Gulf of Maine quarterly climate impacts and outlook: June 2015

Spring temperatures (averaged over March, April, and May) ranged from near normal to 3°C (5.4°F) below normal. March was quite cold, with temperatures 2°C (3.6°F) to 5°C (9°F) below normal. For instance, Fredericton, NB, had only four days with temperatures above the freezing mark, compared to 22 days normally. April temperatures ranged from near normal in Massachusetts to 3°C (5.4°F) below normal in the Maritimes. April 6 was particularly cold, with 10 sites in New Brunswick setting or tying daily record lows and Caribou, ME, having its all-time lowest April temperature. May was quite warm, with temperatures 1°C (1.8°F) to 4°C (7.2°F) above normal. Massachusetts and New Hampshire each had a record-warm May, while Maine had its third warmest.

Temperature and precipitation normals based on 1981-2010. Canada and ocean precip data: Canadian Precipitation Analysis. U.S. precipitation data: interpolated station data.

Spring precipitation (accumulated during March, April, and May) ranged from 25% of normal to near normal for most of the region. Massachusetts and New Hampshire had their fourth driest spring. March was extremely dry in the U.S. and New Brunswick, with areas seeing 25-75% of normal precipitation. Maine and New Hampshire ranked this March among their top 12 driest. Conversely, March was wet in Nova Scotia and Prince Edward Island, with areas seeing up to 175% of normal precipitation. April precipitation ranged from 50% of normal in the U.S. to near normal in the Maritimes. May was also extremely dry, with most of the region seeing from less than 25% of normal precipitation to 75% of normal. Massachusetts had its second driest May, while New Hampshire had its 16th driest.

Spring sea surface temperatures in the Gulf of Maine were colder than normal by as much as 1°C (1.8°F) over all shallow coastal regions, especially along the Maine and New Brunswick coasts, southwest Nova Scotia, and Minas Basin. Cold anomalies were also present offshore in the central Gulf of Maine south of Penobscot Bay and over most of the Scotian Shelf. These cold anomalies continued from the strong winter cooling that started in February. Surface water over deeper basins in the Gulf of Maine (Wilkinson and Jordan Basins) still had weak [around 0.5°C (0.9°F)] warm anomalies left over from the strong warm anomalies that were present throughout 2014 and even into winter 2015.

Sea surface temperature anomalies based on 1985-2014. Mean SST anomalies from NOAA AVHRR data. Credit: University of Maine School of Marine Sciences and NERACOOS

Snow cover remained in place later into spring than normal for much of the region. The start of the growing season was delayed by up to a month, as many fields were too wet or still snow-covered in April. The late spring also contributed to above-average tree pollen counts, leading to a shortened but concentrated allergy season. In April and May, sea ice and frozen harbors around Prince Edward Island, northern Nova Scotia, and western Cape Breton delayed the start of the spring lobster and snow crab seasons by up to 11 days. Shellfish harvesters and ferry services were also delayed by the ice. In Maine, the ice fishing season was extended, but the start of the open water fishing season was delayed.

Nova Scotia’s above-normal snow cover made it difficult for migratory birds and wildlife to find food, causing some to become weak or die. A late snowmelt in northern New England cut short the development period for amphibians that hatch in pools created by melted snow and need several months to grow legs before these pools dry up. Above-normal snowfall likely insulated blacklegged (deer) ticks, which transfer diseases to humans.

Lingering snow cover caused Nova Scotia golf courses to open several weeks late and the Portland Sea Dogs baseball team to postpone their first two games of the season. In Prince Edward Island, snow cover and wet conditions made many seasonal roads impassable and delayed the opening of campgrounds and trails in some provincial parks. The harsh spring kept real estate agents from showing cottages in PEI and delayed new home construction in Nova Scotia. Spring weight restrictions were extended by a week in parts of the Maritimes so roads could recover from frost heaves.

Maine, New Hampshire, Massachusetts, and northern New Brunswick were abnormally dry during spring due to a continued lack of precipitation. By late May, moderate drought conditions were present in Massachusetts, southern New Hampshire, and part of southern Maine. Stream flows were much below normal in these areas. Topsoil moisture as of May 31 was rated short or very short in 51% of New Hampshire. U.S. Department of Agriculture crop reports indicated that plant growth was slow due to lack of moisture, with some farmers already irrigating. The dry conditions also contributed to multiple wildfires in Maine and New Hampshire. Wildfires were also reported in Nova Scotia and New Brunswick. Precipitation in early June helped ease dryness in some areas.