Winter Storm back on for Thanksgiving?

Back on Wednesday we first indicated a chance of wintry weather for Thanksgiving. The GFS computer model continued with a wintry outcome for the western Great Lakes on Thursday as well. On Friday, the model had all but given up on the system and gave us a brief period of rain with some light mixy weather for Tuesday/Wednesday.

Well folks, that may have been a fluke! The Saturday morning and midday GFS model is again showing a potential winter storm for parts of the Upper Midwest for Thanksgiving proper. Here is a look at the output for Thursday morning. It shows a moderately strong closed-low pressure system just east of Toledo, Ohio. If this case were to come to fruition there would be just enough cold air to support snowfall over Northwestern Illinois and Southern Wisconsin. I drew in the freezing line (which generally follows the "540" line on surface maps).

From the Milwaukee NWS: "THE ON-AGAIN OFF-AGAIN WINTER STORM DEPICTED BY THE GFS FOR THEUPPER MIDWEST BY MID WEEK IS BACK ON. THE 12Z OPERATIONAL RUN OFTHE GFS SHOWS A CLASSIC...RAPIDLY DEEPENING SFC LOW MOVING JUSTSOUTH OF CHICAGO WITH ENOUGH COLD AIR BOTTLED UP TO THE NORTH THATCAN BE TAPPED TO BRING SNOW. LAKE AIR WOULD BRING A MIX TO THE FAR EAST. IT ISWAY TOO EARLY TO JUMP ON ANYTHING LIKE THIS AT THIS POINT AS THEREIS MUCH UNCERTAINTY. THE ECMWF IS STILL A VERY PROGRESSIVE SOLUTION FOR THAT TIME PERIOD AND ESSENTIALLY HAS HIGH PRESSUREOVER US WITH THE LOW MOVING MORE UP THE EAST COAST."

We will pay close attention to the computer models over the next few days as a system like this could pose a major problem for holiday travel. Stay tuned! -ERIC