Another rain event will get underway later tonight in the Mid-Atlantic region as a strong storm begins to lift northeast from the central Plains towards the Great Lakes. As the storm moves to the west of here on Friday, warmer air will surge up the Atlantic seaboard and temperatures may reach the 60 degree mark in parts of the I-95 corridor. Another low pressure system threatens for Sunday, but it is likely to stay just to the south of here as we close out the weekend. Yet another low pressure system will likely impact the Mid-Atlantic region on Monday and Monday night and with an expected track again to the west of here, it is most likely going to result in plain rain. Finally, by the middle of next week, there will be cold air nudging its way southeastward across the Upper Midwest and Ohio Valley at the same time there will be plenty of moisture in the southeastern US. It is too early to say if the cold from the northwest and the moisture from the southeast will meet up over the Mid-Atlantic region, but it’ll be something to monitor in coming days as this active pattern continues right into 2019.
Clouds will increase this evening as strong low pressure pulls out of the central Plains and heads towards the Great Lakes region. Moisture will push towards the Mid-Atlantic region from the Gulf of Mexico over the next several hours and rain should break out in the overnight hours in the DC-to-Philly-to-NYC corridor. The rain can come down hard at times late tonight and during Friday morning as breezy and milder conditions develop in the warm sector of the storm. Given the already well-saturated grounds, any heavy rainfall could result in more localized flooding conditions. Temperatures on Friday should climb to the 55-60 degree range for highs in the I-95 corridor and then colder, drier air will arrive tomorrow night as NW winds intensify.
The weekend will turn gradually colder following the passage of a cold frontal system later tomorrow night. Winds will pick up tomorrow night out of the northwest and temperatures will hold primarily in the 40’s on Saturday and then perhaps be confined to the 30’s on Sunday. On Sunday, low pressure will be heading towards the coastline of the Southeast US and it appears its precipitation field will stay just to the south of the Mid-Atlantic region.
Yet another low pressure system will pull out of the southern states on Monday and it appears this too will slide to the west of the I-95 corridor and have an impact on the region. Milder air is likely to push into the Mid-Atlantic region on Monday and plain rain is likely to break out in the PM hours. If by chance, however, the precipitation arrives early enough in the day on Monday, there is the possibility for something frozen at the onset. The rain is likely to continue into Monday night, New Year’s Eve, and then wind down by Tuesday as drier air arrives following the departure of the storm to the northeast of here.
An Arctic outbreak is likely to plunge into the Northern Plains/Upper Midwest early next week and temperatures may drop to well below zero levels by mid-week in places like Minnesota, northern Iowa and western Wisconsin. After the initial plunge of the Arctic air mass into the Northern Plains/Upper Midwest, the upper atmospheric setup will act to slow down its push to the southeast and it will only grudgingly cross over the Ohio Valley at mid-week. At the same time, there will be lots of moisture meandering across the southeastern states. It is simply too early to tell if the cold to the northwest of here and the moisture to our southeast will ever meet up in the Mid-Atlantic region, but it is something we’ll closely monitor in coming days.
Meteorologist Paul Dorian