Tuesday, January 14, 2020

Winter Storm Isaiah Event Summary

Storm Summary Number 7 for Southern Plains to Northern New England
Winter Storm
NWS Weather Prediction Center College Park MD
400 PM EST Sun Jan 12 2020

...Light snow exiting northern Maine as storm system departs from
the region...

All warnings and advisories related to this system have ended.

For a detailed graphical depiction of the latest watches, warnings
and advisories, please see www.weather.gov

At 300 PM EST...an area of low pressure with a central pressure of
1006 mb, or 29.71 inHg, was located about 50 miles, or 80
kilometers, east of Lunenberg, NS. From this low, a strong cold
front extended southward through the western Atlantic into the
southeastern U.S. as a stationary front. National Weather Service
radar and surface observations indicated that most, if not all,
precipitation has changed over into light and moderate snow across
central to northern Maine as the storm system tracks quickly to
the east away from New England. All rain has exited the region
with the exception of a few showers and thunderstorms near the
frontal boundary in the Southeast.

...Selected preliminary Storm Total Snowfall in inches from 700 PM
EST Thu Jan 09 through 300 PM EST Sun Jan 12...

...MAINE...
FORT KENT                        10.5                 
STOCKHOLM 3 W             9.0                 
CARIBOU NWS                  8.9                 
SINCLAIR                           8.8                 
LILLE 4 SSE                        8.0                 
VAN BUREN 1 NNW          4.5                 
JACKMAN                          3.0 ....

...Selected preliminary Storm Total Sleet in inches from 700 PM
EST Thu Jan 09 through 300 PM EST Sun Jan 12...

...MAINE...
EASTON                         4.00                 
FORT FAIRFIELD            3.00                 
OXBOW                           2.00                 
NEW LIMERICK              1.50                 
HOULTON                       1.10                 
LINCOLN                          1.10                 
ALEXANDER                    1.00                 
CHARLESTON                 0.90                 
MILO                                0.90                 
LEE 3 ENE                        0.70.....

.....The low pressure center offshore of Nova Scotia is forecast to
quickly track east into the open Atlantic through Monday morning.
Lingering snow showers across Maine are expected to persist for
another few hours into the early evening evening with any
additional accumulations minor, if any. Snow will come to an end
early tonight as high pressure builds in the wake of the departing
storm.

This will be the last Storm Summary issued by the Weather
Prediction Center for this event. Please refer to your local
National Weather service office for additional information.

Otto

Weather summary
for New Brunswick
issued by Environment Canada
at 2:18 a.m. AST Sunday 12 January 2020.

Discussion.

The following areas set a daily maximum temperature record on
January 11, 2020:

Grand Manan Area (Grand Manan SAR CS)
New record of 11.2
Old record of 11.1 set in 1980
Records in this area have been kept since 1883

Point Lepreau Area (Point Lepreau CS)
New record of 9.9
Old record of 9.7 set in 2017
Records in this area have been kept since 1928

Note: the temperature records reported here have been derived from a
selection of historical stations in each geographic area that were
active during the period of record.

Please note that this summary may contain preliminary or unofficial
information and does not constitute a complete or final report.

End/ASPC

Weather summary
for Nova Scotia
issued by Environment Canada
at 2:19 a.m. AST Sunday 12 January 2020.

Discussion.

The following areas set a daily maximum temperature record on
January 11, 2020:

Greenwood Area (Greenwood A)
New record of 14.7
Old record of 14.6 set in 1983
Records in this area have been kept since 1914

Kentville Area (Kentville CDA CS)
New record of 14.0
Old record of 13.5 set in 1983
Records in this area have been kept since 1898

Note: the temperature records reported here have been derived from a
selection of historical stations in each geographic area that were
active during the period of record.

Please note that this summary may contain preliminary or unofficial
information and does not constitute a complete or final report.

End/ASPC

Winter/Spring Potential Flood Outlook For Northern & Eastern Maine

000
FGUS71 KCAR 092206
ESFCAR
MEC003-009-019-021-029-130000-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE CARIBOU ME
506 PM EST THU JAN 9 2020

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

THIS IS THE FIRST 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 9TH TO JANUARY 23RD, 2019.

THE FLOOD POTENTIAL FOR OPEN WATER FLOODING AND FLOODING DUE TO
ICE JAMS IS NEAR NORMAL FOR THIS TIME OF YEAR.

...CLIMATOLOGICAL GUIDANCE...

NOVEMBER 2019 CAME IN WELL BELOW NORMAL FOR TEMPERATURES AND
ABOVE NORMAL FOR SNOWFALL. A SERIES OF SNOW STORMS AFFECTED THE
REGION DURING THE MONTH. THE NATIONAL WEATHER SERVICE IN CARIBOU
RECORDED 23 INCHES FOR THE MONTH, WHICH WAS 10.5 INCHES ABOVE
NORMAL. BANGOR RECORDED 4.7 INCHES OF SNOWFALL, WHICH WAS 2.4
INCHES ABOVE NORMAL FOR NOVEMBER. DECEMBER 2019 FOLLOWED WITH A
WARMING TREND AND CAME IN ABOVE NORMAL FOR TEMPERATURES AND BELOW
NORMAL FOR SNOWFALL. A SERIES OF RAIN EVENTS EARLY IN THE MONTH
REDUCED THE SNOWPACK SIGNIFICANTLY ACROSS NORTHERN AND CENTRAL
AREAS WHILE THE DOWNEAST REGION LOST ALL ITS SNOW. THIS RAINFALL
LED TO RISES ON RIVERS AND STREAMS AND ALLOWED FOR ICE TO BREAK UP
ON THE RIVERS. TEMPERATURES COOLED DOWN BY THE 3RD AND 4TH WEEK OF
THE MONTH WITH A FEW SNOW EVENTS. THIS COLDER WEATHER ALSO ALLOWED
FOR ICE TO REFORM ON THE RIVERS AND STREAMS, ESPECIALLY ACROSS THE
NORTHERN RIVERS.

JANUARY 2020 STARTED OUT ABOVE NORMAL WITH A SERIES OF WEATHER
EVENTS WHICH BROUGHT SOME LIGHT SNOWFALL TO THE REGION.
TEMPERATURES FOR THE FIRST WEEK OF JANUARY HAVE AVERAGED ABOVE
NORMAL ACROSS THE REGION.

A FAIRLY ACTIVE WEATHER PATTERN LOOKS TO BE IN STORE FOR THE
REGION OVER THE NEXT 5 TO 10 DAYS WITH A SERIES OF WEATHER SYSTEMS
TO AFFECT THE REGION. A SIGNIFICANT STORM SYSTEM IS FORECAST TO
AFFECT THE REGION THIS COMING WEEKEND WITH RAIN CHANGING TO MIXED
PRECIPITATION AND SNOW. ANOTHER SYSTEM A WEATHER SYSTEM THAT
COULD AFFECT THE REGION BY MID TO LATE WEEK THAT COULD BRING
ANOTHER ROUND OF MIXED PRECIPITATION TO THE REGION.

THE OFFICIAL NATIONAL WEATHER SERVICE 6 TO 14 DAY OUTLOOK IS
CALLING FOR NEAR NORMAL TEMPERATURES AND NORMAL TO SLIGHTLY ABOVE
NORMAL PRECIPITATION.

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

SNOW DEPTHS RANGED FROM 10 TO 17 INCHES ACROSS NORTHERN AND
NORTHWEST MAINE, WHILE ACROSS THE MAINE CENTRAL HIGHLANDS, SNOW
DEPTHS RANGED FROM 5 TO 9 INCHES. THE DOWNEAST REGION INCLUDING
THE COAST RECORDED 2 TO 5 INCHES OF SNOW DEPTH. SNOW DEPTHS WERE
BELOW NORMAL FOR EARLY JANUARY.

THE SNOW WATER EQUIVALENT, OR THE AMOUNT OF WATER CONTAINED IN
THE SNOWPACK IS THE HIGHEST ACROSS NORTHERN AND CENTRAL AREAS
WITH 2 TO 4 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,
WITH THE EXCEPTION OF THE DOWNEAST REGION, AS SNOW WATER
EQUIVALENTS WERE BELOW NORMAL.

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

SOIL MOISTURE WAS NEAR NORMAL ACROSS NORTHERN AND CENTRAL AREAS,
WHILE 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, WAS SHOWING NEAR NORMAL
CONDITIONS.

LOOKING AT THE GROUNDWATER LEVELS, COURTESY OF THE USGS, NEAR
NORMAL WITH THE EXCEPTION OF THE BANGOR AND INTERIOR DOWNEAST
REGION, AS LEVELS WERE ABOVE NORMAL.

...RIVER AND ICE CONDITIONS...

RIVER FLOWS WERE NEAR NORMAL FOR THIS TIME OF YEAR FOR A MAJORITY
OF THE REGION. THE EXCEPTION TO THIS WAS ACROSS WASHINGTON COUNTY
ALONG THE ST. CROIX RIVER BASIN, WHERE FLOWS WERE ABOVE NORMAL.

THE VERY COLD TEMPERATURES FROM NOVEMBER INTO THE FIRST WEEK OF
DECEMBER ALLOWED ICE TO FORM EARLY ON THE RIVERS AND THICKEN UP
SOME. THE GOOD SNOWPACK THAT SET UP IN NOVEMBER HELPED TO KEEP THE
ICE FROM THICKENING UP MORE. THE WARMUP THAT OCCURRED DURING THE
14TH AND 15TH ALLOWED ICE TO BREAK UP WITH A SUBSTANTIAL
REDUCTION IN THE SNOWPACK. AS A MATTER OF FACT, MUCH OF THE ICE
ACROSS THE PENOBSCOT RIVER, ESPECIALLY SOUTH OF GRINDSTONE,
FLUSHED OUT. ICE ALSO FLUSHED OUT ALONG THE ST. CROIX RIVE BASIN.
COLDER AIR FOLLOWING AFTER THE 15TH, ALLOWED THE ICE ACROSS THE
NORTHERN MAINE RIVERS TO FREEZE BACK UP. THIS LEAD TO A ICE
BUNCHING UP ON ST. JOHN RIVER NEAR DICKEY. AN ICE JAM DEVELOPED ON
THE AROOSTOOK RIVER IN FORT FAIRFIELD. THIS ICE JAM IS ABOUT 3
MILES IN LENGTH. THERE WAS SOME OPEN WATER NOTED ALONG THIS
STRETCH OF THE RIVER TOWARD THE CARIBOU AREA, AND IN THE TOWN OF
ASHLAND. SOME OPEN WATER WAS ALSO NOTED ALONG THE ST. JOHN RIVER
SOUTH OF FORT KENT TO MADAWASKA. ICE REFORMED ON THE PISCATAQUIS,
PENOBSCOT AND ST. CROIX RIVERS. THERE WAS ALSO OPEN WATER NOTED ON
THESE RIVERS.

ICE COVERAGE AND THICKNESSES WERE BELOW NORMAL FOR EARLY JANUARY.

...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 FOR EARLY JANUARY, 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, JANUARY
23RD.

$$

HEWITT