Ice Forecast
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1
594
FZUS81 KCLE 291016
ICEFBO

GREAT LAKES FREEZE-UP OUTLOOK
NATIONAL WEATHER SERVICE CLEVELAND OH
514 AM EST TUE NOV 29 2016

GREAT LAKES ICE SEASON FOR 2016-2017 STILL ON TRACK TO BE CLOSE TO
NORMAL AS A LA NINA ADVISORY REMAINS IN EFFECT.

LA NINA CONDITIONS ARE PRESENT IN THE CENTRAL AND EAST CENTRAL
PACIFIC OCEAN MEANING SEA SURFACE TEMPERATURES ARE BELOW AVERAGE.
THERE IS A 55 PERCENT PROBABILITY THAT THE LA NINA WILL PERSIST
THROUGH THE WINTER OF 2016-2017.  SINCE THE MIDDLE OF APRIL
2016...NEAR TO BELOW AVERAGE SEA SURFACE TEMPERATURES HAVE
EXPANDED WESTWARD TOWARD THE INTERNATIONAL DATE LINE.  THIS
MEANS DURING THE WINTER OF 2016-2017...THE GREAT LAKES CAN
EXPECT TO SEE TEMPERATURES BELOW NORMAL IN THE WESTERN LAKES
AND AN EQUAL CHANCE IN THE EASTERN HALF OF THE GREAT LAKES.
EQUAL CHANCE MEANS THERE IS NO STRONG INDICATION FROM ALL OF
THE COMPUTER MODELS THAT TEMPERATURES WILL TREND TOWARD
BELOW...NEAR...OR ABOVE NORMAL.  PRECIPITATION ACROSS THE
GREAT LAKES THROUGH THE WINTER MONTHS OF DECEMBER...
JANUARY...AND FEBRUARY IS EXPECTED TO BE ABOVE NORMAL.

SO FAR THIS FALL...TEMPERATURES HAVE BEEN RUNNING ABOVE TO WELL
ABOVE NORMAL ACROSS THE GREAT LAKES.  THE WARMEST AVERAGE
TEMPERATURES OCCURRED IN THE WESTERN GREAT LAKES DURING THE LAST
30 DAYS.  THE AVERAGE TEMPERATURE AT DULUTH AS OF NOVEMBER 26
WAS 11.1 DEGREES FOR THE MONTH OF NOVEMBER.  THE EASTERN LAKES
WERE ALSO ABOVE NORMAL IN TEMPERATURES THIS PAST MONTH BUT NOT AS
HIGH AS IN THE WEST.  FOR EXAMPLE...AVERAGE TEMPERATURES RANGED
FROM 7.2 DEGREES ABOVE NORMAL AT SAULT STE MARIE TO 3.4 DEGREES
AT BUFFALO. PRECIPITATION HAS BEEN RUNNING NEAR TO SLIGHTLY BELOW
NORMAL OVER THE LAST 30 DAYS.

THE WARM TEMPERATURES AND SLIGHTLY BELOW NORMAL PRECIPITATION
HAS BEEN THE RESULT OF FAST MOVING STORM SYSTEMS WITH LITTLE
IN THE WAY OF PRECIPITATION.  SO FAR...OVER THE LAST COUPLE
MONTHS...STORM SYSTEMS HAVE BEEN TRYING TO TAKE THE TRADITIONAL
TRACK FROM THE OKLAHOMA PANHANDLE NORTHEAST INTO THE WESTERN
OR CENTRAL GREAT LAKES.  BUT FOR THE MOST PART...DUE TO THEIR
WEAKENED STATE...THEY HAVE HAD SOME DIFFICULTY IN TAPPING INTO
COPIOUS AMOUNTS OF MOISTURE TO ENHANCE PRECIPITATION.  SO FAR...
ONLY A COUPLE LAKE EFFECT SNOW EVENTS HAVE CONTRIBUTED TO THE
PRECIPITATION TOTALS FOR THE GREAT LAKES. THE FAST MOVING STORMS
CONTINUE TO TAP INTO THE WARM AIR FROM THE SOUTH. ARCTIC HIGH
PRESSURE CENTERS AND THE ASSOCIATED ARCTIC AIR MASSES HAVE YET
TO PLUNGE INTO THE GREAT LAKES AREA LEAVING VERY LITTLE COLD
AIR FOR THE STORM SYSTEMS TO TAP INTO ONCE THEY MOVE EAST.
DURING THE NEXT SEVERAL DAYS...LOW PRESSURE IS FORECAST TO
REMAIN PARKED OVER THE NORTH POLE.  THIS WILL PREVENT ARCTIC
HIGH PRESSURE CENTERS FROM DEVELOPING AND TRANSPORTING ARCTIC
AIR SOUTH INTO THE GREAT LAKES AREA FOR THE TIME BEING.
GRANTED...THIS OVERALL TREND COULD CHANGE FAIRLY QUICKLY.

THE WATER TEMPERATURES ON THE GREAT LAKES HAVE BEEN RUNNING
NEAR NORMAL IN THE WESTERN LAKES AND ACTUALLY BELOW NORMAL
IN THE EASTERN LAKES.  THIS IS DUE IN PART TO THE ACTIVE
WEATHER PATTERN WE HAVE SEEN THIS FALL HELPING TO KEEP THE
WATERS STIRRED UP AND RELEASING ITS STORED HEAT.

RELATIVE TO THE WATER TEMPERATURES...THE FREEZING DEGREE DAYS
ARE RUNNING SLIGHTLY BELOW NORMAL AS OF NOVEMBER 29.

SO...WHAT DOES ALL OF THIS MEAN FOR THE ICE SEASON THIS YEAR.
IF THE 90 DAY OUTLOOK HOLDS TRUE AND A WEAK LA NINA REMAINS
IN PLACE THROUGH THE WINTER AS EXPECTED...THEN IN COMPARISON
TO PREVIOUS WEAK LA NINA WINTERS...THE GREAT LAKES IS STILL
IN STORE FOR SEEING NEAR NORMAL ICE ACCUMULATIONS THIS
WINTER.  THIS MEANS LAKE ERIE COULD FREEZE OVER COMPLETELY...
GREEN BAY...THE BAYS DE NOC...AND SAGINAW BAY WILL ALSO
FREEZE OVER COMPLETELY.  SHORE ICE WILL FORM ALONG THE SHORES
OF LAKE SUPERIOR WHILE THE REST OF THE LAKES EXCLUDING LAKE
ERIE SHOULD REMAIN ICE FREE IN THE CENTERS.  THE BEGINNING
OF ICE FORMATION WHERE IT WILL CAUSE PROBLEMS FOR NAVIGATION
STILL APPEARS TO BE ON TRACK FOR THE FIRST WEEK OF JANUARY...
ESPECIALLY IN THE WESTERN BASIN OF LAKE ERIE.

KEEP IN MIND THAT ICE COULD DEVELOP EARLIER OR LATER SINCE ICE
DEVELOPMENT IS HIGHLY DEPENDENT ON THE OCCURRENCE OF COLD AIR
OUTBREAKS AND WARM PERIODS ACROSS THE GREAT LAKES DURING THE NEXT
TWO MONTHS.

ICE FORMATION IS DETERMINED BY TWO FACTORS--THE AMOUNT OF HEAT
STORED IN THE WATER FROM THE SUMMER AND HOW FAST THAT HEAT CAN BE
REMOVED BY ARCTIC OUTBREAKS OF POLAR AIR AND HIGH WINDS. LONG RANGE
OUTLOOKS DO NOT CONSIDER THE "STORMINESS" FACTOR WHICH CAN
SIGNIFICANTLY ALTER THE LAKES THERMAL STRUCTURE OVER SHORT PERIODS
OF TIME.

THE ISSUANCE OF ROUTINE ICE FORECASTS FOR THE GREAT LAKES COULD
BEGIN IN LATE DECEMBER OR EARLY JANUARY DEPENDING ON WHEN
SIGNIFICANT ICE BEGINS TO FORM.

FREEZING DEGREE DAY TOTALS AS OF LATE NOVEMBER IN THE LAST 10 YEARS:

                   2016 2015 2014 2013 2012 2011 2010 2009 2008 2007

DULUTH              24   39  141    9   27    0  114    0  159   52
MARQUETTE           41   40  134    2   12    0   44    0  109   41
SAULT STE MARIE     14   13   95    0    0    0   11    0   65   23
ESCANABA             0   12   78    0    0    0    5    0   70   13
GREEN BAY            0   11   57    0    0    0   13    0   65    9
MILWAUKEE            0   23   49    0    0    0    0    0   21    0
CHICAGO              0    0   28    0    0    0    2    0    9    0
MUSKEGON             0   12   89    0    0    0    0    0   15    0
ALPENA               0    9   43    0    0    0    2    0   55   19
DETROIT              0   11   41    0    0    0    0    0   16    2
TOLEDO               0    0   20    0    0    0    0    0   32    5
CLEVELAND            0    0   51    0    0    0    0    0   19    0

HARBOR WATER TEMPERATURES COMPARED TO PREVIOUS YEARS FOR MID NOVEMBER:

                 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 NORMAL

DULUTH            44   43   42   44   43   33   41   38   34   41   44
SAULT STE MARIE   45   46   39   48   41   44   47   45   35   46   47
CHICAGO           46   46   40   46   46   44   47   36   40   44   53
ALPENA            46   35   34   45   43   44   44   46   42   45   48
DETROIT           42   43   36   43   43   48   48   48   39   43   52
CLEVELAND         48   50   35   49   48   51   48   51   41   46   56
BUFFALO           47   48   39   46   48   52   48   50   40   45   54

WATER TEMPERATURES FROM THE MID-LAKE BUOYS COMPARED TO PREVIOUS YEARS:

                 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007

LAKE SUPERIOR
WEST              44   MM   MM   42   37   34   42   44   41   41
CENTRAL           42   MM   MM   40   39   44   45   43   41   40
EAST              44   MM   MM   45   37   41   45   43   40   42

LAKE MICHIGAN
NORTH             49   48   42   47   36   35   48   47   44   47
SOUTH             50   48   42   46   41   49   42   49   46   46

LAKE HURON
NORTH             MM   46   42   43   46   47   45   47   43   45
SOUTH             MM   MM   43   46   48   40   48   49   46   47

LAKE ERIE
WEST              46   46   39   45   44   48   46   49   38   MM
CENTRAL           50   MM   45   49   50   51   49   52   47   MM
EAST              49   49   43   50   50   46   48   51   49   MM

THE NEXT FREEZE UP OUTLOOK WILL BE ISSUED IN APPROXIMATELY TWO WEEKS.

$$

LOMBARDY



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.