Plain-language summary:
The deluge since Friday night that
ended the record October heat is ending today as a storm that was over New
England yesterday moves into northwestern Quebec today and slows down. Northwestern
New York, eastern Ontario, and western Quebec will still get some more rain
through Tuesday, with snow mixing in the higher terrain of the Laurentians,
though it will gradually get lighter and more intermittent as the storm weakens.
It will be drier with a mix of sun and clouds to the southeast, with somewhat
warmer but still slightly below average temperatures. Even with the cooler air
mass, breezy conditions and/or clouds will prevent frost for the whole week. As
the storm slowly moves to the northeast, a mix of sun and clouds with
occasional showers looks likely from Wednesday through Saturday. The
temperature roller-coaster that was earlier expected looks unlikely now, with temperatures
generally staying slightly below average for the foreseeable future. Another
storm could move in and slowly cross our area next Sunday, with the weather
pattern remaining relatively slow-moving but perhaps moving a little faster for
the following week.
Meteorological discussion:
An impressive setup of a digging
trough to the west turning negatively tilted, a potent ridge to the northeast
leftover from the record October heat earlier in the week, and the remnants of
Philippe have combined to spark quite the deluge across the region since Friday
night. Two main areas of heavy rain developed: one from upstate New York into
southern Quebec associated with the moist Atlantic air colliding with a
slow-moving front, and the other in Maine and western New Brunswick associated
with Philippe’s remnants. Had Philippe’s remnants phased with the digging
trough a little earlier, even more impressive rainfall amounts would have
resulted.
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| Source: TropicalTidbits |
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| Source: CoCoRaHS |
The low pressure will move northwestward
into northwest Quebec today as the whole system becomes cut off and starts to weaken
and move much slower. With the low pressure setting up that far northwest, most
of northern New England will dry out completely by this afternoon. Northwestern
New York will still get rain due to lake-effect showers, with the much cooler
air going over the still warm Lake Ontario in the southwesterly flow. Some
showers will also affect eastern Ontario, with wet snow mixing in the higher
terrain of the Laurentians to the northwest. This will continue through Tuesday,
with precipitation becoming lighter and more scattered as the storm weakens,
and all precipitation changing to rain by Monday afternoon. Meanwhile, to the
southeast, it will be dry and not so cool (only slightly below average), with
periods of sunshine. Breezy southwesterly winds will prevent any nighttime
frost.
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| Source: TropicalTidbits |
After models going all over the place,
we finally have some clarity for this upcoming week’s weather pattern. The
temperature roller-coaster that was earlier expected looks unlikely now, as the
cut-off low only very slowly moves eastward and prevents any surge of warmer air
into our region. Instead, from Wednesday through Saturday, it looks partly to
mostly cloudy with temperatures slightly below average for most areas, with
occasional showers with any weak disturbance rotating around the closed low.
After that, another storm could approach from the west, slow down, and
strengthen upon reaching the U.S. East Coast, a bit like a winter Nor’easter,
but bring more rain instead. For now, it looks like any rain is the most likely south of the U.S./Canada borderWith the strongly negative NAO persisting through
next weekend, any storm will not move very fast, with a strong ridge to the
north. The +PNA will promote a ridge in western North America and troughs or cut-off lows in the eastern U.S. tunneling underneath the central Canada ridge. The anomalous ridge and warmth to the north also means that even on the
northern side of the storm, it will not be particularly chilly, and any storm
would still be all rain except in the highest elevations, if even that.
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| Source: TropicalTidbits |
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| Source: Climate Prediction Center |
There may still be one more slowly
moving storm for the following week, though it could also stay to the south. The
-NAO may ease afterward, leading to storms moving a bit faster, a stronger jet
stream and temperature gradient, and less ridging to the north. Still, big
temperature swings look rather unlikely, with slightly below average
temperatures, frequent clouds and/or showers, and little frost risk likely to
dominate for most of the following week.
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| Source: TropicalTidbits |
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