2:00 PM | *Snow or a wintry mix likely early tomorrow in the I-95 corridor…interior New England to get a major snow storm…widespread cold across the nation by the end of next week*
Paul Dorian
Euro model forecast map for early Friday morning; map courtesy Weather Bell Analytics
Much colder air has moved into the Mid-Atlantic region following the passage of a cold frontal system on Wednesday. Meanwhile, another cold front is headed towards the east coast and this will be supported by vigorous upper-level energy. As a result, low pressure is likely to form on Thursday just off the New Jersey coastline and then rapidly intensify as it moves northeastward reaching Maine’s east coast as a powerful storm by early Friday morning. This storm will become a major snow producer for interior sections of New England by tomorrow night where more than a foot can pile up in portions of (inland) Maine, Vermont and New Hampshire – coastal New England will receive far less (e.g., 1-3 inches around Boston).
In the Mid-Atlantic region, there can be snow or a wintry mix for awhile late tonight and early Thursday depending on location. In the DC metro region, a wintry mix is possible late tonight and early Thursday morning before a changeover to plain rain takes place. Any icing that occurs will likely be confined to the far northern and western suburbs (e.g., northern Montgomery County in MD and western Loudoun County in VA). In Philly and NYC metro regions, snow could break out around daybreak and then turn into a wintry mix for awhile before changing to plain rain. Small grassy accumulations of snow are possible early tomorrow in the northern and western suburbs of both metro regions before the changeover to plain rain (e.g., western Chester County, western Montgomery County, Upper Bucks County in PA; interior sections of NW NJ). Following the storm, northwest winds will strengthen noticeably around here late tomorrow night and Friday, temperatures will be held in the 30’s for highs and flurries can fall at just about any time as we close out the work week – perhaps even a heavier snow shower.
12Z GFS Ensemble forecast map of 850 mb temperature anomalies on Friday night, January 6th, 2017; map courtesy tropicaltidbits.com, NOAA
Looking ahead, after another quick and significant warm up in the Mid-Atlantic region early-to-mid next week, much colder air will return by the end of next week. In fact, there have been persistent signs in numerous computer forecast models for widespread cold to encompass much of the US by the 6th or 7th of January. One such forecast example is shown above from the 12Z GFS Ensemble model run which features colder-than-normal temperatures in the lower part of the atmosphere from coast-to-coast by the end of next week. Whether the upcoming early January cold gets "locked in" remains an open question at this time, but there are signs for just that possibility as strong upper-level ridging appears increasingly likely to form over Greenland and Alaska (i.e., a blocking pattern in the northern latitudes).
Stay tuned.
Meteorologist Paul Dorian
Vencore, Inc.
vencoreweather.com