Watching Two Snow Threats Later This Week and Into the Weekend
Good Evening!
Today has been quite cold and calm across much of the Mid-Atlantic and Northeast as the storm system that impacted much of the Central US to the Mid-Atlantic moved offshore very early this morning. High pressure has now begun to build in from the west in this system’s wake, ushering in colder mid-level temperatures from the Northwest. With cold mid-levels and mainly clear conditions in place today, highs were able to only reach into the upper 20’s to lower 30’s across much of the New York metro area-which is just slightly below-normal for this time of year.
Continued clear skies, cold mid-levels, and light winds will aid in the development of decent radiational cooling during the overnight hours. Low temperatures should drop steeply into the middle teens to lower 20’s across much of the forecast area tonight, with single-digit readings possible for elevated locations well off to the north and west of the city.
This evenings high-resolution regional radar and surface observations showing a cold, but very calm evening in place for much of the Northeast (Simuawips)
Cold and Clear Through Midweek
High pressure will remain in control for much of the day on Tuesday before a very weak and moisture-starved system begins to approach the Northeast from Canada. As this system approaches the area, lower to mid-level winds will shift from northwesterly to more westerly, allowing for only slightly “warmer” air to move in. This system may also have a chance to briefly increase cloudiness over the Northeast during the afternoon hours. Some slightly increased cloudiness and westerly flow aloft will likely allow for highs tomorrow to head into the middle 30’s to lower 40’s across much of the forecast area. While these temperatures are slightly warmer than today’s highs, they will still be right around normal for this time of year. As this weak system moves through moves through tomorrow afternoon/evening, there may be some light snow showers over portions of New York State and Northern Pennsylvania, but the entire New York metro area should remain dry. Once this system moves on through the area, a weak cold front will then quickly move from west to east, eliminating any remaining clouds in the area. With a relatively more mild airmass overhead tomorrow night, highs will likely only be slightly warmer than this evening’s, with readings in the upper teens to middle 20’s likely.
Wednesday will start off much like Tuesday with calm, clear, and cold conditions in place for the morning commute. Temperatures will be rather cold, with lower to middle 20’s likely for much of the immediate metro area. Another weak mid-level system will be moving very quickly well to our north on Wednesday afternoon, with the potential for some increased cloudiness over the area. Highs will reach the middle to upper 30’s, with lower 40’s likely closer to the coast.
The potential will exist for some light snow snow showers off to the north and west of the city on Wednesday afternoon/evening, but it is highly unlikely that these snow showers are able to make their way south into portions of New Jersey and New York City due to the best dynamics remaining well off to our north. As the evening continues on, another weak cold front will move through during the evening and overnight areas, bringing in another reinforcement of drier conditions. Wednesday night will likely be another cold and mostly clear night for the area, with lows dropping down into the lower to middle 20’s.
~Updated Weekly Planner for the NYC area~
Watching Two Potential Snow Threats Later This Week and Into the Weekend
Conditions will likely remain quite calm and cold through the middle of the week and into the first half of Thursday. However that looks to quickly change as we shift our attention towards the Ohio Valley. A weak northern stream disturbance will be moving quickly from west to east, with just enough moisture moving up from the south to produce a swath of light precipitation. Additionally, an area of high pressure will be located over New England, which should help this system continue on eastward towards the New York City area by Thursday evening. Light precipitation should move into the metro area by 7-9 pm, with most of the area starting as light snow. Initially, the aforementioned high pressure area should help the entire forecast area stay as mostly snow, with locations over Southern New Jersey possibly experiencing some mixing issues.
As we head deeper into the overnight hours, warmer air may continue to work its way into the immediate New York City area, causing a mix or change to rain. Precipitation will likely continue into the AM commute on Friday before quickly tapering off from west to east. At this time it does appear that this system could drop a quick coating to an inch or two across portions of the NYC metro area, with some locally higher amounts for elevated locations off to our north and west. The exact amount of snow/rain will be highly reliant on the track of this system, and we will have an update tomorrow as more data becomes available!
This evenings GFS model showing a weak disturbance producing an area of light snow over the Northeast late Thursday night and into Friday morning
Lastly, we mentioned the possibility of a “larger” system that could impact the East Coast this upcoming weekend all the way back on Friday. Since that time, the reliable computer model guidance has shifted away somewhat from a significant/pure-snowstorm, to more of a “thump” of moderate to heavy snow-along with a mix of sleet, freezing rain, and plain rain for much of the forecast area.
At this time we feel that the mostly likely scenario based on all available data is that another large storm system will develop over the Midwestern states on Friday night, with a large swath of moderate to heavy snow extending along the northern edge of the precipitation shield. This system will then have the potential to interact with a much larger mid-level system over Canada on Saturday, which will likely cause it to strengthen a bit as it tracks over the Southeast. A large and expansive upper level jet streak will help to “vent” this system out, allowing for precipitation to expand into the Northeast by Saturday afternoon. Thermal profiles appear to be cold enough for precipitation to start and stay as mostly snow for the NYC area during the afternoon and early evening hours. There is the potential that the snow could eventually change to a mix of sleet, freezing rain, or even plain rain by the overnight hours of Saturday or early Sunday, but this is where the models begin to diverge significantly. Depending on just how much this system interacts with the large tropospheric polar vortex over Canada will dictate just how much cold air can get involved and where exactly this system will track.
There is still quite a bit of time to track this system, and we could still see a shift towards either side (colder with more snow or warmer with more rain) over the next few days, so make sure to check back for updates!
This afternoons ECMWF model showing a large area of wintry precipitation breaking out over the East Coast on Sunday
Have a great night!
-Steve Copertino
