(KPLR) - Major winter storm is still on track for the entire Bi-State area despite the fact there are some questions about how much snow vs. sleet will fall in the metro area late Saturday night through Sunday, making exact accumulations tough to call. In general, the trends remain the same, snow north, ice storm south, and a messy mix in the middle (including St. Louis).
Drizzle and freezing drizzle will begin to pop-up in spots Saturday evening making for some slick spots on untreated secondary roads, subdivisions, sidewalks and parking lots. The main show gets going after midnight and through Sunday, ending in the evening or early Sunday night.
Light Blue: This zone will be all snow with 6” to 10” expected.
Darker Blue: Cover metro St. Louis, the I-44 corridor and areas along and north of I-70 in IL.
Freezing drizzle will ramp up to freezing rain between midnight and 3 am, before mixing with and changing to sleet. In the metro area, freezing rain and sleet may enhanced by thunderstorms around sunrise. Glaze icing could reach 0.1” on trees and power lines, not enough for power outages. Precipitation will be a mix of sleet and snow by morning and become all snow through the day. The winter mix will come in waves with total accumulations of sleet and snow combined from 4” to 6” possible in this zone. That range is just a touch below my initial thinking from Friday, but it’s still a high impact winter event.
Pink Zone: From Salem, MO. through Farmington, to near Salem, IL. This is the northern edge of a nasty ice storm. Here the precipitation will begin as freezing drizzle by or just after midnight with developing thunderstorms with heavy freezing rain and sleet by 4 am. Significant freezing rain and sleet accumulations are likely before a change to snow Sunday afternoon. I expect glaze icing of 0.2” to almost 0.5” followed by 2” to 4” of sleet and snow.
Red Zone: Ellington to Carbondale. Crippling ice storm appears likely along with power outages. Thunderstorms with freezing rain will develop after 4 am and continue through Sunday. There will be a gradual mix with and then change to sleet. Then a secondary surge of moisture Sunday evening will come mostly in the form of sleet and snow. Ice accumulations of 0.5” to almost 1.0” are possible along with 1” to 3” of snow and sleet.
This entire mess will be followed up by near record cold for the month of March with overnight lows near or just above zero by Monday night into Tuesday morning.