snow_ruler.jpgSunny skies and temperatures above fifty will do a quick number on the snow. The sidewalks will a gloppy, sloppy mess for a few days. If there's any snow mounds left by the weekend they are going to freeze hard. A relatively dry cold front looks like it will move through on Friday. The front will bring high winds and cold air. Saturday and Sunday will be chilly. The cold spell will only last a few days. Normally this would be the time of year when Gothamist starts getting spring fever. With our almost total lack of winter weather this year we are confused. We still want more snow, but at the same time we are pleased to see bylines from places like Port St. Lucie and Tampa as pitchers and catchers begin reporting to spring training.

There was some discussion yesterday on Gothamist about the record snowfall and whether it was representative of the city. You might think measuring snowfall would be easy but snow is a sneaky substance. If the surface temperature is warm enough snow may melt before its depth can be measured. As snow piles up the lower levels of the snow cover compress from the weight above. Blowing and drifting snow may also decrease or increase the depth snow.

To address these issues the National Weather Service long ago decided upon a standardized set of snow measurement guidelines for their cooperative observers. Observers should place a snowboard (a square wooden board painted white) in a location that minimizes blowing and drifting. Snowfall should be measured at least once, but no more than four times, a day. If snow falls and melts between observations the greatest accumulation since the last observation should be reported. Cooperative observers are not meteorologists, but people like you and me who have had some training in proper observation techniques. It ticked Gothamist off to no end to read the dismissive manner in which Times reporter Any Newman treated the observers at the Central Park Zoo. Saying you don't want to cast aspersions does not then give you permission to cast aspersions. Can you spell "passive-aggressive" Andy Newman?

The bottom line is the storm produced a record snowfall for Central Park. Whether that station is representative of the city as a whole is an arguable point. However, it is also irrelevant because snowfall is determined by depth of snow at a point, not volume of snow over an area.

Snow measurement photo from Michael Schachter's presentation at a National Weather Service Snow workshop