Winter Conditions For Great Lakes On Halloween

A potent storm system is expected move from Manitoba to the Southeast US over the next three days. By Friday evening, 850 temps as cold as -10C are forecast reach the south Lake Michigan buoy, where the water temperature is currently 53F:

This would result in a lake-850 delta t of over 20C, which could produce thunder snow for Halloween in Wisconsin, Michigan, Northwest Indiana and Chicago. In addition, with temperatures dropping into the upper 30s combined with 30 mph winds with gusts near 50, wind chill values may be as low as 20, along with blowing snow. Winds will be even stronger over the Lakes, resulting in waves over 20 feet. A storm warning has just been issued for southern Lake Michigan, and a lakeshore flood advisory has been issued for Chicago, Northwest Indiana and Southwest Michigan.

Significant snow accumulations are likely in the Central and Southern Appalachians on Halloween. Freezing temperatures may reach Oklahoma and Tennessee by Saturday morning.