Weather Journal: Temperatures See-Saw This Weekend

April-like weather will resume after a short hiatus this weekend in Greater New York, with rain showers abounding and temperatures in the 50s and 60s.

Put into context, the warmest of the next few days’ weather will be about 15 to 18degrees above the typical early December day. However, the warmth won’t come all in one chunk. Alternating cold and warm fronts will keep things interesting with a see-saw in local temperatures to show for it. Day-to-day changes in high temperatures over the next four days will average about 12.5 degrees, with an up-down-up-down nature throwing outerwear fashion experts into a tizzy.

Saturday and Monday will be the warmest of the next five, with highs near or above 60degrees in the city. Friday, Sunday and Tuesday will all be near or only slightly warmer than average — victims of cold fronts. The biggest rain chances are Friday night and Monday night into Tuesday. Given the warm temperatures, no snow is expected in any of the looming storms.

Things should mellow out in the longer term, with temperatures steadying to the mid-40s for afternoon highs, and just above freezing for overnight lows during the latter part of next week.

2012 likely to be warmest year on record locally, nationally
In a story Weather Journal has been tracking all year, new data shows Greater New York remains on pace to make 2012 the warmest year in the region’s history.

With the addition of November’s data released on Thursday, NOAA scientists now believe that 2012 is “virtually certain to become the warmest year on record for the nation,” as well as for Greater New York. In fact, nationally averaged December temperatures would have to be more than one degree colder than the coldest December on record for a new national annual record not to be set (which, by the way, ain’t gonna happen, given the month’s exceptionally warm start).

The most likely scenario is that 2012 will beat 1998 — the current warmest year — by more than a full degree in the national race, a landslide in terms of weather records. A remarkable nine of the top 10 warmest 12-month periods since 1895 have all ended during 2012, and an index of extreme weather is currently more than double the long-term average.

New records appear likely statewide for New Jersey, New York and Connecticut as a whole. The January to November temperatures across the tri-state were the warmest on record, among 18 total states that set that mark. A chart of the last 12 months of temperatures for Greater New York in context clearly shows a new record high.

The record in New York City may end up being close. According to a Weather Journal analysis, factoring in the forecast for the next several days and the warm temperatures that already occurred during the first week of December, it’s very likely that 2012 will at least tie 1990, 1991, and 1998 (57.2F) for the city’s warmest year since at least 1869. Eight of the city’s 10 warmest years have occurred since 1990.

Further upstate, in Syracuse, the heat has been much more boldly pronounced — among the most unusually warm spots of anywhere in the country. In fact, a year as warm as Syracuse has experienced in 2012 would be expected purely by chance onlyonce in about a thousand years.

Although standardized national weather records only go back to 1895, there’s ample evidence that 2012′s warmth in the tri-state and beyond may be unprecedented for at least hundreds if not thousands of years. Tree rings, ice cores and other so-called “proxy” data show that the climate is warmer now than it has been throughout much of recorded human history, and the odds of exceptional heat waves like those experienced this year are now greater due in large part to human activities like the burning of fossil fuels.

Link: http://blogs.wsj.com/metropolis/2012/12/06/weather-journal-temperatures-see-saw-this-weekend/