Winter storm triggers heavy snows/severe storms

by: WGN-TV Weather Team

Posted: Dec 11, 2022 / 11:29 PM CST

Updated: Dec 11, 2022 / 11:35 PM CST

Monday – Wednesday outlook

As the major winter storm deepens over the Rockies Monday and moves ENE into the Plains Tuesday-Wednesday, heavy snow will fall north and west of the low pressure center, while severe storms develop to the south and east.

Heaviest snows in excess of 2 feet

Heavy snow (4-8-inches) is forecast over a broad area of the Rockies Monday. Then Tuesday-Wednesday, as the low center moves east into the central plains, heavy snows are forecast over the foot hills of the Rockies into the northern plains/upper Mississippi Valley. Heaviest snows in excess of 2-feet will be possible in western portions of South Dakota and Nebraska into the NE corner of Colorado.

Severe weather outlook

Severe storms look to develop over central portions of Kansas, Oklahoma and Texas Monday, then Tuesday Eastern Texas into Louisiana, southern Arkansas and southern Mississippi. Wednesday storms are expected to advance east out of Louisiana across much of Mississippi and Alabama into western Georgia and northern Florida.

Monday’s predicted set-up

• Tongue of Arctic-source bitter-cold air knifing into the northern Rockies and northern plains
• Low pressure through aloft over the Rockies will slow in it’s eastward movement during the next 24 to 48 hours, due to the wavy pattern aloft shaped as the Greek letter Omega – depicting a semi-blocking pattern
• Chicago is positioned in the southernmost section of “Cool” air with the WNW jet stream flow overhead.
• In the Tuesday – Wednesday timeframe, the center of deepening/developing low pressure at the surface will move ENE out of Colorado into Kansas/Nebraska where warm/mild moist air from the south and bitter cold air from the north will wrap into the low pressure system, resulting in heavy snow to the N-NW and severe storms to the SE of the storm center.