Flood Potential Outlook
Issued by NWS Caribou, ME

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FGUS71 KCAR 152053

450 PM EST Thursday Mar 15 2018


This is the sixth Winter/Spring Flood Potential Outlook for 2018,
issued by the National Weather Service in Caribou, Maine. This
Outlook is for Northern, Central and Downeast Maine for the two week
period of March 15th to March 29th, 2018. These outlooks will be
issued every two weeks until the end of the snow melt season, and
will assess the potential for flooding based on a number of factors.

The flood potential for open water flooding is now above normal for the
entire area. The potential for flooding due to ice jams is near to slightly
above normal for the central and northern rivers respectively.


The past two weeks featured two major snow events that brought a heavy
amount of snow to the region as temperatures continued above normal.
Precipitation ran above normal for the first two weeks of March.

The first major event came on the 8th and 9th as intense low pressure moved
across the Gulf of Maine and then through the Maritimes. This system
brought anywhere from 8 to 17 inches of snow across the Central Highlands
and Downeast areas. Across Northern and Northwest Maine, snowfall ranged
from 6 to 12 inches. The second major event came on the 13th and 14th as
another intense low pressure system moved across the Gulf of Maine and
lifted up through the Maritimes. This system brought anywhere from 18 to
25 inches across the Central Highlands and Downeast Maine with some sites
reporting up to 30 inches of wet snow from this event. Across Northeast
and Northwest Maine, snowfall amounts ranged from 7 inches in Caribou to
16 inches in Allagash. Some sites in Southeast Aroostook County came in
with a range of 18 to 23 inches. Hodgdon in Southeast Aroostook County
reported new snowfall of 23 inches as of this morning.

A look into the next two weeks shows the weather pattern turning colder
and much more tranquil than the past two weeks. There is the possibility
for a system to affect the region by late next week, mainly for Downeast
Maine with the potential for some snow.

The official National Weather Service 8 to 14 day outlook is calling for
below normal temperatures with below normal precipitation.


Snow depths ranged from 30 to 40 inches across Northern and Northwest Maine
which includes the Houlton area. Winterville came in with a snow depth of
43 inches as of March 13th. Further south into the Central Highlands,
snow depths ranged from 20 to 30 inches. The interior Downeast region
including the Bangor area increased significantly with a range of 18 to 28
inches. As of this morning, Bangor reported a snow depth of 28 inches.
Snow depths increased dramatically along coast with a range of 15 to
25 inches.

Snow depths are slightly above normal across Northern Maine into the
Central Highlands while the rest of region was near normal.

The snow water equivalents, or the amount of water contained in the
snowpack, increased to 8 to 11 inches across Northern and Northwest
Maine. The forecast office in Caribou recorded 8.6 inches of water
in the snowpack with 34 inches on the ground as of this morning.
Across the Central Highlands and interior Downeast, snow water equivalents
increased to a range of 7 to 9 inches. Snow water equivalents along the
coast ranged from 4 to 6 inches. The snow water equivalents were near normal
across entire region.


Soil moisture across the region remained above normal. The
latest Palmer Drought Severity Index, which measures soil moisture
in the longer term, continued to show above normal conditions.

A look at the groundwater levels, courtesy of the USGS, showed
levels remaining at near to above normal across the region.


River flows were near normal throughout much the region with
the exception of Washington County where river flows continued above

Rivers across Northern Maine were 90% snow and ice covered. Open water
was noted on the Aroostook River near Ashland and along the Fish River
south of Fort Kent. The Penobscot River had open water south of Eddington.
Across the northern Branch of the Penobscot, ice remained locked in. The
Piscataquis River had open water with some ice still locked in east of the
town of Milo. The ice was showing signs of weakening. The Pleasant
River and The Kingsbury Stream in Southern Piscataquis County still had a
good deal of ice but open water was noted.

Ice still remained on the Kenduskeag Stream in Bangor but was showing
signs of weakening. A few small ice jams remain on the Pleasant River and
Kingsbury Stream with signs of settling.

Ice thicknesses remain around 24 inches across the the Northern Maine
rivers including the St. John and Aroostook River. An ice thickness of
24 to 30 inches remained on the Seboeis River in northern Penobscot County.
Ice thicknesses were in the range of 10 to 12 inches on the Piscataquis
and Penobscot Rivers as well as the St. Croix river basin. Above normal
temperatures over the last couple of weeks has allowed for the ice to

Given the latest 8 to 14 day outlook calling for below normal temperatures,
most of the ice should remain in place into the last week of March, especially
across the northern rivers. At this time, ice thicknesses are not expected to
increase given that we are into the third week of March.


Based on the above information, the flood potential for open
water flooding is now above normal across the region.

The threat for ice jam flooding is slightly above normal for the northern
river basins.

It is important to remember that a heavy rainfall event along
with mild temperatures can lead to an increased potential for
flooding with snowmelt and runoff. Ice breaking up and jamming can
elevate the threat for flooding in a short period of time.

The next Winter/Spring Flood Potential Outlook will be issued by
the NWS in Caribou on March 29th.



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