Tuesday, December 3, 2019

Local Weather Observations

One of the hobbies I've acquired over the last 15 years has been the weather. "It All Started When...." I went to work for Boeing on the Sea Launch program, and one of my job responsibilities was to maintain the Weather Monitoring and Recording System and the Weather Radar System. As a kid growing up in Northern Illinois, I remember the little "Weather Station" my Dad had. Very simple thing, just a barometer for local air pressure, a thermometer for local temperature, and a hygrometer for local humidity.

It was an Airguide unit like this:



Some years later, he gave me one of these that I had for many, many years:



So I had a fairly basic idea of weather in general, which got much more detailed when I took flying lessons, and was formally taught "WEATHER!" in ground school. We got a pretty good education in weather, obviously geared towards flying, but we got to learn how to read the charts, read the forecast, and make an informed decision on whether to fly or stay on the ground.

In 1982 I moved to Southern California, where the weather is pretty boring compared to Illinois and now Colorado, so my weather skills kinda got archived.

In 2004 I went to work for Boeing, and woke those skills back up as part of my job duties. Working with the Meteorologists was very educational, and in short order I had a weather station set up at my apartment, and connected to the Internet so I could watch the (boring) weather back in SoCal while we were out to sea.

I brought those skills with me in retirement, and now have my own "Weather Monitoring and Recording System" here at home, which occasionally shows some interesting things, like what happened here last night:



Look at the Outside Temperature and Humidity graphs, right at midnight.

The temperature shot up about 25*, from 25* to 50*, in less than an hour, with a corresponding drop in Relative Humidity.

At midnight.

With no "unusual" barometric activity.

This had me scratching my head for a while until I noticed the wind data. The winds kicked up approx 1MPH to 4MPH, with gusts to 15~20MPH, and the vector (direction and velocity) indicates they're coming from a West to Northwest direction, from down out of the mountains.

Reading the Forecast Discussion for today shows mention of Downslope Winds, known as "Santa Ana" winds in SoCal, and "Chinooks" here in the Rockies.

And it looks like I caught one coming through.

No boring weather here!

14 comments:

  1. It's cold tonight in AZ with snow expected tonight, and tomorrow. Not a lot on the ground. Just enough to be annoying.

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    1. Yep. I watch the weather down there daily.

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  2. Front Range weather can get bizarre. Almost every afternoon mountain waves in places making for strong updrafts and downdrafts. In the summer combine that with thermals and you get epic thunderstorms with tops over 70,000'. Weld County to your East has more tornadoes than any county in the country. Summer/fall we can expect "Albuquerque Lows" which bring moisture from the Gulf, stall against the Front Range, and flood the slot canyons. At anytime we can get downslope flows (Chinooks). You don't like Front Range Weather? Wait a day, it will change.

    Mountain waves. One time I was going East over Corona Pass in a C-182. At idle power, 70 mph indicated, and 30° flaps, saw an 1800 foot per minute climb. Spit us out at around 18,000' from 11,000'. Good thing I'm a Rocky Mountain lad or hypoxia would have been a rapid problem. Soon, same configuration, we were descending 1,200 foot per minute.

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    1. Yes, I've seen the big thunderstorms East of here and immediately thought "Somebody's getting hammered". One of the times we were out here visiting, we came out of the kid's place in Bellvue, and I saw the thunderheads to the East. I told my wife as we started the car that it was "pretty severe", and as soon as the car radio came on we heard the weather alert squawking in the speaker.

      I don't mind the weather a bit. Watching and learning to local weather gives me something to do, and helps me learn the geography here. I finally understand what the Palmer Divide is, and I'm still working on the Colorado Piedmont.

      I'll bet some of the glider pilots at the Owl Canyon Gliderport have some good stories to tell!

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  3. Weather is always interesting in 'some' places... :-D

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    1. And it's nice to make educated guesses about it so you can be prepared!

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  4. Interesting info, thanks for sharing. I don't have a weather station, just bumble along with watching the sky and feeling from years on the ranch.

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    1. My knees are pretty good "weather stations" these days!

      And they're (somewhat) portable.

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  5. The temperature went from ~28 to 48 in a half hour? That would feel pretty outrageous if you were outside in it.

    I need to ponder (read about) conditions that force hot air to sink instead of rise.

    I've been thinking of putting in one of those weather stations that can be networked, but the neighborhood has so many trees that I don't see where I could get a good, fair, wind measurement.

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    1. It heats up as it comes down the slopes because of compression. Pretty common in mountainous areas.

      I spent several days looking for a place to site the instrument package. I found the least obstructed area and mounted the wind instruments on two sections of mast bolted to the top fence rail. It's in the clear as well as it can be. The only 'better' place would be up on the roof, and that's not gonna happen.

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  6. The weather does all kinds of interesting stuff in the middle of the night when no one is looking. We get those zero-dark micro-Chinooks fairly regularly in this neck of the woods. One thing that I find fascinating is the way mid-Pacific sea temps and co-located air pressure gradients seem to be so highly correlated with weather patterns across North America. It's fun not being a knowitall and therefore having permission to learn cool stuff.

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    1. I've seen the effect once or twice before in the six months I've had the weather station on-line, but this is the first time I read the forecast, which explained it.

      I've seen the temperature DROP something like 60 degrees in 24 hours, but this was the first time it caught my eye for a rapid temperature increase, at night, with no apparent change in the barometer.

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  7. Mountains shape & shift the weather patterns. There are so many mountains here, where six ranges converge on this part of the state, that there's a different weather system around every sweeping turn. BTW, ° = [Alt]248.

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    1. I keep trying to use the correct symbol for degrees, but this Linux system doesn't like the keyboard combination. Or maybe Firefox doesn't like it.

      Even in SoCal we had local weather patterns that made forecasting difficult. Catalina Island could cause a front coming in to shift, and either miss us, or dump on us.

      But nothing like here, or in Alaska. Sometimes the winds will hook around the Rockies, and come wailing down from the North, and sometimes they don't.

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Keep it civil, please....