An approaching storm over the southern United States will bring heavy rain and the risk of urban flooding to parts of the Midwest, Appalachian Mountains and the Atlantic Coast from this weekend into early next week. AccuWeather meteorologists also warn that there will be just enough cold air at the front end of the storm to form a layer of ice in some areas.

Shortly after a storm unleashed severe weather and downpours across parts of the south-central states through Friday, a second storm will emerge and move northeast as it taps into a stream of moisture from the Gulf of Mexico starting this weekend.

Rain will return over the south-central states, extending from the lower Mississippi Valley to the Tennessee and Ohio valleys, the southern and central Appalachians, and the Great Lakes region Saturday through Sunday. 1 to 2 inches of rain will fall across much of this zone, but there will also be a significant area where 2 to 4 inches will fall, with locally higher amounts between 6 and 8 inches.

Much of this rain may fall in a four to eight hour period, enough to push small streams to the bank and potentially trigger flooding of smaller streams. At a minimum, significant and rapid runoff on streets and side streets will result in flooding. In mountainous areas, dirt can be washed onto the roads.

As the storm continues to progress, the band of moisture containing the heavy rain will swing from the Appalachian Mountains to the mid- and southern Atlantic coasts and New England from midday Sunday through early Monday. The heaviest rain is expected to fall along much of I-95 Sunday afternoon into Sunday evening. During this period, poor visibility, downpours and urban flooding will cause significant travel delays. If possible, moving the travel time well before or after the storm passes may be a better option.

Just enough cold air remains in the lower part of the atmosphere, as well as some cold surfaces, to increase the risk of patchy ice over the interior Northeast when the main storm arrives.

“Similar to what occurred Thursday morning over the higher elevations of the central Appalachians, a more widespread zone of freezing drizzle will extend from western Maryland across portions of western, central and northern Pennsylvania and part of the southern tier of New York, lasting through Friday morning. AccuWeather meteorologist Brandon Buckingham said.

“A major zone where ice glaze may occur is likely Friday night through Saturday morning from western Maryland to north-central and northeastern Pennsylvania, northwestern New Jersey, upstate eastern New York, inland Connecticut, western and “Central Massachusetts and southern and northeastern Pennsylvania, central parts of Vermont and New Hampshire,” added AccuWeather Senior Meteorologist Dave Dombek. added.

From Saturday night into Sunday morning, the ice zone may extend from the northeast corner of New York to northern parts of Vermont, New Hampshire and much of Maine.

Milder air with light rain extends to the Canadian border. This means that, aside from intermittent ice, the snow on ski slopes across the northern Appalachians tends to become soft and slushy in many cases.

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Even a thin, patchy and unexpanded layer of ice can be dangerous for drivers and pedestrians. Surfaces may appear wet but may instead have a thin layer of clear ice. Ice of this type can also form where the air temperature is slightly above freezing at 32°F.

Long nights and humid air are the perfect ingredients for fog in winter. The fog can be particularly thick when a storm passes over the snowpack or even just over cold ground.

As the storm rotates, two types of fog may occur. On the one hand, it is weak fog near the ground, and on the other hand, it is low clouds that obscure the mountain ridges and can impair visibility for motorists on the highways and aircraft attempting to land and take off. Due to the dangerous conditions, significant delays may occur.

The storm’s intensity will be great enough to produce gusty and locally severe thunderstorms from the central Gulf Coast to the Tennessee Valley on Saturday and along the southern Atlantic Coast on Sunday.

Some tornadoes may occur in the strongest storms, with strong wind gusts and flash flooding posing the greatest threat.

Shortly after the major rainstorm leaves the region, a trailing storm could tap just enough cold air to bring snow to a portion of the Interior Northeast from next Tuesday through New Year’s Day.

At this point, the storm will likely bring rain to the coast, including major I-95 cities in the Northeast, with the possibility of snow further inland. However, a shift in the storm’s track could change which areas receive rain and which areas are covered with snow.

A possible third storm could draw on colder air near the coast. From the end of next week through the first weekend of 2025, a portion of I-95 and some inland locations will be monitored for winter-related issues.

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