

The tabular data below is from my home weather station.
To view its August 2010 monthly summary and graphs at Weather Underground, click here.

The "historical average" numbers for temperature and rainfall are from the Hood River MCAREC data. Historical wind average is from my station's 2000 to 2009 data. Note that average wind speeds include all 24 hours of the day and night, which is why they are way lower than daytime peak winds. In addition, the wind speeds at my station are considerably lower than on the Columbia River.

HighLowAverageHistorical Average
Temperature (F) 101
Wind (mph)34

Rainfall (in)0.07

0.10 (total)

Even though August wasn't remarkably cool, at least at my station, the 2010 June through August summer period was definitely on the bluish side.

Thursday, September 9, 2010

I Was Wrong... OK??

In the previous post, regarding this summer's dry spell being perhaps some sort of record, I lied. I didn't know I was lying at the time, but that doesn't make it right, and I'm disgusted with myself, which is pretty much normal.

I finally found a way (and the time) to look back through HOXO's daily summer precipitation records, which go back to 1987. And, much to my dismay, I found a longer dry spell.

It turns out that our 71 day dry spell this summer actually tied for 2nd longest, since there was also a 71 day run back in 1994. The longest dry spell here was 85 days in 2000 (June 15 thru Sept 7).

Therefore, I apologize profusely, and I'm really, really sorry (that I got caught), and I'll try to do better next time. Please find it in your hearts to forgive me. My legal team (if I had one) said I should just come right out and say this, and that's the only reason I'm doing this humiliating post.

So yeah, go ahead and enjoy your gleeful moments of schadenfreude, and I hope you're happy.

And, now that I know that 85 days is the apparent record, I'm happy too. :)