A New Low

[Mother Natures Son]

Mount Washington has set a new record low........-100F !https://www.mountwashington.org/experience-the-weather/higher-summit-forecast.aspx

[Rain Man]

"Has set" and "forecast" are two different things.

[chknfngrs]

Clicky linky...

[peakbagger]

Maybe for this date. When I read the link the are saying it could be record for a decade not for as long as they have records.

I have lived in the area since 1987 and realistically I have seen a couple of stretches where the temps down low were consistently in the -30 F range, it doesnt take much wind up on the summit along with temps that low or lower to get to minus 100 F. Still quite impressive.

[Tipi Walter]

I think when Kate Matrosova checked out the wind chill temps were around -100+F, or maybe that was the actual wind speeds.

I don't put much stock in wind chill numbers as they are often used by weathermen to instill greater fear in the listening audience. Just give me ambients and I'm okay.

We are having a cold snap here in the mountains of TN/NC with mt peak temps around 0F or below. A couple nights ago in the TN valley it reached around 5F on my back porch.

And so with these temps there's a sorry habit nowadays with our local weathermen to post the actual temps for 2 seconds and then show their screen of "What It Feels Like" temps for 30 seconds and these numbers are always mind blowingly low. It could be 15F but "it feels like" -10F etc.

But feels like to who? Maybe 15F feels like 40F to a black bear? Maybe 15F feels like 15F to someone accustomed to the cold. Maybe 15F feels like -30F for someone with walking pneumonia? Totally useless number in my opinion as it's too subjective.

[TexasBob]

.......I don't put much stock in wind chill numbers as they are often used by weathermen to instill greater fear in the listening audience......... And so with these temps there's a sorry habit nowadays with our local weathermen to post the actual temps for 2 seconds and then show their screen of "What It Feels Like" temps for 30 seconds and these numbers are always mind blowingly low. ........

I hear you. Most local TV weather forecasts suck these days.

[devoidapop]

They never factor in the sun for that "feels like" temp. Just like the wind somehow doesn't affect the heat index.

[Deadeye]

minus 100 wind chill is meaningless. at that point, nobody is outside to see what it "feels like", even the folks that live/work on top of Mt. Washington. ambient temp is what matters to the record books

[Hatchet_1697]

...it’s getting pretty cold up there, I wonder if it will hit -100 (wind chill)

https://uploads.tapatalk-cdn.com/20180106/5034e63a6c34b8ec38c0c8303676d94a.jpg


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[Slo-go'en]

-45 + 60 MPH wind = -98 wind chill, according to a NWS wind chill chart. -100 would literally "be off the chart".

[Traveler]

They never factor in the sun for that "feels like" temp. Just like the wind somehow doesn't affect the heat index.
That would be the "heat index" which measures the effects of heat on the body, much as windchill does. Both indexes are helpful for determining exposure levels and how to mitigate them.

[cmoulder]

While I agree that the wind chill number is favored by TV weather people for its sensationalism, it is true that wind transports heat away even faster (and faster) and is definitely a factor. Once acclimating to cold, -20°F with no wind can be quite comfortable with surprisingly light clothing.

But frequently I too find myself growling at the TV fear-mongers, saying "What's the damn actual temp, fer cryin' out loud?!" :mad:

[FrogLevel]

We are having a cold snap here in the mountains of TN/NC with mt peak temps around 0F or below. A couple nights ago in the TN valley it reached around 5F on my back porch.
.

It's 4 right now in Johnson City. I just wish we had some snow to make it a bit more enjoyable.

[blw2]

I agree.... I really get irritated with the "feels like" temperatures.
32F, feels like 26F......uh..... NO.... it feels like 32F with a 6MPH wind and 59% humidity. THAT is what it is, and that is what if FEELS like.
I feel like it only dumbs us down so we are loosing touch with what 32F feels like.

I also agree about the TV news. They never show surface analysis charts and prognosis charts anymore. Don't they know that a picture is worth a thousand words?
and yeah, I know...most folks don't know how to read them...but of course they don't because they never see them!

[Tipi Walter]

That would be the "heat index" which measures the effects of heat on the body, much as windchill does. Both indexes are helpful for determining exposure levels and how to mitigate them.


While I agree that the wind chill number is favored by TV weather people for its sensationalism, it is true that wind transports heat away even faster (and faster) and is definitely a factor. Once acclimating to cold, -20°F with no wind can be quite comfortable with surprisingly light clothing.

But frequently I too find myself growling at the TV fear-mongers, saying "What's the damn actual temp, fer cryin' out loud?!" :mad:

Maybe you guys could help me with a weather related question.

If our bodies are at 98.6F, why does a summer day in East Tennessee feel so hot and crappy when it's 100F??????????????????? Both numbers are almost identical, so why wouldn't 100F feel perfect????

[egilbe]

Our bodies try to cool off when it gets that hot. It uses evaporative cooling using sweat. The higher the relative humidity, the slower sweat evaporates, the harder it is to cool off. We are naturally accustomed to be naked at ~ 84*. At 100*, our bodies are really struggling to cool off and for modesty reasons we are wearing clothing. We are dumping moisture on the surface of our skin to cool off, but it doesn't evaporate quickly enough to cool us, especially in high energy outputs like climbing or hiking.

[blw2]

I'm no doctor or medical expert....but I believe that our bodies generate more heat than we need at any given exertion level, so we are designed to generate more heat and dump it to atmosphere....warm blooded. It's our design. When it gets hotter, we can't speed our metabolism to keep up.
cold blooded creatures on the other hand are set up to acclimate to whatever the ambient temperature is....so if we were cold blooded, our happiest condition would be an ambient of 98.6F when at rest. Warmer than that we'd just speed up to keep up, and colder we'd slow down....
but since our design is what it is, when ambient temps get to near 98.6F or more, we can't dump our excess..... and our bodies can't adjust to the higher state.
Again, just my theory....

[blw2]

Our bodies try to cool off when it gets that hot. It uses evaporative cooling using sweat. The higher the relative humidity, the slower sweat evaporates, the harder it is to cool off. We are naturally accustomed to be naked at ~ 84*. At 100*, our bodies are really struggling to cool off and for modesty reasons we are wearing clothing. We are dumping moisture on the surface of our skin to cool off, but it doesn't evaporate quickly enough to cool us, especially in high energy outputs like climbing or hiking.

That 84F number is interesting, and interesting to think about the point at which we tend to be comfortable. Seems about right to me I suppose. Did you get that number form someplace or is it your anecdotal idea of where it is?

I find it interesting relating back to other recent threads about sleep system ratings
and the apparent baseline of 70 degrees used in those ratings. It seems like the rating are based on 70F being the temp at which we would want to sleep naked..... but 70F isn't my number.....I'd guess more like 80ish...so maybe about 84, depending on humidity....
I'm still searching to understand why they seem to use 70F.....

[cmoulder]

Yes, even at rest our bodies burn 5-6 kcal of energy per minute just to maintain basic function, which of course produces waste heat.

Moderate aerobic exercise brings the burn rate up to 10-11 kcal per minute. Evaporative cooling from the skin cannot keep up at 100°F even with low relative humidity. With high relative humidity — East TN! — better to take a swim or a long siesta!

My favorite weather tool is the satellite water vapor loop (https://www.accuweather.com/en/us/northeast-region/satellite-wv?play=1). A lot of info packed into a few frames.

[TexasBob]

....I also agree about the TV news. They never show surface analysis charts and prognosis charts anymore. Don't they know that a picture is worth a thousand words?.....and yeah, I know...most folks don't know how to read them...but of course they don't because they never see them!

Exactly right. I grew up watching real weathermen on TV like Harold Taft on WBAP who actually where meterologists. They explained to viewers the why behind the weather and didn't just give a forecast.

[Tipi Walter]

Our bodies try to cool off when it gets that hot. It uses evaporative cooling using sweat. The higher the relative humidity, the slower sweat evaporates, the harder it is to cool off. We are naturally accustomed to be naked at ~ 84*. At 100*, our bodies are really struggling to cool off and for modesty reasons we are wearing clothing. We are dumping moisture on the surface of our skin to cool off, but it doesn't evaporate quickly enough to cool us, especially in high energy outputs like climbing or hiking.

I still don't quite understand. If our body temp is close to 100F, why does it need to cool off when outside temps are 100F?? it seems like both numbers are perfectly in balance. Why does a 98.6F body need to cool off in let's say 98.6F temperatures?? I'm an idiot, flunked algebra and geometry in high school . . .

Maybe our core and hearts are at 98.6F and our arms and legs and heads and skin tissue are at lower temps and likes these temps better, i.e. around 84F or 72F etc. Sorry for the thread drift. Let's get back to freezing to death at one hundred below.


I'm no doctor or medical expert....but I believe that our bodies generate more heat than we need at any given exertion level, so we are designed to generate more heat and dump it to atmosphere....warm blooded. It's our design. When it gets hotter, we can't speed our metabolism to keep up.
cold blooded creatures on the other hand are set up to acclimate to whatever the ambient temperature is....so if we were cold blooded, our happiest condition would be an ambient of 98.6F when at rest. Warmer than that we'd just speed up to keep up, and colder we'd slow down....
but since our design is what it is, when ambient temps get to near 98.6F or more, we can't dump our excess..... and our bodies can't adjust to the higher state.
Again, just my theory....

Good stuff.

[4eyedbuzzard]

I still don't quite understand. If our body temp is close to 100F, why does it need to cool off when outside temps are 100F?? it seems like both numbers are perfectly in balance. Why does a 98.6F body need to cool off in let's say 98.6F temperatures?? I'm an idiot, flunked algebra and geometry in high school . . .

Maybe our core and hearts are at 98.6F and our arms and legs and heads and skin tissue are at lower temps and likes these temps better, i.e. around 84F or 72F etc.Your body regulates its "normal" temperature between 97.7° to 99.5°F only because it is always constantly cooling off when ambient conditions are warm (capillary dilation, perspiration, elevated heart-rate, fast breathing); or trying to conserve and even create more heat when the ambient conditions are really cold - hence shivering ( blood flow reduced to skin surfaces and extremities, etc.) Your body produces a lot of excess heat energy - if you were to completely stop evaporation (sweat) and convective (circulating air) heat losses from removing heat from your body by way of say a vapor barrier and lots of insulation to prevent heat transfer to the atmosphere, you would quickly overheat just from the energy created while resting. Hyperthermia results when body temp hits 104°F. At 106° you're in the potential brain and organ damage area, and death is pretty certain at 113°.

An analogy would be an auto engine running at a colder than normal automobile temperature. Now normally, an uncooled/unregulated auto engine will produce very high temps, (over 400° at the exhaust valves). But let's say we get a thermostat set at 98°F and run the engine at that temperature. On a cool day, say 50°F, the thermostat would stay closed until the engine temp got to 98°, then it would open and allow coolant to flow through engine and the radiator, where air would blow over it, cool the fluid, and indirectly the engine, keeping it purring along at 98°. But if the outside temp approached 98°, there would be no way to keep the engine at 98°, even with the thermostat wide open. But, if we could spray water on it, we could add the effects of evaporative cooling and maintain that happy 98° temperature even with temps above 100° (like a swamp cooler).

Your body is a bit like this engine (parts of it run pretty warm relatively, like the exhaust valves in the car), and it produces a lot of heat even when it's just idling. Your body uses both convective (radiator/skin) and evaporative (sweat) to varying degrees. When it's cold, your capillaries constrict (reduces blood/coolant) flow to the radiator (skin). When its warm it opens them up. When it's hot, it adds evaporative cooling (sweat). When it gets beyond certain "operating" limits, you have to help it - by adding insulation, or helping it cool off (reduce activity, seek shade, take a dip).


Sorry for the thread drift. Let's get back to freezing to death at one hundred below. Good stuff.

Inre the wind chill stuff. The science behind wind chill is how the RATE of heat loss increases due to convection / wind. For example if it is 15°F and the wind is 15 mph, the perceived rate of heat loss on EXPOSED skin will be the same as if it were 0°F with no wind. The skin will actually freeze faster because the rate of heat loss increases with the number of air molecules passing over the warm body and carrying that heat away (because it's windy). It's not meaningless junk. As anyone who has spent time in the cold will attest, increased wind speed freezes exposed skin much faster than still conditions. Increased wind and lower wind chills require greater attention to the amount and types of layers people need - both insulating and wind resistant. Yes, it's an imaginary number in the sense that it never gets colder than the ACTUAL temperature - but not only do you feel colder - you actually freeze faster as well. Wind chill is how we quantify that "not just cold but windy too" quality.

[illabelle]

...Inre the wind chill stuff. The science behind wind chill is how the RATE of heat loss increases due to convection / wind. For example if it is 15°F and the wind is 15 mph, the perceived rate of heat loss on EXPOSED skin will be the same as if it were 0°F with no wind. The skin will actually freeze faster because the rate of heat loss increases with the number of air molecules passing over the warm body and carrying that heat away (because it's windy). It's not meaningless junk. As anyone who has spent time in the cold will attest, increased wind speed freezes exposed skin much faster than still conditions. Increased wind and lower wind chills require greater attention to the amount and types of layers people need - both insulating and wind resistant. Yes, it's an imaginary number in the sense that it never gets colder than the ACTUAL temperature - but not only do you feel colder - you actually freeze faster as well. Wind chill is how we quantify that "not just cold but windy too" quality.
So if it's 40° with a stiff breeze, will things freeze?

[Traveler]

So if it's 40° with a stiff breeze, will things freeze?
Water won't, but your body will be stripped of heat much faster than if it were calm outside, leading to other problems if you are not properly prepared.

Windchill effect is especially useful in winter as a time to frostbite indicator. Recently here the temperature was -7 degrees, with a light 10 mph breeze effectively reducing temperature to about -25, which at that level skin will freeze in approximately 30 minutes. With a wind of around 20 mph, it changes the effective temperature to about -35 degrees and skin will freeze in approximately 10 minutes. At -50 degrees, exposed skin freezes in about 5 minutes. This is dangerous weather.

I am not sure why people are dismissive of windchill information as being "hype" by weather forecasters and not understood. However this is important information and people who are outside in cold weather climates for long periods of time pay attention to this number. It provides a good indication of how you should dress depending on how long you plan on being out. Frostbite can be difficult to self assess. There are some warning signs but one has to be attentive to them, you won't feel your skin freezing.

[blw2]

I'm not dismissive of it as hype..... no not at all. I know it's a real concept and a real calculated number
but
it's not really a measurable thing.... and it's misleading. There's no real way to use the information to relate to a clothing system.
By presenting only the wind chill....or the "feels like"..... they are dumbing us down. We no longer know what it feels like at any given 'actual' temperature/humidity/wind condition.

4eyedbuzzard, very nice write up.
Your post makes me wonder........ what temperature would a human body stabilize at if placed in a theoretically perfect insulation chamber, at rest, with no way for heat to transfer away and discounting organ damage, death...etc?.... Would a body just keep generating more and more heat? Like tipiwalter was saying earlier, intuition may make it seem that at some point it would find equilibrium.....but I suppose no.

[egilbe]

I'm not dismissive of it as hype..... no not at all. I know it's a real concept and a real calculated number
but
it's not really a measurable thing.... and it's misleading. There's no real way to use the information to relate to a clothing system.
By presenting only the wind chill....or the "feels like"..... they are dumbing us down. We no longer know what it feels like at any given 'actual' temperature/humidity/wind condition.

4eyedbuzzard, very nice write up.
Your post makes me wonder........ what temperature would a human body stabilize at if placed in a theoretically perfect insulation chamber, at rest, with no way for heat to transfer away and discounting organ damage, death...etc?.... Would a body just keep generating more and more heat? Like tipiwalter was saying earlier, intuition may make it seem that at some point it would find equilibrium.....but I suppose no.

If there was no way to get rid of waste heat. You would overheat and die. Your skin is the largest organ in your body. It regulates body temperature. It's one of the reasons widespread burns are so dangerous. Sunburn can lead to heatstroke because it damages the skin layer that transfers heat away from the body.

[Leo L.]

A human body generates approx. 100 Watt of energy while ideling. When ideling, almost all of this energy goes into warmth.
The body has to get rid of this warmth, otherwise it would heat up slowly and would fail at approx. 42°C core temperature.
If you were situated inside a totally and perfectly isolated chamber, give you had a sufficent supply of Oxygen which would not influence the heat flow, thats exactly what would happen: You'd die at 42-44°C.
Would take some time though. Not a nice way to die.

As to the true temperature vs. windchill, there is much more to this when being outside.
Humidity plays a big role, and the wind changes every few meters under common hiking conditions (under trees vs. open landscape etc.). It also makes a huge difference whether the wind attacks you from the back or blows against your face. And in the mountains there might be pools of really stiff cold air in places, and a warm breeze in others, sometimes only some 100 meters apart.

Personally I'm not a big fan of mentioning windchill temps more prominent than the real temps. I rather prefer knowing the real temperatures and would estimate the windchill myself.

[Venchka]

As of 9am Saturday, January 6, 2018:
Boone, NC, elevation ~3,300', recorded 170 hours below freezing.
The AT through the Roan Highlands is nearby and considerably higher.
New England doesn't get all of the cold air.
Wayne

[egilbe]

As of 9am Saturday, January 6, 2018:
Boone, NC, elevation ~3,300', recorded 170 hours below freezing.
The AT through the Roan Highlands is nearby and considerably higher.
New England doesn't get all of the cold air.
Wayne

No, but we get it first :p and we warm it up for those fragile Southerners ;-)

[Venchka]

No, but we get it first :p and we warm it up for those fragile Southerners ;-)
Y’all never will change. Our cousins to the North sent it your way. 😃😎
I also saw an awesome photo of ice climbers on Linville Falls.
Wayne

[egilbe]

Ice climbers are a special kind of nuts

[Venchka]

Ice climbers are a special kind of nuts
Amen! I’m totally envious!
Wayne

[nsherry61]

No, but we get it first :p and we warm it up for those fragile Southerners ;-)
Yeah, generally, but apparently not this time around. Drove down south from NH earlier in the week and drove from nice weather into that damn blizzard and to 12 inches of new snow at my house south of Boston.

[Carbo]

Temp is all the way up to 20 F here at the Jersey shore! Think I'll sleep with the window open tonight!

[Pony]

it was -9 in Ohio last night. In my opinion anything below 20 is just ridiculous.

[fiddlehead]

4eyedbuzzard's got it right. IMO
Wind chill is how it feels on EXPOSED skin.
40 years ago (or so) when they started that wind chill stuff, they would explain that.
Now, I guess they take it for granted that we know.

I say you get used to what environment you are in.
When I lived and worked (outside) through the winter of 1989-90 in northern Maine (Sugarloaf), I thought it was warm when it was above freezing.
Now, I live 7 deg. north of the equator, and 28C is my normal (that's 82F)
That's what I set the aircon on and consider it perfect.
Of course, it took me a few years to be comfortable at that temp.

If I was in northern NH or Maine now, with these temps, I'd have a neck gaiter, and goggles, and big (Russian type) hat.
As well as LL Bean boots and a couple pair of fleece socks on.
I my older age, I'd probably still be cold.
But it wouldn't be from the wind chill.
I'd have that **** covered.