Sunday, January 26, 2020

Winter/Spring Potential Flood Outlook For Northern & Eastern Maine

000
FGUS71 KCAR 240300
ESFCAR
MEC003-009-019-021-029-310300-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE CARIBOU ME
1000 PM EST Thu Jan 23 2020

...SPRING FLOOD POTENTIAL OUTLOOK FOR NORTHERN... CENTRAL...AND
DOWNEAST MAINE...

This is the second Winter/Spring Flood Potential Outlook for
2020, issued by the National Weather Service in Caribou, Maine.
This outlook is for Northern, Central, and Downeast Maine for the
two-week period of January 23rd to February 6th, 2020.

The flood potential for open water flooding and flooding due to
ice jams is near normal for this time of year.

...CLIMATOLOGICAL GUIDANCE...

The second and third week of January 2020 continued with an active
weather pattern with a series of storms hitting the region with a
variation in temperatures. The first storm came across the region
on the weekend of January 11th and 12th. This system brought
snowfall up to 12 inches across portions of Northern Maine with
sleet of 2 to 4 inches, while the Maine Central Highlands received
5 to 8 inches with sleet of 1 to 2 inches. Further south from
Bangor to the coast, warmer air held on longer for rain until the
very end of the event as colder air moved in allowing for a
changeover to some freezing rain and snow with light snowfall
amounts. Much colder air poured in behind this system by the
middle of the following week. A second system moved across the
southern portion of the region affecting mainly the Maine Central
Highlands down to the coast with snowfall of 4 to 7 inches. A
third storm moved in across the region during the weekend of the
18th and 19th. This system brought 8 to 12 inches of snow across
Aroostook County with the highest amounts across the Houlton
area. Further south from the Maine Central Highlands into the
Bangor region down to the coast, snowfall amounts averaged 4 to 9
inches. These latest snowfall events increased the snowpack
across the region.

In regards to temperatures, after a stretch with above normal
temperatures, Arctic air pushed its way into the region by the
beginning of the 3rd week of January brought temperatures down
below normal. The mornings of Martin Luther King Day and on
Tuesday, saw early morning temperatures below zero. Temperatures
on Tuesday morning were some of the coldest reading so far this
winter season. Masardis in Central Aroostook County, recorded a
morning low on Tuesday of -26 degrees. Ripogenus Dam in
Piscataquis County had a morning low temperature of -20 and Lincoln
in Central Penobscot County, came in with a morning low of
-19.

The weather pattern looks like it could be rather active over the
next 5 to 10 days with a few weather systems affecting the
region. A storm system is forecast to affect the region this
coming weekend with snow or mixed precipitation. There is the
possibility that another system could affect the region late next
weekend which could bring another round of snow or mixed
precipitation to the region.

The official National Weather Service 6 to 14 day outlook is
calling for near to slightly above normal temperatures and near
to slightly above normal precipitation.

...OBSERVED SNOW DEPTH AND WATER EQUIVALENTS...

Snow depths ranged from 17 to 24 inches across Northern and
Northwest Maine, with the Maine Central Highlands showing snow
depths of 10 to 18 inches. Snow depths from the Bangor area down
to the coast ranged from 5 to 9 inches. Snow depths increased to
near normal.

The snow water equivalent, or the amount of water contained in
the snowpack continues to be the highest across northern and
central areas with 3 to 5 inches of water being recorded. Across
the Maine Central Highlands to the Downeast region, 1 to 3 inches
of water was common in the snowpack.

The snow water equivalent is near normal for this time of year.

...SOIL MOISTURE AND WATER SUPPLY CONDITIONS...

Soil moisture was near to slightly above normal across northern
and central areas, while across the Downeast region including the
coast, soil moisture was above normal. The latest Palmer Drought
Severity Index, which measures soil moisture in the longer term,
continued to show near normal conditions.

Looking at the groundwater levels, courtesy of the USGS, levels
are near normal across northern and central areas, while across
the Bangor and interior Downeast region, levels continued above
normal.

...RIVER AND ICE CONDITIONS...

River flows continue to be near to slightly above normal for this
time of year across the region. The exception to this continues
to be across Washington County along the St. Croix River basin,
where flows are above normal.

The return of the colder air has allowed the ice to thicken up
across the region. River ice reformed across the southern rivers
including the Piscataquis, Penobscot and St. Croix rivers. There
was still some open stretches along these rivers. Ice covered a
majority of the St. John, Aroostook and Allagash River. Some open
channels were noted on the Aroostook River near Ashland and on the
St. John River near the International Bridge in Fort Kent.

Ice thicknesses ranged from 16 to 20 inches along the Aroostook
River and from 10 to 16 inches along the St. John and Allagash
River. Across the Piscataquis and Penobscot River, ice thickness
was generally 6 to 10 inches with the exception of East Branch of
the Penobscot River at Grindstone, where ice thickness was
measured at 15 inches. The Kingsbury Stream in Abbot in
Piscataquis County had an ice thickness measured at 15 inches.
Ice thickness along the St. Croix River was estimated to be 6 to
10 inches in spots.

An ice jam remains in place on the Aroostook River in Fort
Fairfield. This ice jam is about 3 miles in length. Some small ice
jams are locked in place on the Aroostook River in the vicinity of
Washburn. Ice was also reported to be bunched up on the St. John
River near the International Bridge in Madawaska.

Ice coverage and thicknesses were near normal, with the exception
of the Penobscot, Piscataquis and the St. Croix river basins,
where ice coverage and thicknesses are below normal.

...IN CONCLUSION...

Based on the above information, the flood potential for open water
flooding is near normal across the region at this time. The threat
for ice jam flooding is near normal, especially across the northern
rivers.

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 Outlook will be issued on Thursday,
February 6th.

$$

Hewitt

Late January Winter Storm Update Four


























Late January Winter Storm Update Three


























10:26 AM AST Sunday 26 January 2020
Rainfall warning in effect for:

Lunenburg County
Rain, heavy at times is expected. The frozen ground has a reduced ability to absorb this rainfall.

Total rainfall: 25 to 35 mm.

Locations: southwestern Nova Scotia.

Time span: until this afternoon.

Localized flooding in low-lying areas is possible.

Rainfall warnings are issued when significant rainfall is expected.

Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to NSstorm@canada.ca or tweet reports using #NSStorm.