584  
FZUS81 KCLE 141651  
ICEGL  
 
GREAT LAKES ICE BREAK-UP OUTLOOK  
NATIONAL WEATHER SERVICE CLEVELAND OH  
1253 PM EDT FRI MAR 14 2025  
 
...MAXIMUM ICE COVERAGE FOR THE 2024-2025 SEASON BRIEFLY REACHED  
AVERAGE, BUT WAS BELOW AVERAGE ON THE WHOLE...  
 
THE STRONG EL NINO FROM THE 2023-2024 ICE SEASON TRANSITIONED TO  
NEUTRAL CONDITIONS LATE SUMMER/EARLY FALL OF 2024, AND THEN TO WEAK  
LA NINA INTO THE WINTER OF 2024-2025. USING DATA FROM PAST STRONG EL  
NINO TO WEAK LA NINA EVENTS AND THE RESULTANT ICE COVERAGE, THE  
TREND WAS FOR BELOW NORMAL ICE COVERAGE, WHICH WAS A MAIN COMPONENT  
OF THE FORECAST THIS PAST FALL ALONG WITH THE ONE MONTH AND THREE  
MONTH OUTLOOKS PROVIDED BY THE CLIMATE PREDICTION CENTER.  
 
ICE COVERAGE PEAKED AT 52.23 PERCENT ON FEBRUARY 21ST. THE RUNNING  
AVERAGE MAXIMUM ICE COVERAGE FOR THE GREAT LAKES SINCE THE EARLY  
1970S IS 52 PERCENT.  
 
LOOKING BACK AT THE WEATHER SUMMARIES OVER THE SEASON, DECEMBER WAS  
SLIGHTLY WARMER THAN NORMAL (GENERALLY 1-3F) ACROSS THE ENTIRETY OF  
THE GREAT LAKES, WHILE JANUARY AND FEBRUARY BOTH TRENDED SLIGHTLY  
BELOW NORMAL (GENERALLY 1-4F). THE SECOND HALF OF DECEMBER WAS THE  
MILDER PORTION OF THAT MONTH, AND THIS DID SERVE TO DELAY ICE  
FORMATION OF ANY SIGNIFICANCE. IT ALSO NEEDS TO BE RECALLED THAT  
WATER TEMPERATURES WERE STILL RIDING WELL ABOVE NORMAL AT THAT TIME,  
CARRYING OVER FROM THOSE CONDITIONS FROM THE FALL SEASON, AND ICE  
FORMATION WAS ULTIMATELY PUSHED TO 2025. JANUARY AND FEBRUARY WERE  
LARGELY CHARACTERISTIC OF FREQUENT COLD AIRMASSES OVER THE GREAT  
LAKES WITH LIMITED AND BRIEF TEMPERATURE RECOVERIES TO NEAR OR ABOVE  
FREEZING VALUES. THE TYPICAL AREAS IN THE GREAT LAKES FROZE  
FIRST...THE WESTERN BASIN OF LAKE ERIE, GREEN BAY/BIG BAY DE  
NOC/LITTLE BAY DE NOC, SAGINAW BAY, ST. MARYS RIVER, AND LAKE ST.  
CLAIR. IN JANUARY, THE SOUTHERN GREAT LAKES WERE MORE SIGNIFICANTLY  
COLDER THAN NORMAL WITH CLEVELAND THE OUTLIER AT 5.6F BELOW NORMAL  
FOR THE MONTH AND TOLEDO AT 3.7F BELOW NORMAL. LAKE ERIE FROZE  
NEARLY COMPLETELY, AND HAD AT LEAST 80 PERCENT ICE COVERAGE FROM THE  
END OF JANUARY THROUGH THE END OF FEBRUARY, PEAKING AROUND 95  
PERCENT IN MID FEBRUARY. BUT THE GREAT LAKES ON THE WHOLE WERE  
FAIRLY WINDY OVER THE JANUARY THROUGH FEBRUARY PERIOD, AND ON LAKE  
ERIE, THE ICE WAS FREQUENTLY PUSHED AROUND WITH VERY LITTLE DOMINANT  
FAST ICE. EVENTUALLY, WHITEFISH BAY AND THE STRAITS OF MACKINAC  
FROZE OVER WITH EXTENSIVE FAST ICE INTO FEBRUARY. OPEN WATER REGIONS  
OF THE OTHER GREAT LAKES OUTSIDE OF ERIE SAW VERY LITTLE ICE, AND  
THE WATER TEMPERATURES THERE HAD TROUBLE GETTING BELOW THE UPPER  
30S. SATELLITE DERIVED WATER TEMPERATURES IN THE OPEN WATERS OF  
NORTHERN LAKE HURON IN LATE JANUARY INTO EARLY FEBRUARY WERE STILL  
PEAKING AROUND 40F. FURTHER TO THE NORTH AND WEST, MUCH OF DULUTH  
HARBOR REMAINED ICE FREE. SHORELINE ICE WAS PRESENT IN MANY AREAS OF  
THE LAKES, BUT NOT EXTENSIVE. FOR THE OPEN WATERS OUTSIDE OF LAKE  
ERIE, IT IS BELIEVED THAT PERSISTENTLY WINDY CONDITIONS IN JANUARY  
AND FEBRUARY DID PLAY A ROLE INHIBITING ICE FORMATION.  
 
FREEZING DEGREE DAY ACCUMULATIONS AT SELECTED STATIONS  
COMPARED TO NORMAL CALCULATED ON THU MAR 13:  
 
LOCATION DATE NORMAL CURRENT  
----------------------------------------  
 
DULUTH, MN MAR 12 1768 1760  
MARQUETTE, MI MAR 12 1556 1448  
SAU_S_MAR, MI MAR 12 1257 1118  
GREENBAY, WI MAR 12 1006 874  
MILWAUKEE, WI MAR 12 451 482  
CHICAGO, IL MAR 12 316 321  
MUSKEGON, MI MAR 12 311 290  
ALPENA, MI MAR 12 929 801  
DETROIT, MI MAR 12 329 366  
TOLEDO, OH MAR 2 211 357  
CLEVELAND, OH MAR 12 69 272  
BUFFALO, NY MAR 12 426 382  
 
 
NORMAL TEMPS FOR SELECTED LOCATIONS AROUND THE  
GREAT LAKES FOR THU MAR 13  
 
LOCATION HIGH LOW  
----------------------------------------------  
 
DULUTH,MN 35 17  
MARQUETTE,MI 35 18  
GREENBAY,WI 41 22  
MILWAUKEE,WI 43 26  
CHICAGO,IL 47 29  
MUSKEGON,MI 43 27  
ALPENA,MI 39 19  
DETROIT,MI 46 28  
TOLEDO,OH 47 28  
CLEVELAND,OH 47 29  
BUFFALO,NY 43 26  
 
THE FIRST HALF OF MARCH HAS BEEN WELL ABOVE NORMAL ACROSS THE GREAT  
LAKES, AND AS SUCH, THERE HAS BEEN SIGNIFICANT ICE DECAY DURING THIS  
TIME PERIOD. THERE HAS ALREADY BEEN NOTICEABLE DECREASES IN COVERAGE  
IN THE NORTHERN BAYS AND STRAITS, AS WELL AS THE SHORELINE ICE. ICE  
HAS BEEN STUBBORN TO DECAY IN THE EASTERN BASIN OF LAKE ERIE, AND  
ONLY RECENTLY HAVE WE SEEN A MARKED DECREASE IN THE FAST ICE OVER  
TOWARDS BUFFALO. SATELLITE IMAGERY HAS SHOWN THAT THIS IS REALLY  
STARTING TO BREAK UP FAIRLY EFFICIENTLY NOW. THERE IS STILL SOME  
FAST ICE IN THE NORTHERN LAKES, MAINLY ON THE WESTERN SIDE OF THE  
STRAITS OF MACKINAC AND IN WHITEFISH BAY.  
 
THAT SAID, WHITEFISH BAY HAS ENOUGH ICE THAT IT COULD STILL CREATE  
ISSUES, ESPECIALLY IN NORTHWESTERLY WINDS OR SOUTHERLY WINDS.  
 
WITH THE CLIMATE PREDICTION CENTER 6-10 DAY, 8-14 DAY, AND 3-4 WEEK  
OUTLOOKS ALL LOOKING AT ABOVE NORMAL TEMPERATURES FOR THE ENTIRE  
GREAT LAKES REGION, THE CHANCES OF ANY ADDITIONAL ICE FORMATION IS  
VERY LOW AT THIS POINT. THE SOUTHERN GREAT LAKES ARE PARTICULARLY  
WARM OVER THE NEXT WEEK TO TEN DAYS, AND BY THIS TIME OF YEAR,  
INCREASING DAYLIGHT HOURS AND INCREASING SUN ANGLES ALSO WORK HARD  
AGAINST ICE FORMATION. AS A RESULT, NO SIGNIFICANT ICE FORMATION IS  
EXPECTED, AND OVERALL ICE DECAY SHOULD CONTINUE RELATIVELY UNIMPEDED  
THROUGH THE SECOND HALF OF MARCH.  
 
WHEN ICE EXISTS EXTENSIVELY IN THE RIVERS, FLUSHING OF THE ICE  
NORMALLY BEGINS THE FIRST WEEK OF MARCH. THE STRAITS OF MACKINAC AND  
THE ST. MARYS RIVER USUALLY SEE THEIR LAST ICE IN MID TO LATE APRIL.  
 
THIS WILL BE THE LAST ICE PRODUCT ISSUED FOR THE 2024-2025 ICE  
SEASON. SPECIAL THANKS TO THE US NATIONAL ICE CENTER FOR THEIR  
COORDINATION THIS SEASON. THE NEXT FREEZE-UP OUTLOOK FOR THE  
UPCOMING 2025-2026 WINTER SEASON WILL BE ISSUED DURING THE FIRST  
WEEK OF NOVEMBER AND WILL BE ISSUED EVERY TWO WEEKS UNTIL ICE BEGINS  
TO DEVELOP ON THE GREAT LAKES.  
 
 
 
MARSALEK  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab OH Page
The Nexlab PA Page
Main Text Page