All That Falls May Not Be Real Snow

Snow has been conspicuous in its almost total absence so far this winter, and even the few flakes that have fallen so far might not be typical snow but, meteorologists say, the result combination of natural and man-made factors.

Weather forecasters have called for no snow in the city this week, but there have been some light dustings, and the Moscow weather bureau says these are partly a product of industry.

"The steam from the city's industries has contributed to the process, along with a current high pressure system in the area," said weather bureau spokeswoman Tatyana Pozdnyakova.

She said this was mostly the case in the city, and snow in the Moscow region was the result of natural weather patterns, with a low-pressure front meaning there is warmer, more humid air at higher altitudes, leading to condensation and precipitation.

Vladimir Filonov / MT Steam billowing from a heating station in northwestern Moscow on Tuesday. Such steam is producing light snow.

Inside the city, the chimneys of numerous factories are contributing to the development of a warmer, more humid layer of air higher up all on their own.

Mikhail Volobuyev, deputy head of the Federal Meteorological Service, said that dust in the atmosphere also helps generate snowfall because dust particles often form the center of snowflakes and, especially on windless days, industrial emissions contribute to the effect.

"It is not best for the city when we have a high pressure system and no wind," Volobuyev said. "The wind isn't carrying any of the emissions away, so everything is coming right back down."

Although there is little or no snow expected in the city until Sunday, daytime temperatures are expected to hover between 1 and 4 degrees Celsius and fall to minus 3 to minus 8 C at night.