From the ABC 7 Weather team

Major Arctic Blast Heading for D.C.

January 5, 2014 - 06:17 PM
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An Arctic plunge is about to swoop across the Mid-Atlantic, driving in the coldest weather since the late 1980s in some cases.

The weather is known for extremes, especially in the height of summer and winter months and what is coming down the pike early next week is no exception. An Arctic cold front chopping through the Tennessee Valley is quickly heading east this evening. Temperatures are dropping quickly in the front’s wake with rain changing to snow across Kentucky, southern Indiana and Ohio.

satelliteradar

To provide insight into how cold the air mass is behind the Arctic front, the lowest temperature in the lower 48 states this morning was -40 degrees in Babbitt and Embarrass, Minn. “To every action there is an equal and opposite reaction,” according to Sir Isaac Newton’s Third Law of Motion. Therefore, ahead of the front, with southerly winds, temperatures will warm overnight instead of drop inside the Capital Beltway.

temperatures

The warmest temperatures, with 40s and 50s expected, will immediately precede the cold front, which will arrive right during the morning commute. The temperatures will quickly drop in the band of rain that will be followed by a transition to snow in the front’s wake between 6 a.m. and 9 a.m. The front will also transport gusty winds to the surface, with gusts approaching 40 mph.

Allow yourself extra time for the morning commute as the snow, although it won’t last more than 30 minutes or so, could quickly accumulate on secondary roads, parking lots and untreated surfaces. The snow will fall quickly, likely overcoming the rate of melting on warm surfaces (since temperatures will have warmed into the 40s and 50s prior to the front’s arrival).

A mix of several different model runs (called an ensemble solution) below shows a period of snow is likely following the front but accumulation would be less than one-half inch. This solution looks logical since rain is changing to snow immediately behind the front in the western Tennessee Valley and Midwest tonight.

snow potential

The core of the coldest air will arrive Monday night into Tuesday. Following a day with falling morning temperatures and steady afternoon temperatures, readings will plummet by sunset into Tuesday morning. Wind Chill Watches have been posted along the Blue Ridge into the Shenandoah Valley. These watches will get upgraded to warnings with wind chills expected to drop below minus-20 degrees, making for life-threatening conditions overnight Monday. Inside the Capital Beltway, wind chills will drop to minus-5 degrees.

The following are the records in jeopardy Tuesday and Wednesday. Several of these records, specifically for Dulles International and BWI Thurgood Marshall Airport, have been standing since 1988.

records

Dressing in layers (long-sleeved shirt, sweater, winter coat, for instance) is the best way to trap body heat (provides more insulation than one heavy layer) and stay warm if you must venture out in the cold weather. Most heat escapes through the head, so wear a warm hat and cover all extremities to prevent frostbite. Also, be sure to keep faucets dripping and open cabinet doors to keep pipes from freezing and busting. Keep pets inside and check on the elderly.

Temperatures will finally moderate by Wednesday. Click here for the latest 7-day forecast.

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