The mean warming climate trends are making their mark globally and locally. Caitlin Dewey outlined this winter’s numbers for you on Sunday.
Going beyond that time scale, the trends are clear. Despite suffering our coldest month on record in February 2015, winters have been warming this decade. Nationally, this past winter was the sixth warmest on record. The lower 48 states all had winters warmer than their 20th century average, and 22 states had top 10 warmest winters on record. Here is the overview of December-February from NOAA’s National Center for Environmental Information.
This past decade has been the hottest on record, year round. It follows cold snaps within the winter season have grown shorter in duration. In Buffalo, the length of cold snaps has shown a significant reduction.
Many of us associate noticeable warming more with summer than winter. However, for much of the country the most significant warming has occurred during winter months.
Climate Central reports of 242 reporting stations analyzed, 232 had shorter cold snaps this decade. This warming has its pluses, but among its minuses is less pest kill. Many parts of the nation now endure longer mosquito seasons. Fruit trees, such as apple, peach and cherry, require a colder dormant season in order for better fruit production. In some parts of the country, yields may be going down.
Going back further in time, the warming trend near Buffalo is even more significant since 1970. Statistically, the increase is considered very significant.
Nationally, only seven of the 242 reporting stations have cooled during this period in the winter, with 190 warming at least 2 degrees, shy of our local 3.2 degrees.
In New York State, the rate of warming has been considerably greater in winter months than in warmer months.
That is also the case in the majority of the lower 48 states. Winter is warming faster than spring, summer or fall.
As to how the rate of winter warming compares to the other three seasons, Climate Central produced this graphic based on NOAA/NCEI station reports.
Climate Central’s overview includes faster warming at northern latitudes than to the south and west: “Since 1970, winter has warmed at least 1 degree F in all states analyzed, and at least 3 degrees F in two thirds of those states. Northern winters have heated up the most, with over 5 degrees F of warming in Alaska, Minnesota, Vermont, and Wisconsin.” Only in this past winter has Alaska proven to be an exception, experiencing its coldest winter in years, and proving to be one of the only locations in the Northern Hemisphere to have consistent cold.
Even our points of bottoming out — our most extreme low temperatures — have warmed near Buffalo since 1970.
The trend in snowfall is somewhat less noticeable. This past winter not only was below average in snowfall, but it has been well below average in lake-effect snowfall, despite the wide open lakes. That lack of lake snow is a clear marker for the lack of polar air masses to trigger the lake-effect. But since 1970, smoothed data shows some modest decline in Buffalo snowfall.
Looking ahead to spring this year, it remains to be seen how the milder winter will be affecting pollen counts and eventual crop yields. Our seasonal precipitation is a bit below average since the start of the year. Last year the excessive spring rainfall led to higher mosquito populations. We can hope we don’t revert to a wetter pattern because that, in tandem with the mild temperatures, could again lead to high mosquito populations.