As last night's storm pulls away, strong cold air advection will continue as a cold front clears the region. Temperatures will be falling through the afternoon region-wide. With wind gusts of 20-30mph accompanying the falling temperatures, wind chills will drop into the single digits to negative teens in southern and central New England and the -20s to -30s across the northern tier.
For this, an extreme cold warning has been issued for northernmost New Hampshire and northeast Maine, the first such alert for New England under the cold weather alerts format (wind chill warnings were replaced with extreme cold warnings and wind chills advisories with cold weather advisories).
A strong area of high pressure with a central pressure of around 1,040mb will set up overhead of New England tonight into Sunday morning. This will lead to nearly perfect radiational cooling conditions region-wide. With light winds, clear skies and a refreshed snowpack, there will be little stopping temperatures from bottoming out tonight. Sunday morning lows will likely range from around zero for many to the -10s and low -20s across the northern tier and mountains.
Very calm winds will be needed to achieve these very low air temperatures. Should even a slight breeze remain leftover from this evening's gusty weather, temperatures will not be able to bottom out to the current forecast lows. Areas that are directly under this high pressure Saturday morning have dropped to as low as -26°. With that said, should perfect cooling conditions develop, actual air temperatures will likely reach their coldest point that we will see this winter.
This strong high pressure setting up the extremely cold Sunday morning will quickly move eastward during the day on Sunday. This will make room for the region's next system. Clouds will increase through Sunday as a clipper system is poised to cross the region. This system will lift a warm front into New England, providing the forcing for a period of light to steady snow moving west to east Sunday evening through Monday morning.
Despite the warm air advection, this does appear to be a mainly snow event for all of New England. Temperatures will likely slowly rise through Sunday night into Monday morning, but still remain old enough to support snow for most. Southernmost New England (likely the Mass Pike and points south) may be able to warm enough to see more of a rain/snow mix. With that said, should precipitation hang on a bit longer, the mixing could be pushed a bit farther north.
Below: CMC showing potential weather from Sunday evening through about midday Monday:
There will likely be a quick burst of steady snow with this system Sunday night to early Monday morning, but it will be just that...quick. Overall moisture with this storm is limited and the storm itself is not very strong. This should support another wide swath of 2-4 inches of snow across northern New England, with a dusting to 3 inches across southern New England.
A system passing to the north of New England later Monday will drag a cold front across the region Monday afternoon into Tuesday morning. This timing should allow for mild temperatures on Monday before a cooling trend heading toward midweek. The front will likely produce another round of snow showers later Monday into the night for the northern tier of New England, but these look to dry up as they move southward in the region.
Another quick and weak system may skirt through New England Tuesday night into Wednesday. This system is poised to very quickly sweep through and with limited moisture, little, if any, precipitation, is expected. Should precipitation develop, it will be non-impactful. The next organized system is poised to move through New England later in the week, likely Thursday into Friday.
This frontal system will likely be ejecting out of the Great Lakes by Thursday morning. This will lift a warm front toward New England initially. A secondary area of low pressure may form along this front and track in the vicinity of the Gulf of Maine. This will be New England's next chance for notable precipitation.
This system has a larger range in potential tracks than many of this winter's previous systems. Mainly, the system could take a track much farther west, potentially being an "inside-runner" type of storm. This would promote much more widespread mixed precipitation and rainfall across New England as a warm front lifts into the region, allowing for strong warm air advection.
Should a more eastward trend occur, it would allow for less warming and more frozen precipitation or snowfall. This could potentially occur if a secondary low forms, limiting the amount of warm air advection. Basically, the farther west the system tracks, the more widespread mixing and rainfall would be as opposed to snowfall. For now, the trend points toward wintry precipitation gradually changing to wetter precipitation as the event goes on.
Below: Current Weather Prediction Center probabilities of winter weather impacts Wednesday to Thursday morning (1st image) and Thursday to Friday morning (2nd image):
There remains a large spread in the outcome and precipitation types with this system. This spread stems from differences among the potential development and timing of a secondary low near the Gulf of Maine. Should this low develop quickly and gain strength, more wintry prescription will occur. If not, then the warmer solution would play out.
Below: Model roundup (Euro, GFS, CMC and GraphCast) for Thursday (February 6):
New England's active pattern looks to continue beyond this storm with another potential system approaching next weekend.
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