Unusually strong winter storms expected to drop heavy snow in the US

WASHINGTON - A couple of quick but unusually strong winter storms this week are expected to deliver a messy mix of heavy snow and gusty winds across the US Upper Midwest, North-east and Mid-Atlantic.

Forecasters said some areas could see as much as 46cm of snow by the weekend.

Mr Brian Hurley, a meteorologist at the Weather Prediction Center, said the systems – also known as “clippers” – typically produce light snow as they race across the northern United States.

But this week, he said, a powerful atmospheric river parked over the Pacific Northwest is sending moisture into the upper atmosphere, making the storms on the other side of the country more potent.

“The snowfall rates will be pretty decent,” he said. “In the lower terrain areas of Iowa, Illinois, Indiana, Ohio, a lot of these areas are going to get three to five inches, and usually one to three inches is likely with these clipper systems.”

The first storm will move from the Upper Midwest into New York, Pennsylvania and the Appalachian region on Dec 10.

Snowfall totals of 7.72cm to 12.7cm are forecast across much of the area, but forecasters said that, with lake-effect snow, parts of upstate New York could receive 20.3cm to more than 30.5cm by the morning of Dec 12.

The Weather Prediction Center issued a range of winter weather advisories and warnings through Dec 11.

Blizzard warnings were also issued for parts of West Virginia and for western Maryland through the morning of Dec 11.

Forecasters expect that up to 30.5cm of snow, paired with wind gusts up to 80.5 kmh, may “significantly reduce visibility,” at times to a quarter-mile or less.

The Weather Prediction Center said the hazardous conditions were likely to affect the commutes on the evening of Dec 10 and the morning of Dec 11.

More snow is expected later this week

The next system will track closely behind the first, entering the Midwest by the evening of Dec 11 and introducing another round of winter weather from the Northern High Plains into the Ohio Valley.

According to the Weather Prediction Center, a narrow corridor of light to moderate snow will stretch from the eastern Dakotas and southern Minnesota into northern Iowa.

Snow from this system is expected to shift into the Lower Ohio Valley on the night of Dec 11 and reach the central Appalachians by early on Dec 12.

More than 10.2cm are forecast from central Minnesota southeastward across northern Illinois, south-central Indiana and southern Ohio.

The National Weather Service office in Charleston, West Virginia, said snowfall from this storm would most likely be “more impactful” across the region. The heaviest accumulations will be expected during the Friday morning commute.

Mr Hurley said the higher elevations of eastern West Virginia and western Maryland were expected to receive the most substantial totals, with combined accumulations from both storms reaching 15.2cm to nearly 46cm by the morning of Dec 12.

Parts of the Mid-Atlantic may also see light snow on Dec 12, particularly along the Blue Ridge Mountains in Virginia and West Virginia and possibly in northern Virginia, northern Maryland and southern Pennsylvania.

But the Weather Prediction Center said that most snow should be light and that any effect on travel would probably be minor. NYTIMES