* WHAT. Heavy lake effect snow. Additional snow accumulations between 6 and 12 inches. Winds gusting as high as 40 mph. * WHERE. Forest, Jefferson PA, Mercer, Venango, and Clarion Counties. * WHEN. Until 1 PM EST Friday. * IMPACTS. Travel could be very difficult. The hazardous conditions could impact the Wednesday evening and Thursday morning commutes.

* WHAT. Heavy lake effect snow expected. Total snow accumulations between 6 and 15 inches. Winds gusting as high as 50 mph. * WHERE. Cameron, Elk, McKean, Potter, and Warren Counties. * WHEN. Until 8 PM EST Friday. * IMPACTS. Whiteout conditions are expected at times and will make travel difficult and treacherous. The strong winds combined with the weight of snow on tree limbs may down power lines and could cause sporadic power outages. Areas of blowing snow could significantly reduce visibility.

* WHAT. West winds 15 to 25 mph with gusts 45 to 55 mph expected. * WHERE. Central Pennsylvania. * WHEN. From 1 AM to 7 PM EST Thursday. * IMPACTS. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result.

* WHAT. Heavy lake effect snow. Additional snow accumulations between 3 and 12 inches. Winds gusting as high as 45 mph. * WHERE. Cameron, Elk, McKean, Potter, and Warren Counties. * WHEN. Until 8 PM EST Friday. * IMPACTS. Whiteout conditions are expected at times and will make travel difficult and treacherous. The strong winds combined with the weight of snow on tree limbs may down power lines and could cause sporadic power outages. Areas of blowing snow could significantly reduce visibility.

* WHAT. West winds to 35 knots and waves 10 to 14 feet. * WHERE. The nearshore waters of Lake Erie from Ripley to Buffalo. * WHEN. Until 7 PM EST this evening. * IMPACTS. Strong winds will cause hazardous waves which could capsize or damage vessels and reduce visibility.

* WHAT. West winds 35 to 45 knots with gusts up to 50 knots and waves 10 to 15 feet. * WHERE. The nearshore waters of Lake Erie from Vermilion OH to Ripley NY, and the open waters of Lake Erie from Vermilion OH to Buffalo NY. * WHEN. Until 7 PM EST this evening. * IMPACTS. Strong winds will cause hazardous waves which could capsize or damage vessels and reduce visibility.

* WHAT. Heavy lake effect snow. Additional snow accumulations 10 to 18 inches in the most persistent lake snows. Winds gusting as high as 50 mph, producing considerable blowing and drifting snow. * WHERE. Chautauqua and Cattaraugus Counties. * WHEN. Until 4 AM EST Saturday. * IMPACTS. Travel will be very difficult. Areas of blowing snow will significantly reduce visibility, creating near whiteout conditions at times. The hazardous conditions will impact the morning and evening commutes today. Gusty winds may down tree branches and cause isolated power outages.

* WHAT. Heavy lake effect snow. Additional snow accumulations 6 to 12 inches in the most persistent lake snows. Winds gusting as high as 45 mph, producing considerable blowing and drifting snow. * WHERE. Chautauqua and Cattaraugus Counties. * WHEN. Until 4 AM EST Saturday. * IMPACTS. Travel will be very difficult. Areas of blowing snow will significantly reduce visibility. The hazardous conditions will impact the evening commute today and Friday morning commutes. Gusty winds will down tree branches and cause isolated power outages.

* WHAT. West winds 30 to 40 knots with gusts up to 50 knots and waves 9 to 14 feet. * WHERE. The nearshore waters of Lake Erie from Vermilion OH to Ripley NY, and the open waters of Lake Erie from Vermilion OH to Buffalo NY. * WHEN. Until 7 PM EST this evening. * IMPACTS. Strong winds will cause hazardous waves which could capsize or damage vessels and reduce visibility.

* WHAT. West winds to 35 knots and waves 10 to 13 feet. * WHERE. The nearshore waters of Lake Erie from Ripley to Buffalo. * WHEN. Until 7 PM EST this evening. * IMPACTS. Strong winds will cause hazardous waves which could capsize or damage vessels and reduce visibility.

* WHAT. Heavy lake effect snow. Additional snow accumulations between 3 and 12 inches. Winds gusting as high as 45 mph. * WHERE. Cameron, Elk, McKean, Potter, and Warren Counties. * WHEN. Until 8 PM EST Friday. * IMPACTS. Whiteout conditions are expected at times and will make travel difficult and treacherous. The strong winds combined with the weight of snow on tree limbs may down power lines and could cause sporadic power outages. Areas of blowing snow could significantly reduce visibility.

* WHAT. West winds 15 to 25 mph with gusts 45 to 55 mph expected. * WHERE. A portion of central Pennsylvania. * WHEN. Until 7 PM EST this evening. * IMPACTS. The wind could blow down tree limbs and cause power outages. The wind will also create very poor visibility when snow is falling at the same time. Drifting snow may also lead to poor road conditions even when the snow is not falling. * ADDITIONAL DETAILS. The risk for power outages and treacherous travel will be greatest across the Allegheny Mountains and Laurel Highlands.

* WHAT. Heavy lake effect snow. Additional snow accumulations between 6 and 12 inches. Winds gusting as high as 40 mph. * WHERE. Forest, Jefferson PA, Mercer, Venango, and Clarion Counties. * WHEN. Until 1 PM EST Friday. * IMPACTS. Travel could be very difficult. The hazardous conditions could impact the Thursday morning and evening commutes.

* WHAT. Heavy lake effect snow. Additional snow accumulations between 10 and 20 inches with higher amounts possible where bands are most persistent. Winds gusting as high as 50 mph, mainly this morning. * WHERE. Crawford County. * WHEN. Until 1 AM EST Saturday. * IMPACTS. Visibilities may drop below 1/4 mile due to falling and blowing snow. Near-blizzard conditions are expected through late this morning. Roads, and especially bridges and overpasses, will likely become slick and hazardous. Travel could be very difficult to impossible. The hazardous conditions will impact the commutes through Friday evening. Gusty winds could bring down tree branches and power lines. * ADDITIONAL DETAILS. An Arctic front and associated snow squall have crossed the area this morning and has allowed for some travel impacts across the region. The strongest winds are expected through late this morning, when near-blizzard conditions are expected. Lake effect snow bands are developing and will be the main concern for the rest of the event with some lingering snow on Friday. Additionally, the gusty winds and density of the large snowpack across far northern Crawford County could result in damage to structures.

* WHAT. Heavy lake effect snow. Additional snow accumulations between 6 and 12 inches with locally higher amounts where bands persist and in the higher terrain of eastern Ashtabula County. Winds gusting as high as 55 mph leading to significant blowing and drifting snow, especially near the lakeshore. * WHERE. Ashtabula Inland and Ashtabula Lakeshore Counties. * WHEN. Until 1 AM EST Saturday. * IMPACTS. Visibilities may drop below 1/4 mile due to falling and blowing snow. Near-blizzard conditions are expected through late this morning. Roads, and especially bridges and overpasses, will likely become slick and hazardous. Travel will be very difficult to impossible, especially this morning. The hazardous conditions will impact the commutes through Friday evening. Gusty winds could bring down tree branches and power lines. * ADDITIONAL DETAILS. An Arctic front and associated snow squall have crossed the area this morning and has allowed for some travel impacts across the region. The strongest winds are expected through late this morning, when near-blizzard conditions are expected. Lake effect snow bands are developing and will be the main concern for the rest of the event with some lingering snow into Friday. Additionally, the gusty winds and density of the large snowpack across far Northeast Ohio could result in damage to structures.

* WHAT. Blizzard conditions. Additional snow accumulations of 10 to 18 inches north of I-90 increasing to 12 to 20 inches with locally higher amounts south of I-90. Wind gusts up to 60 mph north of I-90 and up to 50 mph south of I-90, mainly this morning. * WHERE. Northern Erie and Southern Erie Counties. * WHEN. Until 1 AM EST Saturday. * IMPACTS. Visibilities will drop below 1/4 mile due to falling and blowing snow. Significant drifting of snow is likely, including across some roadways. The strong winds may cause downed trees and power outages. Whiteout conditions are expected and will make travel treacherous and potentially life-threatening. Travel is expected to be impossible today and should be postponed. The hazardous conditions will impact the commutes this morning and evening. * ADDITIONAL DETAILS. An Arctic front and associated snow squall have crossed the area this morning and has allowed for some travel impacts across the region. Lake effect snow with the strongest winds and blizzard conditions of the event are developing and will last through midday today. Lake effect snow bands will continue for this afternoon and be the main concern for the rest of the event through Friday as wind gusts slowly diminish. The strong winds and density of the large snowpack across Northwest Pennsylvania could result in damage to structures.