Tuesday, February 25, 2014

Winter and Spring Flood Potential Outlook issued on February 20th

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FGUS71 KCAR 201918
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MEC003-009-019-021-029-210730-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE CARIBOU ME
218 PM EST THU FEB 20 2014

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

THIS IS THE FOURTH WINTER/SPRING FLOOD POTENTIAL OUTLOOK FOR
2014...ISSUED BY THE NATIONAL WEATHER SERVICE IN CARIBOU, MAINE.
THE WINTER/SPRING FLOOD POTENTIAL IS FOR NORTHERN, CENTRAL AND
DOWNEAST MAINE FOR THE TWO WEEK PERIOD FROM FEBRUARY 20 TO MARCH
6, 2014.

THE WINTER/SPRING FLOOD POTENTIAL FOR NORTHERN, CENTRAL AND
DOWNEAST MAINE IS NEAR NORMAL THROUGH THE NEAR TERM, THOUGH IT IS
SOMEWHAT ABOVE NORMAL THROUGH THE LONG TERM. LIKEWISE, THE
POTENTIAL FOR FLOODING DUE TO ICE JAMS ACROSS THE REGION IS NEAR
NORMAL IN THE NEAR TERM BUT ABOVE NORMAL GOING FORWARD TOWARDS
SPRING.

...CLIMATOLOGICAL GUIDANCE...

SO FAR FEBRUARY HAS BEEN MARKED BY COLD AND SNOWY CONDITIONS.
AVERAGE TEMPERATURES ARE ALREADY SOME 1.5 TO 4 DEGREES COLDER
THAN NORMAL WITH MONTHLY SNOWFALL AVERAGING 10 OR MORE INCHES
HIGHER THAN NORMAL. A BRIEF BREAK FROM THIS PATTERN IS EXPECTED
THROUGH THIS WEEKEND AS A POTENT STORM SYSTEM LIFTS NORTH THROUGH
THE GREAT LAKES AND INTO CANADA. ALREADY THIS HAS ALLOWED A
WARMER FLOW TO SET UP, WITH TEMPERATURES CURRENTLY IN THE LOWER
30S TO LOWER 40S AREAWIDE. THIS TREND WILL CONTINUE INTO THE
WEEKEND AS A WINTRY MIX OF PRECIPITATION SPREADS OVER THE REGION,
CHANGING TO ALL RAIN AS FAR NORTH AS HOULTON. RIGHT NOW, FLOODING
IS NOT ANTICIPATED AS RAIN AMOUNTS WILL NOT BE ENOUGH TO CAUSE
ICE BREAKUP, AND THE MILD CONDITIONS WILL NOT BE STRONG ENOUGH
NOR LONG-LIVED ENOUGH TO CAUSE COPIOUS AMOUNTS OF SNOWMELT AND
RUNOFF.

AS WE GET INTO EARLY NEXT WEEK, ALL SIGNS POINT TO ANOTHER ARCTIC
OUTBREAK ACROSS NORTHERN NEW ENGLAND AS DEEP TROUGHING LOOKS TO
SET UP ACROSS THE EASTERN CONTINENTAL UNITED STATES. THIS COLD
PATTERN WILL LIKELY LINGER INTO THE FIRST WEEK OF MARCH. THE
OFFICIAL NATIONAL WEATHER SERVICE 6 TO 10 DAY OUTLOOK FOR THE END
OF FEBRUARY MATCHES THIS THINKING WELL, CALLING FOR BOTH
TEMPERATURES AND PRECIPITATION TO AVERAGE BELOW NORMAL.

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

SNOW DEPTHS AND WATER EQUIVALENTS HAVE INCREASED DRAMATICALLY
ACROSS ALL OF NORTHERN, CENTRAL, AND DOWNEAST MAINE AS SEVERAL
MAJOR SNOWSTORMS HAVE DUMPED 1 TO 2 FEET OF ADDITIONAL SNOW ACROSS
THE REGION. AS A RESULT, SNOW DEPTHS AND SNOW WATER EQUIVALENTS
ARE NEAR TO ABOVE NORMAL OVER THE ENTIRE AREA.

SNOW DEPTHS ACROSS DOWNEASTERN AREAS ARE GENERALLY 1.5 TO 2.5
FEET WITH AROUND 1 FOOT ALONG THE IMMEDIATE COAST. A VERY
LOCALIZED HEAVY SNOW BAND SET UP ACROSS PORTIONS OF HANCOCK AND
WASHINGTON COUNTIES EARLIER THIS WEEK, WITH ISOLATED SNOW DEPTHS OF
45 TO 50 INCHES BEING REPORTED. AS YOU HEAD NORTH BACK UP INTO THE
CENTRAL HIGHLANDS AND NORTHERN MAINE, SNOW DEPTHS ARE GENERALLY 20
TO 30 INCHES, WITH AROUND 3 FEET BEING REPORTED IN SOME LOCATIONS.
THESE DEPTHS ARE ALL NEAR TO ABOVE NORMAL.

SNOW WATER EQUIVALENT, OR THE AMOUNT OF WATER CONTAINED IN THE
SNOWPACK, IS ALSO NEAR TO ABOVE NORMAL OVER THE ENTIRE FORECAST
AREA. COASTAL AREAS GENERALLY HAVE 2 TO 4 INCHES OF WATER IN THEIR
PACK, BUT THESE NUMBERS INCREASE TO 4 TO 6 INCHES AS YOU HEAD
INLAND. THE SNOW ACROSS NORTHERN MAINE CONTAINS 6 TO 8 INCHES,
WITH THE BIG WOODS OF FAR NORTHWESTERN MAINE PERHAPS HOLDING
AROUND 9 INCHES OF WATER IN THE SNOW.

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

WITH THE COLD AND SNOWY WEATHER WE'VE EXPERIENCED OVER THE PAST
COUPLE OF WEEKS, THERE HAS BEEN VERY LITTLE RUNOFF FROM EITHER
RAIN OR SNOWMELT. HOWEVER, SOIL MOISTURE STATES STILL REMAIN ON
THE WET SIDE OWING TO THE JANUARY THAW AND RAINS EARLIER THIS
YEAR. THE LATEST PALMER DROUGHT SEVERITY INDEX, WHICH IS AN
INDICATOR OF MORE LONG- TERM MOISTURE STATES, SHOWED NEAR TO ABOVE
NORMAL MOISTURE ACROSS THE REGION.

GROUNDWATER MONITORING WELLS SHOW MOST AREAS SEEING NEAR TO BELOW
NORMAL GROUNDWATER CONDITIONS FOR THIS TIME OF THE YEAR. THE
EXCEPTION LIES ACROSS DOWNEAST MAINE WHERE GROUNDWATER LEVELS ARE
ABOVE NORMAL.

...RIVER AND ICE CONDITIONS...

SINCE TEMPERATURES HAVE REMAINED COLD ENOUGH OVER THE PAST SEVERAL
DAYS TO LIMIT ANY SIGNIFICANT SNOWMELT AND KEEP PRECIPITATION IN
THE FORM OF SNOW, RIVER FLOWS CONTINUE TO HOLD AT OR A BIT BELOW
NORMAL OWING TO LITTLE TO NO RECENT RUNOFF. THIS TREND IS EXPECTED
TO CONTINUE OVER THE NEXT COUPLE OF WEEKS. WHILE A WARM UP WITH
SOME RAIN IS EXPECTED THROUGH THE WEEKEND, THE SNOWPACK WILL BE
ABLE TO ABSORB THIS LIQUID AND PROHIBIT ANY MAJOR RUNOFF FROM MAKING
IT INTO THE RIVERS. THEREFORE, NO SIGNIFICANT RIVER RISES ARE
EXPECTED.

THE ICE ALONG NORTHERN, CENTRAL, AND DOWNEAST MAINE'S WATERWAYS
CONTINUES TO STRENGTHEN. ACCORDING TO ENVIRONMENT CANADA, THE
SAINT JOHN RIVER EXPERIENCED ITS EARLIEST FREEZE UP IN 20
YEARS. SINCE THE SAINT JOHN AND ITS NORTHERN COUNTERPARTS (THE
AROOSTOOK AND ALLAGASH) DID NOT EXPERIENCE A BREAKUP DURING THE
JANUARY THAW, ICE THICKNESSES IN THESE AREAS ARE ESTIMATED TO BE
1.5 TO 2.5 FEET, WITH SOME SPOTS POSSIBLY APPROACHING 3 FEET.
ISOLATED LOCATIONS, LIKELY THOSE WITH FASTER FLOWS, ARE REPORTING
THICKNESSES CLOSER TO 15 INCHES. THE UPPER REACHES OF THE CENTRAL
AND SOUTHERN RIVERS, INCLUDING THE PENOBSCOT, THE PISCATAQUIS, AND
THE MATTAWAMKEAG, ARE GENERALLY COVERED WITH AROUND 1 FOOT OF ICE.
THE LOWER REACHES THAT EXPERIENCED BREAKUP DURING THE JANUARY THAW
ARE LIKELY ONLY COVERED WITH ICE THAT IS 6 TO 10 INCHES THICK.
WITH COLDER CONDITIONS TO SETTLE OVER THE REGION AFTER THIS
WEEKEND'S MILDER CONDITIONS, THE ICE WILL CONTINUE TO INCREASE IN
THICKNESS AND COVERAGE.

SEVERAL JAMS REMAIN LOCKED IN PLACE ACROSS CARIBOU'S FORECAST
AREA. THESE INCLUDE BUT ARE NOT LIMITED TO ICE JAMS ALONG THE
SAINT JOHN RIVER UPSTREAM OF FORT KENT, THE EAST BRANCH OF THE
PENOBSCOT RIVER DOWNSTREAM OF GRINDSTONE, THE PENOBSCOT RIVER
NEAR WINN, THE PISCATAQUIS RIVER UPSTREAM OF HOWLAND, AND THE
KENDUSKEAG STREAM IN DOWNTOWN BANGOR. THESE JAMS ARE NOW WELL
FROZEN IN PLACE AND ARE NOT EXPECTED TO MOVE OVER THE NEXT
SEVERAL DAYS, IN SPITE OF THE UPCOMING SHORT WARM SPELL AND RAIN
EVENT. HOWEVER, SHOULD A PROLONGED WARM UP OCCUR, ESPECIALLY
ACCOMPANIED BY SIGNIFICANT RAINFALL, THESE EXISTING JAMS WILL
LIKELY SERVE AS A FOCUS FOR ADDITIONAL JAMMING AND POTENTIAL
FLOODING. IN ADDITION, THE ICE ALONG THE UNBROKEN STRETCHES IS
VERY WELL ESTABLISHED AND WHILE IT WILL TAKE MAJOR RIVER RISES TO
BREAK IT UP, IT WILL BE MORE SUSCEPTIBLE TO CAUSING JAMMING ONCE
IT DOES RELEASE.

...IN CONCLUSION...

BASED ON THE AFOREMENTIONED INFORMATION, THE SHORT-TERM WINTER/SPRING
FLOOD POTENTIAL IS NEAR NORMAL FOR ALL OF NORTHERN, CENTRAL, AND
DOWNEAST MAINE. RIVER FLOWS, GROUNDWATER LEVELS, AND ANTECEDENT
MOISTURE ARE ALL NEAR NORMAL. SNOW DEPTHS AND SNOW WATER
EQUIVALENTS ARE NEAR TO A BIT ABOVE NORMAL, WHICH HELPS TO OFFSET
THE ANTECEDENT DRYNESS AND LOW RIVER FLOWS. THE CURRENT WARM UP
AND FORECASTED RAINFALL EVENT FOR THE END OF THE WEEK ARE NOT
EXPECTED TO PROVIDE ENOUGH RUNOFF TO BRING A SIGNIFICANT FLOODING
THREAT. WITH COLD TEMPERATURES TO RESUME NEXT WEEK AND HOLD INTO
EARLY MARCH, IT LOOKS LIKE THE OVERALL FLOOD POTENTIAL WILL REMAIN
NEAR NORMAL. IN THE LONGER TERM, HOWEVER, THE FLOOD POTENTIAL IS
ABOVE NORMAL AS WE HAVE BUILT UP AN EXTENSIVE SNOWPACK HEADING
INTO THE SPRING MELT.

THE POTENTIAL FOR ICE JAM FLOODING IS ALSO NEAR NORMAL THROUGH THE
NEAR TERM. ALTHOUGH ICE JAMS EXIST ALONG SEVERAL RIVERS IN
CARIBOU'S FORECAST AREA, THESE JAMS ARE LOCKED IN PLACE. THE ICE
IS WELL ESTABLISHED ON THE SAINT JOHN, AROOSTOOK, AND ALLAGASH
WATERWAYS. ICE THICKNESSES ACROSS THE REGION ARE GENERALLY 1 TO AS
MUCH AS 3 FEET. AS MENTIONED EARLIER, THE NEAR-TERM WARM UP AND
RAINFALL WILL NOT BE SUBSTANTIAL ENOUGH TO MOVE ANY OF THIS ICE.
WITH ARCTIC AIR TO RETURN BY EARLY NEXT WEEK AND LINGER INTO EARLY
MARCH, NO ICE BREAKUP OR JAMMING IS EXPECTED THROUGH THE NEXT
COUPLE OF WEEKS. HOWEVER, THIS MEANS WE WILL LIKELY ENTER MARCH
WITH A VERY SUBSTANTIAL AMOUNT OF RIVER ICE. AS SUCH, THERE IS AN
ABOVE NORMAL THREAT FOR ICE JAM FLOODING THROUGH THE LONGER TERM.
THE RIVERS WILL NEED TO BE MONITORED CLOSELY AS WE HEAD INTO
SPRING.

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, MARCH 6, 2014.

$$

HASTINGS

A Cold and Snowy Winter for northern and eastern Maine


SINCE DECEMBER 1ST...THE AVERAGE TEMPERATURE AT CARIBOU OF 12.4 DEGREES IS 1.3 DEGREES BELOW THE 30-YEAR AVERAGE (1981-2010). IT HAS BEEN THE COLDEST METEOROLOGICAL WINTER (DECEMBER THROUGH FEBRUARY) SINCE THE WINTER OF 2008-09. AT BANGOR...THE AVERAGE TEMPERATURE SO FAR THIS WINTER OF 18.2 DEGREES IS 2.7 DEGREES BELOW AVERAGE. IT ALSO RANKS AS THE COLDEST WINTER SINCE 2008-09.

THERE HAVE BEEN A TOTAL OF 25 NIGHTS WHEN THE TEMPERATURE HAS FALLEN BELOW ZERO AT BANGOR...COMPARED TO AN AVERAGE OF 16 BY THIS POINT IN THE WINTER. AT CARIBOU...THERE HAVE BEEN 37 NIGHTS WITH A LOW BELOW ZERO...WHICH COMPARES TO A NORMAL OF 31 BY THIS POINT IN THE WINTER. ON AVERAGE THE LAST NIGHT WITH A LOW BELOW AT CARIBOU IS MARCH 11TH...AND AT BANGOR FEBRUARY 25TH.

SNOWFALL IS RUNNING ABOVE NORMAL AT BOTH CARIBOU AND BANGOR THIS WINTER. A TOTAL OF 97.1 INCHES OF SNOW HAS BEEN OBSERVED AT CARIBOU WHICH IS 20.8 INCHES ABOVE NORMAL. AT BANGOR...A TOTAL OF 63.1 INCHES OF SNOW HAS BEEN OBSERVED...WHICH IS 16.3 INCHES ABOVE NORMAL. IT HAS BEEN THE SNOWIEST WINTER AT CARIBOU SINCE THE WINTER OF 2007-08...AND SINCE THE WINTER OF 2010-11 AT BANGOR.