1:00 PM | ***Two upcoming threats of rain/snow in the Mid-Atlantic…Friday into early Saturday…Sunday night into Monday...first system to feature inverted trough, off-shore rapid intensification***
Paul Dorian
Low pressure will rapidly intensify off the Mid-Atlantic coastline and will feature an inverted trough that will extend back to the coast. Colder air will wrap into the system from northwest-to-southeast late Friday likely changing any rain that still is falling to snow in eastern PA, New Jersey/NYC with some accumulations possible. Map courtesy Canadian Met Centre, tropicaltidbits.com
Overview
The overall weather pattern will remain active during the next several days in the Mid-Atlantic region with two upcoming chances of rain and snow. The first threat of rain and snow will come from Friday into Saturday and there will likely be a second chance from Sunday night into Monday. In both cases, the more favored areas for snow will the interior higher elevation locations of the Mid-Atlantic; however, even parts of the I-95 corridor can see some accumulating snow. Both systems have to be closely monitored in coming days as, for example, rapid intensification and an “inverted trough” early Saturday morning can result in some last minute surprises.
An initial low pressure system will heads to Ohio on Friday, weaken, and then a secondary low will form off the Mid-Atlantic coastline by early Saturday and this will become the main player. Map courtesy Canadian Met Centre, tropicaltidbits.com
Details
By mid-to-late morning on Friday, surface low pressure will likely be located over Ohio and precipitation could break out from central Virginia and the DC metro region northward into central PA. By mid-day to early afternoon, precipitation is likely to push eastward into eastern PA, New Jersey and New York City. The initial precipitation can be rain or a mix of rain and snow when it arrives in the immediate metro regions, and all snow is possible across some of the northern and western suburbs. By evening, the initial surface low pressure system over Ohio will begin to weaken and a secondary low will start to form off the Mid-Atlantic coastline and it’ll soon become the main player. In fact, this western Atlantic low will intensify quite rapidly from late Friday night into early Saturday and this strengthening will allow for colder air to wrap around from northwest-to-southeast.
As a result, any rain that still is still falling late Friday can change to snow across eastern PA, New Jersey, NYC and possibly as far south as the suburbs of DC. Accumulations of a couple of inches are on the table in all of these areas with the best chances to the north and west of the big cities. There can be lingering snow or snow showers on Saturday morning before the system pulls away to the open waters of the western Atlantic.
One final note on the first system…if there are to be any surprises, it would come early Saturday while the surface low is rapidly intensifying over the western Atlantic. There will be an inverted trough (aka Norlun Trough) extending back to the west or northwest from the center of the low to the Mid-Atlantic region and this may act to pull the system closer to the coast which could increase precipitation (primarily snow) amounts on Saturday morning in some areas such as New Jersey, NYC and eastern PA.
A second threat for rain and snow in the Mid-Atlantic region will come on Sunday night and Monday as low pressure likely heads right towards the Mid-Atlantic coastline. Map courtesy Canadian Met Centre, tropicaltidbits.com
By Sunday night and Monday, there may be somewhat of a repeat performance with low pressure headed towards the Mid-Atlantic coastline and the threat of rain and snow. This second system may have a little more support in the upper atmosphere allowing it to “dig” a little farther to the south and east into the Carolinas on the front side and then climb farther to the north into New England on the back end…something to monitor in coming days. From this vantage point, it looks like precipitation could break out in the Mid-Atlantic region later Sunday night and continue into Monday and once again, there will be a battle between rain and snow in the I-95 corridor. As in the case for the system at the end of the work week, threat “number 2” has the potential for some accumulating snow in at least in the usual more favored areas of the interior, high elevation Mid-Atlantic, but also a chance exists for the immediate I-95 corridor. Those details may not be able to be worked out this weekend as the end result of the first system could actually impact the atmosphere for the second system.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com
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