ST. LOUIS, Mo. - There are some significant changes to the forecast. This complex storm has come together differently than I expected, even as of last night, with a shift a bit more to the southeast. This is most likely because of the pressure being put on it from the north for the strong, cold high-pressure system.
Rain should actually taper off for a while this morning as the cold arrives in St. Louis. There may be some brief light snow and flurries as the cold arrives between 6am and 10am. Meanwhile, the main system, still lurking to our southwest, will begin to lift northeast around midday and into this afternoon. This will bring a new surge of precipitation up from the southwest. This time it stays mainly near and southeast of I-44 in Missouri and south of I-70 in Illinois. With the arrival of the cold air, most, if not all of this precipitation will fall as snow.
The heaviest snow axis has shifted from near I-44 to southeast of I-44 and is now focused more on the Farmington, Park Hills, Perryville region. That is where I'm forecasting 2-4" now with a sharp drop off to the north to 1-2" from near Steelville to Festus and then northeast from there and dropping to 1" or less for most of the St. Louis area.
What hasn't changed are the very cold temperatures and strong winds blowing in from the north. Much colder air will be arriving this afternoon across the entire region, just without much snow from St. Louis to the north and west.