Extended Streamflow Guidance
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SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE
NORTHEAST RIVER FORECAST CENTER TAUNTON MA
616 PM EDT WED APR 13 2016

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

SPRING FLOOD POTENTIAL FOR THE NORTHEASTERN U.S. /8/

THE SPRING FLOOD POTENTIAL FOR THE NORTHEASTERN UNITED STATES IS
BELOW NORMAL...EXCEPT NEAR NORMAL ACROSS MAINE.

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS HAS PASSED FOR MOST OF
THE REGION...EXCEPT IT REMAINS NEAR NORMAL ACROSS FAR NORTHERN AND
NORTHWESTERN MAINE.

...CLIMATE GUIDANCE...

AN ACTIVE WEATHER PATTERN PERSISTED FROM MARCH INTO EARLY APRIL.
A DEEPENING UPPER LEVEL TROUGH ACROSS THE NORTHEAST ALLOWED FOR
SEVERAL DISTURBANCES TO CROSS THE REGION WITH PERIODIC SNOW AND
RAIN. THE RECENT NEGATIVE NORTHERN ATLANTIC OSCILLATION PATTERN
(NAO) WITH BLOCKING UPSTREAM ACROSS GREENLAND...HELPED KEEP THE
COLDER AIR LOCKED IN ACROSS THE NORTHEAST TO BEGIN THE MONTH OF
APRIL.

AVERAGE APRIL TEMPERATURES SO FAR HAVE RANGED FROM 3 TO 6 DEGREES
BELOW NORMAL ACROSS EASTERN NEW YORK AND NEW ENGLAND...AND 5 TO 8
DEGREES BELOW NORMAL ACROSS CENTRAL AND WESTERN NEW YORK STATE.

APRIL PRECIPITATION TOTAL DEPARTURES HAVE BEEN NEAR NORMAL ACROSS
MOST OF THE REGION...EXCEPT ABOVE SLIGHTLY ABOVE NORMAL ACROSS
NORTHERN AND EASTERN MAINE AND PARTS OF SOUTHERN NEW ENGLAND.

FOUR WEATHER SYSTEMS IMPACTED THE REGION WITH SNOW AND RAIN APRIL
1...APRIL 3-4...APRIL 7 AND APRIL 12TH. DAILY SNOWFALL RECORDS WERE
BROKEN AT BOSTON...PROVIDENCE...WINDSOR LOCKS CONNECTICUT WORCESTER
MASSACHUSETTS AND THE BLUE HILLS OBSERVATORY IN MILTON MASSACHUSETTS
ON APRIL 4TH.

IT APPEARS THAT THE ACTIVE WEATHER PATTERN WILL TAKE A BREAK IN THE
NEAR TERM. A OMEGA STYLE BLOCKING PATTERN WILL ALLOW FOR A NEARLY
STATIONARY RIDGE TO BUILD ACROSS THE NORTHEAST FOR PART OF WEEK ONE
FROM THE 14TH-18TH. WE WILL NOTE A WARMUP AWAY FROM THE COAST.

THE UPPER LEVEL TROUGH MAY RETROGRADE TO THE WEST FOR A TIME AROUND
THE 20TH. IT APPEARS THAT THE WEATHER PATTERN SHOULD BECOME
PROGRESSIVE AGAIN DURING A PORTION OF WEEK TWO AS THE NORTHERN
ATLANTIC OSCILLATION (NAO) AND PACIFIC NORTH AMERICAN OSCILLATION
(PNA) TURN MORE NEUTRAL.

THE NEXT CHANCE FOR PRECIPITATION WILL PROBABLY OCCUR ON MONDAY THE
18TH AS A COLD FRONT SWEEPS ACROSS THE REGION. MOISTURE WILL BE
LIMITED BUT 0.25 TO 0.50 INCH AMOUNTS ARE POSSIBLE ACROSS NORTHERN
MAINE WITH NIL TO LESS THAN 0.25 INCH ELSEWHERE. RAIN SHOWERS ARE
ANTICIPATED EXCEPT SOME SNOW SHOWERS POSSIBLE ACROSS THE HIGHER
TERRAIN OF NORTHERN NEW ENGLAND.

IT APPEARS THE NORTHERN STREAM ENERGY WITH THE COLD FRONT COULD
MERGE WITH AN OCEAN STORM. DEPENDING ON THE TIMING...THIS COULD
ALLOW FOR AN INVERTED STYLE TROUGH SETUP TO DEVELOP AND EXTEND
ACROSS NORTHERN MAINE. THIS SCENARIO WOULD POTENTIALLY BRING A
PERIOD OF SNOW AND RAIN ACROSS NORTHERN MAINE AROUND THE 21ST-22ND.
OTHERWISE THE REGION SHOULD SEE AN EXTENDED PERIOD OF DRY WEATHER.
ANOTHER LOW SYSTEM AND WARM FRONT MAY APPROACH FROM THE GREAT LAKES
THE WEEKEND OF THE 23RD AND 24TH AS THE OFFSHORE CUTOFF SYSTEM LIFTS
AWAY FROM THE REGION.

CONFIDENCE IN DETAILS IN THE EXTENDED TIMEFRAME IS SOMEWHAT LOW AT
THIS TIME. THE MODELS TEND TO HAVE SOME TROUBLE HANDLING THE TIMING
AND PLACEMENT OF SPRING CUTOFF LOW PRESSURE SYSTEMS.

THE 6 TO 10 AND 8 TO 14 DAY OUTLOOKS THROUGH APRIL 27TH FROM THE
CLIMATE PREDICTION CENTER ARE GENERALLY IN SUPPORT. CHANCES LEAN
TOWARDS BELOW NORMAL TO NEAR NORMAL TEMPERATURES AND BELOW NORMAL
PRECIPITATION IN THE NEAR TERM...THEN NEAR NORMAL TEMPERATURES AND
BELOW NORMAL PRECIPITATION DAYS 8 TO 14.

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

LATEST SNOW COVER AND SNOW WATER EQUIVALENTS REMAIN CONFINED ACROSS
FAR NORTHERN NEW ENGLAND INCLUDING NORTHERN MAINE. THERE ARE ALSO
SOME LEFTOVER PATCHES OF SNOW ACROSS THE ADIRONDACKS OF NEW YORK
STATE.

WE ARE WELL AHEAD OF SCHEDULE THIS SPRING FOR MELTING THE LEFTOVER
SNOW COVER...ESPECIALLY COMPARED TO LAST WINTER.

...VERMONT AND NEW HAMPSHIRE...

SPOTTY 1 TO 3 INCH SNOW DEPTHS REMAIN ACROSS NORTHERN NEW HAMPSHIRE
AND NORTHERN VERMONT...LOCALIZED 6 TO 12 INCH SNOW DEPTHS REMAIN
ACROSS THE HIGHEST TERRAIN INCLUDING MOUNT WASHINGTON. SNOW WATER
EQUIVALENTS ARE GENERALLY LESS THAN ONE INCH EXCEPT ACROSS THE
HIGHER TERRAIN. THE EXCEPTION IS ACROSS THE CONNECTICUT LAKES REGION
OF FAR NORTHERN NEW HAMPSHIRE NEAR PITTSBURG AND MOOSE FALLS WHERE 9
TO 18 INCH SNOW DEPTHS ARE FOUND ALONG WITH SOME 1 TO 3 INCH SNOW
WATER EQUIVALENTS.

THESE SNOW WATER EQUIVALENTS ARE GENERALLY LESS THAN 25 PERCENT OF
NORMAL FOR THIS TIME OF YEAR.

...MAINE...

THE GROUND IS BARE ACROSS DOWNEAST MAINE AND THE FOOTHILLS. SNOW
DEPTHS IN NORTHERN MAINE GENERALLY RANGE FROM 3 TO 8 INCHES...BUT
INCREASE UP TO 21 INCHES AT WINTERVILLE AS OF APRIL 12TH.

SNOW WATER EQUIVALENTS IN NORTHERN MAINE RANGE FROM 2 TO 5 INCHES
EXCEPT LOCALLY 6.5 INCHES AT WINTERVILLE AS OF APRIL 12TH.

THESE SNOW WATER EQUIVALENTS RANGE FROM 25 TO 75 PERCENT OF NORMAL
ACROSS NORTHERN MAINE.

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

LOW PRESSURE SYSTEMS ON APRIL 1...APRIL 3-4...APRIL 7TH AND APRIL
12TH IMPACTED THE REGION SINCE LAST PRODUCT ISSUANCE. THE BULK OF
RAIN AND SNOW SINCE LAST ISSUANCE ACCUMULATED ACROSS CENTRAL NEW
YORK STATE INTO THE ADIRONDACKS AND IN NORTHERN AND EXTREME EASTERN
NEW ENGLAND.

THE PALMER INDEX LOOKS AT MOISTURE STATES OVER THE LONGER TERM...ON
THE ORDER OF WEEKS TO MONTHS. THE LATEST PALMER DROUGHT SEVERITY
INDEX...AS OF 09 APRIL 2016 SHOWED NEAR NORMAL ANTECEDENT MOISTURE
STATES ACROSS MOST OF THE REGION EXCEPT VERY MOIST CONDITIONS
PREVAILED IN EASTERN MAINE. ALSO MOIST CONDITIONS PREVAILED ACROSS
NORTHERN MAINE...SOUTHERN VERMONT...EASTERN MASSACHUSETTS... THE
SAINT LAWRENCE VALLEY REGION AND FINGER LAKES REGION OF NEW YORK
STATE.

NEAR SURFACE SOIL MOISTURE MAPS AS OF 12 APRIL 2016 INDICATED
NORTHERN MAINE...NORTHERN NEW HAMPSHIRE AND NORTHEAST VERMONT WERE
EXPERIENCING WETTER THAN NORMAL SURFACE MOISTURE STATES. THIS IS
PRIMARILY DUE SOME SIGNIFICANT RUNOFF DUE TO RAIN AND SNOWMELT ON
APRIL 1...APRIL 7TH AND APRIL 11-12TH. WARMING TEMPERATURES AND THE
INCREASING SUN ANGLE ALSO HAVE CONTRIBUTED TO THE MELT. NEAR NORMAL
MOISTURE STATES WERE GENERALLY OBSERVED ELSEWHERE.

DEVELOPING GREENUP CONDITIONS AND SLIGHTLY BELOW NORMAL
PRECIPITATION HAVE HELPED CONTRIBUTE TO BELOW NORMAL SURFACE
MOISTURE STATES ACROSS SOUTHEASTERN NEW YORK AND SOUTHWESTERN
NEW ENGLAND.

TAKING A LOOK AT GROUNDWATER MONITORING WELLS ACROSS THE REGION
COURTESY OF THE UNITED STATES GEOLOGICAL SURVEY ( USGS )...

IN NEW YORK STATE...GROUNDWATER LEVELS ARE BELOW NORMAL TO NEAR
NORMAL ACROSS THE LOWER TO MID HUDSON VALLEY REGION. GROUNDWATER
LEVELS AT ROCKLAND LAKE AND SUNY ALBANY ARE AT RECORD LOW
GROUNDWATER LEVELS THIS TIME OF YEAR. HOWEVER RECORDS ARE OVER A
RELATIVELY SHORT 10-14 YEAR PERIOD OF RECORD FOR THIS TIME OF YEAR.

HEADING ACROSS THE SOUTHERN TIER INTO THE FINGER LAKES
REGION...GROUNDWATER LEVELS ARE GENERALLY AVERAGING NEAR NORMAL.
ITHACA NEW YORK IS BETWEEN 10-25TH PERCENTILE FOR GROUNDWATER LEVEL
OVER A RELATIVELY SHORT 12 YEAR PERIOD OF RECORD FOR THIS TIME OF
YEAR.

LOOKING ACROSS FAR WESTERN NEW YORK STATE...GROUNDWATER LEVELS RANGE
FROM BELOW NORMAL TO NEAR NORMAL. BATAVIA NEW YORK IS AT A RECORD
LOW GROUNDWATER LEVEL FOR THIS TIME OF YEAR OVER A 19 YEAR PERIOD OF
RECORD WHILE CLARENCE AND SHAWNEE ARE NEAR THE 50TH PERCENTILE.

HEADING ACROSS THE WESTERN MOHAWK VALLEY...ADIRONDACKS..SAINT
LAWRENCE AND CHAMPLAIN VALLEY REGIONS OF NORTHERN NEW YORK
STATE...GROUNDWATER LEVELS ARE GENERALLY NORMAL TO SLIGHTLY ABOVE
NORMAL.

IN SOUTHERN NEW ENGLAND...GROUNDWATER LEVELS ARE GENERALLY NEAR
NORMAL. THE EXCEPTION IS SHEFFIELD MASSACHUSETTS ACROSS THE SOUTHERN
BERKSHIRES WHICH INDICATES GROUNDWATER LEVELS NEAR THE 10TH
PERCENTILE FOR THIS TIME OF YEAR OVER A 29 YEAR PERIOD OF RECORD.

IN NORTHERN NEW ENGLAND...GROUNDWATER LEVELS IN VERMONT AND NEW
HAMPSHIRE ARE AVERAGING NEAR NORMAL. GROUNDWATER LEVELS IN MAINE ARE
AVERAGING NORMAL TO ABOVE NORMAL. CALAIS IS AT THE HIGHEST MEDIAN
OF A 36 YEAR PERIOD OF RECORD FOR THIS TIME OF YEAR.

MOST LAKES AND RESERVOIRS ARE AT OR ABOVE NORMAL POOL HEIGHTS FOR
EARLY APRIL.

LAKE AND RESERVOIR LEVELS WERE ABOVE NORMAL IN NORTHERN NEW
ENGLAND. LAKE WINNIPESAUKEE LEVEL DATA AS OF 12 APRIL 2016
WAS 504.32 FT...AT ITS FULL LEVEL.

IN SOUTHERN NEW ENGLAND...ADEQUATE RESERVOIR LEVELS WERE BEING
REPORTED. THE SCITUATE RESERVOIR LEVEL 13 APRIL 2016 WAS 284.27 FT
WHICH WAS AT 101.9 PERCENT OF CAPACITY AND SLIGHTLY ABOVE THE
HISTORICAL AVERAGE FOR THIS TIME OF YEAR. THIS LEVEL IS ABOUT 0.25
FT ABOVE THE SPILLWAY.

ACROSS SOUTHEAST NEW YORK STATE...THE NEW YORK CITY WATER SUPPLY
SYSTEM...COMPRISED OF 7 LARGE RESERVOIRS ACROSS SOUTHEAST NEW YORK
STATE...WAS AT 96.8 PERCENT CAPACITY AS OF 13 APRIL 2016 WHICH WAS
1.3 PERCENT BELOW NORMAL.

...RIVER AND ICE CONDITIONS...

RIVER FLOWS ACROSS NEW YORK STATE AND SOUTHERN NEW ENGLAND ARE
GENERALLY RUNNING NEAR NORMAL TO SLIGHTLY ABOVE NORMAL AS THE
WEATHER PATTERN HAS BEEN ACTIVE SO FAR THIS MONTH. THE EXCEPTION IS
ACROSS EXTREME SOUTHEASTERN NEW YORK WHERE STREAMFLOW CONDITIONS ARE
AVERAGING SLIGHTLY BELOW NORMAL.

RIVER FLOWS ACROSS SOUTHERN VERMONT AND SOUTHERN NEW HAMPSHIRE ARE
ALSO RUNNING NEAR NORMAL.

RIVER FLOWS ACROSS NORTHEASTERN VERMONT...NORTHERN NEW HAMPSHIRE AND
MAINE ARE GENERALLY RUNNING ABOVE NORMAL DUE TO COMBINED RAINFALL
AND SNOWMELT THIS MONTH.

THERE IS NO RIVER ICE LEFT IN NEW YORK STATE AND MOST OF NEW
ENGLAND EXCEPT ACROSS NORTHERN MAINE.

ACCORDING TO A RECENT ICE SURVEY FROM WFO CARIBOU MAINE...

THE SAINT JOHN RIVER IS MOSTLY OPEN FROM FORT KENT THROUGH GRAND
ISLE. THERE IS A SMALL ICE JAM JUST BELOW THE GRAND ISLE/VAN BUREN
LINE. SOLID ICE EXISTS IN THAT AREA. SHEET ICE EXISTS FROM SAINT
JOHN THROUGH SAINT FRANCIS...EXCEPT A SMALL OPEN STRETCH IS NOTED IN
THE DOWNRIVER SIDE.

A LARGE ICE JAM REMAINS IN PLACE NEAR THE ALLAGASH/SAINT FRANCIS
LINE. MOST OF THE ICE WAS AROUND ONE FOOT THICK. THE ICE JAM IS
APPROXIMATELY 4 MILES LONG.

A SMALL ICE JAM OF 100 YARDS OF LESS SITS IN ALLAGASH JUST
DOWNSTREAM FROM THE ALLAGASH/SAINT JOHN CONFLUENCE.

THE ICE JAM JUST UPSTREAM OF DICKEY ON SAINT CLAIR ISLAND ONLY
COVERS THE ISLAND AND ONE SIDE OF THE RIVER CHANNEL. THE RIVER IS
OPEN ON THE OTHER SIDE OF THE ISLAND.

MINOR FLOODING OCCURRED EARLIER THIS MONTH APRIL 1ST AND AGAIN APRIL
8TH IN NORTHERN MAINE DUE TO SNOWMELT AND RAINFALL AND ICE JAM
FLOODING. THIS COMBINATION WAS ABLE TO RELEASE SOME OF THE ICE
ACROSS THE AREA RIVERS AND STREAMS.

APRIL 1ST...A PORTION OF ROUTE 161 IN THE VICINITY OF ALLAGASH WAS
CLOSED DUE TO FLOOD WATER FROM AN ICE JAM.

APRIL 8TH...MINOR FLOODING OCCURRED AT WASHBURN IN AROOSTOOK COUNTY
WITH GARDNER CREEK ROAD WASHED OUT AND ROUTE 11 CLOSED.

...IN CONCLUSION...

BASED ON THE INFORMATION AVAILABLE AT THIS TIME...THE SPRING FLOOD
POTENTIAL IS BELOW NORMAL FOR ALL OF THE REGION EXCEPT NEAR NORMAL
ACROSS MAINE.

BELOW NORMAL PRECIPITATION IS GENERALLY EXPECTED OVER THE NEXT
COUPLE OF WEEKS. SNOW COVER IS MOSTLY ABSENT EXCEPT ACROSS FAR
NORTHERN NEW HAMPSHIRE AND IN NORTHERN MAINE.

IN NORTHERN MAINE...SNOW WATER EQUIVALENTS ARE AVERAGING 25 TO 75
PERCENT OF NORMAL. IN FAR NORTHERN NEW HAMPSHIRE...SNOW WATER
EQUIVALENTS ARE GENERALLY LESS THAN 25 PERCENT OF NORMAL.
ANTECENDENT CONDITIONS REMAIN MOIST BUT WE ANTICIPATE GRADUAL RUNOFF
OF THE REMAINDER OF THE SNOWPACK DUE TO THE LACK OF SIGNIFICANT
RAINFALL. HOWEVER THERE EXISTS A CHANCE FOR SOMEWHAT CLOSER TO
NORMAL PRECIPITATION IF AN INVERTED STYLE TROUGH DEVELOPS AROUND
THE 20TH-21ST.

GREENUP IS CONTINUING TO SPREAD ACROSS THE REGION. THIS WILL AID
INCREASING ABSORPTION OF EXPECTED PRECIPITATION. THE INCREASING SUN
ANGLE WILL ALSO ALLOW FOR INCREASED EVAPOTRANSPIRATION.

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS NEAR NORMAL ACROSS FAR
NORTHERN MAINE...PRIMARILY THE AROOSTOOK...SAINT JOHN AND ALLAGASH
RIVERS. A FEW ICE JAMS REMAIN ACROSS THESE AREAS. THINNING AND
ROTTING OF THE ICE IS EXPECTED TO CONTINUE AS THE SUN ANGLE
CONTINUES TO INCREASE AND TEMPERATURES WARM.

ELSEWHERE...ACROSS THE REMAINDER OF THE REGION...THE THREAT FOR ICE
JAM FLOODING HAS PASSED FOR THE SEASON

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.

THIS IS THE LAST PLANNED SPRING FLOOD OUTLOOK FOR THE 2016 SEASON.

END/STRAUSS
$$



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