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WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE
NORTHEAST RIVER FORECAST CENTER TAUNTON MA
845 AM EST THU FEB 4 2016

...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 BELOW NORMAL EXCEPT WELL BELOW NORMAL ACROSS MOST OF WESTERN AND
NORTHERN NEW YORK STATE AND PORTIONS OF NORTHERN VERMONT AND
NORTHERN NEW HAMPSHIRE.

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS NEAR NORMAL ONLY
ACROSS NORTHERN MAINE. ELSEWHERE ACROSS NEW ENGLAND AND NEW YORK
STATE...THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS BELOW TO MUCH
BELOW NORMAL FOR EARLY FEBRUARY.

...CLIMATE GUIDANCE...

THE OVERALL MILD WEATHER PATTERN THAT HAS BEEN IN PLACE ACROSS MOST
OF THE NORTHEASTERN UNITED STATES IS IN THE PROCESS OF CHANGING TO A
MORE WINTERLIKE PATTERN...AT LEAST FOR THE NEXT FEW WEEKS. A
DEEPENING AND EXPANDING UPPER LEVEL TROUGH IS EXPECTED TO SET UP
ACROSS THE CENTRAL UNITED STATES AND GRADUALLY PUSH EAST OVER THE
NEXT WEEK OR SO. IN FACT...MEDIUM RANGE NUMERICAL WEATHER MODEL
GUIDANCE IS SHOWING PERHAPS THE COLDEST AIRMASS OF THE SEASON ACROSS
SOUTHERN CANADA BY THE MIDDLE OF FEBRUARY. THERE IS SOME QUESTION AS
TO HOW FAR SOUTH THE COLD WILL DIVE...BUT IT LOOKS VERY LIKELY THAT
IT WILL SWEEP ACROSS THE ENTIRE NERFC SERVICE AREA OVER THE NEXT 2
WEEKS. THE ONE THING THAT WE SEEM TO BE SURE OF IS THAT THE NEAR TO
RECORD WARMTH OF THE PAST WEEK WILL BE A DISTANT MEMORY OVER THE
NEXT FEW WEEKS. THE OFFICIAL NATIONAL WEATHER SERVICE 8-14 DAY
OUTLOOK FOR 10 TO 16 FEBRUARY SEEMS TO AGREE WITH THIS OVERALL
ASSESSMENT AS IT CALLS FOR TEMPERATURES TO AVERAGE BELOW NORMAL
ACROSS ALL OF NEW YORK STATE AND NEW ENGLAND WITH THE EXCEPTION OF
MAINE WHERE TEMPERATURES ARE EXPECTED TO BE CLOSER TO NORMAL.

THE SIGNIFICANT RAINFALL OF THE PAST 24 HOURS IS NOW TRANSITIONING
OFF THE COAST BUT THERE WILL STILL BE LOTS OF ENERGY IN THE PATTERN
INTO NEXT WEEK. ANOTHER STORM SYSTEM EARLY NEXT WEEK LOOKS TO FAVOR
MOSTLY SNOW IN THE INTERIOR WITH RAIN OR SNOW NEARER TO THE COAST.
OVERALL...HOWEVER...WE ARE NOT CURRENTLY EXPECTING ANY
ADDITIONAL MAJOR RUNOFF EVENTS OVER THE NEXT WEEK TO 10 DAYS.

WITH THE EL NINO PATTERN REMAINING WELL ESTABLISHED...THE LONGER
TERM FORECAST STILL FAVORS ABOVE NORMAL TEMPERATURES FOR LATE
WINTER AND SPRING ACROSS ALL OF NEW ENGLAND AND NEW YORK STATE.

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

SNOWPACK ACROSS THE REGION IS REMARKABLY THIN FOR EARLY
FEBRUARY...MAYBE THE THINNEST COVER OVER THE PAST 10 TO 15 YEARS FOR
THIS POINT IN WINTER.

...NEW YORK STATE...

THERE IS BASICALLY NO SNOW ON THE GROUND ANYWHERE SOUTH AND WEST OF
THE MOHAWK RIVER IN NEW YORK STATE. EVEN IN NORTHERN NEW YORK
STATE...THE SAINT LAWRENCE VALLEY IS BASICALLY BARE. SNOW DEPTHS IN
THE ADIRONDACK MOUNTAIN AND TUG HILL PLATEAU REGIONS ARE AVERAGING
LESS THAN 6 INCHES IN THE VALLEYS WITH ONLY 6 TO 12 INCHES ON THE
GROUND ABOVE 1500 FEET. SNOW DEPTHS ARE WELL BELOW NORMAL ACROSS THE
ENTIRE EMPIRE STATE FOR EARLY FEBRUARY.

THE ONLY SNOW WATER WORTHY OF ANY MENTION ACROSS NEW YORK STATE IS
FOUND IN THE ADIRONDACK MOUNTAIN AND TUG HILL PLATEAU REGIONS WHERE
1 TO 3 INCHES OF WATER IS HELD IN THE MEAGER SNOWPACK ABOVE 1500
FEET. MUCH LIKE SNOW DEPTHS...WATER EQUIVALENTS ARE WELL BELOW
NORMAL ACROSS ALL OF NEW YORK STATE FOR MID-WINTER.

...SOUTHERN NEW ENGLAND...

THERE IS NO SNOW OF ANY SIGNIFICANCE FOUND ANYWHERE IN SOUTHERN NEW
ENGLAND AS OF THIS THURSDAY MORNING. ONLY PATCHY SNOW COVER OF AN
INCH OR TWO WITH WATER EQUIVALENTS BELOW AN INCH ARE FOUND ABOVE
1500 FEET IN THE BERKSHIRE MOUNTAINS IN NORTHWEST MASSACHUSETTS.
SNOW DEPTHS AND WATER EQUIVALENTS ARE WAY BELOW NORMAL ACROSS
SOUTHERN NEW ENGLAND FOR EARLY FEBRUARY.

...VERMONT AND NEW HAMPSHIRE...

ACROSS LOWER ELEVATIONS IN BOTH VERMONT AND NEW HAMPSHIRE...SNOW
DEPTHS RANGE FROM NONE TO AS MUCH AS 6 INCHES. THESE AMOUNTS
INCREASE TO BETWEEN 6 AND 12 INCHES ABOVE 1500 FEET IN THE NORTHERN
GREEN MOUNTAINS OF VERMONT AND WHITE MOUNTAINS OF NEW HAMPSHIRE WITH
ONLY ISOLATED HIGHER AMOUNTS. FOR EXAMPLE...AS OF 2 FEBRUARY
2016...THERE WERE JUST 14.2 INCHES OF SNOW OBSERVED AT MOOSE FALLS
AT AN ELEVATION OF 1950 FEET IN FAR NORTHERN NEW HAMPSHIRE. NORMALLY
THERE WOULD BE DOUBLE THAT AMOUNT OF SNOW ON THE GROUND IN EARLY
FEBRUARY. SNOW DEPTHS ARE WOEFULLY BELOW NORMAL ACROSS BOTH STATES.

BELOW 1000 FEET IN VERMONT AND NEW HAMPSHIRE...SNOW WATER
EQUIVALENTS ARE MOSTLY AN INCH OR LESS. EVEN IN THE HIGHER
ELEVATIONS OF NORTHERN VERMONT AND NORTHERN NEW HAMPSHIRE...SNOW
WATER EQUIVALENTS OF JUST 2 TO 4 INCHES ARE THE NORM WITH ONLY
ISOLATED HIGHER AMOUNTS. THAT 14.2 INCHES OF SNOW OBSERVED IN MOOSE
FALLS NEW HAMPSHIRE ON 2 FEBRUARY 2016 CONTAINED JUST SHY OF 4
INCHES OF WATER. NORMALLY...SNOW WATER EQUIVALENTS WOULD BE
APPROACHING 10 INCHES OR SO IN SOME OF THE HIGHER ELEVATIONS BY
EARLY FEBRUARY.

...MAINE...

WITHIN ABOUT 30 OR 40 MILES OF THE COAST IN MAINE...SNOWCOVER IS
JUST PATCHY WITH ONLY A FEW INCHES ON THE GROUND AT SOME LOCATIONS.
HEADING FURTHER INTO THE INTERIOR...SNOW DEPTHS INCREASE TO BETWEEN
6 AND 12 INCHES ACROSS THE FOOTHILLS AND MOUNTAINS OF MAINE AS WELL
AS OVER THE NORTHWEST LOGGING WOODS. THERE ARE SOME SPOT SNOW DEPTHS
ABOVE 12 INCHES IN THE WESTERN MOUNTAINS AND NORTHWEST LOGGING WOODS
BUT ALL THROUGHOUT MAINE...SNOW DEPTHS ARE BELOW TO WELL BELOW
NORMAL FOR MID-WINTER.

SNOW WATER EQUIVALENTS ACROSS THE COASTAL PLAIN IN MAINE ARE RUNNING
BETWEEN A TRACE AND 1 INCH. THESE AMOUNTS INCREASE ONLY MARGINALLY
ACROSS THE INTERIOR OF MAINE WHERE 1 TO 4 INCHES OF WATER IS HELD IN
THE MEAGER SNOWPACK WITH ONLY ISOLATED HIGHER AMOUNTS IN MOUNTAINS
AND NORTHWEST LOGGING WOODS. MUCH LIKE SNOW DEPTHS...SNOW WATER
EQUIVALENTS ACROSS MAINE ARE BELOW TO WELL BELOW NORMAL FOR EARLY
FEBRUARY.

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

THE LATEST PALMER DROUGHT SEVERITY INDEX AS OF 30 JANUARY 2016
SHOWED MOST OF NEW ENGLAND AND NEW YORK STATE HAVING NEAR NORMAL
ANTECEDENT MOISTURE STATES WITH ONLY COASTAL MAINE AND PORTIONS OF
FAR WESTERN NEW YORK STATE SHOWING SOME LINGERING MOIST CONDITIONS.
THE PALMER INDEX LOOKS AT MOISTURE STATES OVER THE LONG TERM...ON
THE ORDER OF WEEKS TO MONTHS.

THE NEAR SURFACE SOIL MOISTURE ANOMALY MAP FROM 31 JANUARY 2016
SHOWED NEAR TO BELOW NORMAL MOISTURE STATES IN PLACE ACROSS ALL OF
THE REGION EXCEPT FOR NORTHERN AND EASTERN MAINE WHERE CONDITIONS
REMAIN A BIT WET. THE DRIEST CONDITIONS CONTINUE TO BE FOUND ACROSS
THE STATE OF CONNECTICUT WHERE SOME AREAS CONTINUE TO BE DEPICTED IN
MODERATE DROUGHT ON THE LATEST UNITED STATES DROUGHT MONITOR.

TAKING A LOOK AT GROUNDWATER MONITORING WELLS ACROSS THE REGION
COURTESY OF THE UNITED STATES GEOLOGICAL SURVEY ( USGS )...MOST
AREAS OUTSIDE OF MAINE WERE SEEING NEAR TO BELOW NORMAL GROUNDWATER
LEVELS HEADING INTO FEBRUARY. THE LOWEST GROUNDWATER LEVELS WERE
BEING OBSERVED IN CONNECTICUT WHERE MOST WELLS WERE REPORTING BELOW
TO MUCH BELOW NORMAL GROUNDWATER LEVELS FOR EARLY FEBRUARY. IN
FACT...SOME WELLS IN CONNECTICUT WITH SHORTER HISTORICAL RECORDS
LIKE MANSFIELD WERE AT RECORD LOW FEBRUARY LEVELS. THE WELL IN
MANSFIELD...HOWEVER...HAS ONLY BEEN ACTIVE FOR 13 YEARS SO IT IS NOT
REALLY A TRUE MEASURE OF HISTORICALLY LOW LEVELS. ACROSS
MAINE...WARMTH...RAINFALL AND SNOWMELT OVER THE PAST TWO MONTHS HAS
ALLOWED WATER TO CONTINUE TO INFILTRATE INTO THE SOIL. THIS HAS
RESULTED IN GROUNDWATER LEVELS THAT ARE ABOVE NORMAL IN THE NORTH
AND DOWNEAST PARTS OF MAINE AND NEAR NORMAL ACROSS MOST OF THE REST
OF THE STATE.

LAKES AND RESERVOIR SYSTEMS ACROSS NEW YORK STATE AND NEW ENGLAND
ARE GENERALLY AT ADEQUATE LEVELS FOR MID-WINTER. ACROSS NORTHERN NEW
YORK STATE...INDIAN LAKE WAS RUNNING ROUGHLY 1 FOOT BELOW NORMAL FOR
EARLY FEBRUARY WHILE GREAT SACANDAGA LAKE WAS ABOUT 1.5 FEET ABOVE
ITS NORMAL FEBRUARY POOL LEVEL. THE NEW YORK CITY WATER SUPPLY
SYSTEM...COMPRISED OF 7 LARGE RESERVOIRS ACROSS SOUTHEASTERN NEW
YORK STATE...WAS AT 87.6 PERCENT OF CAPACITY AS OF 2 FEBRUARY 2016
WHICH WAS EXACTLY NORMAL FOR THE DATE. IN NEW ENGLAND...RESERVOIR
SYSTEMS WERE GENERALLY AT NEAR OR ABOVE NORMAL POOL HEIGHTS EXCEPT
ACROSS SOUTHERN NEW ENGLAND WHERE SOME RESERVOIRS WERE A BIT BELOW
NORMAL. FOR EXAMPLE...SCITUATE RESERVOIR...THE MAIN WATER SUPPLY
RESERVOIR FOR NORTHERN RHODE ISLAND INCLUDING THE CITY OF
PROVIDENCE...WAS AT A POOL HEIGHT OF 275.29 FEET AS OF 2 FEBRUARY
2016 WHICH WAS ABOUT 9 FEET BELOW THE TOP OF THE RESERVOIR
FLASHBOARDS AND SOMEWHAT BELOW NORMAL. IN MAINE...RESERVOIR STORAGE
IN THE ANDROSCOGGIN RIVER BASIN WERE RUNNING ABOUT 17 PERCENT HIGHER
THAN NORMAL FOR EARLY FEBRUARY WITH ABOVE NORMAL LEVELS ALSO
REPORTED ACROSS THE KENNEBEC RIVER BASIN.

ALTHOUGH WE ARE NOT CURRENTLY CONCERNED ABOUT WATER SUPPLY ACROSS
THE REGION...WE DO HAVE TO BE AWARE THAT THERE IS VERY LITTLE SNOW
WATER CURRENTLY AVAILABLE FOR RECHARGE ACROSS THE REGION SO WE WILL
NEED TO KEEP A STEADY SUPPLY OF RAIN AND SNOW TO ENSURE ADEQUATE
LEVELS GOING THROUGH SPRING INTO SUMMER.

...RIVER AND ICE CONDITIONS...

RIVER FLOWS ACROSS THE SEVEN STATE REGION OF NEW YORK STATE AND NEW
ENGLAND ARE RUNNING ABOVE TO MUCH ABOVE NORMAL DUE TO THE THE RECENT
HEAVY RAINFALL. FLOWS ARE HIGHEST ACROSS CENTRAL AREAS OF NEW YORK
STATE INTO PORTIONS OF CENTRAL AND SOUTHERN NEW ENGLAND WHERE MANY
AREAS SAW OVER AN INCH OF RAIN OVER THE PAST 24 TO 36 HOURS.

RIVER ICE...OR MORE SPECIFICALLY THE LACK OF RIVER ICE...CONTINUES
TO BE A SIGNIFICANT STORY THIS WINTER. AS OF THIS MORNING...MOST
RIVERS ACROSS SOUTHERN/WESTERN NEW YORK STATE AND CENTRAL/SOUTHERN
NEW ENGLAND ARE FLOWING FREE OF ICE...A RARITY FOR EARLY FEBRUARY.
THE ICE IN PLACE ACROSS NORTHERN NEW YORK STATE AND NORTHERN NEW
ENGLAND IS ALSO SPOTTY AND MUCH THINNER THAN NORMAL. IN
FACT...RIVERS NEAR THE COAST IN MAINE LIKE THE LOWER KENNEBEC AT
AUGUSTA ARE ICE FREE. THE THICKEST RIVER ICE IS FOUND FROM THE
WESTERN MAINE MOUNTAINS NORTH INTO FAR NORTHERN MAINE WHERE
THICKNESSES OF 6 TO 12 INCHES ARE COMMON. BUT EVEN IN THESE
LOCALES...THERE ARE STRETCHES OF OPEN WATER ON MANY RIVERS AND THE
ICE OUTSIDE OF FAR NORTHERN MAINE IS A BIT ROTTED FROM THE RECENT
WARM WEATHER. NORMALLY ON NORTHERN MAINE RIVERS LIKE THE SAINT
JOHN...ALLAGASH...AROOSTOOK AND UPPER PENOBSCOT...ICE THICKNESSES
WOULD BE ON THE ORDER OF 12 TO 18 INCHES THICK BY EARLY FEBRUARY.

THERE ARE SOME ICE JAMS LOCKED IN PLACE ACROSS NORTHERN MAINE THAT
WILL LIKELY STAY IN PLACE AND COULD BECOME AN ISSUE LATER IN THE
SPRING. NOTABLE ICE JAMS ARE BEING OBSERVED ON THE SAINT JOHN RIVER
NEAR ALLAGASH AND SAINT FRANCIS AND ALONG THE AROOSTOOK RIVER
UPSTREAM OF THE USGS GAUGE AT WASHBURN.

TEMPERATURES OVER THE NEXT FEW WEEKS SHOULD SUPPORT SOME ADDITIONAL
ICE FORMATION ACROSS INTERIOR NEW YORK STATE AND CENTRAL/NORTHERN
NEW ENGLAND BUT PROBABLY NOT TOO MUCH ACROSS FAR SOUTHEASTERN NEW
YORK STATE OR SOUTHERN NEW ENGLAND.

...IN CONCLUSION...

BASED ON THE INFORMATION AVAILABLE AT THIS TIME...THE WINTER/SPRING
FLOOD POTENTIAL IS BELOW NORMAL ACROSS ALL OF NEW ENGLAND AND NEW
YORK STATE. IN THESE AREAS...ALTHOUGH RIVER FLOWS ARE IN MANY
INSTANCES ABOVE TO MUCH ABOVE NORMAL...THAT IS MAINLY DUE TO RECENT
RAINFALL AND SNOWMELT. THE LACK OF ANY APPRECIABLE SNOWPACK OUTSIDE
OF NORTHERN MAINE COMBINED WITH THE PROSPECT FOR COLD CONDITIONS
GOING FORWARD INTO MID-FEBRUARY POINTS TO A LOW CHANCE FOR ANY
ORGANIZED FLOODING. EVEN A POTENTIAL STORM EARLY NEXT WEEK THAT
COULD BRING SOME HEAVY RAINFALL TO COASTAL SECTIONS OF NEW ENGLAND
WOULD LIKELY DROP MORE SNOW THAN RAIN INLAND BRINGING LITTLE CHANCE
FOR ORGANIZED RUNOFF AWAY FROM THE COAST. AND ON THE COAST...IT
WOULD LIKELY TAKE SEVERAL INCHES OF RAIN TO PRODUCE ENOUGH RUNOFF TO
CAUSE FLOODING WITHOUT A SNOWMELT CONTRIBUTION AND THIS IS SOMETHING
THAT IS NOT LIKELY AT THIS TIME. SO...WITH ALL THIS TAKEN INTO
ACCOUNT...A BELOW NORMAL RISK FOR FLOODING IS DEEMED TO EXIST ACROSS
THE ENTIRE NERFC SERVICE AREA.

WITHIN THE BELOW NORMAL FLOOD THREAT AREA...THE WINTER/SPRING FLOOD
POTENTIAL IS MUCH BELOW NORMAL ACROSS NORTHERN VERMONT...NORTHERN
NEW HAMPSHIRE AND NORTHERN AS WELL AS WESTERN NEW YORK STATE. IN
THESE AREAS...THERE IS LITTLE TO NO SNOW ON THE GROUND OUTSIDE OF
THE HIGH TERRAIN AND THE CHANCES FOR SIGNIFICANT RAINFALL OVER THE
NEXT TWO WEEKS IS NOT NEARLY AS HIGH AS IT IS NEAR THE COAST. THIS
MEANS WE SHOULD HEAD INTO MID TO LATE FEBRUARY WITH LITTLE SNOWCOVER
AND DECREASING RIVER FLOWS. THEREFORE...A WELL BELOW NORMAL THREAT
FOR FLOODING SEEMS JUSTIFIED AS WE HEAD INTO THE MIDDLE AND LATTER
PORTION OF FEBRUARY.

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS NEAR NORMAL ACROSS FAR
NORTHERN MAINE. IN THIS AREA...ALTHOUGH THE ICE COVERAGE AND
THICKNESSES ARE QUITE A BIT LESS THAN NORMAL...COLD WEATHER OVER THE
NEXT FEW WEEKS SHOULD ALLOW ICE TO EXPAND AND THICKEN UP A BIT MORE.
WITH SOME NOTABLE JAMS IN PLACE ALONG THE SAINT JOHN AND AROOSTOOK
RIVERS...THE FEELING IS THAT THESE JAMS WILL REMAIN IN PLACE FOR THE
FORESEEABLE FUTURE AND COULD POSE AT LEAST A NORMAL FLOOD RISK DURING
BREAKUP.

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS BELOW NORMAL ACROSS
THE REMAINDER OF NORTHERN NEW ENGLAND AND NORTHERN NEW YORK STATE.
IN THESE AREAS...THE ICE IN AREA RIVERS IS THIN ( MOSTLY < 6 INCHES
) AND ALREADY A BIT ROTTED. THERE IS ALSO GENERALLY LESS THAN 100
PERCENT ICE COVER IN THE RIVERS. A LOT OF THIS ICE HAS BEEN OR IS IN
THE PROCESS OF BEING FLUSHED OUT OF THE RIVERS DUE TO THE RAINFALL
OF THE PAST FEW DAYS AND WE DO NOT BELIEVE THERE IS ENOUGH
STRUCTURAL INTEGRITY FOR THE ICE TO HOLD BACK SIGNIFICANT AMOUNTS OF
WATER. INSTEAD...WE BELIEVE ANY JAMS THAT FORM WILL QUICKLY BUCKLE
AND MOVE DOWNSTREAM UNDER THE PRESSURE OF ANY BACKWATER THUS
JUSTIFYING A BELOW NORMAL THREAT FOR ICE JAM FLOODING IN THESE AREAS.

ACROSS CENTRAL AND SOUTHERN NEW ENGLAND AND ALL OF NEW YORK STATE
FROM THE MOHAWK RIVER SOUTH AND WEST...THE POTENTIAL FOR FLOODING
DUE TO ICE JAMS IS WELL BELOW NORMAL. IN THESE AREAS...THERE IS
VIRTUALLY NO ICE OF CONSEQUENCE IN AREA RIVERS GIVING VERY LITTLE
THREAT FOR ANY ICE JAMS.

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 18 FEBRUARY 2016.

END/HORWOOD
$$



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