What's the difference between snow grains and graupel?

[Len Wood]

I reckon we have showers of graupel here atm but others may report it as snow grains.

Len
Wembury

[Stephen Davenport]

Snow grains are tiny and precipitate from stratus or fog - like a frozen drizzle. Graupel, (aka "snow pellets" aka "soft hail") forms when snowflakes meet super-cooled water droplets and subsequently gain a thin layer of ice.

Graupel can be convectively formed; snow grains never are.

This might be a useful table of wintry precipitation, albeit with U.S. definitions (and temperatures in Fahrenheit). Sleet in the U.S. is a different animal to simply mixed rain and snow - it's what would be called ice pellets in the UK. 

Stephen

Indianapolis IN

[Paul Garvey]

TY I'd been wondering too. What we experienced in Yorkshire was not therefore grapple - no convection. It was snow grains.

[Len Wood]

So it seems it was graupel as I thought.
Snow pellets but not snow grains apparently.

Beginning to get into dodgy terminology here.

Len

[Jack Harrison]

Stephen

...with U.S. definitions (and temperatures in Fahrenheit...)

We in UK still use Fahrenheit at times to satisfy the public (Although I don't buy tabloid newspapers  I often see headlines using Fahrenheit, pound and ounces, etc) but I think I am correct is saying in any serious scientific context, metric is always used in UK.
So what is the situation in the US? 
Of course NASA screwed up an attempted Mars landing by muddling Imperial and Metric.
I have to confess a personal aversion to Imperial.  My weight at around 118 kilograms sounds a lot better than does the figure in stones and pounds.
AND I DO NOT NEED THE CONVERSION POSTED PUBLICLY ON THIS FORUM THANK YOU:-)

Jack

[Stephen Davenport]

========

: - )

Likewise. I get measured in pounds over here and it's disconcerting. 

Just for clarification, I've been resident in the U.S. for three years but British born and bred - although I have spent a lot of my adult life out of the country (mostly in the Middle East prior to this).

The use of Imperial here drives me nuts, especially as we forecast for both the U.S. and Canada, where they sensibly use metric units - so there's constant switching back and forth and it's a real headache having to adjust some customer interfaces. SI units are generally used for other proper science, I think (Mars missions notwithstanding), but meteorology sticks with inches and mph.
In the UK I do wish that Fahrenheit would be dropped altogether; but the Daily Mail would go crazy.

Stephen

Indianapolis IN

[Len Wood]

In the US the thing is,
it sounds much more alarming to forecast or report 100°F than it does 37.8°C.

It's all about max effect in notifying the public.

Len

[Jack Harrison]

Many years ago I was flying into Gander Newfoundland one fine early spring afternoon.   Barry the co-pilot copied the weather CAVOK (= clear and visibility OK) with temperature 16 degrees adding “what a lovely mild day”.  I did not disillusion him – in those days, Canada was still using Imperial - and I let him believe that it was 16C.  He never got quite as far as stepping outside the aircraft in shirt sleeves: the snow banks gave something of a clue.

 

Jack

[Stephen Davenport]

========

Not really. The U.S. has never used Celsius so there's no comparison for Fahrenheit to be more alarming than! Excuse my tortured grammar.

UK tabloids might use that ruse, though.

Stephen.

[Stephen Davenport]

On Sunday, February 12, 2017 at 10:51:32 AM UTC-5, Jack Harrison wrote:

Many years ago I was flying into Gander Newfoundland one fine early spring afternoon.   Barry the co-pilot copied the weather CAVOK (= clear and visibility OK) with temperature 16 degrees adding “what a lovely mild day”.  I did not disillusion him – in those days, Canada was still using Imperial - and I let him believe that it was 16C.  He never got quite as far as stepping outside the aircraft in shirt sleeves: the snow banks gave something of a clue.

 

Jack

=========

Nice story. That's pretty funny.

A similar thing: way back in the day the London Weather Centre forecast room had no windows. But it did have a shower for freshening up on long shifts or after a bike ride or whatever.

One early morning towards the end of a night shift the forecasters were winding down and relaxing with a benign and dry day to come. Or so they had forecast. In anticipation of that, one of the oncoming day shift thought that it would be a caper to dress in a raincoat, bring an umbrella and step into the shower on his way in. 

He damply walked into the forecast room shaking drops off his brolly: "Pi$$ing down out there".

Cue an unholy and panicked rush to the front windows.

Stephen.

[Len Wood]

The Americans have never officially used Celsius but have heard of it.
Those that have travelled abroad that is.
They just love their 100°F.
That's what they told me when I've been  visiting.

Len

[Stephen Davenport]

On Sunday, February 12, 2017 at 6:04:58 PM UTC-5, Len Wood wrote:

 

 

They just love their 100°F.

But not because it's "alarming", I would suggest. They're not using 100 F because it stands out per se more than 38 C, it's just because that's the scale they virtually always use; there's no deliberate decision to use the Fahrenheit figure than the Celsius because the latter would never have been considered in the first place. And 100 F is pertinent because, well, it certainly is very hot but also because a century is a landmark in any context. Similarly, in the UK 30 C is notable because that's uncommonly warm. And so is 32 C, which is when one would expect to see certain tabloids reaching for their "90 degree scorcher" headlines.

 

The Americans have never officially used Celsius but have heard of it.

And we've all heard of Kelvin but it never enters our minds when we're describing ambient temperatures!

 Stephen. 

[Jack Harrison]

But even the tabloids often use Celsius for very cold weather for similar reasons.  Minus 5C sounds a lot colder than 23F.
Jack

[Tudor Hughes]

On Sunday, 12 February 2017 09:33:48 UTC, Jack Harrison wrote:

Of course NASA screwed up an attempted Mars landing by muddling Imperial and Metric.

 

I have to confess a personal aversion to Imperial.  My weight at around 118 kilograms sounds a lot better than does the figure in stones and pounds.
  

Are you sure?  Some of us are "bilingual". 

Tudor Hughes (5' 7½", 12 st 12 lb) 

[Len Wood]

Some people carry more weight than others with their postings.
I would not dare to post my weight here.

I'm far too modest and PC.

😇 😇

Len
Wembury

[Jack Harrison]

I googled the damaged Oroville Dam in California and came across this:

capable of storing more than 3.5 million acre-feet (4.4 km³)

Well, you learn something every day : acre-feet.  I wonder how many Trumps that would convert to?

Jack