Snow returns tonight to the interior, higher elevations

The second snow event in the Interior Northeast in as many days will unfold later this afternoon and evening, likely lingering through Wednesday morning, as a storm system develops into the Ohio Valley and eventually off the Mid Atlantic Coast. The primary surface low will drive northward into the Ohio Valley, helping moisture surge northward into the Northeast United States with a southwesterly flow.

Meanwhile, the secondary surface low will develop off the Mid-Atlantic coast which at least in some small scale will aid in cold air filtration into the system from a cold high pressure to the north. The main process allowing snow to fall in Northeast Pennsylvania, Northwest New Jersey, and Southeast New York, however, will be dynamic cooling, which occurs when precipitation falls heavily enough to cool the air around it.

Although the atmospheric column is not necessarily “prime” for snow to fall in these areas, the rate of precipitation — including the lift in the atmosphere — is strong enough to allow the process of dynamic cooling to occur. So while these areas may start as rain, when precipitation intensity picks up, the atmosphere cools enough so that snow will reach the ground.

Forecast models aren’t pulling any punches, either; the snow could be quite heavy for some periods of time. This will obviously be more likely in the higher elevations, including mountain ranges and peaks. Areas to the south and southeast of these higher elevations not only will have lighter precipitation, they’ll also have a warmer atmospheric column, meaning snow is extremely unlikely.

For higher elevations, it looks likely to be a wintry several hours beginning this afternoon and continuing into the overnight period from Tuesday into Wednesday. Snow accumulation may exceed a few inches in some spots — and as mentioned above, this will be especially true in the higher elevation mountains.

The storm is expected to linger through Wednesday morning before slowly pulling away. The coldest air of the season thus far arrives later this week.

For more information on the storm system including snowfall maps and detailed breakdowns, visit the dashboard or contact us about direct consulting.