donsutherland1 Posted January 28, 2013 Share Posted January 28, 2013 The ground was whitened by this morning's snowfall. As a result, the major airports in and around the NYC area reported the following totals: JFK: 0.1" LGA: 0.2" EWR: 0.3" Central Park, though, recorded a trace. My guess as to what is happening is that the snow is not being measured once it stops falling. Instead, the measurement takes place at regular intervals. Unfortunately, in cases of marginal snowfalls and/or a change to rain, the snow has either melted or been washed away by the time that measurement occurs. Although the issue involves small accumulations of snow being missed, it does have an impact on the integrity of the Park's overall climate record. Hopefully, those responsible for measuring the snow will be reminded how to do it properly, as well as of the importance of measuring the accumulation when the snow stops falling. If they are unwilling or unable to handle that responsibility properly, perhaps the value for the lower of the accumulations at JFK and LGA should be substituted in such cases. Proper measurement would be the best outcome, but a realistic attempt to estimate the snow would be preferable to a lack of proper measurements. Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 28, 2013 Share Posted January 28, 2013 The ground was whitened by this morning's snowfall. As a result, the major airports in and around the NYC area reported the following totals: JFK: 0.1" LGA: 0.2" EWR: 0.3" Central Park, though, recorded a trace. My guess as to what is happening is that the snow is not being measured once it stops falling. Instead, the measurement takes place at regular intervals. Unfortunately, in cases of marginal snowfalls and/or a change to rain, the snow has either melted or been washed away by the time that measurement occurs. Although the issue involves small accumulations of snow being missed, it does have an impact on the integrity of the Park's overall climate record. Hopefully, those responsible for measuring the snow will be reminded how to do it properly, as well as of the importance of measuring the accumulation when the snow stops falling. If they are unwilling or unable to handle that responsibility properly, perhaps the value for the lower of the accumulations at JFK and LGA should be substituted in such cases. Proper measurement would be the best outcome, but a realistic attempt to estimate the snow would be preferable to a lack of proper measurements. Isn't proper measurement once every 6 hours? Link to comment Share on other sites More sharing options...
SnowGoose69 Posted January 28, 2013 Share Posted January 28, 2013 The ground was whitened by this morning's snowfall. As a result, the major airports in and around the NYC area reported the following totals: JFK: 0.1" LGA: 0.2" EWR: 0.3" Central Park, though, recorded a trace. My guess as to what is happening is that the snow is not being measured once it stops falling. Instead, the measurement takes place at regular intervals. Unfortunately, in cases of marginal snowfalls and/or a change to rain, the snow has either melted or been washed away by the time that measurement occurs. Although the issue involves small accumulations of snow being missed, it does have an impact on the integrity of the Park's overall climate record. Hopefully, those responsible for measuring the snow will be reminded how to do it properly, as well as of the importance of measuring the accumulation when the snow stops falling. If they are unwilling or unable to handle that responsibility properly, perhaps the value for the lower of the accumulations at JFK and LGA should be substituted in such cases. Proper measurement would be the best outcome, but a realistic attempt to estimate the snow would be preferable to a lack of proper measurements. Don, this has always been my feeling too...if the snow occurs say at around 2-3pm or 8-9am hours before those usual measuring times it get missed. The 12/26 event which thumped around 3-4pm they recorded correctly the 0.4 inches, however the event 2-3 days later where I think I recorded 0.4 or so again the snow fell I think around 11am and then CPK mixed with some RA before they could correctly record it. They also missed 0.3 another day but I cannot recall offhand which one but I had them as 0.7 too low on the year, today they missed 0.2 probably or so. I think the 1.5 measured a few days back though was too high so they may be right in the end anyway. Link to comment Share on other sites More sharing options...
BxEngine Posted January 28, 2013 Share Posted January 28, 2013 Isn't proper measurement once every 6 hours? No. Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 28, 2013 Author Share Posted January 28, 2013 Isn't proper measurement once every 6 hours? No. In general, it should not be measured more than 4 times during a 24-hour period. However, in cases such as today's snowfall, the greatest depth of the accumulation should have been measured (as almost certainly was the case at LGA, JFK, and EWR). http://www.crh.noaa.gov/iwx/program_areas/snow_spotters/SnowMeasurement.pdf Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 28, 2013 Share Posted January 28, 2013 Measure and record the greatest amount of snowfall that has accumulated on your snowboard (wooden deck or ground if board is not available) since the previous snowfall observation. This measurement should be taken minimally once-a-day but can be taken up to four times a day, (every 6 hours) and should reflect the greatest accumulation of new snow observed (in inches and tenths, for example, 3.9 inches) since the last snowfall observation. Snowfall amounts can be measured hourly or at any interval as long as the snow measurement board is NOT cleared more frequently than once every 6 hours. Link to comment Share on other sites More sharing options...
BxEngine Posted January 28, 2013 Share Posted January 28, 2013 Measure and record the greatest amount of snowfall that has accumulated on your snowboard (wooden deck or ground if board is not available) since the previous snowfall observation. This measurement should be taken minimally once-a-day but can be taken up to four times a day, (every 6 hours) and should reflect the greatest accumulation of new snow observed (in inches and tenths, for example, 3.9 inches) since the last snowfall observation. Snowfall amounts can be measured hourly or at any interval as long as the snow measurement board is NOT cleared more frequently than once every 6 hours. Thats not the entire procedure. Also, link your cut n paste job. Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 28, 2013 Share Posted January 28, 2013 Thats not the entire procedure. Also, link your cut n paste job. http://www.weather.gov/gsp/snow Link to comment Share on other sites More sharing options...
BxEngine Posted January 28, 2013 Share Posted January 28, 2013 http://www.weather.gov/gsp/snow The rest of that page clearly answers your question. Link to comment Share on other sites More sharing options...
uncle W Posted January 28, 2013 Share Posted January 28, 2013 there are many small events that go under measured...Some bigger ones too...The January 2000 storm had 5.5" for 1/25 but only a trace for 1/26...It snowed from midnight 1/26 to dawn lightly and I had at least a half inch more giving me 6"... Link to comment Share on other sites More sharing options...
famartin Posted January 28, 2013 Share Posted January 28, 2013 Measure and record the greatest amount of snowfall that has accumulated on your snowboard (wooden deck or ground if board is not available) since the previous snowfall observation. This measurement should be taken minimally once-a-day but can be taken up to four times a day, (every 6 hours) and should reflect the greatest accumulation of new snow observed (in inches and tenths, for example, 3.9 inches) since the last snowfall observation. Snowfall amounts can be measured hourly or at any interval as long as the snow measurement board is NOT cleared more frequently than once every 6 hours. Thats not the entire procedure. Also, link your cut n paste job. No, actually that is essentially it. You will notice the caveat: "the greatest amount of snowfall that has accumulated on your snowboard (wooden deck or ground if board is not available) since the previous snowfall observation". In other words, if you get 1.5", but only 1" is on the board when you clear, you would still record the 1.5" total. The 6-hour rule has to do with CLEARING the board *ONLY*. You can measure every 5 seconds, and ideally you should measure when the snow ends, at least. As far as what's been going on in Central Park... sometimes I do wonder if it would be better to get someone who would really be interested in doing it, as opposed to the zoo staff. Link to comment Share on other sites More sharing options...
BxEngine Posted January 28, 2013 Share Posted January 28, 2013 No, actually that is essentially it. You will notice the caveat: "the greatest amount of snowfall that has accumulated on your snowboard (wooden deck or ground if board is not available) since the previous snowfall observation". In other words, if you get 1.5", but only 1" is on the board when you clear, you would still record the 1.5" total. The 6-hour rule has to do with CLEARING the board *ONLY*. You can measure every 5 seconds, and ideally you should measure when the snow ends, at least. As far as what's been going on in Central Park... sometimes I do wonder if it would be better to get someone who would really be interested in doing it, as opposed to the zoo staff. No, thats not it. Considering noreaster's initial comment, its clear he was basing it on that only, and assumed that you only measure every 6 hrs. Considering knyc recorded a trace, due to accumulated snow melting, the rest of the procedure clearly comes into play:"Special cases: - Snow falls and accumulates on the snowboard, but then melts. In this case, the snowfall is the greatest depth of snow observed on the board before it begins to melt. If this occurs several times, measure the snowfall after each snow shower and add each measurement for the total snowfall." Link to comment Share on other sites More sharing options...
BxEngine Posted January 28, 2013 Share Posted January 28, 2013 You are not reading it correctly. Yes i am. Link to comment Share on other sites More sharing options...
famartin Posted January 28, 2013 Share Posted January 28, 2013 No, thats not it. Considering noreaster's initial comment, its clear he was basing it on that only, and assumed that you only measure every 6 hrs. Considering knyc recorded a trace, due to accumulated snow melting, the rest of the procedure clearly comes into play: "Special cases: - Snow falls and accumulates on the snowboard, but then melts. In this case, the snowfall is the greatest depth of snow observed on the board before it begins to melt. If this occurs several times, measure the snowfall after each snow shower and add each measurement for the total snowfall." Nor'easter read it incorrectly. And I don't think the second part of the special case came into play today. Link to comment Share on other sites More sharing options...
BxEngine Posted January 28, 2013 Share Posted January 28, 2013 Nor'easter read it incorrectly. And I don't think the second part of the special case came into play today. I only posted the first part. And i know he read it incorrectly, thats why i corrected him. Link to comment Share on other sites More sharing options...
famartin Posted January 28, 2013 Share Posted January 28, 2013 I only posted the first part. And i know he read it incorrectly, thats why i corrected him. Yes, but the part he quoted was essentially correct. Particularly for east-coast locations like the park. Repeated snow showers that accumulate and then melt are extremely rare there. What Nor'easter posted was relevant to today's situation, even if he didn't interpret it correctly. Link to comment Share on other sites More sharing options...
BxEngine Posted January 28, 2013 Share Posted January 28, 2013 Yes, but the part he quoted was essentially correct. Particularly for east-coast locations like the park. Repeated snow showers that accumulate and then melt are extremely rare there. What Nor'easter posted was relevant to today's situation, even if he didn't interpret it correctly. That doesnt make sense. You dont need repeated snow showers, just fluctuation in temp and/or temp that can cause melting before the 6 hour mark, no? In which case you should measure before the melting occurs? Link to comment Share on other sites More sharing options...
famartin Posted January 28, 2013 Share Posted January 28, 2013 Measure and record the greatest amount of snowfall that has accumulated on your snowboard (wooden deck or ground if board is not available) since the previous snowfall observation. This measurement should be taken minimally once-a-day but can be taken up to four times a day, (every 6 hours) and should reflect the greatest accumulation of new snow observed (in inches and tenths, for example, 3.9 inches) since the last snowfall observation. Snowfall amounts can be measured hourly or at any interval as long as the snow measurement board is NOT cleared more frequently than once every 6 hours. That doesnt make sense. You dont need repeated snow showers, just fluctuation in temp and/or temp that can cause melting before the 6 hour mark, no? In which case you should measure before the melting occurs? The parts of the quote which say "greatest amount of snowfall" and "measured hourly or at any interval" cover that. Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 29, 2013 Share Posted January 29, 2013 I didnt read anything incorrectly, while we all know the park would provide a more accurate snow measurement if they measured more frequently, what they are doing is technically not wrong. At a minimum snowfall should be measure every 6 hours and thats what they do, they have set times to measure reguardless of the snow time. While this method does miss some accumulation on snow events that fall and start to melt, they are not breaking NWS guidelines. Link to comment Share on other sites More sharing options...
uncle W Posted January 29, 2013 Share Posted January 29, 2013 when I was a kid all that mattered was how much was on the ground when the snow stopped...It's looks like they measured that way in the past...during snow events you need to be alert for change overs or mixing...When I was measuring snow way way back I cleared the snow board as soon as I heard the pings on the skylight...the February 1995 storm changed to rain in a matter of minutes... Link to comment Share on other sites More sharing options...
BxEngine Posted January 29, 2013 Share Posted January 29, 2013 The parts of the quote which say "greatest amount of snowfall" and "measured hourly or at any interval" cover that. Right, you said thats rare here. I find that hard to believe, especially in lower accumulation "storms" such as this. I was pointing out that the quotes dont reflect that it should only occur (more frequent measurements) during snow showers, but during an example such as today. Link to comment Share on other sites More sharing options...
uncle W Posted January 29, 2013 Share Posted January 29, 2013 I didnt read anything incorrectly, while we all know the park would provide a more accurate snow measurement if they measured more frequently, what they are doing is technically not wrong. At a minimum snowfall should be measure every 6 hours and thats what they do, they have set times to measure reguardless of the snow time. While this method does miss some accumulation on snow events that fall and start to melt, they are not breaking NWS guidelines. are the airports measuring at the same time?...If so how/why did they get more?... Link to comment Share on other sites More sharing options...
famartin Posted January 29, 2013 Share Posted January 29, 2013 I didnt read anything incorrectly, while we all know the park would provide a more accurate snow measurement if they measured more frequently, what they are doing is technically not wrong. At a minimum snowfall should be measure every 6 hours and thats what they do, they have set times to measure reguardless of the snow time. While this method does miss some accumulation on snow events that fall and start to melt, they are not breaking NWS guidelines. If snow melts before observation time, then they aren't actually measuring the "greatest accumulation on the board" since the last observation, and are therefore in violation. Link to comment Share on other sites More sharing options...
BxEngine Posted January 29, 2013 Share Posted January 29, 2013 I didnt read anything incorrectly, while we all know the park would provide a more accurate snow measurement if they measured more frequently, what they are doing is technically not wrong. At a minimum snowfall should be measure every 6 hours and thats what they do, they have set times to measure reguardless of the snow time. While this method does miss some accumulation on snow events that fall and start to melt, they are not breaking NWS guidelines. Thats not what it says. Link to comment Share on other sites More sharing options...
famartin Posted January 29, 2013 Share Posted January 29, 2013 Right, you said thats rare here. I find that hard to believe, especially in lower accumulation "storms" such as this. I was pointing out that the quotes dont reflect that it should only occur (more frequent measurements) during snow showers, but during an example such as today. No no, the special case mentioned instances where snow accumulated, melted, then accumulated AGAIN, all within the 6-hour period. I'm saying that THAT is extremely rare. Obviously there are often cases where snow falls and then starts to melt before ob time, but the "greatest amount" and "measure at any interval" caveats cover that within the main body of the guidelines. Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 29, 2013 Share Posted January 29, 2013 If snow melts before observation time, then they aren't actually measuring the "greatest accumulation on the board" since the last observation, and are therefore in violation. If the last observation is 6 hours ago, then they are. Yes they are missing the time inbetween the observations if the snow was higher at an point on the line, but that isnt a requirement for the NWS. Link to comment Share on other sites More sharing options...
BxEngine Posted January 29, 2013 Share Posted January 29, 2013 No no, the special case mentioned instances where snow accumulated, melted, then accumulated AGAIN, all within the 6-hour period. I'm saying that THAT is extremely rare. Obviously there are often cases where snow falls and then starts to melt before ob time, but the "greatest amount" and "measure at any interval" caveats cover that within the main body of the guidelines. Ahh ok. That makes much more sense, thanks for clarifying. Link to comment Share on other sites More sharing options...
famartin Posted January 29, 2013 Share Posted January 29, 2013 If the last observation is 6 hours ago, then they are. Yes they are missing the time inbetween the observations if the snow was higher at an point on the line, but that isnt a requirement for the NWS. Thanks for telling me what is and isn't a requirement of the organization I work for. I had no idea. Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 29, 2013 Share Posted January 29, 2013 Thanks for telling me what is and isn't a requirement of the organization I work for. I had no idea. Show me an NWS doc saying one is REQUIRED to measure snow every hour or any other interval besides once every 6 hours. We all agree it would be nice if the park actively measured snow during storms, all I am saying is that they are not required to. Link to comment Share on other sites More sharing options...
famartin Posted January 29, 2013 Share Posted January 29, 2013 Show me an NWS doc saying one is REQUIRED to measure snow every hour or any other interval besides once every 6 hours. They aren't required to measure at any other interval, but the specification states in the very first line "the greatest accumulation on the board since the previous observation". I feel you are having trouble with "greatest accumulation". Yes, that means that if it snows 1.5" but a half inch melts before ob time, they are supposed to report the 1.5" (and by extension, they should've measured that). The 6-hour rule is for reporting and for clearing the board. Nothing more. Link to comment Share on other sites More sharing options...
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