Monday, January 01, 2024

December 2023 Climate Summary for Northern and Eastern Maine

...DECEMBER 2023 CLIMATE NARRATIVE FOR NORTHERN/EASTERN MAINE...

DECEMBER 2023 FOR THE REGION AS A WHOLE FINISHED WITH WELL ABOVE 
AVERAGE TEMPERATURES AND PRECIPITATION, BUT WELL BELOW AVERAGE 
SNOWFALL AND SNOW DEPTH.  

TEMPERATURES ACROSS THE AREA RANGED FROM 5.5 TO 7.0 DEGREES F ABOVE 
1991-2020 NORMALS, RANGING FROM NEAR 26.0 OVER THE SAINT JOHN VALLEY 
TO 32.0 OVER DOWNEAST AREAS. IT WAS THE 2ND WARMEST DECEMBER ON 
RECORD FOR CARIBOU AND HOULTON, A TIE FOR 3RD WARMEST FOR 
MILLINOCKET, AND 4TH WARMEST FOR BANGOR. THE FIRST HALF OF THE MONTH 
WAS CLOSE TO AVERAGE, BUT THE SECOND HALF OF THE MONTH WAS WELL 
ABOVE AVERAGE CULMINATING WITH RECORD HIGH TEMPS OF 50S UPWARDS TO 
AROUND 60 ON THE 18TH AND 19TH WITH DAILY DEPARTURES ON THE 18TH AS 
HIGH 30 DEGREES ABOVE NORMAL. LOWEST TEMPERATURES OF THE MONTH 
OCCURRED ON THE MORNING OF THE 6TH WITH MANY LOCATIONS EXPERIENCING 
LOWS OF ZERO OR LESS WITH FAR NORTHWEST VALLEY LOCATIONS AS LOW AS 
10 BELOW. BANGOR EXPERIENCED SUB-ZERO LOWS FROM THE 6TH-8TH.

AVERAGE TOTAL PRECIPITATION ACROSS THE AREA VARIED GREATLY FROM 90 
PERCENT OVER THE FAR NORTHEAST UPWARDS TO 200 PERCENT OR MORE OF 
1991-2020 NORMALS OVER SOUTHWEST PORTIONS OF THE REGION WITH THE 
VAST MAJORITY RECEIVING WELL ABOVE NORMAL PRECIPITATION FOR 
DECEMBER. TWO EVENTS COMPOSED THE MAJORITY OF PRECIPITATION FOR THIS 
MONTH WITH THE FIRST ON THE 10-11TH AND THE SECOND ON THE 18TH WHERE 
1.50-2.50 INCHES OCCURRED WITH EACH EVENT AT THE CLIMATE SITES, 
MOSTLY OR ENTIRELY IN THE FORM OF RAIN.

WARMER THAN AVERAGE TEMPERATURES THIS MONTH PRECLUDED MUCH IN THE 
WAY OF SNOWFALL AT THE CLIMATE SITES, RANGING ONLY 25 TO 50 PERCENT 
OF NORMAL. SNOWFALL WAS GREATER OVER THE CENTRAL HIGHLANDS AND FAR 
NORTHWEST NEAR THE QUEBEC BORDER, UPWARDS TO 75 PERCENT OF AVERAGE. 
AT CARIBOU, THE GREATEST SNOW DAY OF 2.7 INCHES ON THE 13TH WAS A 
RESULT OF ORGANIZED NARROW SNOW SHOWER BANDING ASSOCIATED WITH THE 
PASSAGE OF AN ARCTIC FRONT RATHER THAN A LARGE SCALE LOW PRESSURE 
SYSTEM, WITH LOCATIONS JUST NORTH IN THE CENTER OF THE BAND 
RECEIVING UPWARDS TO 6 INCHES. AT BANGOR THE HEAVIEST SNOWFALL OF 
THE MONTH WAS THE 6.4 INCH EVENT THAT FELL ON THE 4TH WITH A 
DEVELOPING COASTAL LOW PRESSURE SYSTEM.

DUE TO MANY THAWING TEMPERATURE DAYS, LITTLE SNOWFALL, AND TWO MAJOR 
RAIN EVENTS, AVERAGE SNOW DEPTH ACROSS ALL OF THE REGION WAS WELL 
BELOW AVERAGE ABOUT 20 TO 50 PERCENT OF 1991-2020 NORMALS. THE HEAVY 
WARM RAIN EVENT OF THE 18TH COMPLETELY ERADICATED ANY SNOW PACK 
ACROSS THE ENTIRE REGION. FOR INSTANCE, CARIBOU HAD A TRACE OR LESS 
OF SNOW ON THE GROUND FROM THE MORNING OF THE 16TH THROUGH THE 
MORNING OF THE 29TH WITH ZERO SNOW ON THE GROUND FROM 18TH-28TH. 
NEEDLESS TO SAY, THIS GREATLY IMPACTED THE TRADITIONAL START OF 
SKIING AND SNOW MOBILE SEASON USUALLY UNDERWAY BY THE LAST WEEK OF 
THE MONTH. WITH A LIGHT TO MODERATE SNOWFALL LATER ON THE 28TH INTO 
THE 29TH, A LIGHT SNOW PACK RETURNED TO MOST OF THE REGION AT THE 
CLOSE OF THE MONTH, BUT NOT ENOUGH FOR SNOW MOBILING AT THIS TIME.

LASTLY OF SPECIAL NOTE WAS THE HEAVY RAIN/HIGH WIND EVENT OF THE 
18TH. IN ADDITION TO HEAVY RAINFALL PREVIOUSLY MENTIONED AT THE 
CLIMATE SITES, WAS FLOODING RAINFALL TOTALS UPWARDS TO 5 INCHES OVER 
THE CENTRAL MAINE HIGHLANDS WHICH RESULTED IN SIGNIFICANT RIVER 
FLOODING OVER THE PISCATAQUIS AND PENOBSCOT RIVER VALLEYS. FOR THE 
SECOND DECEMBER IN A ROW, THIS EVENT WAS ALSO ACCOMPANIED BY 
WIDESPREAD DAMAGING WINDS, THIS TIME FROM THE SOUTH, RESULTING IN 
NUMEROUS DOWNED TREES AND POWER LINES AND OVER 90,000 POWER OUTAGES. 
ALTHOUGH BY CHRISTMAS DAY, THE VAST MAJORITY WHO SUFFERED OUTAGES 
HAD POWER RETURNED, THERE WERE STILL SOME RESIDENCES WITHOUT POWER.
STRONG SOUTH WINDS ALSO RESULTED IN SOME MINOR COASTAL FLOODING AT 
THE TIME OF HIGH TIDE.

THE CLIMATE PREDICTION CENTER'S FORECAST FOR JANUARY 2024 IS CALLING 
FOR MUCH GREATER ODDS OF ABOVE NORMAL RATHER THAN NORMAL OR 
ESPECIALLY BELOW NORMAL TEMPERATURES AND SIGNIFICANTLY ABOVE AVERAGE 
ODDS OF ABOVE RATHER THAN NEAR NORMAL OR BELOW NORMAL PRECIPITATION. 
AVERAGE TEMPERATURES RANGE FROM LOWS/HIGHS OF AROUND ZERO/20 DEGREES 
F OVER THE FAR NORTH TO AROUND 10/AROUND 30 ALONG THE DOWNEAST 
COAST. AVERAGE PRECIPITATION FOR THE ENTIRE REGION IS AROUND 3.00 
INCHES. AVERAGE MONTHLY SNOWFALL/SNOW DEPTH RANGES FROM 15/5 INCHES 
ALONG THE DOWNEAST COAST UPWARDS TO 30/15 INCHES OVER THE NORTHERN 
AND CENTRAL MAINE HIGHLANDS.