Snow: Another portent?

Worldwide, last month tied for the warmest in the period of satellite temperature record, dating to the late 1970s, according to NASA data released this week.

Perhaps incongruously, however, the Northern Hemisphere snow cover last month was the third most-extensive for an October in the period of observation, which begins in 1967, as tabulated by the Rutgers University Global Snow Lab.

This followed quite a snow-covered September, and last month we posted on the possible link between that and the Philly winter.

One highlight for those who don't feel like re-reading the whole post: When the Northern Hemispheric snow cover is above median in September, the average snowfall in Philly came in at 30.2 inches.

That compares with the average of 22.6 inches for the 45 years on the Rutgers list – a couple are missing.

Taking this a few steps further, the combined September-October coverage for 2014 ranked No. 3 among the 45 years.

In the 22 winters in which the September-October total ranked above the median coverage, 15 subsequent winters had median or above snowfall officially in Philadelphia, or 68 percent.

The average  snowfall in those winters was 28 inches for the 22 years, and it was 31.4 in the 10 years with the highest September-October extent.

We almost wouldn't nowhere to start with the caveats here.

Intuitively, one could see a logical connection between snow cover in the fall and the subsequent winter, but almost nothing happens linearly in the atmosphere.

We also will point out that on the top 10 September-October list are two of the Hall of Fame snow duds.

One was 2001-01, in which a grand total of 4 inches was measured in Philadelphia, and that was downright snow blitz compared with another one on the list 1972-73, the only season without any measureable snow.