Winter/Spring Flood Potential Outlook For Northern & Eastern Maine - 03/18/2021
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FGUS71 KCAR 190205
ESFCAR
MEC003-009-019-021-025-029-260215-
WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE CARIBOU ME
1005 PM EDT THU MAR 18 2021
..SPRING FLOOD POTENTIAL OUTLOOK FOR NORTHERN... CENTRAL...AND
DOWNEAST MAINE...
THIS IS THE SIXTH WINTER/SPRING FLOOD POTENTIAL OUTLOOK FOR 2021,
ISSUED BY THE NATIONAL WEATHER SERVICE IN CARIBOU, MAINE. THIS
OUTLOOK IS FOR NORTHERN, CENTRAL, AND DOWNEAST MAINE FOR THE TWO-
WEEK PERIOD OF MARCH 18TH TO APRIL 1ST, 2021.
THE FLOOD POTENTIAL FOR OPEN WATER FLOODING REMAINS SLIGHTLY
BELOW NORMAL ACROSS THE ENTIRE REGION. THE FLOOD POTENTIAL DUE TO
ICE JAMS REMAINS NEAR NORMAL ACROSS THE NORTHERN AND CENTRAL MAINE
RIVERS, WHILE THE DOWNEAST REGION REMAINS BELOW NORMAL.
...CLIMATOLOGICAL GUIDANCE...
VERY MINOR SNOWFALL ACCUMULATIONS OCCURRED MARCH 9TH, MAINLY OVER
EASTERN AREAS. SNOWFALL AMOUNTS RANGED FROM 0.3 TO 3.5 INCHES.
BELOW NORMAL PRECIPITATION INCLUDES BELOW NORMAL SNOWFALL AMOUNTS
FOR THE AREA, EXCEPT FOR SLIGHTLY BELOW NORMAL SNOWFALL FOR THE
CARIBOU AREA.
NEAR NORMAL TEMPERATURES OCCURRED ACROSS MOST OF THE AREA ALTHOUGH
CARIBOU EXPERIENCED 1.7 DEGREES BELOW NORMAL FOR THE FIRST HALF
OF THE MONTH.
AN ACTIVE SPLIT JET STREAM PATTERN IS FORECAST TO CONTINUE THE
REMAINDER OF MARCH. THIS OFFERS SOME CHALLENGES TO THE FORECAST
DUE TO TIMING AND PHASING OF LOW PRESSURE SYSTEMS WITH RESPECT TO
QUANTITATIVE PRECIPITATION FORECAST. SOME SIGNIFICANT TEMPERATURE
FLUCTUATION LIKELY TO OCCUR OVER THE NEXT TWO WEEKS, TYPICAL FOR
THIS TIME OF YEAR.
THE OFFICIAL NATIONAL WEATHER SERVICE 6 TO 14 DAY OUTLOOK IS CALLING
FOR ABOVE NORMAL TEMPERATURES AND NEAR TO SLIGHTLY ABOVE NORMAL
PRECIPITATION.
...OBSERVED SNOW DEPTH AND WATER EQUIVALENTS...
SNOW DEPTHS ACROSS NORTHERN AREAS RANGED FROM 16 TO 25 INCHES.
SOUTHEAST AROOSTOOK COUNTY IS SEEING BETWEEN 12 TO 16 INCHES,
WHILE THE MAINE CENTRAL HIGHLANDS RANGED FROM 8 TO 12 INCHES.
INTERIOR DOWNEAST AND THE PENOBSCOT VALLEY AVERAGED BETWEEN 1 TO 6
INCHES, WITH THE COAST SEEING TRACE AMOUNTS TO NO SNOW. SNOW
DEPTHS ARE NORMAL ACROSS THE NORTH BUT BELOW NORMAL OVER SOUTHERN
AREAS.
SNOW DEPTHS HAVE DECREASED OVER THE PAST TWO WEEKS, WITH THE
HIGHEST SNOW DEPTH BEING 23.1 INCHES OF SNOW STILL REMAINING ON
THE GROUND IN WINTERVILLE. THE NWS IN CARIBOU RECORDED A DEPTH OF
16 INCHES AS OF 8 AM THIS MORNING. INTERESTINGLY ENOUGH, CHIMNEY
POND AT BAXTER STATE PARK, RECORDED A SNOW DEPTH THIS MORNING OF
AN INCREDIBLE 37 INCHES.
SNOW DEPTHS ARE NEAR NORMAL ACROSS NORTHERN MAINE, WHILE SNOW
DEPTHS ARE BELOW NORMAL ELSEWHERE.
THE SNOW WATER EQUIVALENT, OR THE AMOUNT OF WATER CONTAINED IN
THE SNOWPACK, HAS DECREASED SOME OVER THE PAST TWO WEEKS ACROSS
NORTHERN MAINE. NORTHERN MAINE IS STILL SEEING 5 TO 7 INCHES,
WHILE THE MAINE CENTRAL HIGHLANDS HAD 2 TO 4 INCHES. THE NWS IN
CARIBOU RECORDED A SNOW WATER EQUIVALENT OF 5.6 INCHES. THE SNOW
WATER EQUIVALENT ESSENTIALLY REMAINED THE SAME AS TWO WEEKS AGO,
ALTHOUGH THE SNOW DEPTH HAD DECREASED FROM 25 TO 16 INCHES. THE
HIGHEST SNOW WATER EQUIVALENT WAS REPORTED IN ALLAGASH WITH 6.8
INCHES OF WATER IN THE SNOWPACK.
SNOW WATER EQUIVALENTS ACROSS THE PENOBSCOT VALLEY AND THE
DOWNEAST REGION RANGED FROM 1 TO 2 INCHES.
SNOW WATER EQUIVALENTS ARE NEAR NORMAL ACROSS THE NORTH WITH
BELOW NORMAL ELSEWHERE.
THE FROST DEPTH AT NWS CARIBOU REMAINS AT 6 INCHES.
...SOIL MOISTURE AND WATER SUPPLY CONDITIONS...
THE LATEST PALMER DROUGHT SEVERITY INDEX, WHICH MEASURES SOIL
MOISTURE IN THE LONGER TERM, SHOWS NEAR NORMAL CONDITIONS FOR ALL
AREAS.
A LOOK AT THE GROUNDWATER LEVELS, COURTESY OF THE USGS, SHOWED
MAINLY NEAR NORMAL ACROSS THE REGION. A COUPLE OF EXCEPTIONS WERE
CLAYTON LAKE IN NORTHWEST AROOSTOOK COUNTY AND AMHERST IN HANCOCK
COUNTY, REPORTING BELOW NORMAL GROUNDWATER LEVELS. THERE STILL
EXISTS ENOUGH OF A SNOWPACK NORTH AND WEST OF THE DOWNEAST REGION
THAT IS AVAILABLE FOR RECHARGE.
...RIVER AND ICE CONDITIONS...
RIVER FLOWS WERE NEAR NORMAL ACROSS MUCH OF THE REGION, WITH THE
EXCEPTION OF THE ST. CROIX RIVER BASIN, AS FLOWS REMAIN SLIGHTLY
BELOW NORMAL.
ABOUT 90% OF THE STREAMS AND RIVERS ACROSS THE REGION ARE SNOW
AND ICE COVERED, INCLUDING THE PENOBSCOT AND PISCATAQUIS RIVERS.
THERE ARE OPEN AREAS OF WATER ON THE NORTHERN AND CENTRAL MAINE
RIVERS, INCLUDING THE PENOBSCOT, PISCATAQUIS, AROOSTOOK AND ST.
JOHN RIVER. ACROSS THE DOWNEAST REGION, THE MILDER TEMPERATURES
HAVE ALLOWED THE ICE TO WEAKEN AND FLUSH OUT. THIS CAN BE SEEN
ALONG THE ST. CROIX RIVER, WHERE MANY OPEN AREAS OF WATER WERE
OBSERVED DURING THE PAST WEEK.
ICE THICKNESSES RANGED FROM 14 TO 20 INCHES ACROSS THE AROOSTOOK
AND ST. JOHN RIVER BASINS, INCLUDING THE ALLAGASH RIVER. THE
THICKEST ICE WAS ACROSS THE ST. JOHN RIVER WEST OF FORT KENT AND
ON THE ALLAGASH RIVER. THE FISH RIVER HAS OPENED UP CONSIDERABLY
ESPECIALLY IN THE FORT KENT REGION OVER THE LAST TWO WEEKS. THERE
IS STILL A GOOD STRETCH OF THE RIVER, SOUTH OF THE FORT KENT
REGION, THAT STILL HAD SOME SNOW AND ICE COVER.
THE PENOBSCOT RIVER REMAINED ICE COVERED NORTH OF THE HOWLAND
REGION INTO MILLINOCKET. LARGE OPEN SECTIONS SOUTH OF HOWLAND
DOWN TO THE BANGOR REGION. ICE WAS SHOWING SIGNS OF THINNING OVER
THE PAST WEEK. THE EAST BRANCH OF THE PENOBSCOT RIVER AT
GRINDSTONE WAS ICE COVERED WITH A COUPLE OF OPEN STRETCHES TO THE
SOUTH. ICE THICKNESS WAS MEASURED BY THE USGS TO BE AROUND 18
INCHES AT GRINDSTONE. THE KENDUSKEAG STREAM IN DOWNTOWN BANGOR,
WERE THE KENDUSKEAG STREAM MEETS UP WITH THE PENOBSCOT RIVER, WAS
STILL ICE COVERED WITH ICE THICKNESS OF 15 TO 18 INCHES.
THE MATTAWAMKEAG RIVER WAS 90% ICE COVERED WITH SOME OPEN
SECTIONS OF WATER HEADING TOWARD THE CONFLUENCE OF THE
MATTAWAMKEAG AND PENOBSCOT RIVER. ICE THICKNESS WAS MEASURED BY
THE USGS TO BE 18 INCHES. THE PISCATAQUIS RIVER FROM BLANCHARD TO
DOVER-FOXCROFT WAS ICE COVERED WITH SOME OPEN SECTIONS ALONG THE
SIDES, WHILE ICE REMAINED ON THE PISCATQUIS RIVER TOWARD THE
MAXFIELD AND MEDFORD REGION. ACCORDING TO THE USGS, ICE
THICKNESSES WERE UP TO 18 INCHES IN SOME LOCATIONS.
THERE ARE SOME ICE JAMS REMAINING IN PLACE. ONE BUNCHED UP JAM
RESIDES ON THE AROOSTOOK RIVER JUST EAST OF THE CARIBOU-FORT
FAIRFIELD TO THE FORT FAIRFIELD BRIDGE. THIS JAM IS APPROXIMATELY
7 MILES IN LENGTH. THE JAM REMAINS BROKEN UP IN SPOTS ALONG THIS
STRETCH. AN ICE JAM REMAINS IN PLACE ON THE ALLAGASH RIVER NEAR
THE BRIDGE WHERE THE ALLAGASH RIVER MEETS THE ST. JOHN RIVER. THIS
BUNCHED UP JAMS EXTENDS BACK TO THE WEST FOR ABOUT 2 MILES. THERE
IS SOME LARGE AREAS OF BUNCHED UP ICE ON THE ST. JOHN RIVER FROM
ST. JOHN TO THE TOWN OF ALLAGASH.
ICE COVERAGE AND THICKNESSES ARE BELOW NORMAL FOR THIS TIME OF
YEAR.
...IN CONCLUSION...
THE FLOOD POTENTIAL FOR OPEN WATER FLOODING IS SLIGHTLY BELOW
NORMAL ACROSS THE ENTIRE REGION. THE FLOOD POTENTIAL DUE TO ICE
JAMS REMAINS NEAR NORMAL FOR THE NORTHERN MAINE RIVER BASINS. THE
FLOOD POTENTIAL FOR ICE JAM FLOODING IS ALSO NEAR NORMAL ACROSS
THE PISCATAQUIS AND PENOBSCOT RIVER RIVERS, GIVEN THE LATEST ICE
THICKNESSES AND ICE COVERAGE.
IT IS IMPORTANT TO REMEMBER THAT A HEAVY RAINFALL EVENT ALONG
WITH MILD TEMPERATURES, OR A PROLONGED WARMUP IN TEMPERATURES,
CAN LEAD TO AN INCREASED POTENTIAL FOR FLOODING WITH SNOWMELT AND
RUNOFF. ICE BREAKING UP AND JAMMING CAN ELEVATE THE THREAT FOR
FLOODING IN A SHORT PERIOD OF TIME.
THE NEXT WINTER/SPRING FLOOD OUTLOOK WILL BE ISSUED ON THURSDAY,
APRIL 1ST.
$$
HEWITT
posted by Advackia at 8:39 PM
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