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February 5 quick hitting obs


Typhoon Tip

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You can do whatever you need to in order to keep a consistent record.  I've just never understood the 6 hour parameter.  Why not every two hours or every hour? Why not every 8 hours or 12 hours?  If I recall, the argument at the time was to allow for intensity data but in my mind it's totally inaccurate.  If it snows for 10 hours and I have 10" of new snow on my board, most people are going to look at that and say that I had 10" of snow.  Now, if I clear the board at 6 hours and I have 6" but then the snow gets really fluffy and at the end of the storm I have another 6", the arbitrary clearing the board method now says that 12" of snow fell.

 

I recall that one of the first major events that this came up was I believe in 1996 when PHL set a snowfall record and they said that over 30" of snow had fallen but no one had anything near that on the ground so a lot of the media and public called foul but the NWS cited their new measuring guidelines.

 

Like I said, I accept the fact that it became acceptable at some point but I will keep doing it the original way so I can compare my measurement with storms in the 80s, 70s, 60s and beyond without any compensation or asterisk.

Why not just call your hgihest snow depth your seasonal snowfall?

There's some events where you get LES or deformation 25:1 fluff where it can be snowing 1-2"/hr and the depth doesn't change. Just ask the BUF guys about that. The 6hr mark is just the cutoff made to account for some compaction without letting prolonged heavy snow events penalize themselves due to compaction.

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You can do whatever you need to in order to keep a consistent record.  I've just never understood the 6 hour parameter.  Why not every two hours or every hour? Why not every 8 hours or 12 hours?  If I recall, the argument at the time was to allow for intensity data but in my mind it's totally inaccurate.  If it snows for 10 hours and I have 10" of new snow on my board, most people are going to look at that and say that I had 10" of snow.  Now, if I clear the board at 6 hours and I have 6" but then the snow gets really fluffy and at the end of the storm I have another 6", the arbitrary clearing the board method now says that 12" of snow fell.

 

I recall that one of the first major events that this came up was I believe in 1996 when PHL set a snowfall record and they said that over 30" of snow had fallen but no one had anything near that on the ground so a lot of the media and public called foul but the NWS cited their new measuring guidelines.

 

Like I said, I accept the fact that it became acceptable at some point but I will keep doing it the original way so I can compare my measurement with storms in the 80s, 70s, 60s and beyond without any compensation or asterisk.

 

Its because they had to pick a time frame and 6-hours works well in a 24 hour day.  It could've been 8 hours too, or 12 hours, but you need to put a time limit on it.

 

Sure measuring the snow when it ends works sometimes, but in some areas of the country its not just in and out synoptic storms that make it easy.

 

What if its a 3 day Lake Effect Event?  Or 3-4 days of snow showers where a few inches fall per day but in short bursts during those days.  You can get like an 8 hour break and then it starts up again for a couple inches, then a break and repeat.  Like if you see J.Spin's observations, he can go like 3 straight days of having at least some accumulation in every 6-hour block.

 

You have to set a time limit at some point.  So 6 hours is probably as good as any.

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Ah, I guess I'm thinking of different types of events.  Like up here (when it used to snow, ha ha) you'll get into a pattern where you have say 2.5" between 7am and 3pm, then nothing from 3pm till midnight, then another 5.5" from midnight till 7am from squalls or something.  Total snowfall for 24 hours is 8.0" but the snow depth on an undisturbed area is 6.5"... do you go with 8" or 6.5"?

 

In snowfall like that, in my weather observation class at Lyndon (back in the 80s) to add the two together so I would record 8".  Again, you would make note of the two events in the record.  You can get into grey areas but that's the general idea.

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Up to 5.5" here(on a parked car not on a snowboard though so we'll see what the total is when I get home), hoping this last band puts us over 6".

 

Coastal pointed this out from higher tilts... this last band really blossomed nicely in the past 15 minutes

Will be a nice band for south shore into southeast MA

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Why not just call your hgihest snow depth your seasonal snowfall?

There's some events where you get LES or deformation 25:1 fluff where it can be snowing 1-2"/hr and the depth doesn't change. Just ask the BUF guys about that. The 6hr mark is just the cutoff made to account for some compaction without letting prolonged heavy snow events penalize themselves due to compaction.

 

lol

 

Ask the BUF guys what they did in 1977 or any other LES event prior to the change.  I'm not a LES expert.

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Coastal pointed this out from higher tilts... this last band really blossomed nicely in the past 15 minutes

Will be a nice band for south shore into southeast MA

Yeah good call Scott, beautiful band showing up on radar now. Maybe we make a run at 7"?

Curious to see what I have on my snowboard when I get home. Should make it in about half an hour so hopefully won't compact too much between now and then.

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It's not consistent. You're penalizing a 24hr event with 24hrs of compaction while the shorter one only has 6hrs of compaction.

 

 

How is it not consistent to ALWAYS measure the snow at the end of the event and not in the middle of it?  I am ALWAYS measuring what fell, not a sum of different amounts during the event.

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Its because they had to pick a time frame and 6-hours works well in a 24 hour day.  It could've been 8 hours too, or 12 hours, but you need to put a time limit on it.

 

Sure measuring the snow when it ends works sometimes, but in some areas of the country its not just in and out synoptic storms that make it easy.

 

What if its a 3 day Lake Effect Event?  Or 3-4 days of snow showers where a few inches fall per day but in short bursts during those days.  You can get like an 8 hour break and then it starts up again for a couple inches, then a break and repeat.  Like if you see J.Spin's observations, he can go like 3 straight days of having at least some accumulation in every 6-hour block.

 

You have to set a time limit at some point.  So 6 hours is probably as good as any.

 

I was not part of the discussion groups around the change but I do recall a "request for comments" or something like that but yes, 6 hours does fit in a 24 hour window and yes I agree that not everything is synoptic events everywhere.

 

Like you said, you have to set a time limit at some point and I just choose to do it the same way it was done until the change was made so I can compare my data with historical data. 

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Why not just call your hgihest snow depth your seasonal snowfall?

There's some events where you get LES or deformation 25:1 fluff where it can be snowing 1-2"/hr and the depth doesn't change. Just ask the BUF guys about that. The 6hr mark is just the cutoff made to account for some compaction without letting prolonged heavy snow events penalize themselves due to compaction.

 

The storm total thing works for places that primarily get synoptic events that are very clear cut start and ending.  But then again, if you get a big deformation band dropping 2" per hour on the interstate, but because of compaction you are only seeing your storm total snow go up a half inch, that doesn't seem like a good way to measure snow falling from the sky. 

 

You'll see it all the time with J.Spin's readings... but say it snows hard all day but its high ratio fronto snow so there's 15" on the ground by the time you go to bed.  You wake up to find that it snowed another 3" on your car (that was wiped clean before bed), but yet your total on the ground is 15.5".  Measuring by depth would only account for a half inch overnight, not 3". 

 

I just look at snowfall and snow depth as two entirely different things. 

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How is it not consistent to ALWAYS measure the snow at the end of the event and not in the middle of it?  I am ALWAYS measuring what fell, not a sum of different amounts during the event.

 

You are getting different amounts of settlement and compaction with each event depending on its duration.  It is a consistent way to measure because its what you've always done. 

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