As meteorological winter begins, climate scientists at UMass observe that the fall season just ended – September through November – was the wettest fall ever recorded at the Blue Hill Observatory in Milton, the second wettest in Worcester and Providence, Rhode Island and the fourth wettest in Boston, according to National Weather Service observations.
Michael Rawlins, geosciences, associate director of the Climate System Research Center, and hydrogeology researcher David Boutt add that observations show total precipitation at Amherst from January through November was the second highest recorded there since observations began in 1836. The record highest amount fell in 1888. For the current January through November period, 59.02 inches of precipitation was recorded in Amherst, just 1.1 inches shy of that.
Farther south, Providence received 24.43 inches this fall, 197 percent of normal, they add. Storrs, Connecticut, which has a data record back to 1888 received 23.80 inches, a record for fall, and 10.54 inches above the climatological normal, 1981-2010, Rawlins points out.
Accumulated precipitation was near normal for the first six months of the year, he says. “It's remarkable that little of the rainfall since mid-summer came from tropical cyclones."
Looking at just the past month, it was the wettest November on record at Blue Hill, at most sites in the mid-Atlantic region, and second wettest at Concord, Hartford, Portland, Providence and Worcester, the scientists added. The Fourth National Climate Assessment Report released on Nov. 24 highlighted how heavy precipitation is becoming more intense and more frequent across most of the United States, particularly in the Northeast and Midwest, with the trend projected to continue in the future.
In the Connecticut River Valley, farm fields and basements are showing the effects of such saturated conditions, Boutt says. High soil moisture coupled with cool temperatures and lack of surface evaporation and plant transpiration has led to extremely high water table levels for this time of year, he adds. “We usually see the water table in the fall at its yearly low,” he says, “but not this year.”
Data from the United States Geological Survey’s climate response network of groundwater observation wells show water levels in the region even exceeding levels typically reached during spring thaw.
Boutt added, “Saturated soil moisture conditions and a high water table will likely have cascading impacts into next spring, where the water table will continue to rise contributing to saturated conditions and perhaps significant flooding. It is likely that basement flooding will be a problem for many homeowners, and there is also the potential for septic system failures.”
Further, data from the Massachusetts Water Resources Authority show that the Quabbin Reservoir’s level has risen sharply this fall in recovery from the drought of 2016, to approximately 97 percent of capacity and still rising, the experts note. Data are considered preliminary until the National Weather Service conducts its quality control.