Thursday, December 14, 2006

Phallacy of Measuring Snowfall


Roger Edwards...besides working @ NWS/s SPC...maintains a web log called 'Weather or Not' where he posts under the nom de plume 'Tornado.'

Today...Tornado writes about his perceived fallacy concerning snowfall measurements...maintaining the musical question..."How much snow did you get?"...doesn/t matter one lick b/c all that/s really important is the water equivalent of those billions of frozen hydro-meteors piled up around his house.

To support this crumudgery...he cites as reasons the inherent uncertainty in getting accurate measurements b/c of blowing and drifting...variability of snow:H2O ratios...and a nebulous requirement to take an unspecified number of samples...which are later averaged.

Tornado demands scientific meaning from his atmospheric phenomenon declaring "(s)now depth measurements are arbitrary, inconsistent, misleading and hugely unscientific way to represent fallen winter precipitation."

But that attitude surely misses the point about why snow must be measured with a stick and not a cup.

Sure...snow can be viewed as just 'fallen winter precipitation' but who...other than Tornado and maybe Bartlo...could possibly get excited about a 36-HR water equivalent GooFuS prog for a nor-easter deepening off the SC coast?

Can you imagine the headlines on NWS winter storm advisories...watches...and warnings?

"Winter Storm Warning for Pressure Falls...NY
Heavy Snowfall with up to 3/4" Water Equivalent"

Or a second period zone forecast where 'additional snow accumulations between 1/4" to 1/2" water equivalent.

If measuring water equivalent became the standard...what would it do to Schwartz' Admonition? Schwartz found in an observational study conducted during the mid-80s...the amount of observed snowfall was inversely proportional to the excitement at the map wall.

Beside, which forecasting contest do you think would generate more interest? One that forecasts 'water equivalent or one that forecasts 'storm-total snowfall?'

How about a scenario where a principal has to make a decision about whether to close schools b/c of a winter storm based on the expected 'water equivalent?' Mike4Snow can take this one from here.

Arguing the phallacy of snowfall measurements is just being a dick in the mud. If this idea ever comes to pass...just shoot me.

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