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-   -   Stormy weather (https://www.mersenneforum.org/showthread.php?t=24629)

pinhodecarlos 2021-02-07 11:45

Last time it did snow a lot in my birth city back in the 80’s, between 1983-1986. Can’t precise, but it was wonderful. I couldn’t even make a snowman.

Nick 2021-02-07 14:22

You know it's a blizzard when the auto-focus on your camera can't find anything to latch on to and just keeps cycling!

Dr Sardonicus 2021-02-07 16:16

[QUOTE=Uncwilly;571006]Should not severe winter weather have colours like deep blue, blue, and purple? Red should be for hot, just like it it used to show temps on the maps normally.[/QUOTE]It's a completely different system. Light green is "no warnings." Dark green is a "weather notice" or advisory. Yellow corresponds to a "watch" here in the USA - conditions are favorable for severe weather to develop, so be prepared. The other colors are "warnings" - severe weather is actually occurring. Orange is a possibly strong storm, red a strong storm, and violet an extremely strong storm. Symbols for the [i]type[/i] of bad weather are overlaid. Right now the red, violet and most of the orange areas for Germany indicate heavy snow. The dark green advisory areas north and south of the snowstorm warnings indicate slippery, icy roads. The orange area north and west indicates "storm/hurricane."

At least one local TV weather forecast uses a similar color scheme for the likely "degree of impact" of a forecast "weather event."

Right now it's bitter cold. Last I checked, the temperature was near zero F (-17.8 C). We got a little light, fluffy snow last night, the kind that's easier to broom than to shovel while it's still cold. Some people blow this kind of snow away with a leaf blower.

BTW I've heard that Fahrenheit set zero on his temperature scale at the lowest temperature where salt can melt ice.

xilman 2021-02-07 16:29

[QUOTE=Dr Sardonicus;571091]BTW I've heard that Fahrenheit set zero on his temperature scale at the lowest temperature where salt can melt ice.[/QUOTE]That is what I heard too. The other end of the scale, 100F, is human body temperature.

Yes, I am well aware that the latter is generally taken to be 98.4F these days, but his thermometers were not as accurate as ours are.

ATH 2021-02-07 17:22

[QUOTE=Dr Sardonicus;571091]BTW I've heard that Fahrenheit set zero on his temperature scale at the lowest temperature where salt can melt ice.[/QUOTE]

The highest concentration of [URL="https://en.wikipedia.org/wiki/Saline_water"]Saline water[/URL] at 26% salt can keep water from freezing down to -19.18 C = -2.524 F

For a while I kept a bag of 1-2 liter of 26% saline water in my freezer, it was liquid at the -18 C we use in freezers.
If you wrap -18 C water around your beverage or whatever you want cooled, it gets cold really fast due to waters high specific heat capacity.

xilman 2021-02-07 17:33

[QUOTE=ATH;571093]The highest concentration of [URL="https://en.wikipedia.org/wiki/Saline_water"]Saline water[/URL] at 26% salt can keep water from freezing down to -19.18 C = -2.524 F

For a while I kept a bag of 1-2 liter of 26% saline water in my freezer, it was liquid at the -18 C we use in freezers.
If you wrap -18 C water around your beverage or whatever you want cooled, it gets cold really fast due to waters high specific heat capacity.[/QUOTE]Good advice, of which I wasn't previously aware. Thanks!

Vodka needs to be drunk at seriously sub-zero temperatures, which is why we keep ours in the freezer. We have a jacket which is kept in the freezer and whichs contains some viscous substance, identity otherwise unknown, to put over bottles left out for convenient access. Your suggestion gives us an additional alternative.

storm5510 2021-02-07 17:36

[QUOTE=Dr Sardonicus;571091]...Right now it's bitter cold. Last I checked, the temperature was near zero F (-17.8 C). We got a little light, fluffy snow last night, the kind that's easier to broom than to shovel while it's still cold. Some people blow this kind of snow away with a leaf blower.

BTW I've heard that Fahrenheit set zero on his temperature scale at the lowest temperature where salt can melt ice.[/QUOTE]

That's an interesting notation about salt. I haven't seen plain road salt used here in the U.S. for a really long time. Highway departments have a substance they spray on the roads with a straight-axle tanker before snow is expected to fall. It's easy to see after it's been sprayed. Five stripes in each lane about 3 inches wide each, evenly spaced. I don't know what it is they spray. I've only heard it referred to as "carbide." I imagine it would be really hard on a car body if not washed off. Back when road salt was used, it was stated that it would keep a road surface melted down to 20°F, (-6°C, or there about)

I've had my share of bitter cold in the past. Three weeks after my son was born in 1985, it was -24°F on a Sunday morning. The coldest I've personally experienced outside was -16°F in 2014. I drove my pickup-truck that day. The popping and cracking sounds the body made at is flexed were quite remarkable.

xilman 2021-02-07 17:39

[QUOTE=xilman;571094]Vodka needs to be drunk at seriously sub-zero temperatures, which is why we keep ours in the freezer.[/QUOTE]Is buffalo grass vodka, aka bison grass vodka, readily available in the US?

Just poured myself a dose, at -18C of course, prompted by your post.

ATH 2021-02-07 18:02

[QUOTE=xilman;571094]Good advice, of which I wasn't previously aware. Thanks!

Vodka needs to be drunk at seriously sub-zero temperatures, which is why we keep ours in the freezer. We have a jacket which is kept in the freezer and whichs contains some viscous substance, identity otherwise unknown, to put over bottles left out for convenient access. Your suggestion gives us an additional alternative.[/QUOTE]

Of course it is not super fast like using dry ice but a lot faster than just putting the beverage in the freezer. Fast enough so you do not want to forget it for very long, if it is something that can freeze and shouldn't.

I washed one of those very study 3 liter plastic bags you can buy windshield washer fluid in for the car. I could have used the original windshield washer fluid which was liquid down to -21C, but I did not want it in my freezer in case it should leak, so saline water seemed better.



Edit: The best saline water is actually 23.3% salt by weight, not 26%. It was a while ago I did it: [url]https://en.wikipedia.org/wiki/Brine[/url]

[QUOTE]The lowest freezing point obtainable for NaCl brine is −21.1 °C (−6.0 °F) at the concentration of 23.3% NaCl by weight.[4] This is called the eutectic point.[/QUOTE]

Dr Sardonicus 2021-02-07 18:32

[QUOTE=storm5510;571095]<snip>
I haven't seen plain road salt used here in the U.S. for a really long time. Highway departments have a substance they spray on the roads with a straight-axle tanker before snow is expected to fall. It's easy to see after it's been sprayed. Five stripes in each lane about 3 inches wide each, evenly spaced. I don't know what it is they spray. I've only heard it referred to as "carbide." I imagine it would be really hard on a car body if not washed off. Back when road salt was used, it was stated that it would keep a road surface melted down to 20°F, (-6°C, or there about)
<snip>[/quote]I have heard of brines of various [i]chlorides[/i] used to prevent icing - sodium chloride, calcium chloride, and magnesium chloride. All are bad for the metal in motor vehicles, bad for trees and other plants along the roads, and I've heard stories that they're also bad for overhead power lines along roadways. The problem seems to be that when it's dry, salt dust gets airborne due to traffic, and is deposited on wires, insulators, and poles. A bit of moisture later on provides an electrical path from the wires to ground. Some of the stories I've heard were to the effect that after certain stretches of highway started getting pre-treated against icing, there were suddenly a lot of shorts to ground and/or wooden power poles catching fire along those stretches.

There is a treatment put [i]on top[/i] of packed snow and ice on roads called "antiskid." It's something like very coarse sand, possibly with a little salt mixed in. It provides traction on top of packed snow or ice, but whatever hasn't already wound up off the road clogging the storm drains etc has to be cleaned off the pavement later on.

xilman 2021-02-07 18:56

[QUOTE=Dr Sardonicus;571102]There is a treatment put [i]on top[/i] of packed snow and ice on roads called "antiskid." It's something like very coarse sand, possibly with a little salt mixed in.[/QUOTE]Pretty much, perhaps identical, to what they use in the UK, though generally used ahead of snowfall as well as afterwards.

Works well here.


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