HYDROLOGIC OUTLOOK NATIONAL WEATHER SERVICE CARIBOU ME 1238 PM EST FRI APR 14 2006
...WINTER AND SPRING FLOOD POTENTIAL OUTLOOK FOR NORTHERN...CENTRAL AND DOWNEAST MAINE...
THIS IS THE NINTH WINTER AND SPRING FLOOD POTENTIAL OUTLOOK FOR NORTHERN...CENTRAL AND DOWNEAST MAINE FOR 2006...ISSUED BY THE NATIONAL WEATHER SERVICE IN CARIBOU...MAINE.
THE WINTER/SPRING FLOOD POTENTIAL DUE TO SNOWMELT AND RUNOFF FOR NORTHERN MAINE IS NEAR NORMAL...WHILE THE POTENTIAL FOR FLOODING DUE TO SNOWMELT AND RUNOFF FOR CENTRAL AND DOWNEAST MAINE IS BELOW NORMAL.
IN THE SAINT JOHN AND AROOSTOOK RIVER BASINS...INCLUDING THE BIG BLACK AND ALLAGASH RIVERS...RIVER ICE HAS FLUSHED OUT OF THE REGION. THEREFORE THE THREAT OF FLOODING DUE TO ICE JAMS HAS PAST.
...CLIMATOLOGICAL GUIDANCE...
FOLLOWING A WARM AND DRY MARCH...THE FIRST TWO WEEKS OF APRIL HAVE FOLLOWED SUIT. TEMPERATURES ACROSS THE REGION HAVE BEEN QUITE MILD...AND THE NORTHERNMOST CLIMATE SITES HAVE ALSO MAINTAINED THEIR PRECIPITATION DEFICIT. ALONG DOWNEAST COASTAL MAINE HOWEVER...PERSISTENT WEAK STORMINESS HAS ERASED THE PRECIPITATION DEFICIT...PULLING BACK FROM THE ABNORMALLY DRY CONDITIONS PREVIOUSLY REFLECTED IN THE U.S. DROUGHT MONITOR. A BREAK FROM THE RECENT SPATE OF DRY WEATHER IS EXPECTED THIS WEEKEND WITH A ONE-HALF TO ONE-AND-ONE-QUARTER INCH RAIN EVENT SATURDAY INTO EASTER SUNDAY. AFTER THAT...THE SIX TO 14 DAY GUIDANCE FROM THE CLIMATE PREDICTION CENTER SHOWS THE AREA RETURNING TO MORE SEASONAL TEMPERATURES AND NORMAL PRECIPITATION.
...OBSERVED SNOW DEPTHS AND WATER EQUIVALENTS...
SNOW DEPTHS RANGED FROM ZERO ALONG THE DOWNEAST COAST TO STILL OVER A FOOT IN THE ALLAGASH WILDERNESS WATERWAY AND EASTERN AREAS OF THE SAINT JOHN RIVER VALLEY. THE VERY MILD BEGINNING TO APRIL PRETTY MUCH DID IN ANY SNOW REMAINING OUTSIDE OF THE MOST SHELTERED OR PROTECTED AREAS. WATER CONTAINED IN THE REMAINING SNOW RANGED FROM THREE TO FIVE INCHES IN THE SAINT JOHN VALLEY AND NORTH MAINE WOODS...TO TRACE AMOUNTS IN SHELTERED AREAS OF THE NORTHEAST AND CENTRAL MAINE HIGHLANDS.
...SOIL CONDITIONS AND WATER SUPPLY...
STORAGE IN THE TWO MAJOR NORTHERN MAINE STORAGE BASINS...THE PENOBSCOT WATERSHED AND THE ST. CROIX RIVER WATERSHED...WAS NEARLY 50 PERCENT FULL. SOIL TEMPERATURE AT FOUR INCHES DEPTH IN CARIBOU HAD CLIMBED TO AROUND 40 DEGREES.
...RIVER AND ICE CONDITIONS...
RIVERS LEVELS PEAKED THE FIRST WEEK OF APRIL WITH THE ICE BREAKUP AND FLOE. AS OF APRIL 10...ALL MAINSTEM RIVERS ACROSS THE REGION HAD FLUSHED CLEAR OF ICE. LEVELS REMAIN HIGH IN THE NORTH BUT HAVE FALLEN BELOW NORMAL ELSEWHERE.
...IN CONCLUSION...
FOR NORTHERNMOST MAINE...INCLUDING THE AROOSTOOK...ALLAGASH...BIG BLACK...SAINT JOHN...AND THE EAST BRANCH OF THE PENOBSCOT RIVER...THE SPRING FLOOD POTENTIAL IS NEAR NORMAL. THE WATER CONTAINED IN THE REMAINING SNOWPACK IS SLOWLY BEING RELEASED INTO THE AREA'S RIVER SYSTEMS...AND RIVER LEVELS ON THE UPPER AND MIDDLE SAINT JOHN ARE FLOWING WELL ABOVE NORMAL. RIVER FLOWS AND GROUNDWATER LEVELS ARE SLIGHTLY ABOVE NORMAL ELSEWHERE IN THE NORTH. APART FROM THIS WEEKEND'S ONE-AND-ONE-QUARTER RAIN EVENT IN THIS AREA...WEATHER MODELS DO NOT PREDICT A MAJOR SHIFT TO VERY WET WEATHER. THIS ADDS UP TO A NEAR NORMAL THREAT FOR FLOODING FOR THE REMAINDER OF APRIL.
ELSEWHERE...THE VERY WET ANTECEDENT CONDITIONS...HIGH RIVER FLOWS AND NEAR RECORD GROUNDWATER LEVELS HAVE MODERATED OVER CENTRAL AND DOWNEAST MAINE...WHERE THERE IS ALSO A LACK OF NORMAL SNOWPACK. THEREFORE...THE SPRING FLOOD POTENTIAL ACROSS THESE AREAS IS BELOW NORMAL.
REGARDING THE POTENTIAL FOR ICE JAM FLOODING...RIVER ICE HAS FLUSHED FREE OF THE REGION'S MAINSTEM RIVERS. THEREFORE THE THREAT ICE JAM FLOODING HAS PAST.
REMEMBER...MAJOR FLOODING DOES NOT OCCUR FROM SNOW MELT ALONE. RAINFALL...HOW MUCH AND IN HOW SHORT A PERIOD OF TIME IS THE MOST IMPORTANT FACTOR IN DETERMINING THE SEVERITY OF FLOODING...FLOODING CAN OCCUR IN AREAS WHERE THE FLOOD POTENTIAL IS NOW CONSIDERED BELOW NORMAL.
THIS IS THE FINAL FLOOD POTENTIAL OUTLOOK ISSUED BY THE NATIONAL WEATHER SERVICE IN CARIBOU FOR THIS 2006 SEASON.
MAT