####018004213#### FZUS81 KCLE 202005 ICEGL Great Lakes Freeze-up Outlook National Weather Service Cleveland OH 305 PM EST Wed Dec 20 2023 ...Great Lakes Ice Season for 2023-2024 Expected to Be Below-Average Ice Coverage... The El Nino Advisory continues onward with the moderate to strong El Nino that may be close to peaking. Forecasts continue with high probabilities of El Nino persisting through the winter months, then trending more towards neutral conditions towards late Spring. So far, this has translated to milder conditions overall for the Great Lakes region with limited Arctic air outbreaks combined with limited residence time over the Great Lakes when they have occurred. Over the past two weeks, temperatures overall have been above normal for the region, more substantially over the northern half of the Great Lakes. The lack of cold air and associated stormy conditions has played a roll in limiting the heat loss from the lakes over the last two weeks. While the heat loss does continue, it has been slow, although there was a recent short lived surge of colder air this past weekend/Monday. In Lake Superior, temperatures generally remain in the upper 30s to lower 40s. While the upper 30s are now beginning to dominate the coverage, as they have expanded across western Superior and into Duluth Harbor, the central and eastern portions of the lake remain with sizable pockets of lower 40s. Down into the St. Mary's River and the locks, temperatures are in the lower to mid 30s. Southward into Lake Michigan and Lake Huron, the northern portions of the lakes are in the 40-45F range, while the southern half of Lake Huron excluding the bays still remains in the mid 40s. Saginaw Bay is down into the 30s at this point. The Straits of Mackinac are in the upper 30s to around 40F, and southern Lake Michigan is currently in the mid to upper 40s. The surface temperatures in the mid to upper 30s has expanded and is dominating the western basin of Lake Erie while the central and eastern basins are still in the lower to mid 40s. Coastal areas are showing lower temperatures relative to their open water counterparts, typically 3-8 degrees colder depending on the location. Green Bay/Big Bay de Noc/Little Bay de Noc are also exhibiting the same characteristics of being colder than the adjacent open waters. The Arctic Oscillation and North American Oscillation are forecast to be in a strongly positive phase which sets the stage for the milder longwave pattern across the continental US. There is quite a bit of consistency in the longer range projections for the Great Lakes region over the next couple of weeks. There continues to be strong signals for warmer than normal temperatures in the ensemble long range forecasts as well as the Climate Prediction Center 6-10 day, 8-14 day, and 3-4 week outlooks. There does not appear to be much in the way of Arctic air intrusions into the region currently forecast for the remainder of the month of December and heading into the New Year. Thus, we will continue the delayed wording of significant ice formation for now. FREEZING DEGREE DAY ACCUMULATIONS AT SELECTED STATIONS COMPARED TO NORMAL CALCULATED ON Wed Dec 20: LOCATION DATE NORMAL CURRENT ---------------------------------------- DULUTH, MN DEC 19 340 169 MARQUETTE, MI DEC 19 261 123 SAU_S_MAR, MI DEC 19 129 50 GREENBAY, WI DEC 19 113 23 MILWAUKEE, WI DEC 19 24 7 CHICAGO, IL DEC 19 13 11 MUSKEGON, MI DEC 19 3 0 ALPENA, MI DEC 19 69 7 DETROIT, MI DEC 19 7 0 TOLEDO, OH DEC 19 0 0 CLEVELAND, OH DEC 19 0 2 BUFFALO, NY DEC 19 5 4 This is the last Freeze-Up Outlook and we will be transitioning to the Great Lakes Ice Outlook products which will be issued Monday, Wednesday, and Friday around 5PM EST when ice begins to form on the lakes. $$ Marsalek