Friday, April 18, 2014

Winter and Spring Flood Potential Outlook issued on April 17th

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FGUS71 KCAR 171937
ESFCAR
MEC003-009-019-021-029-180745-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE CARIBOU ME
337 PM EDT THU APR 17 2014

...SPRING FLOOD POTENTIAL OUTLOOK FOR NORTHERN... CENTRAL AND
DOWNEAST MAINE...

THIS IS THE NINTH WINTER/SPRING FLOOD POTENTIAL OUTLOOK FOR
2014...ISSUED BY THE NATIONAL WEATHER SERVICE IN CARIBOU, MAINE.
THE SPRING FLOOD POTENTIAL IS FOR NORTHERN, CENTRAL AND DOWNEAST
MAINE FOR THE TWO WEEK PERIOD FROM APRIL 17 TO MAY 1, 2014.

THE SPRING FLOOD POTENTIAL FOR ALL OF NORTHERN AND CENTRAL MAINE
IS MUCH ABOVE NORMAL. FOR AREAS SOUTH OF A HOWLAND TO TOPSFIELD
LINE, THE SPRING FLOOD POTENTIAL IS ABOVE NORMAL. THESE REGIONS
WILL LIKELY IMPROVE TO NORMAL IN THE LONGER TERM.

THE THREAT FOR FLOODING DUE TO ICE JAMS HAS PASSED FOR MUCH OF
OUR AREA. THE EXCEPTION IS FAR NORTHERN MAINE, ESPECIALLY ALONG
THE SAINT JOHN ALLAGASH RIVER WHERE ICE JAMS HAVE BEEN REPORTED.

...CLIMATOLOGICAL GUIDANCE...

TEMPERATURES HAVE GENERALLY BEEN RIGHT AROUND NORMAL FOR MUCH OF
THIS MONTH. THIS IS A WELCOME RESPITE AFTER A VERY COLD MARCH.
HEAVY RAINS AFFECTED MUCH OF THE REGION EARLIER THIS WEEK, WITH 1
TO 2 INCHES FALLING OVER OUR FORECAST AREA. THIS RAINFALL, ALONG
WITH PRECIPITATION FROM PREVIOUS SYSTEMS, HAS RESULTED IN MONTHLY
PRECIPITATION THAT IS NORMAL TO ABOVE NORMAL SO FAR.

THE NEXT FEW DAYS LOOK TO STAY DRY AS HIGH PRESSURE SETTLES OVER
THE REGION. HOWEVER, AS WE HEAD INTO LATE APRIL, AN ACTIVE WEATHER
PATTERN WILL RESUME. SEVERAL POTENTIAL PRECIPITATION EVENTS WILL
BE POSSIBLE AS A SERIES OF LOW PRESSURE SYSTEMS SLIDE EAST FROM
THE CENTRAL UNITED STATES. AT THIS TIME, IT LOOKS LIKE OTHER THAN
PERHAPS SOME LIGHT RAIN OVER THE UPCOMING WEEKEND, THE NEXT THREAT
FOR HEAVY RAIN WON'T BE UNTIL THE MIDDLE OF NEXT WEEK.

TEMPERATURES WILL REMAIN WARM DURING THE DAY AND BELOW FREEZING AT
NIGHT THROUGH AT LEAST EARLY NEXT WEEK. THIS PATTERN IS IDEAL FOR
GRADUAL SNOWMELT, AS WELL AS THE MELTING OF ANY REMAINING RIVER
ICE.

THE OFFICIAL NATIONAL WEATHER SERVICE 8 TO 14 DAY OUTLOOK MATCHES
THIS THINKING WELL, CALLING FOR NEAR NORMAL TEMPERATURES AND
ABOVE NORMAL PRECIPITATION DURING THE PERIOD.

...OBSERVED SNOW DEPTH AND WATER EQUIVALENTS...

WE LOST A LOT OF SNOW TO SNOWMELT AND RAINFALL OVER THE PAST
SEVERAL DAYS. THERE IS NO SNOW ALONG THE IMMEDIATE COAST, WITH
INTERIOR DOWNEAST REPORTING AT MOST 8 INCHES OF SNOW ON THE
GROUND. HEADING NORTH INTO THE CENTRAL HIGHLANDS AND EASTERN
AROOSTOOK COUNTY, THERE IS CURRENTLY 10 TO 15 INCHES OF SNOW
CURRENTLY COVERING THE GROUND, MAINLY IN SHELTERED AND SHADED
AREAS. OPEN FIELDS HAVE 6 INCHES OR LESS. THE SAINT JOHN VALLEY
AND NORTH MAINE WOODS STILL HAVE 12 TO 18 INCHES IN OPEN AREAS,
WITH UPWARDS TO 2 FEET POSSIBLY IN THE WOODS. THESE LOCATIONS
HAVE ABOVE NORMAL SNOW, WHILE EASTERN AROOSTOOK COUNTY DOWN TO
THE COAST IS NEAR NORMAL FOR SNOWPACK.

SNOW WATER EQUIVALENTS, OR THE AMOUNT OF WATER CONTAINED IN THE
SNOW PACK, ARE ONLY 2 INCHES AT MOST ACROSS WASHINGTON, HANCOCK,
AND SOUTHERN PENOBSCOT COUNTIES. FURTHER NORTH, THE CENTRAL
HIGHLANDS AND EASTERN AROOSTOOK COUNTY STILL HAVE 2 TO 5 INCHES
OF WATER CONTAINED IN THE PACK. THE NORTH MAINE WOODS AND THE FAR
NORTH HAS 6 TO 9 INCHES OF WATER. THE HIGHER WATER AMOUNTS ARE
ABOVE NORMAL, BUT MUCH OF THE REGION HAS NEAR NORMAL WATER
CONTAINED IN WHATEVER SNOW IS ON THE GROUND.

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

PLENTIFUL SNOWMELT AND RAIN FROM EARLIER IN THE WEEK HAVE ALLOWED
FOR INCREASED RUNOFF ACROSS THE FORECAST AREA DURING THE PAST
COUPLE OF WEEKS. HOWEVER, SOIL MOISTURE STATES ARE ACTUALLY NEAR
NORMAL TO SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR. THE LONGER
TERM SOIL MOISTURE, INDICATED BY THE PALMER DROUGHT INDEX, ALSO
SHOWED NEAR NORMAL CONDITIONS. GROUNDWATER LEVELS ARE NEAR TO
ABOVE NORMAL FOR MID APRIL.

...RIVER AND ICE CONDITIONS...

RIVER FLOWS REMAIN HIGH AS RUNOFF FROM SNOWMELT AND THE RECENT
RAINS CONTINUES TO STREAM INTO AREA WATERWAYS. THE CENTRAL AND
SOUTHERN RIVERS, INCLUDING THE PENOBSCOT, MATTAWAMKEAG, AND
PISCATAQUIS, ARE MOSTLY ICE-FREE. HOWEVER, THERE ARE STILL SEVERAL
RIVER GAGES NEAR OR ABOVE FLOOD STAGE, INCLUDING BUT NOT LIMITED
TO THE PENOBSCOT RIVER AT EDDINGTON (EDDM1), THE PENOBSCOT RIVER
AT WEST ENFIELD (WENM1), AND THE MATTAWAMKEAG RIVER NEAR
MATTAWAMKEAG (MATM1). MANY OF THE RIVER GAGES ON THE PISCATAQUIS
RIVER CONTINUE TO SHOW RECEDING WATER LEVELS, AS DOES THE EAST
BRANCH OF THE PENOBSCOT RIVER. HOWEVER, WITH PLENTIFUL SNOW STILL
TO MELT OUT OF THE HEADWATERS OF THESE RIVERS, FLOWS SHOULD REMAIN
HIGH THROUGH AT LEAST THE NEXT FEW DAYS.

FURTHER NORTH, THE ICE HAS PRETTY MUCH FLUSHED OUT OF THE
AROOSTOOK RIVER. WE HAVE BEEN NOTIFIED THAT THERE IS AN ICE JAM IN
OXBOW WHICH HAS FLOODED THE ROAD LEADING TO THE OXBOW GATE TO THE
NORTH MAINE WOODS, AND WATER MAY BE THREATENING SOME UNOCCUPIED
CAMPS. HOWEVER, NO HOMES ARE IMPACTED AT THIS TIME. THIS ICE
SHOULD FLUSH OUT SOON AND IT IS NOT EXPECTED TO CAUSE ANY
ADDITIONAL ISSUES AS IT HEADS DOWNSTREAM.

THE SAINT JOHN RIVER REMAINS OUR BIGGEST CONCERN. THERE ARE TWO
ICE JAMS IN PLACE ALONG THIS RIVER AT THIS TIME: ONE IN SAINT
FRANCIS AND ONE JUST BELOW GRAND ISLE. THE SAINT FRANCIS JAM IS
STILL VERY LONG AND QUITE LOCKED INTO PLACE. WATER IS FLOODING
NUMEROUS FIELDS FROM SAINT JOHN BACK TOWARDS ALLAGASH. ROUTE 161
IS IMPACTED AND CURRENTLY CLOSED BETWEEN SAINT FRANCIS AND SAINT
JOHN. THE ICE JAM NEAR GRAND ISLE IS ALSO NOT MOVING, AS IT IS
CAUGHT UP AGAINST A SOLID ICE SHEET THAT STRETCHES DOWN THROUGH
VAN BUREN. WATER IS FLOWING OUT OF THE RIVER AND INTO FIELDS AS
IT MAKES ITS WAY AROUND THE JAM, BUT NO ROADS, BUSINESSES, OR
HOMES ARE KNOWN TO BE AFFECTED AT THIS TIME. PERSONS WHO HAVE
INTERESTS ALONG THE SAINT JOHN RIVER SHOULD STAY ALERT FOR
RAPIDLY CHANGING WATER LEVELS, AS THESE JAMS MAY RELEASE VERY
SUDDENLY. THE ICE JAM FLOOD THREAT WILL NOT BE OVER ACROSS
NORTHERN MAINE UNTIL THE ICE COMPLETELY FLUSHES OUT PAST HAMLIN.
EVEN THEN, RIVER FLOWS WILL REMAIN HIGH AS SNOWMELT RUNOFF STREAMS
INTO THE RIVERS.

...IN CONCLUSION...

BASED ON THE AFOREMENTIONED INFORMATION, THE SPRING FLOOD
POTENTIAL IS MUCH ABOVE NORMAL ACROSS NORTHERN AND CENTRAL MAINE,
AND ABOVE NORMAL FOR INTERIOR DOWNEAST. THE RIVERS ARE STILL
RUNNING VERY HIGH WITH SNOWMELT AND PRECIPITATION RUNOFF. WHILE
DRY CONDITIONS ARE EXPECTED OVER THE NEXT FEW DAYS, AN ACTIVE
WEATHER PATTERN IS ANTICIPATED AS WE HEAD INTO LATE APRIL. THIS
COMBINED WITH CONTINUED SNOWMELT WILL KEEP RIVER LEVELS HIGH OVER
THE NEXT COUPLE OF WEEKS.

THE THREAT OF ICE JAM FLOODING CONTINUES TO BE HIGHEST ACROSS
NORTHERN MAINE, ESPECIALLY IN THE SAINT JOHN VALLEY. THERE ARE ICE
JAMS CURRENTLY IN PLACE ALONG THE SAINT JOHN, AND FLOODING IS
ONGOING AT THIS TIME. ADDITIONAL FLOODING IS POSSIBLE AT ANY TIME,
AS THESE ICE JAMS MAY SHIFT AND RE-FORM ANYWHERE DOWNSTREAM. FOR
THE REMAINDER OF THE FORECAST AREA, THE THREAT OF ICE JAM FLOODING
HAS PASSED FOR THIS SEASON.

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

THE NEXT WINTER/SPRING FLOOD POTENTIAL OUTLOOK WILL BE ISSUED BY
NWS CARIBOU ON THURSDAY, MAY 1, 2014, IF IT IS DEEMED NECESSARY AT
THAT TIME.

$$

HASTINGS

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