St. Louis weather from Meteorologist Angela Hutti:

ST. LOUIS – Tuesday and Wednesday will be calm before the arrival of arctic air on Thursday. Tuesday will be partly cloudy to mostly cloudy and cold.

Temperature highs are near 40. It’s going to be mostly cloudy for the Winter Solstice Wednesday, with highs in the mid 30s. 

An arctic front arrives Thursday, sending temps plummeting and bringing snow to the bi-state region. Temps look to be just above freezing as the precipitation starts, so we may see a rain/snow/sleet mix Thursday morning before things kick over to all snow by early afternoon.

It will be all snow into Thursday evening. Along and north of I-44 in Missouri and I-70 in Illinois should see at least 2 inches of snow. South of that line, snow totals will be lowered. Higher snowfall totals will be north of a Columbia, Missouri to Pittsfield to Lincoln, Illinois line. 

There will be a dramatic drop in temps around lunchtime Thursday. From around 32 at noon to single digits by evening. Winds will rapidly increase from fairly light southeast winds to northwest with 35 to 45 mile per hour gusts. Roads will get terrible quickly, as this will cause a flash freeze set-up. Blowing snow will also create poor visibility.  

Snow looks like it will be done by Thursday night, but that strong northwest wind won’t go anywhere. Wind chills will be below zero by Thursday evening. We’ll wake up Friday to temps at or below zero, with wind chills between -20 and -25. 

It will also be mostly cloudy and bitterly, dangerously cold all-day Friday, with winds chills of -10 to -20. What snow has fallen will still be blowing around all day. Still bitter cold Christmas Eve Saturday, with highs in the low teens and wind chills of 0 to -10.  Winds will ease into Christmas Sunday. 

Please note, the timing of the frontal passage is key to precipitation type and when the cold air comes rushing in.