Dry and seasonably cool through Wednesday, though still rather cloudy at times for many, but with frosts and freezes on clear nights; heavy rain and strong winds possible Thursday and/or Friday; drier but still rather cloudy for a few days afterward, then turning colder and maybe unsettled with first chance of snow for most and drought continuing to ease

Plain-language summary:

 

After the wettest and cloudiest week in 3 or 4 months across the region, it will be dry and seasonably cool through Wednesday. Clouds still dominate today and Monday, especially along and northwest of the Appalachians, but at least partial clearing is likely for Tuesday and Wednesday in these areas, with coastal areas perhaps turning cloudier. Frosts and freezes are likely on clear nights away from urbanized areas and large bodies of water. A storm could bring heavy rain and strong winds Thursday and/or Friday. It then dries out for a few days but perhaps still remaining rather cloudy. It likely turns colder, though not extremely cold, and unsettled later the following week, with the first chance of snow for most. This weather pattern should continue to slowly ease the drought.

 

Meteorological discussion:

 

Dry and seasonably cool through Wednesday, still mostly cloudy for most today and Monday before gradual clearing in northern areas through Wednesday 

 

After the wettest and cloudiest week in 3 or 4 months across the region, it is now dry and seasonably chilly as the slow-moving cut-off low has weakened and moved off to the east and is replaced by a broad slow-moving high-pressure system over eastern Canada. However, it is still rather cloudy in many places, especially along and northwest of the Appalachians as low-level moisture is trapped under the subsidence inversion, and the sun angle is too low to break up the low clouds much at this time of year. This is a frequent occurrence in late fall into early winter. Southeast of the Appalachians, the subtle downsloping resulting from the weak northerly flow is just enough to break up most of the clouds. The clouds will likely eventually break northwest of the Appalachians by Tuesday and Wednesday as the atmosphere slowly dries out, whereas coastal areas could actually get cloudier as a surface low-pressure system moves into just offshore the New England coast that switches the flow to easterly off the Atlantic Ocean and also brings both marine low-level clouds and mid-level clouds from the broader storm system. However, the blocking high-pressure system to the north over Quebec (connected to the high-latitude blocking or -NAO that persists) will squash the storm far enough to the south to prevent any rain for the region, and areas north of the U.S./Canada border will turn increasingly sunny. The location of the surface high-pressure system to the north of our region will prevent any warmup that was previously expected during this time, and widespread frosts and freezes are likely where there are clear skies at night, except for heavily urbanized areas and shorelines of large bodies of water.

Source: College of DuPage and TropicalTidbits

Source: TropicalTidbits

Source: Climate Prediction Center

 

 

Storm arrives Thursday or Friday with potential heavy rain and strong winds 

 

Unlike previous dry, sunny spells, this dry and somewhat sunny spell will already be over by later Thursday, as another storm approaches from the southwest. It is a rather amplified setup that should be amplified enough to push into and weaken the blocking ridge and bring a widespread rain to the region. It could also be accompanied by strong southeasterly or easterly winds, especially along the coast and in downslope regions just west of the Green Mountains and Adirondacks. Most likely, the storm tracks just to the northwest, with southeasterly winds leading to upslope enhancement along the Green and White Mountains and to the southeast, as well as in the Laurentians, with less rain in the downsloped Champlain Valley, though if it tracks a little more to the east, more like an early-season Nor'easter, there would be a more even distribution of rainfall. The timing of the storm is also still a bit uncertain due to the relatively slow-moving nature of the blocked pattern, with the storm coming anywhere between Thursday afternoon and later Friday. However, it is becoming more certain that Hurricane Melissa will be too far east to have a direct influence on our weather, though Melissa could impact parts of Atlantic Canada and there may not be much of a separation between Melissa and the extratropical storm impacting our region, with perhaps some moisture from Melissa being siphoned into the storm in our region. 

Source: TropicalTidbits

Turning drier by next Sunday but still cloudy for a few days, then colder and turning unsettled with first chance of snow for most

 

By next Sunday, the storm will have passed to the east, but lingering low clouds are likely as is common during late fall and early winter. The weather pattern becomes a bit uncertain; most likely, another a few days of mostly dry weather ensues, with a broad, weak low-pressure system passing to the south early the following week possibly bringing showers to southern areas but leaving areas to the north dry. The blocking pattern appears to weaken (NAO turning neutral), but the positive PNA will lead to a classic upper-level ridge in western North America and trough in eastern North America, which should lead to cool temperatures and unsettled weather at times. Given the northwesterly flow of chilly air associated with this type of weather pattern, it is likely that many locations will receive their first snowflakes, even measurable snowfall, with one of the low-pressure systems that reaches our region and taps into the greater supply of cold air, even at lower elevations, though higher elevations are still much more likely to receive accumulating snow, as is typical for this early in the season. Also, central and northern Canada is still much warmer than average and will likely remain so for the foreseeable future, limiting just how cold the cold air from the northwest can get, and temperatures aren't expected to reach anywhere near record lows, but warmth will also be largely absent though there are signs of a brief warmup later that week. The colder temperatures and increased storminess should continue to slowly ease the drought.

Source: TropicalTidbits

Unseasonably warm and breezy with high fire danger today; rain briefly heavy Monday while turning cooler; drier Tuesday, then rain and showers Wednesday and Thursday; clears out Friday into next weekend with widespread frost and freeze; dry with modest warmup early following week before turning cooler and unsettled again

Plain-language summary:

 

It is unseasonably warm and breezy today, with the warmest in eastern Ontario and northwestern New York, with high fire danger. Widespread drenching rain will occur tomorrow, with even a broken squall line featuring a brief period of heavy rain and strong winds for many before it abruptly turns cooler. No major rainfall is then expected for the rest of the week, but cooler temperatures, increased clouds, lower sun angle, and higher relative humidity will prevent the ground from drying out as quickly as after previous rain events this autumn and should prevent the drought from intensifying further. It will be mostly dry on Tuesday with some breaks of sunshine and seasonably warm temperatures before widespread showers occur Wednesday and some showers still possible on Thursday with cooler but not particularly cold temperatures. Lake-effect rain is possible on Thursday in northwestern New York. It gradually clears out later Friday into next weekend with widespread frost and freezes likely. It then likely warms up modestly and stays dry for a few days before turning cooler, cloudier, and more unsettled again, though it is unclear if any major rainfall will occur. There is also still no sign of true arctic air entering our region, leading to modest cooldowns and muted temperature swings again.

 

Meteorological discussion: 

 

Unseasonably warm and breezy with high fire danger today, then rain, briefly heavy Monday before turning abruptly cooler 

 

Today is briefly unseasonably warm across the region as the weather pattern has finally become more amplified temporarily, with a short-wavelength but deep trough in the Great Lakes associated with a rather strong though elongated surface cyclone in northern Ontario and upper-level ridging over Atlantic Canada. Today, our region is east of the storm, with decent sunshine filtered through high clouds and strong southerly flow bringing breezy conditions and much warmer air. It is the warmest in eastern Ontario and downsloped regions of northwestern New York and extreme southwestern Quebec, where isolated temperatures of 80F (27C) are occurring! To the east, the southerly flow is modified by the previous cooler air mass and the northwestern Atlantic Ocean. Given the warm weather, strong winds, drought, and lack of rain for several days, the fire danger is unusually high today, with a rare red flag warning issued for northern Vermont and northwestern New York. On Monday, the storm will have moved into our region, with widespread rain and even a weak broken squall line with brief heavy rain and strong winds along the cold front, especially south of the U.S./Canada border, with abruptly cooler air behind it. A few spots could even have thunder, though the clouds will prevent daytime heating and instability, and it is so late in the year that there is virtually no chance of anything severe.

 

Source: PivotalWeather, TropicalTidbits, National Weather Service

 

 

Seasonably warm temperatures with breaks of sun Tuesday, then widespread rain and showers on Wednesday, then leftover showers and modest cooldown for Thursday

 

The warmth will not last and will be gone by later Monday, with a -NAO and increasing PNA favoring upper-level ridging in western North America and deep upper-level troughing in eastern North America. The -NAO and associated high-latitude blocking will also slow the weather pattern down and make it easier for storm systems to cut-off and move very slowly, bringing showers to an area for several days. After Monday's storm, Tuesday should be dry for most, perhaps with some sunshine and seasonably warm temperatures as the true cool air mass remains to the west, and the southwesterly flow modifies any cooler air that initially gets pushed into the Great Lakes. Another system, this one being cut off, will slowly move into the region on Wednesday, bringing a period of widespread showers but without the strong dynamics that Monday's storm will have, with the showery nature of the rain aided by the cooling aloft. As the cut-off low slowly moves across Quebec, any steady rain will end by Thursday, but scattered showers and widespread cloudiness are likely given the low-level moisture and relative low pressure that will be in place, something that is very common in late fall. The west to southwesterly low-level flow and the Great Lakes still warm from summer will even favor lake-effect rain to affect northwestern New York. Temperatures will be seasonably cool, but the west to southwesterly flow will lead to any cold air taking an indirect path and being modified over the Great Lakes before reaching our region. Wind and clouds will likely prevent a frost or freeze for most locations. Also, even with the upper-level troughing, there is still no real arctic air involved, perhaps due to the neutral to increasing positive AO. Despite the lack of major rainfall after Monday, the clouds, lower sun angle, and higher relative humidity will lead to slower evaporation and slower drying of the ground than after previous rain events this autumn, preventing the drought from intensifying further.

 

Source: TropicalTidbits

 

 

Source: Climate Prediction Center

 

 

Gradually clearing out Friday into next weekend with widespread frost and freeze likely 

 

By Friday, the cut-off low will have moved farther east, and surface Canadian high-pressure will slowly push into our region into next weekend, which should gradually clear the skies out and lessen the wind. If the surface high-pressure traverses directly over our region as models currently indicate, widespread frost and freezes are likely, the most widespread of the fall so far, perhaps except for the immediate shoreline of large bodies of water like Lake Champlain or the Atlantic Ocean and in downtowns of urban areas. The high-pressure system will likely squash another storm slowly traveling across the U.S. to our south during this time, though this is not a guarantee yet.

 

Source: TropicalTidbits

 

 

Dry and modest warmup early following week, then cooler, cloudier, and more unsettled again but not particularly cold later in the week

 

For early the following week, the PNA eases back to near neutral as an upper-level trough moves into the western U.S., which will promote upper-level ridging in eastern Canada and dry and maybe warming weather, at least during daytime, in our region. The surface high-pressure location over eastern Canada does not favor the southerly or southwesterly flow needed for a truly major warmup. There might actually be low-level cold air sneaking in from the northeast instead, with continued nighttime frosts and freezes if the sky is clear enough. Whatever warmup will not last long, as the PNA will likely return back to positive later in the week while the NAO remains negative. This will encourage upper-level troughing to return to eastern North America, including our region, with a return to cooler, cloudier, more unsettled conditions, though it is unclear if there will be any actual major rainfall. Any system that affects our region will be slow-moving with the high-latitude blocking, and there is even a small possibility that future Hurricane Melissa that develops this upcoming week in the Caribbean has at least a small impact on our weather the following week if it is timed right to be picked up by an amplifying upper-level trough over the central and eastern U.S., though it is way too far out to tell. There also still appears to be a lack of true arctic air, rendering any cooldown relatively modest and limiting the temperature swings that have been less pronounced than usual for most of this autumn. Even the arctic itself appears to remain much warmer than average for the foreseeable future.

 

Source: TropicalTidbits

 

Dry today with increasing clouds in southern areas; light to moderate rain in southern areas tonight into Monday night; then dry and cooler through Friday with frost and freeze outside urban areas and large bodies of water; warmer and breezy next weekend with at least light rain likely; then cooler and eventually cloudier following week

Plain-language summary:

 

It will be dry again today, though with increasing clouds ahead of an approaching storm in southern areas. Light to moderate rain will fall from Vermont to southern Maine tonight through Monday night, with areas to the north staying dry and only seeing increased clouds. It will turn cooler and breezy Wednesday before winds lighten later in the week with widespread frost and freeze outside urban areas and away from large bodies of water then, all while remaining dry and mostly sunny. It turns warmer and breezy next weekend with at least some rain likely for our region. It then likely turns dry and mostly for a couple of days and then cooler and cloudier for the following week, though it remains to be seen if any major rainfall can occur. Regardless of rainfall, the more up-and-down temperature pattern and increased cloudiness will be more typical of late autumn, even if the lack of true arctic air will mute the cooldowns somewhat.

 

Meteorological discussion:

 

Dry and mostly sunny today, especially in northern areas, then light to moderate rain in southern areas tonight through Monday night 

 

Today will be another familiar dry, sunny day except from southern Vermont to southern Maine as a big surface high-pressure and upper-level ridging dominates the region, especially in Quebec. It will also be warmer than earlier in the week in the sunnier areas in northern New England and especially southeastern Canada, though not nearly as warm as last weekend. However, an early-season Nor'easter slowly coming up the East Coast will spread thickening clouds to southern areas this afternoon and then eventually a period of light to moderate rain south of the U.S./Canada border and south of central Maine tonight into Monday night. The actual low-pressure center will be just off the South Carolina coast, but it is also interacting with a weak disturbance extending well to the northeast over the western Atlantic and another one over upstate New York, leading to the rain shield expanding well to the north into central New England. However, the blocking ridge to the north will block the movement of the overall storminess any farther north, and the storm will then stall out, occlude, and weaken, with the rain shield to the north collapsing by Monday night. As such, areas north of the U.S./Canada border will only see increasing clouds with no rain to relieve the drought. Even southern areas will receive much less rain than areas in the coastal Mid-Atlantic U.S., though up to 1" (25 mm) is still possible in some areas from southern Vermont to extreme southern Maine. The rain and clouds will also cause cooler daytime temperatures tomorrow south of the U.S./Canada border and south of central Maine.

 

Source: TropicalTidbits

 

 

Dry afterward through Friday, turning cooler again mid-week with widespread frost and freeze likely late week 

 

With the storm's miss for northern areas, those areas will have to wait a while before any seeing any drought relief, with little or no rain expected until at least next weekend. Despite this, the lack of unseasonably warm temperatures and lowering sun angle will lead to lower evaporation and likely prevent the drought from intensifying much further. A dry cold front will arrive Tuesday night, with another big Canadian surface high-pressure system approaching for Wednesday and Thursday, though the leftovers of the previous storm will still be moving very slowly off the East Coast and reintensifying south of Atlantic Canada, which will keep the chilly northerly flow into our region for several days, and with the surface high-pressure system remaining to the west, there could initially be enough low-level moisture to still promote low clouds on Wednesday, especially along and northwest of the Appalachians, something that becomes more and more common as autumn progresses. The NAO turning negative is aiding in slowing down weather systems and amplifying the upper-level wave train. Eventually, the surface high-pressure system will slowly move east into our region by Friday, with lighter winds and greater chance for another widespread frost and freeze outside urban areas and away from large bodies of water.

 

Source: TropicalTidbits

 

 

Source: Climate Prediction Center

 

 

Turning warmer and breezier next weekend with likely some rain 

 

By Friday, a deep upper-level trough will move into the western U.S., leading to a surface low-pressure system ejecting from the Rockies and a downstream upper-level ridge and warmup with southwesterly flow in eastern North America, including our region. It might be mostly sunny initially, but then clouds will increase as the storm slowly approaches our region, likely arriving next Sunday or the following Monday. The amplified upper-level weather pattern likely favors a low-pressure track northeastward into the Great Lakes and then north of our region, meaning that the heaviest rain stays off to the northwest, with our region turning breezy and warmer with at least some rain likely with the warm front and then cold front.

 

Source: TropicalTidbits

 

 

Perhaps drier and sunnier for a couple of days after next weekend before turning cooler and cloudier for following week, though not clear if any major rainfall

 

After next weekend's storm, another Canadian surface high-pressure system is likely to lead to a couple of dry, mostly sunny days again, though not particularly chilly as the high-pressure system is not tapping into any arctic air. However, that is likely not to last long as later that week, the whole wave train slowly moves eastward with a likely shift to an upper-level ridge/trough in western/eastern U.S. respectively (+PNA), with the -NAO leading to a slower-moving and less progressive weather pattern allowing for the mid-latitude jet stream to dip south with cold air from the west and northwest coming into our region. Right now, it is not clear if the cold air will come straight from the north like this week's cold shot, or if it will come south into the Great Lakes first and then push eastward, in which case the cold air will be modified. It is also not clear if we will see substantial storm systems providing a prolonged period of light to moderate rain that would be needed to truly relieve the drought, though the upper-level troughs and cyclonic flow predicted tend to lead to low-level moisture and clouds and even showers, especially at this time of year when Hudson Bay, the Great Lakes, and all the other lakes in eastern Canada are not frozen yet and supplying the boundary layer with moisture. This would lead to cloudier weather more typical for late autumn and lower evaporation rates. The temperature swings are also more typical of late autumn as the mid-latitude jet stream pushes south into our region and strengthens with the strengthening north-to-south temperature gradient. However, the northwesterly flow associated with the upper-level troughs is still largely detached from the true arctic air (perhaps at least partially due to the AO remaining neutral or slightly positive), and the arctic it self will be much warmer than average. This will mute the temperature swings somewhat and cause the average of the temperature swings to still likely be above the climatological average even with the +PNA and eastern North America troughs.

 

Source: TropicalTidbits

 

Record warmth through Monday before sharp cold front brings rain later Tuesday; frost/freeze Wednesday and Thursday nights, then warms up again while staying dry through middle of following week; then perhaps more typical up-and-down temperature pattern

Plain-language summary:

 

Record warmth and sunshine, more typical of mid-summer, will dominate the region today and Monday. The warmth will abruptly end later Tuesday with rain before turning much cooler and dry again on Wednesday. Widespread frost and freezes are likely Wednesday and Thursday nights away from urban areas and large bodies of water, and then it will warm up again next weekend into the middle of the following week while staying dry, though not nearly as warm as today and Monday. Uncertainty drastically increases afterward, but it is likely that the inevitable progression of autumn will lead to more frequent and perhaps bigger temperature swings as well as more frequent storminess, though whether there will be enough rain to dent the drought remains to be seen, and it still appears to be warmer than average overall.

 

Meteorological discussion: 

 

Record warmth today and Monday with dry and sunny conditions 

 

A classic, rather amplified upper-level trough in western North America (-PNA) and ridge in eastern North America will be dominating through Monday, with daily and possibly even monthly record highs in jeopardy today and Monday. Full sunshine, modest dry southwest flow, and drought conditions that allow all of the sun's energy (even with the much lower October sun angle) to go into heating up the ground and near-surface air. The downslope areas of far southwestern Quebec, eastern Ontario, and central Maine could approach 86F (30C)! Increasing southwesterly wind and clouds will lead to a warmer night Monday night, with parts of the St. Lawrence and Champlain Valleys not even getting below 60F (16C) as the wind stays up all night and gets channeled in the valleys.

 

Source: TropicalTidbits

 

 

Record warmth comes to abrupt end with rain later Tuesday, then much cooler with widespread frost and freeze Wednesday and Thursday nights

 

The summer weather will come to an abrupt end later Tuesday, although most of Tuesday will still be quite warm south of the U.S./Canada border ahead of a strong cold front that will bring widespread modest rain for several hours at any one location, the first rain in almost 2 weeks. The rain will be short-lived, and by Wednesday, another broad dry Canadian surface high-pressure system will be in our region again, but with much cooler air from the northwest. Wednesday and Thursday nights will likely feature the most widespread freeze and frost so far this fall across the region, including even the lower elevations except for urban areas and areas near large bodies of water.

 

Source: TropicalTidbits

 

Warms up and remains dry for weekend into middle of the following week

 

The cooldown will not last long, with the +NAO and +AO allowing for a rather fast-moving weather pattern. The surface high-pressure system will move southeastward into our region by Friday, allowing the cool air mass to become stable and a decent warmup to ensue but with no moisture, a very familiar cycle over the past 2 months with these high-pressure systems. Another upper-level trough will big into the western U.S. next weekend, allowing another persistent upper-level ridge to dominate across eastern North America, a change from model runs just a few days ago, and signaling a delay in any real change in the weather pattern. While it won't be as warm as today and Monday, this means that it will likely remain dry and mostly sunny again for a while through the middle of the following week.

 

Source: TropicalTidbits

 

 

Source: Climate Prediction Center

 

 

Uncertain afterward, but likely more typical autumn temperature swings and at least occasional storminess

  

Afterward, there is considerable model disagreement, as we would expect for so far out. With the PNA, NAO, and AO both rapidly trending towards near zero, allowing for the West trough/East ridge pattern to break down somewhat and also allow subarctic to arctic air to push farther south into the mid-latitudes, it appears unlikely that we will get such long stretches of warm, dry, and sunny weather again. Upper-level troughs and surface low-pressure systems will likely become more frequent, bringing at least occasional rain chances, though it is not clear if these systems will have rich Gulf of Mexico or western Atlantic moisture to dent the drought, or if they will have less moisture with unimpressive rainfall amounts like most recent systems. It also still looks to be warmer than the climatological average overall, but it does appear that there will finally be more frequent and perhaps larger temperature swings more typical of autumn, rather than the consistent warmth or very gradual temperature changes with the huge surface high-pressure systems that we have frequently seen in the past 2 months. However, it is also noteworthy that impressive cold outbreaks that models have shown in the long-range lately have turned out to be short-lived dry, cool spells with continuing and intensifying drought, with any big change to the weather pattern that the models show keep being delayed.

 

Source: TropicalTidbits