Extended Streamflow Guidance
Issued by NWS Northeast RFC

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WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE
NORTHEAST RIVER FORECAST CENTER...TAUNTON MA
430 JAN 21 2015

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

WINTER/SPRING FLOOD POTENTIAL FOR THE NORTHEASTERN U.S. /2/

THE WINTER/SPRING FLOOD POTENTIAL FOR THE NORTHEASTERN UNITED STATES
IS BELOW NORMAL.

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS BELOW NORMAL.

...CLIMATE GUIDANCE...

NEAR TO ABOVE NORMAL TEMPERATURES CHARACTERIZED THE FIRST WEEK OF
JANUARY 2015 AFTER A MILDER THAN NORMAL DECEMBER 2014. HOWEVER,
EXCEPT FOR A COUPLE OF MILDER DAYS RECENTLY, MUCH OF JANUARY SINCE
THEN HAS EXPERIENCED NORMAL TO BELOW NORMAL TEMPERATURES.

THE EAST PACIFIC OSCILLATION IS EXPECTED TO REMAIN PRIMARILY IN THE
NEGATIVE PHASE WHILE THE PACIFIC NORTH AMERICAN TELECONNECTION
REMAINS NEUTRAL TO POSITIVE. THIS UPPER AIR PATTERN FAVORS RIDGING
ACROSS THE WESTERN UNITED STATES AND CROSS POLAR WIND FLOW
TRAJECTORY INTO THE EASTERN UNITED STATES. IN THIS PATTERN, THERE IS
ALSO CONCERNS OF THE SOUTHERN STREAM MOISTURE BECOMING INVOLVED IN
CYCLOGENESIS ALONG THE EAST COAST.

IN THE LONGER TERM...TELECONNECTION SIGNALS INDICATE THAT THE UPPER
LEVEL JET STREAM PATTERN COULD REMAIN AMPLIFIED WITH A RIDGE IN THE
WEST AND POSSIBLE TROUGHINESS IN THE EAST.

THE NORTHERN ATLANTIC OSCILLATION AND ARCTIC OSCILLATION
TELECONNECTIONS HAVE BEEN PRIMARILY IN THE POSITIVE PHASE AND WILL
TREND TOWARDS NEUTRAL IN THE NEXT COUPLE OF WEEKS

A WEAK EL NINO PATTERN ALONG WITH AVAILABLE SUBTROPICAL MOISTURE
WILL ALLOW COASTAL LOW PRESSURE TO FORM AND APPROACH...WITH PERHAPS
A COUPLE OF SNOW/MIXED PRECIPITATION EVENTS POSSIBLE DURING THE NEXT
2 WEEKS.  TIMING AND PHASING OF SYSTEMS REMAIN A POSSIBLITY AT THIS
TIME. IT IS ALSO NOTED THAT THE PATTERN TENDS TO BE RATHER
PROGRESSIVE AND ANY STORM SYSTEM WITH GULF ORIGINS SHOULD BE A QUICK
MOVER.

THE OFFICIAL NATIONAL WEATHER SERVICE 8 TO 14 DAY OUTLOOK INDICATES
BEST CHANCES FOR BELOW NORMAL TEMPERATURES AND NEAR NORMAL
PRECIPITATION DURING THE PERIOD.

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

MUCH OF THE NERFC SERVICE AREA IS EXPERIENCING SNOW DEPTHS AND SNOW
WATER EQUIVALENTS BELOW NORMAL FOR THE 3RD WEEK OF JANUARY.

...NEW YORK STATE...

PATCHY LIGHT SNOW COVER FROM ONE TO THREE INCHES WAS NOTED ACROSS
THE CATSKILLS AND TACONICS...WITH SPOTTY SNOW COVER GENERALLY AN
INCH OR LESS ACROSS THE MID TO LOWER HUDSON VALLEY...NEW YORK CITY
AREA AND LONG ISLAND. SNOW WATER EQUIVALENTS GENERALLY RANGE FROM
0.50 INCH OR LESS.

SPOTTY SNOW COVER OF ONE TO TWO INCHES OR LESS REMAINS ACROSS THE
FINGER LAKES REGION IN WESTERN NEW YORK...WITH HIGHER AND MORE
CONCENTRATED AMOUNTS 4 TO 12 INCH AMOUNTS NOTED IMMEDIATELY EAST OF
LAKE ERIE AND THE HIGHER TERRAIN OF SOUTHWESTERN NEW YORK. SNOW
WATER EQUIVALENTS ACROSS THESE AREAS ALSO GENERALLY RANGE FROM 0.75
INCH OR LESS EXCEPT UP TO 1.5 INCHES DUE EAST OF LAKE ERIE.

HEADING NORTH ACROSS THE ADIRONDACKS AND INTO NORTH COUNTRY
REGION...SNOW DEPTHS VARY CONSIDERABLY...FROM 4 TO 8 INCHES ACROSS
THE NORTHERN ADIRONDACKS...NORTH COUNTRY AND SAINT LAWRENCE VALLEY
REGION...6 TO 12 INCHES ACROSS THE SOUTHERN ADIRONDACKS BUT MUCH
HIGHER AMOUNTS ACROSS THE TUG HILL REGION WITH 12 INCHES UP TO
LOCALLY 2 FEET NOTED.

SNOW WATER EQUIVALENTS GENERALLY RANGE FROM NIL UP TO 2 INCHES...BUT
LOCALLY UP TO 3 INCHES ACROSS THE TUG HILL REGION.

...SOUTHERN NEW ENGLAND...

LIGHT SNOW COVER IS OBSERVED ACROSS NORTHWEST CONNECTICUT. SNOW
DEPTHS WERE  THE GREATEST OVER WESTERN FRANKLIN COUNTY AND THE HIGH
TERRAIN OF THE NORTHERN BERKSHIRES WHERE 4 TO 12 INCHES HAVE BEEN
REPORTED.  SNOW WATER EQUIVALENTS WERE GENERALLY LESS THAN 0.50 INCH
ACROSS THESE AREAS EXCEPT AROUND AN INCH APPROACHING NORTHWESTERN
FRANKLIN COUNTY AND NORTHERN BERKSHIRES.

THE FROST DEPTH ACCORDING TO A NWS OBSERVER IN NORTON MA IS 18
INCHES IN THE SANDY SOIL PROFILE ON AN OPEN LAWN AND NEAR 2 INCHES
IN THE WOODS IN THE SAME AREA.

...VERMONT AND NEW HAMPSHIRE...

SNOW COVER VARIES CONSIDERABLY IN VERMONT...2 TO 4 INCHES ACROSS
MOST OF THE REMAINDER OF VERMONT...EXCEPT 8 TO 12 INCHES ACROSS THE
NORTHEAST KINGDOM...WITH LOCALLY HIGHER AMOUNTS OVER ONE FOOT
REPORTED ACROSS THE HIGHEST TERRAIN NEAR CABOT AND GREENSBORO.

SNOW WATER EQUIVALENTS RANGE FROM NIL UP TO AROUND ONE INCH MOST
AREAS...EXCEPT 2 TO 4 INCHES ACROSS THE HIGHER TERRAIN.

IN NEW HAMPSHIRE...SNOW COVER RANGED FROM 2 TO 4 INCHES ACROSS THE
SOUTHERN MONADNOCKS WITH TRACE TO ONE INCH AMOUNTS APPROACHING ALONG
THE SEACOAST...3 TO 5 INCHES ACROSS THE UPPER MERRIMACK...AND 4 TO 8
INCHES ACROSS THE WHITE MOUNTAINS TO THE CANADIAN BORDER. LOCALLY
HIGHER AMOUNTS UP TO 13 INCHES WAS NOTED AT PINKHAM NOTCH. SNOW
WATER EQUIVALENTS RANGED FROM NIL TO AROUND ONE INCH MOST AREAS...
EXCEPT 2 TO 4 INCHES ACROSS THE HIGHER TERRAIN.

...MAINE...

SNOW COVER IS FAIRLY WIDESPREAD ACROSS THE STATE WITH SNOWPACK
BUILDING ACROSS WESTERN AND NORTHERN PORTIONS. SNOW DEPTHS RANGED
FROM LITTLE TO NO SNOW ACROSS DOWNEAST MAINE...4 TO 6 INCHES ACROSS
THE CENTRAL HIGHLANDS AND 10 TO 16 INCHES ACROSS NORTHERN AND
WESTERN MAINE WITH LOCALLY HIGHER AMOUNTS UP TO 20 INCHES AROUND
ANDOVER AND EUSTIS.

SNOW WATER EQUIVALENTS RANGED FROM ONE INCH OR LESS ACROSS EASTERN
MAINE....2 TO 3 INCHES ACROSS THE FOOTHILLS AND 3 TO 6 INCHES ACROSS
THE NORTHERN AND WESTERN MAINE HIGHER TERRAIN AND WOODED AREAS.


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


PRECIPITATION TOTALS SINCE THE BEGINNING OF DECEMBER HAVE ALSO BEEN
SLIGHTLY LOWER THAN NORMAL ACROSS CENTRAL AND WESTERN NEW YORK
OUTSIDE OF THE IMMEDIATE HARDEST HIT LAKE EFFECT SNOW LOCATIONS EAST
OF LAKES ERIE AND ONTARIO.

NEAR SURFACE SOIL MOISTURE MAPS AS OF 19 JANUARY 2015 INDICATED
SLIGHTLY DRIER THAN NORMAL SURFACE MOISTURE ANOMALIES NEAR THE
FINGER LAKES IN NEW YORK STATE. NEAR NORMAL SURFACE SOIL MOISTURE
ANOMALIES WERE INDICATED ACROSS THE REST OF NEW YORK AND MOST OF NEW
ENGLAND EXCEPT SLIGHTLY WETTER THAN NORMAL ANOMALIES WERE INDICATED
IN CENTRAL MAINE.

THE PALMER DROUGHT INDEX EXAMINES THE LONGER TERM SOIL MOISTURE
STATES OVER A PERIOD OF WEEKS TO SEVERAL MONTHS. THE PALMER INDEX AS
OF JANUARY 17TH 2015 INDICATED MOIST CONDITIONS PRESENT ACROSS MOST
OF NEW YORK STATE EXCEPT LONG ISLAND AND PORTIONS OF EASTERN NEW
YORK. VERY MOIST SOIL CONDITIONS HAVE ALSO PREVAILED ACROSS COASTAL
NEW ENGLAND EXCEPT NEAR NORMAL CONDITIONS ACROSS THE LAKE CHAMPLAIN
VALLEY REGION AND CONNECTICUT. EXTREMELY MOIST SOIL CONDITIONS WERE
OBSERVED IN EASTERN MAINE.

EXAMINING GROUNDWATER MONITORING WELLS ACROSS THE REGION COURTESY OF
THE UNITED STATES GEOLOGICAL SURVEY (USGS)...

IN NEW YORK STATE GROUNDWATER LEVELS AS OF JANUARY 21ST 2015 VARIED
BUT WERE GENERALLY NEAR NORMAL TO BELOW NORMAL. SOME RECENT
REPLENISHMENT DUE TO RECENT RAINFALL AND SNOWMELT IN EARLY-MID
JANUARY...HAS BROUGHT GROUNDWATER LEVELS ABOVE NORMAL ACROSS THE
SOUTHERN ADIRONDACKS AND CENTRAL AND WESTERN MOHAWK VALLEY IN
CENTRAL NEW YORK.

IN SOUTHERN NEW ENGLAND...GROUNDWATER LEVELS WERE REPORTED TO REMAIN
AROUND NORMAL TO SLIGHTLY ABOVE NORMAL LEVELS DUE TO RECENT RAINFALL
EARLY IN JANUARY.

IN NORTHERN NEW ENGLAND...GROUNDWATER LEVELS WERE REPORTED TO BE AT
OR ABOVE NORMAL LEVELS...INCLUDING NEW HAMPSHIRE AND MAINE. ABOVE
NORMAL PRECIPITATION AND MILDER THAN NORMAL CONDITIONS HAS HELPED
PRODUCE SOME RUNOFF AND THIS HAS HELPED MAINTAIN WATER SUPPLY LEVELS.

RESERVOIR LEVELS...

IN NEW YORK STATE...THE NEW YORK CITY WATER SUPPLY SYSTEM WAS
RUNNING 79.5 PERCENT OF CAPACITY AS OF JANUARY 21 2015. THIS IS 6.0
PERCENT BELOW NORMAL.

IN RHODE ISLAND...SCITUATE RESERVOIR WAS HOLDING AT 85.1 PERCENT OF
CAPACITY. THE RESERVOIR POOL ELEVATION LEVEL AS OF 8AM JANUARY 21ST
2015 WAS OBSERVED AT 278.5 FEET. THIS LEVEL IS 5.5 FEET BELOW THE
SPILLWAY.

...RIVER AND ICE CONDITIONS...

AS OF JANUARY 21ST 2015...STREAMFLOWS ACROSS NEW YORK STATE WERE
RUNNING NEAR NORMAL LEVELS EXCEPT SOMEWHAT BELOW NORMAL LEVELS IN
PORTIONS OF WESTERN NEW YORK. SEVERAL RIVER LOCATIONS WERE AFFECTED
BY ICE PARTICULARLY ACROSS NORTHERN NEW YORK STATE AND NORTHERN NEW
ENGLAND AS COLDER TEMPERATURES CONTINUED TO OVERSPREAD THE REGION.

STREAMFLOWS ACROSS SOUTHERN NEW ENGLAND RANGED FROM AROUND NORMAL TO
ABOVE NORMAL LEVELS IN CONNECTICUT AND MASSACHUSETTS
(HOOSIC/HOUSATONIC/CONNECTICUT RIVERS)...EXCEPT NEAR NORMAL TO
SLIGHTLY BELOW NORMAL IN RHODE ISLAND.

STREAMFLOWS ACROSS NORTHERN NEW ENGLAND RANGE FROM NORMAL TO ABOVE
NORMAL LEVELS. HOWEVER THERE ARE A GROWING NUMBER OF ICE AFFECTED
RIVERS AND STREAMS AS OF JANUARY 21ST 2015. ALMOST ALL RIVERS AND
STREAMS ACROSS NORTHERN VERMONT...NORTHERN NEW HAMPSHIRE AND MAINE
ARE CURRENTLY ICE AFFECTED.

THE RECENT RAINFALL AND MILD TEMPERATURES ON THE
HOUSATONIC/CONNECTICUT/UPPER MERRIMACK RIVERS HAVE RIVER FLOWS
RUNNING HIGHER THAN NORMAL FOR THIS TIME OF THE YEAR....BUT MANY
RIVERS IN THIS REGION ARE NOW EXPERINCING STEADY OR RECEDING
CONDITIONS.

IN NORTHERN MAINE THE ICE IS THINNER THAN USUAL FOR THIS TIME OF
YEAR. ACROSS THE AROOSTOOK...ALLAGASH AND SAINT JOHN RIVERS THERE
ARE SEVERAL FREEZUP AND OR BREAKUP JAMS IN PLACE. THESE INCLUDE A 10
TO 15 MILE LONG ICE JAM ON THE SAINT JOHN RIVER IN SAINT FRANCIS AND
ALLAGASH AND A 5 TO 8 MILE LONG ICE JAM ON THE AROOSTOOK FROM
CROUSEVILLE TO WASHBURN AND THERE ARE SEVERAL OTHER SMALLER JAMS ON
THE AROOSTOOK INCLUDING ONE BELOW FORT FAIRFIELD. THE CENTRAL AND
FAR SOUTHERN RIVERS WERE MOSTLY OPEN IN LATE DECEMBER BUT FRAZIL AND
OR SOLID ICE COVER HAS LIKELY NOW FORMED DUE TO THE COLDER WEATHER.

THE NUMBER OF ICE AFFECTED RIVERS AND STREAMS IS ANTICIPATED TO
REMAIN STEADY OR CONTINUE TO GROW AS COLDER THAN NORMAL TEMPERATURES
ARE FORECAST ACROSS THE REGION.

...CONCLUSION...

BASED ON THE INFORMATION AVAILABLE AT THIS TIME...

BELOW NORMAL FLOOD POTENTIAL IS ANTICIPATED ACROSS NEW YORK AND NEW
ENGLAND AND ALL OF THE NERFC SERVICE AREA AT THIS TIME.

LONGER TERM ANTECEDENT CONDITIONS REMAIN MOIST TO VERY MOIST ACROSS
MANY AREAS. HOWEVER CURRENT SNOWPACK AND SNOW WATER EQUIVALENTS
REMAIN BELOW NORMAL FOR THIS TIME OF YEAR. BELOW NORMAL SNOWPACK
SHOULD ALLOW FOR NEAR SURFACE MOISTURE LEVELS TO REMAIN BELOW
NORMAL.

SOME BUILDUP IN SNOWPACK SHOULD OCCUR WITH BELOW NORMAL TEMPERATURES
FORECAST OVER THE NEXT TWO WEEKS. HOWEVER WITH THE COLD TEMPERATURES
AND BELOW NORMAL SNOW WATER EQUIVALENTS...THE THREAT FOR FLOODING
REMAINS LOWER THAN NORMAL.

ICE FORMATION IS EXPECTED TO CONTINUE AND EVEN INCREASE ACROSS AREA
RIVERS AND STREAMS. SOME INCREASE IN THE NUMBER OF FREEZE UP ICE
JAMS IS POSSIBLE...HOWEVER THE ICE BUILDUP IS EXPECTED TO BE
GRADUAL.

IT IS IMPORTANT TO REMEMBER THAT VERY HEAVY RAINFALL CAN BRING
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.ERH.NOAA.GOV/NERFC/SFPOG.HTML***

ALL IN LOWER CASE.

THE NEXT WINTER/SPRING FLOOD POTENTIAL OUTLOOK WILL BE ISSUED BY THE
NERFC ON THURSDAY FEBRUARY 6 2015.

END/CAPONE
$$



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