A strengthening storm system will produce a major severe weather outbreak over the Plains Saturday. In Chicagoland, storm-related problems may be two-pronged.
The developing storm system marks an end to the tranquil weather being experienced over much of the nation in recent weeks.
During Saturday, building warmth over the Plains will contribute to severe thunderstorms from Iowa to north-central Texas. The risks from the storms include damaging wind gusts, large hail, flash flooding and a few tornadoes.
The storm will rout out chilly air during Saturday in Chicago. However, the process is likely to unleash areas of very heavy rain and thunderstorms. There is a risk of flash and urban flooding problems with the greatest chance across the northern suburbs into Milwaukee.
Building warmth to the south on Saturday can reach into Chicagoland for a time Saturday night. If it is successful, there will be an elevated risk of violent thunderstorms late Saturday night into Sunday morning.
The storms could still pack enough punch moving in from the Plains to bring 55-mph wind gusts, which can knock down tree limbs and cause sporadic power outages as a result.
During the balance of Sunday, a strong flow of air on the storm system's back side will make for a windy day. Frequent gusts between 30 and 40 mph are possible. Enough dry air may come in from the west to end the showers and allow clouds to break during the afternoon.
Sun and warm temperatures will be disrupted by weekend rain and possible thunderstorms.
Cold air sweeping in this weekend will help pave the way for a snowstorm Sunday afternoon into Monday morning around Harrisburg, Pennsylvania.
Cold air sweeping in this weekend will help pave the way for a winter storm Sunday into Monday morning around Pittsburgh.
A snowstorm reaching Detroit on Sunday will bring colder air and 3 to 6 inches of snow, and more snow is expected next week.
Cold air sweeping in this weekend will help pave the way for a snowstorm by Monday around Boston.
Cold air sweeping in this weekend will help pave the way for a snowstorm Sunday night into Monday around New York City.
Major Oregon Snowstorm: 25.0 inches at Salem, 16.0 inches at Portland.
Stampede Pass, WA (1946)
192.0 inches of snow in January; record snowfall for one month.
Philadelphia, PA (1977)
The coldest January on record in 211 years of record-keeping.