Monday, September 11, 2017

Summer 2017 Climate Summary for Northern and Eastern Maine

...Northern and eastern Maine summer seasonal climate narrative...

The meteorological summer of 2017 comprising the 3-month period of
June through August finished with near average temperatures and
below average precipitation.

Temperatures were very close to the 30-year average and ranged
from just 5 tenths of a degree below average at Bangor to 6 tenths
of a degree above average at Caribou. Precipitation ranged from 50
To 90 percent of average across most of northern and eastern
Maine. The only exception was across parts of northern Somerset
and western Piscataquis counties where precipitation ranged from
100 to 130 percent of average.

At Houlton, only 7.59 inches of rain was observed all summer, which
made it the driest summer since 1999, and ranked as the 10th
driest summer since 1948. At Caribou, 9.29 inches of rain was
observed making it the 13th driest summer on record, and at Bangor
7.87 inches of rain made it the 22nd driest summer on record.

June started cool the first week but then warmed significantly
with record highs at Caribou, Houlton, Millinocket, and Bangor on
The 11th. The high of 91 degrees at Caribou and Bangor were the
only 90 degree days observed during the meteorological summer. The
highs of 90F at Houlton and 93F at Millinocket on the 11th were
the only 90 degree days observed all summer. Of note, the
temperature dropped below freezing on the morning of the 27th at
Estcourt station with a low of 31F. Rainfall was generally light
the first half of the month, but it became rainier the 2nd half of
the month.

Temperatures in July were at or a bit below average with well
below average precipitation. Late July featured a number of nights
with lows in the 40s and even 30s at the typically cool northwest
valley locations. Estcourt station even dropped below freezing on
the morning of the 23rd with a low of 31 degrees. Precipitation
ranged from just 40 to 70 percent of average, and by the end of
the month much of eastern Maine was abnormally dry with moderate
drought conditions according to the U.S. Drought Monitor in parts
of Washington and southern Aroostook counties.

August also had near to slightly below average temperatures and
well below average precipitation. There were a total of 12 nights
with lows in the 40s at Caribou, the most in August since 2006. At
Bangor, six of the last 7 nights of the month had lows in the
40s. Estcourt station in far northwest Maine had 2 nights with low
of freezing late in the month. Rainfall was only 25 to 70 percent
of average, and Millinocket with only 1.14 inches of rain ranked
as the 7th driest August on record. By the end of the month, the
Downeast region north into parts of southern Aroostook county were
In moderate drought according to the U.S. Drought Monitor.

Overall, the number of reports of severe weather were below
average. The most significant event was a pair of EF-1 tornadoes
that touched down late on the evening of August 5th. The first
touched down 2 miles to the northeast of Millinocket in Penobscot
County, and the 2nd in the Sherman area in Aroostook County.

The outlook for meteorological fall (September through November)
for northern and eastern Maine from the Climate Prediction Center,
calls for an increased likelihood of above average temperatures.
There are no strong climate signals that would point toward an
unusually wet or dry fall.