WEST MICHIGAN -- After tying a record high temperature of 61 on Saturday and readings in the 40s the last few days, it will soon be time to return to "normal" the second half of this week. A developing low pressure system will move in to the Great Lakes from the Central Plains on Wednesday brining snow, rain, and eventually sharply cooler temperatures with accumulating lake effect snow.
Several states to our west already have WINTER STORM WARNINGS and WINTER WEATHER ADVISORIES posted for this next system with as much as six to ten inches of snow likely. Once the system exits Michigan, we'll see breezy conditions on Thursday with several days of lake effect snow showers. Below is an image from our computer forecast model at noon on Wednesday. Note the rain/snow mix from Grand Rapids northward...with mainly rain south of GR.
The next image below shows conditions at 6 PM on Wednesday. Most of the area should be seeing rain, with a changeover to snow expected in the evening and overnight.
Once the low pressure area tracks off to our north and east, it will pull down colder air from Canada and force a pattern change that will create colder temperatures and accumulating lake effect snow from Thursday through Sunday. The image below shows the weather map for Thursday morning at 6 AM.
The pattern change can easily been seen in our upper level of the atmosphere in the map below. The colors represent the air masses and the colors correspond to air temperatures. Note the colors on the map in green (around 40 degrees or so) Tuesday at 6 PM. The "L" or low to our west is the one that will affect us on Wednesday and drive the pattern change the remainder of this week.
Below is the same map (valid on Sunday). Note the colder tones over the Great Lakes and the thin gray lines represent the trough and ridge pattern. The trough over our area where the jet stream dips to our south will allow the colder air to flow in from Canada. The blue colors represent air temperatures in the 20s.
Make sure to stay up on later forecasts this week. Get the complete details at www.fox17online.com/weather.