While Lakes Michigan and Huron appear headed to an all-time-low level this month, Lake Superior is holding its own in January, moving closer to normal and farther from record-low territory.
The reversal in the lake's trend provides a hint that the Northland's drought might be over.
Lake Superior declined by 2 inches in December, but that's less than the usual 3-inch decline for the last month of the year.
Superior now sits 11 inches below its long-term average but is 6 inches above the level one year ago, the International Lake Superior Board of Control reported Friday.
The data is compiled by the U.S. Army Corps of Engineers.
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The amount of rain and snow that fell on the Lake Superior basin in December was well above normal, with Duluth recording its sixth-snowiest December of all time. That comes after a near-record wet October.
Lake Superior generally has been rising away from record territory since mid-September, after setting all-time monthly lows in August and September. The rise seems to coincide with the end of a 14-month-long drought in the Northland, though it's still too early to say if a nearly three-year dry period is behind us.
It's still unclear how much Lake Superior will drop over the winter before it begins its annual rise sometime in April. But it's looking less likely that the lake will break its record low level set in April 1926.
Because the lake's level is above last year's at this time -- when a record was not set -- and because it has been inching toward normal in recent months, an all-time record may not occur, said Cynthia Sellinger, deputy director of the Great Lakes Environmental Research Laboratory operated by the National Oceanic and Atmospheric Administration.
"It's higher than it was last year. But it is also warmer, which means less ice'' and probably more evaporation this winter, Sellinger said. That could mean rapidly declining levels if winter snows don't keep up.
It also matters if the snow comes from western storms, which adds water, or is lake-effect snow, which offers no net gain of moisture.
Lakes Michigan and Huron declined by their usual 2 inches in December and now sit a whopping 26 inches below normal and 13 inches below the Jan. 1 level last year.
Experts believe Michigan and Huron could set their all-time low, previously reached in March 1964, when the January monthly average level is figured at month's end.
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A U.S.-Canadian panel is studying why the Great Lakes have been lower in recent years -- whether the issue is climate change, natural drought cycles, man-made channels, dam regulation or a combination of several factors.
Whatever the causes, low lakes levels have hampered recreational boaters and the maritime industry, which has been forced to reduce loads and avoid areas of some ports.
Sellinger noted that factors affecting Lake Superior might not be related to what's causing Lakes Michigan and Huron to decline so much.
"The Great Lakes cover such a huge area that they really have different climate patterns,'' she said. "And the level of the [lower lakes] really has little impact on Superior. Because of their elevation differences, you could drain Michigan and Huron, and Lake Superior wouldn't discharge any more than its natural flow. ... They can hold flow back [with dams and gates], but they can't make it flow out faster than it naturally would.''
