US gripped by winter blast: Lake-effect snow, snow squalls threaten travel

AN active winter pattern will continue to sweep across the Great Lakes and the interior Northeast over the next two days, according to the NWS Weather Prediction Center.

Lake-enhanced snow showers will persist as one clipper system exits the region and another approaches on Friday. Moderate accumulations are expected downwind of the Upper Great Lakes and Lake Ontario.

Light snow is also likely across the northern Plains.

The NWS warns that a trailing cold front may trigger potentially dangerous snow squalls in the interior Northeast today (December 4), creating sudden white-out conditions and hazardous travel.

Major mountain snow

A series of upper-level disturbances dropping south across the western US will produce significant snowfall in the Cascades and northern Rockies today, spreading into the central Rockies on Friday, the NWS Weather Prediction Center said.

Winter Storm Watches are in effect for 8–14 inches, with 2–3 feet possible at high elevations.

Mountain valleys may receive 3–6 inches.

A wintry mix is expected in nearby areas of the northern/central Great Basin and northern High Plains, while the Pacific Northwest sees rain.

Heavy rain for Gulf coast

Moist southerly flow ahead of a system moving toward the southern Plains and western Gulf is producing widespread precipitation this morning, the NWS Weather Prediction Center reported.

Thunderstorms will cluster along a quasi-stationary front from the western to central Gulf Coast, with moderate showers inland.

The system will shift east into the Southeast by Friday.

Locally heavy rainfall may lead to isolated flash flooding.

Further north, colder air will support wintry precipitation from the southern Plains into the Ohio Valley, then into the central and southern Appalachians and the southern Mid-Atlantic from Thursday night through Friday.

Winter Weather Advisories note forecasts of 1–2 inches of snow and light ice accumulations.

Arctic air to challenge low temperature records

A fresh surge of Arctic air is expected to bring brutally cold temperatures to the Midwest today, spreading into the northern Mid-Atlantic and New England by Friday morning, according to the NWS WPC.

Lows may plunge into the negative single digits and teens across the Midwest, with single digits and teens for the northern Mid-Atlantic and New England—potentially nearing or breaking daily record lows.

High temperatures will remain well below average:

-Teens–20s in the Midwest

-20s–30s in New England

-30s–40s from the central Plains to the Mid-Atlantic

-40s–50s for Texas and the Southeast

The High Plains will see near-normal to slightly above-normal readings due to downsloping winds. Much of the West will remain mild, with 40s inland, 50s–60s along the coast, and 60s–70s in the Desert Southwest.

Western US stays milder

The Four Corners region will experience somewhat cooler highs in the 30s and 40s, but most of the West will remain at or above seasonal averages, the NWS WPC stated.
AccuWeather warns of dangerous travel conditions

Snow squalls are expected to sweep across more than a dozen states from the Great Lakes to the Northeast between Wednesday night and Thursday, with AccuWeather meteorologists warning that the fast-moving bursts of snow could create extremely hazardous travel conditions.

According to AccuWeather, snow squalls are among the most dangerous winter hazards for motorists, especially on highways where visibility can abruptly drop to near zero. This week’s event could be one of the strongest and most widespread so far this season as an Arctic cold front tied to a southward shift of the polar vortex pushes through the region.

Motorists unfamiliar with snow squalls may be unprepared for how quickly driving conditions deteriorate. AccuWeather Meteorologist Alex Duffus said that “major highways and secondary roads can be coated in snow, and visibility can be drastically reduced in a matter of seconds, creating slippery and dangerous driving conditions.”

Snow squalls are often accompanied by a rapid temperature drop and a sudden freeze-up. Tire tracks may briefly melt the first flakes before the moisture refreezes into ice, creating extremely slick stretches. AccuWeather notes that when this combines with drivers travelling at or above the speed limit, even small skids can escalate into multi-vehicle crashes.

Several major highways could be impacted, including Interstates 70, 76, 78, 79, 80, 81, 87 and 90. Experts cited by AccuWeather advise that if travel cannot be avoided, reduced speeds on secondary roads may be safer, and the best option is often to exit highways and wait for the squall to pass.

Duffus also urged motorists to prepare for the dangerous cold. AccuWeather’s RealFeel Temperatures are expected to plunge into the teens or lower on Thursday in Chicago, Detroit, Cleveland and Pittsburgh. With dry Arctic air arriving Thursday night, the snow squalls are forecast to diminish to flurries, though icy patches may persist on untreated surfaces.

Temperatures have already dipped into the single digits, 10s and 20s from the Plains to the Ohio Valley and interior Northeast. Later this week, a similar cold is forecast to reach the Interstate 95 corridor, according to AccuWeather.