HAZARDS. A snow squall accompanied by winds of up to 30 MPH which can rapidly reduce visibility to less than one mile. LOCATION AND MOVEMENT. At 354 AM EST, a snow squall was along a line extending from Ashland to near Weigelstown to Emmitsburg and moving east at 45 MPH. LOCATIONS IMPACTED INCLUDE. Lancaster, Harrisburg, York, Lebanon, Lower Allen, Hanover, Pottsville, Hershey, Ephrata, Colonial Park, Weigelstown, Elizabethtown, Columbia, Progress, Lititz, Middletown, Millersville, Gettysburg, Willow Street, and Mount Joy. This includes the following Interstates. The Pennsylvania Turnpike from mile markers 242 to 295. Interstate 78 from mile markers 0 to 8. Interstate 81 from mile markers 72 to 139. Interstate 83 between mile markers 1 and 38, and from mile markers 45 to 48. Interstate 283 from mile markers 0 to 2. SAFETY INFO. Use extra caution if you must travel into or through this squall. Rapid changes in visibility and potentially slick roads may lead to accidents.

A strong cold front moves across the area this morning, then much colder and windy conditions quickly develop into tonight. For areas along and west of the Blue Ridge Mountains, a period of snow showers, possibly mixed with some rain, is likely this morning until around 6 AM. For areas east of the Blue Ridge, a mix of rain and snow showers is likely between 4 AM to 8 AM. Additional light snow showers are possible through late morning. In areas along and west of the Blue Ridge and in north-central Maryland, near freezing temperatures could allow some of this snow to stick on roadways, possibly creating slick conditions. Commuters this morning should allow extra time to reach their destination, and use extra caution when driving through any snow shower. Windy conditions quickly develop around or just after sunrise this morning, and continue through this evening. Wind gusts of 45 to 55 mph are expected across the area, with up to 60 mph possible. These strong winds could result in downed trees and power lines. Those outdoors this morning will notice a rapid decrease in temperature when those strong winds begin. The strong winds and cold temperatures will produce wind chills in the teens to low 20s the entire day, even in sunnier conditions during the afternoon. It is important to wear appropriate clothing to avoid frostbite and hypothermia. Take needed actions to protect yourself, children, pets, plants, and pipes from the cold.

There is a potential for hazardous commuting conditions for this morning's commute. A period of snow showers or squalls is POSSIBLE (a 50 percent chance) this morning across the far northwest suburbs of Baltimore / Washington, especially over higher elevations such as Parr's Ridge and the Catoctin Mountains where up to around an inch of snow accumulation is possible on area roads. If this threat does materialize during this morning's rush-hour, many roads could quickly turn icy. This could lead to dangerous traveling conditions, multiple accidents, and extensive delays. If commuting this morning, be aware of the POSSIBILITY of significant travel disruptions. Plan ahead by allowing for extra travel time, and consider using public transportation and telework options. Stay tuned for updates on this potential winter weather episode.

* WHAT. West winds 20 to 30 mph with gusts up to 55 mph expected. * WHERE. Portions of DC, central, north central, northeast, northern, southern, and western Maryland, central, northern, northwest, and western Virginia, and eastern and panhandle West Virginia. * WHEN. Until 6 PM EST this evening. * IMPACTS. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. The cold wind chills could result in hypothermia if precautions are not taken.

* WHAT. For the Small Craft Advisory, southwest winds 15 to 25 kt with gusts up to 30 kt. For the Gale Warning, west winds 20 to 30 kt with gusts up to 45 kt and waves 2 to 4 ft expected. * WHERE. Tidal Potomac River from Key Bridge to Cobb Island MD, Chesapeake Bay north of Sandy Point MD, Patapsco River including Baltimore Harbor, Chester River to Queenstown MD, and Patuxent River to Broomes Island MD. * WHEN. For the Small Craft Advisory, until 6 AM EST Thursday. For the Gale Warning, from 6 AM to 7 PM EST Thursday. * IMPACTS. Strong winds will cause hazardous waves which could capsize or damage vessels.

* WHAT. For the Small Craft Advisory, southwest winds 15 to 25 kt with gusts up to 30 kt. For the Gale Warning, west winds 20 to 30 kt with gusts up to 45 kt and waves 2 to 4 ft expected. * WHERE. Tidal Potomac River from Key Bridge to Cobb Island MD, Chesapeake Bay north of Sandy Point MD, Patapsco River including Baltimore Harbor, Chester River to Queenstown MD, and Patuxent River to Broomes Island MD. * WHEN. For the Small Craft Advisory, until 6 AM EST Thursday. For the Gale Warning, from 6 AM to 7 PM EST Thursday. * IMPACTS. Strong winds will cause hazardous waves which could capsize or damage vessels.

* 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.