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FGUS71 KCAR 311343
ESFCAR
MEC003-009-019-021-029-021345-
WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE CARIBOU ME
943 AM EDT THU MAR 31 2016
...WINTER/SPRING FLOOD POTENTIAL OUTLOOK FOR NORTHERN...
CENTRAL...AND DOWNEAST MAINE...
THIS IS THE SEVENTH WINTER/SPRING FLOOD POTENTIAL OUTLOOK FOR
2016, ISSUED BY THE NATIONAL WEATHER SERVICE IN CARIBOU, MAINE.
THIS OUTLOOK IS FOR NORTHERN, CENTRAL AND DOWNEAST MAINE FOR THE
TWO- WEEK PERIOD FROM MARCH 31 THROUGH APRIL 14, 2016.
THE WINTER/SPRING FLOOD POTENTIAL FOR OPEN WATER FLOODING IS
ABOVE NORMAL ACROSS NORTHERN MAINE, INCLUDING THE AROOSTOOK, SAINT
JOHN, ALLAGASH, AND EAST BRANCH OF THE PENOBSCOT RIVER BASINS.
FOR THE CENTRAL HIGHLANDS AND SOUTHERN AROOSTOOK COUNTY, THE
THREAT FOR OPEN WATER FLOODING IS NEAR NORMAL. THE BANGOR REGION
DOWN TO THE COAST AND DOWNEAST AREAS HAVE A BELOW NORMAL FLOODING
POTENTIAL.
THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS NEAR NORMAL ACROSS
NORTHERN MAINE, MAINLY ALONG THE AROOSTOOK, SAINT JOHN, AND
ALLAGASH RIVERS. ELSEWHERE, WHERE RIVER ICE COVERAGE IS MINIMAL,
THE ICE JAM THREAT IS BELOW NORMAL AND LIKELY OVER FOR THE SEASON.
...CLIMATOLOGICAL GUIDANCE...
THE PINE TREE STATE HAS BEEN UNDER THE INFLUENCE OF AN ACTIVE AND
PROGRESSIVE WEATHER PATTERN OVER THE PAST COUPLE OF WEEKS.
TEMPERATURES HAVE BEEN UP AND DOWN DURING THIS TIME, WITH
WARMER-THAN-NORMAL CONDITIONS INTERRUPTED FROM TIME TO TIME BY
COLDER SPELLS. AS SUCH, PRECIPITATION HAS FALLEN AS A MIX OF RAIN
AND SNOW, THOUGH IT`S BEEN MOSTLY SNOW IN THE NORTH AND MOSTLY
RAIN IN THE SOUTH. THIS HAS ALLOWED NORTHERN MAINE TO HOLD ON TO,
AND EVEN BUILD, ITS SNOWPACK SINCE THE MIDDLE OF MARCH.
IN THE IMMEDIATE NEAR TERM, THROUGH THE END OF THIS WEEK, WE ARE
ANTICIPATING A MILD AND WET STRETCH. TEMPERATURES ARE ALREADY
ABOVE FREEZING ACROSS OUR ENTIRE FORECAST AREA AT THE TIME OF THIS
WRITING AND THEY ARE EXPECTED TO REMAIN SO THROUGH SATURDAY.
FRIDAY WILL BE THE WARMEST DAY AS HIGHS WILL TOP OUT IN THE 50S TO
NEAR 60. RAIN IS EXPECTED TO DEVELOP TODAY AND CONTINUE THROUGH
FRIDAY. THE GREATEST RAINFALL TOTALS WILL OCCUR ACROSS THE FAR
NORTH, WHERE AMOUNTS OF 0.75 TO 1.25 INCHES ARE EXPECTED. FAR
SOUTHERN AROOSTOOK COUNTY BACK TO THE CENTRAL HIGHLANDS AND SOUTH
THROUGH DOWNEAST MAINE, RAINFALL TOTALS WILL BE AROUND A HALF INCH
AT MOST.
BEYOND THIS WEEKEND, WE ARE ANTICIPATING A RETURN TO MORE WINTER-
LIKE TEMPERATURES AS AN ARCTIC AIRMASS WILL SETTLE OVER THE
NORTHEASTERN UNITED STATES THROUGH EARLY NEXT WEEK. THEREAFTER,
TEMPERATURES LOOK TO MODERATE A BIT AS THE UPPER FLOW TURNS MORE
WESTERLY OR SOUTHWESTERLY. A SERIES OF LOW PRESSURE SYSTEMS WILL
KEEP THE THREAT OF PRECIPITATION AROUND OVER THE NEXT SEVERAL
DAYS.
THE OFFICIAL NATIONAL WEATHER SERVICE 6-10 DAY FORECAST FOR APRIL
5-9 SUPPORTS THE ABOVE THINKING WELL, CALLING FOR COLDER-THAN-NORMAL
TEMPERATURES AND WETTER-THAN-NORMAL CONDITIONS.
...OBSERVED SNOW DEPTH AND WATER EQUIVALENTS...
AS HAS BEEN THE TREND THROUGH MARCH, THERE CONTINUES TO BE A BIG
DIFFERENCE BETWEEN NORTHERN MAINE AND SOUTHERN MAINE WHEN IT COMES
TO SNOW CONDITIONS. SIGNIFICANT SNOW COVER DOESN`T EXIST SOUTH OF
A DOVER-FOXCROFT TO DANFORTH LINE, WITH NO SNOW BEING REPORTED
FROM BANGOR DOWN TO THE COAST. THE CENTRAL HIGHLANDS ARE COVERED
WITH A FOOT OR LESS OF SNOW. THIS INCREASES RATHER QUICKLY AS YOU
HEAD NORTH INTO AROOSTOOK COUNTY AND THE NORTH WOODS. THE SAINT
JOHN VALLEY AND ALLAGASH REGIONS HAVE THE DEEPEST SNOW PACK, WHERE
20 TO 30 INCHES IS COMMON. HIGHER AMOUNTS ARE LIKELY IN THE HIGHER
TERRAIN. THIS AMOUNT OF SNOW IS NEAR NORMAL FOR LATE MARCH.
THE SNOW WATER EQUIVALENT, OR THE AMOUNT OF WATER CONTAINED IN THE
SNOW PACK, IS ALSO NEAR NORMAL FOR THIS TIME OF YEAR. AS SHOULD
BE EXPECTED, THE HIGHEST SWE LIES ACROSS NORTHERN MAINE WITH 5 TO
8 INCHES BEING REPORTED FROM HOULTON NORTH. LOCALLY HIGHER AMOUNTS
EXIST IN THE HIGHER TERRAIN OF THE NORTH WOODS. DOWN INTO THE
CENTRAL HIGHLANDS, THE SNOW HAS ONLY 1 TO 3 INCHES OF WATER
EQUIVALENT.
IT SHOULD BE NOTED THAT, OUTSIDE OF THE FAR NORTH WOODS AND THE
SAINT JOHN VALLEY, A LOT OF THE SNOW PACK IS VERY RIPE. THIS
MEANS THAT LITTLE IF ANY SNOW MELT OR RAIN WILL BE ABSORBED BY THE
SNOW COVER. INSTEAD, IT WILL BECOME RUNOFF THAT WILL FLOW INTO
AREA WATERWAYS. THE RAIN COMBINED WITH EXPECTED SNOWMELT WILL
CAUSE RIVERS AND STREAMS TO SHOW SIGNIFICANT RISES. THIS MAY
RESULT IN OPEN WATER FLOODING AS WELL AS POTENTIALLY CAUSE RIVER
ICE TO MOVE AND BREAK UP.
...SOIL MOISTURE AND WATER SUPPLY CONDITIONS...
THE ACTIVE WEATHER PATTERN THAT WE`VE EXPERIENCED OVER THE PAST
COUPLE OF WEEKS, ALONG WITH PERIODS OF SNOWMELT, HAVE KEPT NEAR-
SURFACE SOIL MOISTURE STATES WETTER THAN NORMAL ACROSS THE
CARIBOU FORECAST AREA. LOOKING AT THE LONGER TERM SOIL CONDITIONS,
THE LATEST PALMER DROUGHT SEVERITY INDEX ALSO CONTINUED TO SHOW
UNUSUALLY MOIST CONDITIONS ACROSS THE ENTIRE AREA. AS WOULD BE
EXPECTED, GROUNDWATER LEVELS ARE ABOVE NORMAL AS WELL.
...RIVER AND ICE CONDITIONS...
AFTER DECREASING THROUGH THE MIDDLE PART OF THE MONTH, RIVER
FLOWS HAVE BEEN INCREASING OVER THE PAST SEVERAL DAYS IN THE
NORTHERN AND CENTRAL RIVER BASINS AS RAIN AND SNOWMELT HAVE
CREATED RUNOFF. THIS TREND IS EXPECTED TO CONTINUE THROUGH THE END
OF THE WEEK. THESE FLOWS ARE LIKELY NEAR TO PERHAPS JUST A BIT
ABOVE NORMAL. FURTHER SOUTH, AFTER A BRIEF INCREASE DUE TO A HEAVY
RAIN EVENT ON THE 28TH AND 29TH, WATERWAYS IN THE BANGOR REGION
AND DOWNEAST MAINE HAVE SHOWN A DOWNWARD TREND. FLOWS ARE NEAR
NORMAL IN THESE LOCATIONS.
ONLY THE ALLAGASH, SAINT JOHN, AND AROOSTOOK RIVERS HAVE TRULY
SIGNIFICANT RIVER ICE COVERAGE. EVEN ALONG THESE WATERWAYS, OPEN
AREAS HAVE BEEN SEEN AND MANY OF THE SMALLER FEEDER STREAMS ARE
OPEN. IN SPITE OF BOUTS OF SNOW AND COLDER WEATHER, THE ICE HAS
BEEN ROTTING IN PLACE AND IS LIKELY THINNER AND WEAKER THAN
NORMAL. THERE ARE A FEW LOCALIZED AREAS OF ICE JAMS, SPECIFICALLY
ON THE SAINT JOHN RIVER NEAR THE ALLAGASH/SAINT FRANCIS TOWN LINE
AND ON THE AROOSTOOK RIVER UPSTREAM OF WASHBURN. WATER IS FLOWING
THROUGH OR AROUND BOTH OF THESE JAMS AND THEY ARE CURRENTLY NOT
CAUSING ANY FLOODING.
OUTSIDE OF THE ABOVE-MENTIONED RIVER BASINS, ICE COVERAGE IS
SPOTTY. THE UPPER REACHES OF THE PISCATAQUIS AND THE PENOBSCOT
RIVERS MAY STILL HAVE SOME ICE COVER. THE LOWER REACHES THESE
WATERWAYS ARE LIKELY MOSTLY ICE FREE.
...IN CONCLUSION...
BASED ON THE AFOREMENTIONED INFORMATION, THE WINTER/SPRING FLOOD
POTENTIAL FOR OPEN WATER FLOODING FOR THE NEXT TWO WEEKS IS ABOVE
NORMAL ACROSS NORTHERN MAINE. THIS INCLUDES BUT IS NOT LIMITED TO
THE AROOSTOOK, SAINT JOHN, ALLAGASH, AND EAST BRANCH OF THE
PENOBSCOT RIVER BASINS. THESE RIVERS ARE ALREADY RUNNING HIGH AND
FLOWS WILL ONLY INCREASE OVER THE NEXT DAY OR TWO OWING TO RAIN
AND SNOWMELT. ALTHOUGH WE ARE EXPECTING A RETURN TO COLDER WEATHER
EARLY NEXT WEEK, AN ACTIVE WEATHER PATTERN WILL KEEP THE THREAT OF
PRECIPITATION ACROSS THE AREA. IN ADDITION, EVEN UNDER DRY
CONDITIONS, THE STRONG SPRING SUNSHINE WILL ALLOW SNOWMELT TO
CONTINUE DURING THE DAY. AND WITH SOIL MOISTURE STATES ALREADY
WET, MUCH OF THE MELT AND RAIN WILL RUN INTO RIVERS RATHER THAN
PERCOLATING INTO THE GROUND. AS SUCH, FLOWS WILL LIKELY REMAIN
HIGH, EVEN AFTER WE TURN COLDER.
FOR CENTRAL MAINE, INCLUDING THE PISCATAQUIS AND LOWER PENOBSCOT
BASINS, THE THREAT OF OPEN WATER FLOODING IS NORMAL FOR LATE
MARCH. FLOWS HERE, WHILE HIGH, ARE CLOSER TO NORMAL. EVEN WITH
RAIN EXPECTED, THE RELATIVELY MEAGER AMOUNT OF SNOW AVAILABLE FOR
MELT LIMITS THE FLOODING THREAT TO JUST NORMAL.
FOR DOWNEAST MAINE, INCLUDING THE BANGOR REGION, THE POTENTIAL FOR
OPEN WATER FLOODING IS BELOW NORMAL. THIS IS MAINLY OWING TO THE
LACK OF SNOW COVER.
THE THREAT FOR ICE JAMS IS MAINLY LIMITED TO THE AROOSTOOK, SAINT
JOHN, AND ALLAGASH RIVERS, AS THESE ARE THE ONLY WATERWAYS THAT
STILL HAVE SIGNIFICANT COVER. WHAT ICE IS THERE IS THINNER AND
WEAKER THAN NORMAL AND THEREFORE WILL BE MORE APT TO MOVE THAN
WHAT WE`D NORMALLY SEE IN LATE MARCH. IT IS LIKELY WE WILL SEE ICE
MOVEMENT OVER THE NEXT 24 TO 48 HOURS AS RIVERS WILL RISE IN
RESPONSE TO INCREASING RUNOFF. IT SHOULD BE STRESSED THAT EVEN
THOUGH THE ICE IS RELATIVELY WEAK, ICE JAMS ARE A THREAT ANY TIME
THE RIVER ICE COVER BREAKS UP. PERSONS WITH INTERESTS ALONG THESE
RIVERS NEED TO STAY ALERT FOR RAPIDLY CHANGING RIVER AND ICE
CONDITIONS UNTIL THE ICE HAS COMPLETELY FLUSHED OUT.
THE THREAT FOR FLOODING DUE OT ICE JAMS IS BELOW NORMAL ACROSS
THE REST OF OUR FORECAST AREA, AND IS LIKELY OVER. THE UPPER
REACHES OF THE PISCATAQUIS AND PENOBSCOT RIVERS MAY STILL HAVE
SOME SPOTTY ICE COVER. UNTIL THIS ICE FLUSHES OUT COMPLETELY, THE
THREAT FOR JAMS IS STILL THERE. HOWEVER, WITH WELL BELOW-NORMAL
COVERAGE, ANY JAMS THAT DO OCCUR WOULD BE VERY LOCALIZED AND
LIMITED IN SCOPE.
IT IS IMPORTANT TO REMEMBER THAT VERY HEAVY RAINFALL CAN BRING
FLOODING AT ANY TIME OF THE YEAR, EVEN IN AREAS THAT DON`T HAVE A
SIGNIFICANT SNOWPACK.
THE NEXT WINTER/SPRING FLOOD POTENTIAL OUTLOOK WILL BE ISSUED BY
NWS CARIBOU ON THURSDAY APRIL 14, 2016.
$$
HASTINGS
