2:00 PM (Tuesday) | *An Arctic air mass arrives in the Mid-Atlantic region on Thursday and sets the stage for a wintry mess on Saturday including the likelihood of some accumulating snow*
Paul Dorian
Colder-than-normal conditions should dominate the weather scene next week in the central and eastern US; map courtesy NOAA, tropicaltidbits.com
Overview
Temperatures will climb back into the 50’s on Wednesday in the I-95 corridor which is well above-normal for this time of year, but a strong frontal passage early Thursday will usher in a big change for the end of the week. Arctic air will flood the region later Thursday and Thursday night riding in on strong NW winds which can gust past 40 mph. As a strong cold high pressure system builds into southeastern Canada on Friday, temperatures in the I-95 corridor will struggle to reach the middle 30’s. The influx of an Arctic air mass anchored by strong high pressure to the north will set the stage for a wintry mess on Saturday in the Mid-Atlantic region that is likely to include some accumulating snow; especially, north of the PA/MD border. This late week blast of Arctic air does not look like it will be an isolated event as there will likely be numerous cold air outbreaks for the central and eastern US in coming weeks.
With cold, dry air in place, the arrival of precipitation on Saturday in the Mid-Atlantic could result in a wintry mess including some accumulating snow; especially, north of the PA/MD border; map courtesy NOAA, tropicaltidbits.com
Details
An amplifying upper-level trough will push a fast-moving surface low pressure system east of New England on Thursday and this will drag a strong cold front through the Mid-Atlantic region. Arctic air will pour into the region later Thursday and Thursday night riding in on strong NW winds that can gust past 40 mph and dew points will drop noticeably in this upcoming very dry air mass. Strong high pressure will build across southeastern Canada on Friday and this system will be a key player in the likelihood of wintry precipitation on Saturday including the good chance for some accumulating snow; especially, north of the PA/MD border.
A widespread area so far this month of warmer-than-normal conditions; map courtesy Weather Bell Analytics,, NOAA
Another intensifying upper-level trough will cross the central Plains later Friday into Saturday and this will generate low pressure over the Upper Midwest that will take a track towards the central Great Lakes. A warm front extending well to the east of this low pressure system will generate west-to-east moving precipitation and given the cold, dry air mass in place, is most likely going to arrive in the I-95 corridor as snow sometime during Saturday morning As the surface low pressure heads towards the central Great Lakes, strengthening warm air advection will result in quick intensification of the precipitation on Saturday in those areas where it remains cold enough for snow - such as north of the PA/MD border - there can be a pretty decent thumping of snow.
A flip in the overall weather pattern could result in quite a turnaround in temperatures during February fof the central and eastern US as depicted here by NOAA’s CFS v2 forecast; map courtesy tropicaltidbits.com, NOAA
Eventually, the warming aloft is likely to result in a transition from snow to a wintry mix and then perhaps to all rain, but the low-level cold, dense air mass will be reluctant to give up its ground given the strong high pressure to the north and especially if a secondary low tries to form near the Mid-Atlantic coastline (a small but real chance). Another shot of cold air will follow the low pressure system as it treks to the northeast of here on Sunday and this could result in a change back of the precipitation to snow before it ends early in the day. Next week looks to remain colder-than-normal and the coming flip in the overall pattern may result in numerous cold air outbreaks in coming weeks for the central and eastern US - even through much of the month of February.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
Follow us on Facebook, Twitter, YouTube
Video discussion: