000
FGUS71 KCAR 012005
ESFCAR
MEC003-009-019-021-025-029-082015-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE CARIBOU ME
405 PM EDT THU APR 1 2021

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

THIS IS THE SEVENTH 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 APRIL 1ST TO APRIL 15TH 2021. 

THE FLOOD POTENTIAL FOR OPEN WATER FLOODING IS NEAR NORMAL 
ACROSS THE ENTIRE REGION. THE FLOOD POTENTIAL DUE TO ICE JAMS 
REMAINS NEAR NORMAL ACROSS THE NORTHERN MAINE RIVERS, WHILE THE
THREAT FOR ICE JAM FLOODING ACROSS THE CENTRAL AND DOWNEAST AREAS.
NO THREAT OF ICE JAM FLOODING, WHILE THE DOWNEAST REGION REMAINS 
BELOW NORMAL.

...CLIMATOLOGICAL GUIDANCE... 
PRECIPITATION WAS BELOW NORMAL ACROSS THE SOUTHERN HALF OF THE
REGION WITH NO SNOWFALL REPORTED DURING THE LAST HALF OF THE 
MONTH OF MARCH. NORTHERN AREAS REPORTED ABOVE NORMAL
PRECIPITATION DURING THE PERIOD WITH SNOWFALL BETWEEN 1 TO 3 
INCHES FALLING ON THE 27TH AND 28TH. 

TEMPERATURES AVERAGED ABOVE NORMAL DURING THE LAST HALF OF THE
MONTH OF MARCH. THIS HAS HELPED ACCELERATE THE SNOWMELT ACROSS THE
REGION AND IS RUNNING ABOUT 1 TO 2 WEEKS AHEAD OF SCHEDULE.

AN UPPER LEVEL BLOCKING RIDGE IS EXPECTED TO DEVELOP DOWNSTREAM 
OF NEW ENGLAND LEADING TO A NEGATIVE NORTH ATLANTIC 
OSCILLATION(NAO) PATTERN. THIS WILL ALLOW COLD AIR FROM CANADA TO 
BE DIRECTED SOUTHWARD AROUND THE BLOCKING UPPER LEVEL RIDGE SOUTH 
OF GREENLAND. THIS PATTERN IS EXPECTED TO HOLD RIGHT INTO THE 
SECOND WEEK OF APRIL WITH TEMPERATURES NEAR TO SLIGHTLY BELOW 
NORMAL FOR APRIL. 

THE OFFICIAL NATIONAL WEATHER SERVICE 6 TO 14 DAY OUTLOOK IS 
CALLING FOR NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES AND NEAR 
TO SLIGHTLY BELOW NORMAL PRECIPITATION. SOME OF THE NUMERICAL 
MODEL GUIDANCE IS SHOWING THAT THERE COULD BE A SHIFT IN THE 
PATTERN TOWARD THE END OF THIS TERM, WHICH COULD ALLOW FOR A MORE 
ACTIVE WEATHER PATTERN.

...OBSERVED SNOW DEPTH AND WATER EQUIVALENTS...
SNOW DEPTHS SAW A DRAMATIC DROP OVER THE LAST TWO WEEKS THANKS  
TO THE WARMER TEMPERATURES AND RAINFALL. AS OF 8 AM THIS MORNING, 
SNOW DEPTHS RANGED FROM 4 TO 10 INCHES ACROSS NORTHWEST MAINE, 
WHICH INCLUDES THE ALLAGASH AND NORTH WOODS REGION. FURTHER EAST 
ACROSS THE REST OF NORTHERN MAINE, SNOW DEPTHS RANGED FROM A TRACE
TO 4 INCHES WITH THE HIGHEST AMOUNTS IN THE WOODS AND ACROSS THE 
HIGHER TERRAIN. ELSEWHERE, LITTLE IF ANY SNOW WAS LEFT ON THE 
GROUND, WITH THE EXCEPTION OF SOME SNOW BANKS. 

SNOW DEPTHS ARE WELL BELOW NORMAL FOR EARLY APRIL. AS STATED 
ABOVE, THE WARMER TEMPERATURES OVER THE LAST TWO WEEKS 
ACCELERATED THE SNOWMELT, WHICH IS RUNNING ABOUT TWO WEEKS AHEAD 
OF SCHEDULE.

THE SNOW WATER EQUIVALENT, OR THE AMOUNT OF WATER CONTAINED IN 
THE SNOWPACK, DECREASED OVER THE PAST TWO WEEKS ACROSS THE REGION.
AS OF 8 AM THIS MORNING, NORTHWEST MAINE HAD 2 TO 4 INCHES, WHILE
THE REST OF NORTHERN MAINE HAD UP TO 2 INCHES IN THE WOODS AND
HIGHER TERRAIN. 

SNOW WATER EQUIVALENTS ARE WELL BELOW NORMAL ACROSS THE REGION. 

THE FROST DEPTH AT NWS CARIBOU WAS AT 5 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
ABOVE NORMAL ACROSS NORTHERN AND NORTHWEST MAINE. THE CENTRAL
AREAS WERE SEEING NEAR TO SLIGHTLY ABOVE NORMAL, WHILE THE 
DOWNEAST REGION SAW GROUNDWATER LEVELS IMPROVE TO ABOVE NORMAL. 
CALAIS IN CENTRAL WASHINGTON REPORTED GROUNDWATER LEVELS WELL 
ABOVE NORMAL. 

...RIVER AND ICE CONDITIONS...
RIVER FLOWS WERE ABOVE NORMAL ACROSS NORTHERN AND CENTRAL AREAS, 
WHILE THE DOWNEAST REGION WAS SEEING RIVER FLOWS NEAR NORMAL. 

ICE COVER HAD BROKEN UP ACROSS THE RIVERS AND STREAMS THROUGHOUT
THE REGION, THANKS TO THE WARMER TEMPERATURES AND RAINFALL THAT 
TOOK PLACE DURING THE LAST WEEK OF MARCH. THERE IS STILL SOME ICE
COVER ALONG THE ST. JOHN RIVER FROM LILLE TO HAMLIN WITH AN ICE 
JAM IN PLACE JUST SOUTH OF LILLE. THE AROOSTOOK RIVER STILL HAS 
ICE COVER IN THE VICINITY OF THE CARIBOU DAM, AND FROM THE 
CARIBOU-FORT FAIRFIELD TOWN LINE ALL THE WAY TO THE INTERNATIONAL 
BORDER AT TINKER DAM. THERE IS AN ICE JAM THAT IS STILL IN PLACE 
IN FORT FAIRFIELD, FROM THE STRICKLAND ROAD TO THE FORT FAIRFIELD
BRIDGE.

...IN CONCLUSION...
THE FLOOD POTENTIAL FOR OPEN WATER FLOODING IS NEAR 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 FOR THE CENTRAL AND SOUTHERN AREAS
HAS ENDED FOR THE SEASON.

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. 

THIS WILL BE THE LAST WINTER/SPRING FLOOD OUTLOOK ISSUED FOR THE
SEASON, UNLESS CONDITIONS WARRANT OTHERWISE.

$$

HEWITT

  US Dept of Commerce
  National Oceanic and Atmospheric Administration
  National Weather Service
  1325 East West Highway
  Silver Spring, MD 20910
  Page Author: NWSChat Administration Team
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy  
Freedom of Information Act (FOIA)  
About Us  
Career Opportunities