1:00 PM | A wild atmosphere from tonight into Sunday with snow, ice, heavy rain, fog, maybe a thunderstorm, strong winds, potential localized flooding contributed to by ice jams and - for good measure - possible northern lights

Discussion

Quite an interesting 60 hours or so from tonight into Sunday that will bring the Mid-Atlantic region snow, ice, heavy rain, fog, maybe a thunderstorm, strong winds, potential flooding contributed to by ice jams, and - for good measure - possible northern lights from an incoming coronal mass ejection generated by an X-class solar flare on Tuesday (only chance on viewing this will likely be early tonight as clouds roll in later).

Dense, cold Arctic air that reluctantly retreats tomorrow will be followed by a significant one-day thaw in the Mid-Atlantic region and this combination will help to produce some wild weather beginning late tonight and lasting into Sunday. An area of moisture is advancing this way from the south-central part of the country and it will arrive early Friday morning in the I-95 corridor region of DC, Philly and NYC. The atmosphere should be cold enough to allow for a burst of snow and/or ice during the morning hours which, given the still quite cold ground temperatures, will likely produce some slick spots on untreated surfaces. The morning snow and/or ice will tend to slacken off during the afternoon and early evening hours as temperatures creep higher, but there still can be some spotty light rain that freezes on some surfaces north and west of the big cities.

By later tomorrow night, and especially during the day Saturday, the milder air will win out throughout the region and the result will be a significant one-day thaw (55-60 degrees) along with soaking rain that will continue into Saturday night. In fact, up to two inches of rainfall is possible along the I-95 corridor by the time the precipitation winds down late Saturday night. Additionally, winds will become quite strong from a southerly direction during the day on Saturday ahead of a strong frontal system, and then there will be strong winds late Saturday night and Sunday behind the frontal system from a northwesterly direction. Hydrologically speaking, Pennsylvania Rivers (Delaware, Susquehanna) have had several ice jams reported since earlier this week and localized flooding problems can form on Saturday with the heavy rainfall and the runoff that is likely to occur with limited saturation into the frozen grounds.

Enjoy today’s calm weather.