1:00 PM | ***Low pressure will strengthen dramatically next 48 hours...big impact on Great Lakes, Mid-Atlantic, NE US...snow/squalls, powerful winds, Arctic cold and the lowest wind chills so far***
Paul Dorian
Winds will strengthen later today and during the night from a southwesterly direction ahead of the incoming strong cold front and then can gust past 50 mph on Thursday and Thursday night from a northwesterly direction on the heels of the frontal passage. Some of the high winds shown on this 850 millibar forecast map for early tomorrow evening can be “mixed” down to the surface level. Map courtesy NOAA, tropicaltidbits.com
Overview
Low pressure will move in a general “west-to-east” fashion across southern Canada during the next 48 hours and it will strengthen dramatically by the time it reaches the Canadian Maritime Provinces on Friday morning. This intensifying storm system and its associated strong cold front will have a big impact on the Great Lakes, Mid-Atlantic and Northeast US between later today and Friday to include some accumulating snow, possible snow squalls, powerful and potentially damaging wind gusts of 50 mph or so, and the ushering in of another Arctic air mass which will produce the lowest wind chills of the season so far.
Snow showers are likely in much of the Mid-Atlantic region and Northeast US from later tonight into Thursday morning and there can be heavier snow squalls that form along the strong cold front. The timetable for potential impact in the DC-to-Philly-to-NYC corridor from these possible snow squalls is between about 5 and 10 AM. Map courtesy NOAA, tropicaltidbits.com
Details
A low pressure system is currently located over the south-central part of Canada with a central pressure of around 995 millibars (29.38 inches). This system will move in a general easterly direction during the next 48 hours reaching the Canadian Maritimes by Friday morning and it will strengthen in a dramatic fashion between tomorrow morning and Friday morning on the order of some 25 millibars or so to around 970 millibars (28.64 inches). With this expected intensification, the pressure difference between the low pressure and an incoming strong high pressure system over the middle of the nation will increase markedly. The ultimate result of this strengthening pressure gradient will be a widespread area from the Great Lakes to the Mid-Atlantic/Northeast US that can experience powerful and potentially damaging wind gusts of 50+ mph from early tomorrow into Friday. These winds can bring down some tree limbs which can, unfortunately, result in some scattered power outages across the northeastern states anytime from early tomorrow into the day on Friday.
While snowfall amounts will be on the minor side along the I-95 corridor, the ground is so cold that even light amounts can result in slippery road conditions. More significant snowfall is expected in the higher elevation locations of the interior Mid-Atlantic and Northeast US and there can actually be blizzard-like conditions up in the mountainous areas for a brief time on Thursday making for dangerous travel. Map courtesy NOAA, tropicaltidbits.com
In addition to the winds, precipitation associated with the strengthening low pressure system and its trailing strong cold front will become a big factor from later tonight into Thursday with some accumulating snow across interior, higher elevation locations of the Mid-Atlantic/Northeast US. In the immediate I-95 corridor region, there can be snow and/or rain showers later tonight and then snow shower activity on Thursday morning as the strong cold front barrels through to the eastern seaboard. There is even a chance that heavier snow squalls can form right along the advancing strong cold front potentially impacting the DC-to-Philly-to-NYC corridor sometime early Thursday morning...likely in the hours between about 5 and 10 AM with small accumulations on the table. And, as a word of caution, the ground is quite cold all along the I-95 corridor given the recent extended period of below-normal temperatures so any snow that does fall – even if only in minor amounts - can quickly lead to slippery road conditions. Elsewhere, travel in the interior, mountainous areas of the Mid-Atlantic and Northeast US can be downright treacherous for a time on Thursday given the expected blizzard-like conditions of brief heavier snowfall and high winds.
Another Arctic air mass will flood the northeastern states later tomorrow and tomorrow night and - given the expected high winds - this will lead to the lowest wind chill values of the season so far. Map courtesy NOAA, tropicaltidbits.com
One last impact of this system will be the influx of another Arctic air mass on the heels of the cold frontal passage early Thursday morning. This latest outbreak of Arctic air combined with NW wind gusts of 50 mph or so will very likely produce the lowest wind chill values of the season so far from later tomorrow into tomorrow night. On Friday, the winds will stay quite strong with the powerful storm system sitting over the southeastern part of Canada and temperatures will remain far below-normal for this time of year. The weekend will start off quite cold in the Mid-Atlantic and Northeast US, but moderation in temperatures will become quite noticeable by the time Sunday afternoon rolls around…it turns even milder on Monday and Tuesday of next week with the threat for some rain.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com
Follow us on Facebook, Twitter, YouTube
Video discussion: