Plain-language summary:
After unseasonably warm temperatures
for most of this week, it is much colder today with rain in southern areas. A
storm will bring light to moderate rain in southern areas and wet snow in
northern areas tonight into tomorrow morning, with light slushy accumulations possible
in lower elevations and up to 4” (10 cm) possible in higher elevations. It will
turn even colder afterward through Thursday, but with little precipitation
other than a few snow showers. It will likely warm up somewhat next weekend,
but then turn colder again for the following week. Overall below-average temperatures
in the first half of November, with a restoration of a strong temperature
gradient and jet stream, will likely lead to measurable or accumulating snow
for almost everyone at some point.
Meteorological discussion:
After unseasonably warm temperatures
for most of this week, a strong cold front passed through yesterday, bringing
in much colder air today, but its advance has been halted by a strong southeast
U.S. ridge and a couple of weak disturbances. The first disturbance is bringing
rain to the southern Adirondacks to southern Maine this afternoon, with ice
pellets mixing in at times, while it stays mainly dry but cloudy to the north.
The disturbance will move out tonight, but the second, slightly stronger storm will
move in from the southwest tonight. Although the storm is still relatively weak,
the strong temperature gradient will enhance the upward motion, and
precipitation could reach moderate intensity at times. The air will be cold
enough for snow to fall in eastern Ontario, southern Quebec, and northern Maine
Sunday night into Monday morning. With surface temperatures just above freezing
and the ground being still warm from the warm fall so far, a slushy
accumulation of up to 1” (2.5 cm) is possible in the lower elevations like the
Ottawa and St. Lawrence valleys, with up to 4” (10 cm) possible in the higher
terrain, especially in northwestern Maine and neighboring southeastern Quebec where
surface temperatures will be colder and the snow will be more intense. Incredibly,
many areas will see the first snow before the first freeze! Farther south, temperatures
even aloft will be too warm for snow, leading to just rain, even at higher elevations,
except possibly on the front and back ends.
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| Source: TropicalTidbits |
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| Source: PivotalWeather |
Even colder air will filter in behind
the weak storm, with widespread below freezing temperatures Monday, Tuesday,
and Wednesday nights, even in urban areas and near bodies of water. This is
incredibly late for the first freeze, especially away from urban areas and
bodies of water. A deepening trough over the Midwest U.S. will interact with a
disturbance farther southeast and could partially phase with it Wednesday, leading
to a strengthening storm, though it appears now that the storm will get going
too late and too far offshore for more than a few snow showers with little or
no accumulation for most. A high pressure follows for Thursday, but then the
high pressure shifts to the south, leading to southwesterly flow and moderating
temperatures and mostly dry conditions through next weekend.
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