Extended Streamflow Guidance
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WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE
NORTHEAST RIVER FORECAST CENTER NORTON MA
652 PM EST WED FEB 6 2019

...FOR OFFICIAL NATIONAL WEATHER SERVICE USE ONLY...

WINTER/SPRING FLOOD POTENTIAL FOR THE NORTHEASTERN U.S. /3/

THE WINTER/SPRING FLOOD POTENTIAL FOR THE NORTHEASTERN UNITED STATES
IS NEAR TO ABOVE NORMAL ACROSS THE ENTIRE NERFC SERVICE AREA. IN THE
NEAR TERM...THE WINTER/SPRING FLOOD POTENTIAL IS MOST ABOVE NORMAL
ACROSS WESTERN PORTIONS OF NEW YORK STATE AND IN THE LONGER TERM THE
FLOOD POTENTIAL IS MOST ABOVE NORMAL FROM NORTHEAST VERMONT EAST
ACROSS NORTHERN NEW HAMPSHIRE INTO ALL OF INTERIOR MAINE.

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS NEAR TO ABOVE NORMAL
ACROSS INTERIOR NEW YORK STATE EAST OF THE FINGER LAKES AND ACROSS
MUCH OF NORTHERN NEW ENGLAND. THE THREAT FOR ICE JAM FLOODING IS
ELEVATED IN THE NEAR TERM ACROSS MUCH OF CENTRAL NEW YORK STATE AND
CENTRAL NEW ENGLAND AND IN THE LONGER TERM ACROSS NORTHERN NEW YORK
STATE AND NORTHERN NEW ENGLAND. THE POTENTIAL FOR FLOODING DUE TO
ICE JAMS IS NOW BELOW NORMAL ACROSS MOST OF SOUTHERN NEW ENGLAND AND
WEST OF THE FINGER LAKES IN NEW YORK STATE AS MOST OF THAT ICE HAS
BEEN FLUSHED OUT OVER THE PAST WEEK.

...CLIMATE GUIDANCE...

THE WILD SWINGS IN WEATHER CONTINUE THIS WINTER ACROSS A LOT OF NEW
YORK STATE AND NEW ENGLAND AS THE NERFC SERVICE AREA HAS OSCILLATED
BETWEEN NEAR RECORD WARMTH AND NEAR RECORD COLD. OVER THE PAST TWO
WEEKS...WE HAVE SEEN HEAVY RAINFALL...WIDESPREAD FLOODING AND ICE
JAM FLOODING ACROSS NEW YORK STATE AND SOUTHERN/CENTRAL NEW ENGLAND
AND TEMPERATURES OF 20 TO 30 BELOW ZERO ACROSS NORTHERN NEW YORK
STATE AND NORTHERN NEW ENGLAND WITH AN IMPRESSIVE ARCTIC INTRUSION.

THE ONE CONSTANT THIS WINTER HAS BEEN THE INABILITY FOR COLD AIR TO
BECOME ESTABLISHED FOR ANY LENGTH OF TIME ACROSS SOUTHERN NEW
ENGLAND AND SOUTHEAST NEW YORK STATE WHILE AREAS FURTHER NORTH AND
WEST HAVE BEEN CLOSER TO SEASONAL NORMAL TEMPERATURES. THE PRIMARY
FACTOR IN THIS PATTERN SEEMS TO BE THE NORTH ATLANTIC OSCILLATION
INDEX ( NAO ). IT HAS REMAINED LARGELY NEUTRAL TO POSITIVE SINCE THE
BEGINNING OF DECEMBER 2018. WITH A POSITIVE NAO...THERE IS LITTLE IN
THE WAY OF DOWNSTREAM BLOCKING AND ANY INTRUSION OF COLD AIR IS
QUICKLY SHUNTED EASTWARD TOWARDS THE CANADIAN MARITIMES AND NORTH
ATLANTIC OCEAN. WE SAW THIS SCENARIO WITH THE LATEST ARCTIC
INTRUSION IN LATE JANUARY AND EARLY FEBRUARY WHICH ONLY LASTED A DAY
OR TWO BEFORE BEING REPLACED WITH MILD AIR AND EVEN RAINFALL.

GOING FORWARD...THERE ARE NO DEFINITIVE SIGNS THAT THIS OVERALL
PATTERN WILL CHANGE. THE FAVORED STORM TRACK IS EXPECTED TO BE NEAR
OR EVEN WEST OF THE NERFC SERVICE AREA WHICH WILL LIKELY PROVIDE
MORE MIXED PRECIPITATION AND RAINFALL ACROSS SOUTHERN AREAS WITH THE
BEST CHANCE FOR SNOW ACROSS NORTHERN NEW ENGLAND...ESPECIALLY MAINE.
A STORM SYSTEM THURSDAY NIGHT AND FRIDAY WILL TRACK WEST AND NORTH
OF THE REGION AND ANOTHER POTENTIAL STORM SYSTEM NEXT WEEK MAY ALSO
FOLLOW A SIMILAR TRACK.

THE OFFICIAL NATIONAL WEATHER SERVICE 8 TO 14 DAY OUTLOOK FOR 13-19
FEBRUARY 2019 MESHES FAIRLY WELL WITH THIS THINKING. IT CALLS FOR
TEMPERATURES TO AVERAGE NEAR NORMAL ACROSS MOST OF CENTRAL/NORTHERN
NEW ENGLAND AND INTERIOR NEW YORK STATE AND ABOVE NORMAL ACROSS A
LOT OF SOUTHERN NEW ENGLAND AND SOUTHEAST NEW YORK STATE.
PRECIPITATION FOR THE SAME TIME PERIOD IS EXPECTED TO AVERAGE ABOVE
NORMAL ACROSS THE ENTIRE 7 STATE REGION OF NEW ENGLAND AND NEW YORK
STATE.

...OBSERVED SNOW DEPTHS AND WATER EQUIVALENTS...

THE RECENT RAINS AND WARM TEMPERATURES HAVE DECIMATED THE SNOWPACK
ACROSS SOUTHERN NEW ENGLAND AND SOUTHERN/WESTERN NEW YORK STATE BUT
A HEALTHY SNOWPACK REMAINS IN PLACE ACROSS NORTHERN NEW YORK STATE
AND NORTHERN NEW ENGLAND...ESPECIALLY FROM THE MOUNTAINS OF
NORTHEAST VERMONT AND NORTHERN NEW HAMPSHIRE INTO INTERIOR MAINE.

...NEW YORK STATE...

THERE IS LITTLE IN THE WAY OF MEANINGFUL SNOWCOVER SOUTH AND WEST OF
THE MOHAWK RIVER IN NEW YORK STATE. THE ONLY EXCEPTIONS TO THIS RULE
WOULD BE FOUND IN THE CATSKILL MOUNTAINS IN SOUTHEAST NEW YORK STATE
WHERE UP TO A FOOT OF SNOW REMAINS ABOVE 2000 FEET AND IN SOME OF
THE HIGH TERRAIN BETWEEN BINGHAMTON AND SYRACUSE WHERE SNOW DEPTHS
OF UP TO 10 INCHES ARE BEING REPORTED. IN THE TUG HILL PLATEAU AND
SAINT LAWRENCE VALLEY REGIONS OF NORTHERN NEW YORK STATE...SNOW
DEPTHS AVERAGE BETWEEN 6 AND 12 INCHES WITH SOME 1 TO 2 FOOT DEPTHS
OBSERVED ABOVE 1500 FEET IN THE TUG HILL PLATEAU. BY FAR...THE
DEEPEST SNOWPACK ACROSS NEW YORK STATE IS FOUND IN THE ADIRONDACK
MOUNTAINS. THERE...SNOW DEPTHS IN THE VALLEYS AVERAGE BETWEEN 8 AND
16 INCHES...INCREASING TO BETWEEN 1 AND 2.5 FEET ABOVE 2000 FEET.
SNOW DEPTHS ACROSS NEW YORK STATE ARE NEAR NORMAL FOR THE SAINT
LAWRENCE VALLEY AND ADIRONDACK MOUNTAIN REGIONS BUT LARGELY BELOW
NORMAL ELSEWHERE FOR EARLY FEBRUARY.

THERE IS LITTLE MELTWATER IN THE SPARSE SNOWPACK SOUTH AND WEST OF
THE MOHAWK RIVER IN NEW YORK STATE. AS MUCH AS 2 OR 3 INCHES OF
WATER IS HELD IN THE SNOWPACK OVER THE HIGHEST TERRAIN IN THE
CATSKILL MOUNTAIN RANGE AND AN INCH OR TWO IS FOUND IN THE HIGH
TERRAIN SNOWPACK BETWEEN BINGHAMTON AND SYRACUSE. OTHERWISE...MOST
OF SOUTHEAST...CENTRAL AND WESTERN NEW YORK STATE HAS JUST PATCHES
OF SNOW. ACROSS THE TUG HILL PLATEAU AND SAINT LAWRENCE VALLEY
REGIONS OF NORTHERN NEW YORK STATE...SNOW WATER EQUIVALENTS AVERAGE
BETWEEN 2 AND 4 INCHES WITH SOMEWHAT LOWER AMOUNTS IN THE VALLEYS OF
THE TUG HILL PLATEAU WHERE OBSERVATIONS INDICATE LESS THAN 2 INCHES
OF WATER BEING HELD IN THE SNOWPACK. ACROSS THE ADIRONDACK MOUNTAIN
REGION OF NORTHERN NEW YORK STATE...SNOW WATER EQUIVALENTS OF 2 TO 4
INCHES ARE COMMON IN THE VALLEYS...WITH AMOUNTS INCREASING TO
BETWEEN 4 AND 8 INCHES ABOVE 2000 FEET WITH LOCALLY HIGHER AMOUNTS.
SNOW WATER EQUIVALENTS ACROSS NEW YORK STATE ARE BELOW NORMAL EXCEPT
ACROSS THE ADIRONDACKS AND SAINT LAWRENCE VALLEY WHERE THEY ARE
FAIRLY CLOSE TO MID-WINTER NORMALS.

...SOUTHERN NEW ENGLAND...

ACROSS SOUTHERN NEW ENGLAND...THE SNOWPACK HAS RETREATED TO AREAS
WEST OF THE CONNECTICUT RIVER IN NORTHWEST CONNECTICUT AND WESTERN
MASSACHUSETTS WHERE DEPTHS OF 6 INCHES OR LESS ARE BEING OBSERVED.
SNOW DEPTHS ARE LOCALLY HIGHER IN THE HIGHEST TERRAIN OF THE
BERKSHIRE MOUNTAINS IN NORTHWEST MASSACHUSETTS WHERE UP TO A FOOT OR
SO OF SNOW STILL COVERS THE GROUND. SNOW DEPTHS ARE BELOW NORMAL
ACROSS SOUTHERN NEW ENGLAND FOR EARLY FEBRUARY.

SNOW WATER EQUIVALENTS ACROSS NORTHWEST CONNECTICUT AND WESTERN
MASSACHUSETTS WEST OF THE CONNECTICUT RIVER AVERAGE BETWEEN A TRACE
AND 2 INCHES WITH LOCALLY 2 TO 4 INCHES ABOVE 1500 FEET IN THE
HIGHER TERRAIN OF NORTHWEST MASSACHUSETTS. SNOW WATER
EQUIVALENTS...LIKE SNOW DEPTHS...ARE BELOW NORMAL ACROSS SOUTHERN
NEW ENGLAND FOR MID-WINTER.

...VERMONT...

SNOW DEPTHS ACROSS SOUTHERN AND FAR WESTERN VERMONT ( WEST OF THE
GREEN MOUNTAIN SPINE ) AVERAGE 10 INCHES OR LESS IN THE VALLEYS.
SNOW DEPTHS IN THE VALLEYS OF THE NORTHEAST KINGDOM OF VERMONT
AVERAGE BETWEEN 1 AND 2 FEET. ACROSS THE HIGHER ELEVATIONS OF THE
GREEN MOUNTAINS...SNOW DEPTHS AVERAGE BETWEEN 1 AND 2.5 FEET WITH
LOCALLY HIGHER AMOUNTS ABOVE 2000 FEET IN NORTHERN VERMONT. SNOW
DEPTHS ACROSS VERMONT ARE NOT TOO FAR FROM NORMAL...PERHAPS A TAD
BELOW NORMAL IN FAR SOUTHERN VERMONT.

ACROSS THE LOWER ELEVATIONS IN SOUTHERN AND FAR WESTERN
VERMONT...SNOW WATER EQUIVALENTS AVERAGE BETWEEN 1 AND 3 INCHES. THE
VALLEYS OF CENTRAL AND NORTHEAST VERMONT REPORT MORE WATER LOCKED IN
THE SNOWPACK...AVERAGING BETWEEN 2 AND 5 INCHES. ACROSS THE HIGHER
TERRAIN OF THE GREEN MOUNTAINS IN VERMONT...SNOW WATER EQUIVALENTS
OF 4 TO 8 INCHES ARE QUITE COMMON WITH SOME HIGHER AMOUNTS IN AND
AROUND MOUNT MANSFIELD AND IN THE NORTHEAST KINGDOM. SNOW WATER
EQUIVALENTS FOR EARLY FEBRUARY ARE NEAR NORMAL ACROSS THE GREEN
MOUNTAIN STATE EXCEPT FOR THE FAR SOUTH WHERE THEY ARE A BIT BELOW
NORMAL FOR EARLY FEBRUARY.

...NEW HAMPSHIRE...

ACROSS ROUGHLY THE SOUTHERN ONE-THIRD OF NEW HAMPSHIRE...SNOW DEPTHS
ARE NOW AVERAGING NEAR OR UNDER 10 INCHES WITH BARE GROUND COMMON
ALONG THE BORDER WITH MASSACHUSETTS AND ALONG THE SEACOAST. IN
CENTRAL AND NORTHERN NEW HAMPSHIRE...MOST VALLEY LOCATIONS REPORT 1
TO 2 FEET OF SNOW COVERING THE GROUND WITH 2 TO 3 FEET ABOVE 1500
FEET. SNOW DEPTHS ACROSS CENTRAL AND NORTHERN NEW HAMPSHIRE ARE NEAR
NORMAL BUT TRANSITION RAPIDLY TO BELOW NORMAL IN SOUTHERN PORTIONS
OF THE GRANITE STATE.

ACROSS ROUGHLY THE SOUTHERN ONE-THIRD OF NEW HAMPSHIRE...SNOW WATER
EQUIVALENTS RANGE FROM A TRACE TO AS MUCH AS 3 INCHES WITH ONLY
ISOLATED HIGHER AMOUNTS ABOVE 1000 FEET. IN CENTRAL AND NORTHERN
PORTIONS OF THE STATE OF NEW HAMPSHIRE...SNOW WATER EQUIVALENTS IN
THE VALLEYS AVERAGE BETWEEN 3 AND 6 INCHES...INCREASING TO BETWEEN 5
AND 9 INCHES ABOVE 1500 FEET. AS OF THIS MORNING...MOOSE FALLS IN
FAR NORTHERN NEW HAMPSHIRE REPORTED 8.5 INCHES OF WATER LOCKED UP IN
THE 34 INCH SNOWPACK AND THE U.S. ARMY CORPS OF ENGINEERS SNOW
SURVEY TAKEN ON 5 FEBRUARY 2019 INDICATED 10.6 INCHES OF WATER HELD
IN THE SNOWPACK AT BREEZY POINT IN THE WHITE MOUNTAINS OF NORTHERN
NEW HAMPSHIRE. SNOW WATER EQUIVALENTS ARE NEAR TO ABOVE NORMAL
ACROSS THE HIGH TERRAIN OF CENTRAL AND NORTHERN NEW HAMPSHIRE BUT
DROP OFF RAPIDLY TO BELOW NORMAL IN FAR SOUTHERN SECTIONS OF THE
STATE.

...MAINE...

A DEEP AND WATER LADEN SNOWPACK REMAINS IN PLACE ACROSS ALL OF
INTERIOR MAINE.

WITHIN 20 OR 30 MILES OF THE COAST IN MAINE...SNOW DEPTHS AVERAGE
NEAR OR LESS THAN 10 INCHES. SNOW DEPTHS ACROSS INTERIOR DOWNEAST
MAINE ARE A BIT HIGHER...RUNNING BETWEEN 10 AND 20 INCHES. FROM THE
FOOTHILLS AND MOUNTAINS OF WESTERN MAINE NORTH INTO ALL OF NORTHERN
MAINE...SNOW DEPTHS AVERAGE BETWEEN 1.5 AND 3 FEET WITH THE HIGHEST
AMOUNTS FOUND IN THE NORTHWEST LOGGING WOODS AND NORTHEAST POTATO
COUNTRY OF MAINE. AS OF THIS MORNING...32 INCHES OF SNOW WAS
BLANKETING THE GROUND IN CARIBOU. SNOW DEPTHS ARE NEAR TO ABOVE
NORMAL ACROSS ALL OF THE STATE EXCEPT FOR THE COASTAL PLAIN WHERE
THEY ARE NEAR TO BELOW NORMAL FOR THE MIDDLE OF WINTER.

WITHIN 20 OR 30 MILES OF THE COAST IN MAINE...SNOW WATER EQUIVALENTS
AVERAGE BETWEEN A TRACE AND 3 INCHES. THESE VALUES INCREASE TO
BETWEEN 3 AND 6 INCHES ACROSS INTERIOR DOWNEAST SECTIONS OF THE
STATE. ACROSS THE REMAINDER OF THE STATE OF MAINE...TO INCLUDE THE
FOOTHILLS...WESTERN AND CENTRAL HIGHLANDS...NORTHWEST LOGGING WOODS
AND NORTHEAST POTATO COUNTRY...SNOW WATER EQUIVALENTS AVERAGE
BETWEEN 4 AND 8 INCHES WITH AS MUCH AS 9 OR 10 INCHES IN THE HIGHER
TERRAIN OF NORTHERN MAINE. AS OF 4 FEBRUARY 2019...CARIBOU REPORTED
8.4 INCHES OF WATER LOCKED UP IN THE SNOWPACK. SNOW WATER
EQUIVALENTS ARE MOSTLY ABOVE NORMAL ACROSS INTERIOR AREAS OF MAINE
BUT NEAR TO BELOW NORMAL ALONG THE COAST. RECENT SNOW SURVEYS FROM
THE UPPER KENNEBEC WATERSHED IN WESTERN MAINE INDICATED SNOW WATER
EQUIVALENTS RUNNING 30 TO 35 PERCENT ABOVE NORMAL FOR EARLY FEBRUARY.

...SOIL MOISTURE AND GROUNDWATER CONDITIONS...

THE ACTIVE PRECIPITATION PATTERN ALONG WITH FREQUENT ROUNDS OF
SNOWMELT HAVE KEPT ANTECEDENT MOISTURE STATES QUITE HIGH ACROSS THE
7 STATE REGION OF NEW ENGLAND AND NEW YORK STATE DURING THE PAST FEW
MONTHS. IN FACT...ACROSS ALL OF SOUTHERN NEW ENGLAND AS WELL AS ALL
OF SOUTHERN AND WESTERN NEW YORK STATE...THE LATEST PALMER DROUGHT
SEVERITY INDEX ISSUED ON 2 FEBRUARY 2019 SHOWED EXTREMELY MOIST
MOISTURE STATES IN PLACE WHICH IS THE WETTEST POSSIBLE CATEGORY. THE
PALMER INDEX ASSESSES MOISTURE STATES ON A TIME SCALE OF WEEKS TO
MONTHS. NEAR SURFACE SOIL MOISTURE ANOMALY MAPS FROM 4 FEBRUARY 2019
ALSO SHOW ANOMALOUS WETNESS IN THESE AREAS WITH ONLY A SMALL PORTION
OF FAR NORTHERN NEW YORK STATE HAVING NEAR NORMAL SOIL MOISTURE
STATES.

TAKING A LOOK AT GROUNDWATER MONITORING WELLS ACROSS THE
REGION...MOST ALL AREAS ARE REPORTING NEAR OR ABOVE NORMAL
GROUNDWATER LEVELS FOR EARLY FEBRUARY. THE HIGHEST GROUNDWATER
LEVELS WERE BEING SEEN ACROSS THE LOWER HUDSON VALLEY IN SOUTHEAST
NEW YORK STATE AS WELL AS ACROSS COASTAL RHODE ISLAND WHERE RECORD
HIGH GROUNDWATER LEVELS WERE BEING OBSERVED FOR EARLY FEBRUARY. THE
UNITED STATES GEOLOGICAL SURVEY ( USGS ) GROUNDWATER MONITORING WELL
AT HYDE PARK IN SOUTHEAST NEW YORK STATE REPORTED A RECORD HIGH
WATER LEVEL FOR FEBRUARY YESTERDAY WITH A DATA RECORD GOING BACK 56
YEARS. USGS MONITORING WELLS AT BOTH RICHMOND AND EXETER IN
SOUTHWEST RHODE ISLAND ALSO SET RECORD HIGH FEBRUARY LEVELS ON 5
FEBRUARY 2019 WITH RECORDS GOING BACK 41 AND 37 YEARS RESPECTIVELY.

...RESERVOIR LEVELS...

LAKE AND RESERVOIR LEVELS REMAIN NEAR OR ABOVE NORMAL FOR EARLY
FEBRUARY THROUGHOUT JUST ABOUT ALL OF THE NERFC SERVICE AREA. IN NEW
YORK STATE...GREAT SACANDAGA LAKE WAS RUNNING ABOUT 14 FEET HIGHER
THAN NORMAL FOR EARLY FEBRUARY AND LAKE CHAMPLAIN WAS MORE THAN A
FOOT ABOVE ITS NORMAL MID-WINTER LEVEL. FURTHER SOUTH...THE NEW YORK
CITY WATER SUPPLY SYSTEM WHICH IS COMPRISED OF 7 LARGE RESERVOIRS IN
SOUTHEAST NEW YORK STATE...WAS RUNNING AT 96 PERCENT OF CAPACITY AS
OF 4 FEBRUARY 2019 WHICH WAS 8 PERCENT ABOVE NORMAL. 2 OF THE 7
RESERVOIRS WERE ACTUALLY ABOVE CAPACITY AND SPILLING WATER
UNCONTROLLED OVER THEIR SPILLWAY SYSTEMS.

IN NORTHERN NEW ENGLAND...RESERVOIR SYSTEMS IN THE ANDROSCOGGIN RIVER
BASIN DRAINING NORTHERN NEW HAMPSHIRE AND WESTERN MAINE WERE RUNNING
24 PERCENT HIGHER THAN NORMAL AS OF 4 FEBRUARY 2019. AND IN CENTRAL
NEW HAMPSHIRE...LAKE WINNIPESAUKEE WHICH IS THE STATES LARGEST
LAKE...WAS ABOUT 0.5 FEET ABOVE ITS NORMAL EARLY FEBRUARY POOL STAGE.

IN SOUTHERN NEW ENGLAND...THE QUABBIN RESERVOIR WHICH IS THE MAIN
WATER SUPPLY RESERVOIR FOR THE GREATER BOSTON METROPOLITAN
AREA...WAS AT 100.6 PERCENT CAPACITY AS OF 1 FEBRUARY 2019 AND
SPILLING WATER UNCONTROLLED OVER ITS SPILLWAY. IN NORTHERN RHODE
ISLAND...SCITUATE RESERVOIR...THE MAIN WATER SUPPLY RESERVOIR FOR
NORTHERN RHODE ISLAND INCLUDING THE CITY OF PROVIDENCE...WAS AT
103.8 PERCENT CAPACITY AND JUST SHY OF THE TOP OF FLASHBOARDS PUT IN
TO INCREASE RESERVOIR HEIGHT.

NEEDLESS TO SAY...WITH THE MOSTLY ABOVE NORMAL LAKE AND RESERVOIR
LEVELS AND WET SOIL STATES...WE FORESEE NO WATER SUPPLY PROBLEMS
HEADING INTO SPRING. IF ANYTHING...WE ARE WORRIED ABOUT AN EXCESS OF
WATER THAT MAY HAVE TO BE RELEASED AT SOME POINT.

...RIVER AND ICE CONDITIONS...

DUE TO LOCALLY EXCESSIVE RAINFALL AND SNOWMELT OVER THE PAST TWO
WEEKS...RIVER FLOWS REMAIN ABOVE TO MUCH ABOVE NORMAL ACROSS THE
ENTIRE NERFC SERVICE AREA. IN FACT...SEVERAL GAUGED RIVERS AND
STREAMS ARE SETTING RECORD HIGH FLOWS FOR 6 FEBRUARY ACROSS INTERIOR
NEW YORK STATE. ONE OF THESE SITES IS THE OATKA CREEK AT GARBUTT IN
WESTERN NEW YORK STATE WHICH REPORTED ITS HIGHEST FLOW FOR 6
FEBRUARY DURING THE ENTIRE 72 YEARS OF RECORD. THE ONLY LOCALES
WHERE FLOWS ARE ANYWHERE NEAR NORMAL ARE FOUND ACROSS FAR
SOUTHEASTERN NEW YORK STATE AND PORTIONS OF COASTAL SOUTHERN NEW
ENGLAND.

RIVER ICE HAS BECOME QUITE PROBLEMATIC AND VARIABLE ACROSS THE
REGION DUE TO THE INFLUX OF WARMTH AND RAIN AT TIMES OVER THE PAST
FEW WEEKS. RAPID SNOWMELT EARLIER THIS WEEK LED TO SOME FLOOD
PRODUCING ICE JAMS IN METROPOLITAN BUFFALO...SPECIFICALLY ALONG
PORTIONS OF THE CAZENOVIA AND BUFFALO CREEKS. MOST OF THE ICE ACROSS
WESTERN NEW YORK HAS BEEN FLUSHED OUT AS OF THIS MORNING. FURTHER
EAST AND NORTH IN NEW YORK STATE...NOTABLE BREAKUP JAMS THAT HAVE
FROZEN IN PLACE ARE BEING OBSERVED ON THE MOHAWK RIVER BETWEEN LOCK
7 AND 8 IN THE SCHENECTADY AREA...ON THE SCHOHARIE CREEK NEAR
PRATTSVILLE NEW YORK AND ON THE EAST BRANCH AU SABLE RIVER IN THE
TOWNS OF JAY AND KEENE VALLEY. FURTHER SOUTH IN NEW YORK STATE...ICE
IS ROTTING OUT AND WEAKENING ON THE WALLKILL RIVER IN THE LOWER
HUDSON VALLEY.

IN NEW ENGLAND...NUMEROUS ICE JAMS PERSIST...MOSTLY BREAKUP JAMS
FROM JANUARY THAT HAVE FROZEN IN PLACE. AN ICE JAM ALONG THE SOUTH
BRANCH PISCATAQUOG RIVER IN GOFFSTOWN NEW HAMPSHIRE IS CAUSING HIGH
WATER LEVELS AND DAMAGE TO TREES ALONG THE RIVERBANK. A SIZABLE ICE
JAM THAT PREVIOUSLY PRODUCED FLOODING REMAINS IN PLACE ALONG THE
PEMIGEWASSET RIVER AT PLYMOUTH NEW HAMPSHIRE. ICE JAMS ARE ALSO
BEING REPORTED ALONG THE SAINT JOHN RIVER FROM FORT KENT TO
MADAWASKA AND NEAR DICKEY AT THE CONFLUENCE WITH THE ALLAGASH RIVER
IN NORTHERN MAINE. ANOTHER ICE JAM IS CURRENTLY IN PLACE ALONG THE
AROOSTOOK RIVER AT WASHBURN ALSO IN NORTHERN MAINE.

IF THERE ARE NOT ICE JAMS ON RIVERS IN NORTHERN NEW YORK STATE AND
NORTHERN NEW ENGLAND...MOST OF THOSE RIVERS ARE ICE COVERED WITH
THICKNESSES OF 8 TO 14 INCHES WITH 12-18 INCH THICK ICE IN NORTHERN
MAINE. RECENT REPORTS FROM MAINE INDICATE THE ICE IS HARD AND BLACK
INDICATING QUITE A BIT OF STRUCTURAL INTEGRITY. THE AMOUNT OF JAMS
IN PLACE IS ABOVE WHAT WE NORMALLY SEE IN EARLY FEBRUARY.
HOWEVER...MOST OF THE ICE HAS RECENTLY MOVED OUT OF WESTERN AND FAR
SOUTHEASTERN SECTIONS OF NEW YORK STATE AND MOST OF SOUTHERN NEW
ENGLAND WITH JUST POCKETS OF WEAK ICE REMAINING.

...IN CONCLUSION...

BASED ON THE INFORMATION AVAILABLE AT THIS TIME...THE WINTER/SPRING
FLOOD POTENTIAL IS AT OR ABOVE NORMAL ACROSS THE ENTIRE NERFC
SERVICE AREA. THREATS EXIST IN BOTH THE NEAR TERM AND LONG TERM. IN
THE NEAR TERM ( THE NEXT WEEK TO 10 DAYS )...ABOVE TO MUCH ABOVE
NORMAL RIVER FLOWS...EXTREMELY MOIST ANTECEDENT MOISTURE STATES AND
THE PROSPECT FOR ABOVE NORMAL PRECIPITATION INDICATES MUCH OF
WESTERN NEW YORK STATE AND PORTIONS OF SOUTHERN NEW ENGLAND HAVE AN
ENHANCED RISK FOR FLOODING. IN FACT...SOME WESTERN NEW YORK STATE
WATERSHEDS COULD BE IN FLOOD AGAIN AS EARLY AS THURSDAY NIGHT OR
FRIDAY WITH MUCH OF THE ABOVE MENTIONED AREAS POSSIBLY SEEING HIGH
FLOWS AGAIN DURING THE MIDDLE OF NEXT WEEK DEPENDING ON THE TRACK OF
ANOTHER POTENTIAL STORM SYSTEM.

IN THE LONGER TERM...THE WINTER/SPRING FLOOD POTENTIAL REMAINS
SOMEWHAT ABOVE NORMAL ACROSS PORTIONS OF NORTHEAST
VERMONT...NORTHERN PORTIONS OF NEW HAMPSHIRE AND MOST OF INTERIOR
MAINE. IN THESE AREAS...RIVER FLOWS REMAIN ABOVE TO MUCH ABOVE
NORMAL...RESERVOIR AND LAKE LEVELS ARE HIGHER THAN
NORMAL...ANTECEDENT MOISTURE STATES ARE SOMEWHAT WET AND THERE ARE
LARGE AMOUNTS OF WATER AVAILABLE IN THE SNOWPACK FOR MELT RUNOFF.
THESE AREAS ARE ALSO FAR ENOUGH NORTH TO LIKELY ADD TO THE SNOWPACK
OVER THE NEXT FEW WEEKS AS THE FORECAST CALLS FOR ABOVE NORMAL
AMOUNTS OF PRECIPITATION THROUGH MID-FEBRUARY. ALL THESE FACTORS
INDICATE WE ARE LIKELY TO HEAD INTO LATE WINTER AND EARLY SPRING
WITH HIGHER THAN NORMAL SNOW WATER EQUIVALENTS WHICH COULD BECOME A
PROBLEM WITH ANY SUSTAINED WARM AND WET PERIODS. FOR THESE
REASONS...A SOMEWHAT ABOVE NORMAL THREAT FOR FLOODING EXISTS IN
THESE AREAS AS WE HEAD TOWARD SPRING.

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS SLIGHTLY ABOVE NORMAL
ACROSS LARGE AREAS OF CENTRAL AND NORTHERN NEW YORK STATE AND
CENTRAL/NORTHERN NEW ENGLAND IN BOTH THE NEAR TERM AND LONG TERM.

IN THE NEAR TERM...ICE MOVEMENT WILL BE POSSIBLE IN AREAS OF CENTRAL
NEW YORK STATE AND CENTRAL NEW ENGLAND DUE TO A WARMUP AND SOME
RAINFALL THURSDAY NIGHT AND FRIDAY. IN NEW YORK STATE...WE ARE
CONCERNED FOR ICE JAM PROBLEMS ALONG THE MOHAWK RIVER IN AND AROUND
SCHENECTADY AND ALONG THE SCHOHARIE CREEK NEAR PRATTSVILLE.
REMAINING ICE IN CENTRAL NEW YORK STATE COULD ALSO BE FLUSHED IN THE
NEXT FEW DAYS...POSSIBLY CAUSING SOME ADDITIONAL ICE JAMS. WE ALSO
HAVE CONCERNS FOR RIVERS IN SOUTHERN NEW HAMPSHIRE LIKE THE SOUTH
BRANCH PISCATAQUOG IN GOFFSTOWN WHERE ACTIVE ICE JAMS ARE CURRENTLY
OCCURRING.

FURTHER NORTH...ACROSS MUCH OF NORTHERN NEW YORK STATE AND NORTHERN
NEW ENGLAND...THE THREAT FOR FLOODING DUE TO ICE JAMS IS ABOVE
NORMAL AS WE HEAD LATER IN THE WINTER. THE EXISTING ICE JAMS ALONG
RIVERS LIKE THE EAST BRANCH AU SABLE IN NORTHERN NEW YORK
STATE...THE PEMIGEWASSET IN NORTHERN NEW HAMPSHIRE AND THE SAINT
JOHN AND AROOSTOOK IN NORTHERN MAINE WILL LIKELY HOLD IN PLACE BUT
COULD CERTAINLY CAUSE PROBLEMS LATER IN THE WINTER WHEN THE THAW
BEGINS IN EARNEST.

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS HAS RETURNED TO NEAR OR
BELOW NORMAL ACROSS SOUTHERN NEW ENGLAND...FAR SOUTHEASTERN NEW YORK
STATE AND WESTERN NEW YORK STATE. IN THESE AREAS...MOST OF THE ICE
HAS BEEN FLUSHED OUT OR ROTTED OVER THE PAST WEEK. THERE COULD STILL
BE SOME ISOLATED PROBLEMS IN WESTERN NEW YORK STATE NEAR THE
SHORELINE OF LAKE ERIE DUE TO THE LAKE ERIE ICE INHIBITING ICE FROM
CLEANLY MOVING INTO THE LAKE BUT THIS WOULD BE HIGHLY LOCALIZED
AROUND BUFFALO.

IT IS IMPORTANT TO REMEMBER THAT VERY HEAVY RAINFALL CAN RESULT IN
FLOODING AT ANY TIME OF YEAR...EVEN IN AREAS THAT HAVE LITTLE OR NO
SNOW ON THE GROUND.

A GRAPHIC DEPICTING THE FLOOD POTENTIAL ON A BASIN BY BASIN BASIS IS
AVAILABLE ON THE NERFC WEB SITE AT


        ***WWW.WEATHER.GOV/IMAGES/NERFC/OPS/FP1_TODAY.JPG***

ALL IN LOWER CASE.

THE NEXT WINTER/SPRING FLOOD POTENTIAL OUTLOOK WILL BE ISSUED BY THE
NERFC ON THURSDAY 21 FEBRUARY 2019.

END/HORWOOD
$$


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