8:48PM

The new week starts for some of you while others will be enjoying an extra weekend day on Monday, Columbus Day, but now I’m confused, not about the setup of the week, but the weather that will occur therein. There is some significant disagreement in guidance in the configuration of the jet stream and the timing of weather systems. If you remember my last post, I had a system coming through on Wednesday with wet weather followed by some clearing, then lots of clouds Thursday and better weather Friday. I now am going to lean toward a timing that’s about 24 hours slower, so that fair weather and a warm-up that commences Monday will continue through Wednesday. The wet weather will then come through sometime Thursday with lots of clouds Friday and then fair weather next weekend. But this is lower than average confidence and it will be important to check for updates.

SOUTHEASTERN NEW ENGLAND FORECAST…
TONIGHT: Mostly clear. Patchy valley fog. Lows from 40 deep valleys to 50 coast/urban areas. Calm wind.
MONDAY – COLUMBUS DAY: Sunny to partly cloudy. Highs in the 60s. Wind S 5-15 MPH.
MONDAY NIGHT: Partly cloudy. Lows in the 50s. Wind S 5-15 MPH.
TUESDAY: Partly to mostly cloudy. Highs in the 70s. Wind S 10-20 MPH.
WEDNESDAY: Partly sunny. Low 55. High 75.
THURSDAY: Showers likely. Low 55. High 65.
FRIDAY: Variably cloudy. Low 48. High 62.
SATURDAY: Partly cloudy. Low 45. High 60.
SUNDAY: Mostly sunny. Low 44. High 64.

5:44PM original post
8:50AM Saturday time edit

The weekend is here! And if you are lucky enough to have a 3-day one for Columbus Day then a good portion of this weekend will feature weather that is likely favorable for your plans. The only interruption is the wet start as a wave of low pressure passes south of the region. The timing still looks similar, mainly a morning-midday event. However, it may take into late afternoon for rain to exit Cape Cod and the Islands, so if you are heading there, more patience is required. But that patience will be rewarded with fabulous weather Sunday and Monday not only there but in all locations as high pressure builds in Sunday then offshore Monday. This will allow for a warm up Monday after a crisp/cool Sunday. Whatever your plans, please have a safe weekend!

Looking ahead a little, the warm up that commences Monday will continue Tuesday, and it may get quite a bit warmer than average, depending on the amount of sunshine we have. For now, the forecast will remain unchanged from the previous post, but in the back of your mind you can make note that it may end up warmer than the 74 that is currently there (75-80 potential if enough sun). Still looking like a trough pushes east and sends a front into the region with a band of rain/thunderstorms sometime Wednesday. I believe it will be progressive enough that we may salvage part of Wednesday with some fair and mild weather. It should then turn cooler but not that chilly for later next week with clouds dominant on Thursday as an upper level trough swings through, and sunshine Friday as high pressure builds in. But again, these days are a ways off and there is plenty of time to work out those details.

SOUTHEASTERN NEW ENGLAND FORECAST…
SATURDAY: Cloudy with rain exiting from west to east late morning through early afternoon, from Boston north and west, lingering into later afternoon southeast of Boston especially Cape Cod and the Islands. Clearing northwest of Boston by day’s end. Highs upper 50s to middle 60s. Wind NE to N 5-15 MPH.
SATURDAY NIGHT: Clear. Lows upper 30s to middle 40s. Wind NW 5-15 MPH.
SUNDAY: Sunny. Highs 55-60. Wind NW 5-15 MPH.
MONDAY – COLUMBUS DAY: Partly cloudy. Low 39. High 66.
TUESDAY: Partly cloudy. Low 50. High 74.
WEDNESDAY: AM rain/thunderstorms, PM sun/clouds. Low 55. High 75.
THURSDAY: Variably cloudy. Low 45. High 65.
FRIDAY: Mostly sunny. Low 43. High 63.

5:55PM

No changes to previous discussion and forecast for this post other than to slow the onset of any precipitation from the low pressure wave passing to the south to overnight Friday night instead of late in the day Friday. Still expect whatever is passing by to be moving very rapidly and on the way out by morning or midday Saturday, again with the greatest chance of any rain occurring in southern MA and RI. Still looking for high pressure to move in Sunday with cool and dry weather, followed by a warm-up early next week. A trough from the west will send a band of rain into the region at some point next week, looking like Wednesday at this point. Timing will be fine tuned as we get closer to this event. Looking like an upper low hanging around Thursday with an unstable and cooler day expected.

SOUTHEASTERN NEW ENGLAND FORECAST…
TONIGHT: Few clouds interior MA and southern NH dissipate early while a deck of high clouds crosses the South Coast and Cape Cod. Clear elsewhere. Lows in the 40s except lower 50s urban centers. Diminishing W wind.
FRIDAY: Mostly sunny but increasing high clouds especially southern MA and RI later in the afternoon. Highs in the 60s. Wind light W.
FRIDAY NIGHT: Becoming cloudy. Rain pushes into RI and southern MA overnight. Lows around 50. Wind light variable.
SATURDAY: Cloudy start, rain in southern MA and RI exiting morning-midday, lastly on Cape Cod. Clearing northwest to southeast afternoon. Highs upper 50s to middle 60s. Wind NE to N 5-15 MPH.
SATURDAY NIGHT: Clear. Lows upper 30s to middle 40s. Wind NW 5-15 MPH.
SUNDAY: Sunny. Highs 55-60. Wind NW 5-15 MPH.
MONDAY – COLUMBUS DAY: Partly cloudy. Low 42. High 66.
TUESDAY: Partly cloudy. Low 50. High 74.
WEDNESDAY: AM showers, PM sun/clouds. Low 55. High 75.
THURSDAY: Partly cloudy. Low 45. High 65.

3:52PM

Low pressure moving away in eastern Canada and a small high pressure area trying to build in will bring dry, breezy, and cooler weather through Thursday. A wave of low pressure passing south of the region later Friday to early Saturday will bring some cloudiness and a chance of rain mainly for RI and southern MA. High pressure builds in again later in the weekend then offshore early next week with fair weather, starting cool then followed by a warming trend.

SOUTHEASTERN NEW ENGLAND FORECAST…
TONIGHT: Mostly clear. Lows in the 40s. Wind W 5-15 MPH.
THURSDAY: Mostly sunny. Highs around 60. Wind W 10-20 MPH.
THURSDAY NIGHT: Clear. Lows around 40. Wind W 5-15 MPH.
FRIDAY: Increasing clouds. Chance of rain south PM. Highs 55-60. Wind variable up to 10 MPH.
SATURDAY: Decreasing clouds. Chance of rain south AM. Low 42. High 61.
SUNDAY: Mostly sunny. Low 40. High 60.
MONDAY: Partly cloudy. Low 45. High 65.
TUESDAY: Partly sunny. Low 55. High 70.
WEDNESDAY: Partly sunny. Low 55. High 75.

5:50PM

The focus of this update, even though it will contain a full forecast, is the potential severe weather event for Wednesday morning. I will keep it short and to the point. As broad low pressure passes north of the region across southern Canada and a strengthening second low passes northwest of southern New England, its attendant cold front will swing through the region from west to east in the early to mid morning hours of Wednesday, bringing an area of rain including some embedded heavy showers and thunderstorms.

Time-frame: 3AM-9AM for entire event, though the heaviest rain and strongest wind will be relatively short-lived for any given area. Areas west of Boston from western into central MA and adjacent CT/VT/southwestern NH will see activity in the 3AM-6AM window of time, while eastern MA including the Boston area as well as RI and southeastern NH gets it closer to the 6AM-7AM time. Cape Cod and the Islands will be last to see the activity arrive and depart.

Severe? The risk of torrential rain for at least a brief period of time as high. This would disrupt travel and cause localized flooding. The risk of strong and gusty winds of the straight-line variety is moderate. The risk of a brief tornado is low but cannot be ruled out completely.

What happens after? Once the action is out of here Wednesday morning, the rest of the day will feature sun and passing clouds, drying air, and a gusty breeze, though it will still be mild through the daylight hours as a secondary trough, behind which is the cooler air, will not arrive until later in the day.

Between broad low pressure in eastern Canada and a small high pressure area to the south will be a gusty and cool westerly wind but a nice day for Thursday. Low pressure passing south of the region later Friday to early Saturday will bring some cloudiness and a threat of some rain to at least southern MA and RI. Not sure how far north this gets yet. But I do think it gets out of here for later Saturday and Sunday which will be dominated by high pressure and nice Autumn weather.

Still looks like a warm-up early next week, though the tropical threat looks less. More on this later.

SOUTHEASTERN NEW ENGLAND FORECAST
EVENING: Lots of clouds, partial moonshine as it rises in the east. A shower far west to northwest of Boston. Temperatures in the 60s. Wind S 10-20 MPH.
OVERNIGHT: Heavier clouds arrive from southwest to northeast. Rain and embedded thunderstorms arriving west to east after 2AM, heaviest activity west of Boston after 3AM and Boston area northward and southward by the 6AM hour (see details above). Lows around 60. Wind S to SW 5-15 MPH, higher gusts.
WEDNESDAY: Cloudy start with rain and embedded thunderstorms ending in eastern areas by mid morning. Sunshine and passing clouds mid morning on though lingering clouds/showers Cape Cod mid morning. Highs 65-70. Wind SW 10-20 MPH, strongest gusts, shifting to W.
WEDNESDAY NIGHT: Mostly clear. Lows in the 40s. Wind W 5-15 MPH.
THURSDAY: Mostly sunny. Highs around 60. Wind W 10-20 MPH.
FRIDAY: Increasing clouds. Chance of rain south PM. Low 41. High 58.
SATURDAY: Decreasing clouds. Chance of rain south AM. Low 42. High 61.
SUNDAY: Mostly sunny. Low 40. High 60.
MONDAY: Partly cloudy. Low 45. High 65.
TUESDAY: Partly sunny. Low 55. High 70.

6:08PM

SOUTHEASTERN NEW ENGLAND DISCUSSION…
As a large upper level low pressure continues to spin in east central Canada and the north central USA through the middle of the week, it will send some action our way in the form of developing surface low pressure over the Ohio Valley Tuesday. This low will intensify fairly quickly and move northeastward into the St. Lawrence Valley by Tuesday night then northward deeper into Canada by Wednesday. Its broadening circulation will first send a batch of mild and more humid air into southern New England on Tuesday as a weak warm front moves through during the morning and midday. A few showers may occur with this, but otherwise it will just send lots of clouds through the region. A few bands of showers will form well northwest of Boston during the day but it looks like this activity will never make it further east than southwestern NH and north central MA before it dissipates. The main push of wet weather that is destined for southeastern New England is going to be from an occluded front trailing from the parent low pressure area. This front will swing through the region in the pre-dawn to shortly-after-dawn hours of Wednesday, and will be accompanied by a band of rain and possible thunderstorms, and potentially strong wind gusts. This will be watched as it gets closer to occurring. Once this area crosses, it will be followed by gusty west winds, drying but still mild air during the day, a mix of clouds and sun, and a slight risk of a passing additional shower. By Wednesday evening, it will turn significantly cooler behind a trailing trough. Cool and dry weather is expected Thursday along with a gusty breeze as the broad low pressure area continues to push across southeastern Canada. Friday, a small wave of low pressure will bring more cloudiness and the chance for some light rain, depending on its track. This should move right along and evacuate the region in time for high pressure to move in for the weekend, which looks nice. By the start of next week, this high should be shifting offshore and a warm-up will be underway.

SOUTHEASTERN NEW ENGLAND FORECAST…
TONIGHT: Partly to mostly cloudy. Lows in the 50s. Wind S 10-20 MPH.
TUESDAY: Variably cloudy. Isolated showers through midday. Chance of additional showers far northwest of Boston in the afternoon. Highs upper 60s to lower 70s. Wind S 10-20 MPH with higher gusts.
TUESDAY NIGHT: Variably cloudy. Lows around 60. Wind S 10-20 MPH with higher gusts.
WEDNESDAY: Mostly cloudy with a band of showers and possible thunderstorms west to east early morning, perhaps to mid morning Cape Cod, then mixed sun and clouds with a slight chance of passing showers. Highs around 70. Wind SW 10-20 MPH with higher gusts, possibly strong gusts with passage of rain band, shifting to W 15-30 MPH.
THURSDAY: Sunny to partly cloudy. Lows in the 40s. Highs around 60.
FRIDAY: Cloudy. Chance of light rain. Lows in the 40s. Highs in the 50s.
SATURDAY: Clouds linger southeast, sunnier northwest. Lows in the 40s. Highs in the 60s.
SUNDAY: Mostly sunny. Lows around 40. Highs in the 60s.
MONDAY: Partly cloudy. Lows around 50. Highs around 70.

6:23PM

SNE DISCUSSION…
Some media will probably still try to play up the “big vortex” dominating the weather in the US this coming week. While it’s true that a fairly strong closed-off low pressure area will be the rule, and some of its weather includes early frozen precipitation and cold air (mainly central USA), what it will serve to do for the Northeast is keep the pattern on the mild side, with 2 disturbances passing by, one early Wednesday and another late Friday. Shower threats will exist in advance of and with the passage of each of these (late Tuesday to early Wednesday and again during Friday and Friday night, based on current timing). By the weekend, the closed low will have weakened and lifted northeastward into Canada, being replaced by a strong west-to-east jet stream. By early the following week, things may get a little more interesting once again as the overall pattern will be mild and a little wetter, and with a potential threat from the tropics. Long way off – no worries now. That will be addressed in due time.

SNE FORECAST…
TONIGHT: Clear. Patchy frost far inland valleys. Lows in the 30s inland valleys, 40s elsewhere but around 50 immediate shore and urban areas. Wind W dropping to under 10 MPH, calm in some valleys.
MONDAY: Sunny. Highs in the 60s to near 70. Wind SW 5-15 MPH.
MONDAY NIGHT: Partly cloudy. Lows in the 50s. Wind S 5-15 MPH.
TUESDAY: Variably cloudy. Slight chance of showers mainly far northwest of Boston in the afternoon. Highs from the middle 60s to lower 70s. Wind S 10-20 MPH.
WEDNESDAY: Variably cloudy with scattered showers morning. Partly to mostly sunny afternoon. Lows in the 50s. Highs in the 60s.
THURSDAY: Mostly sunny. Lows in the 40s. Highs in the 60s.
FRIDAY: Mostly cloudy. Showers possible mainly afternoon and night. Lows around 50. Highs in the 60s.
SATURDAY: Partly to mostly sunny. Lows in the 40s. Highs in the 60s.
SUNDAY: Sunny to partly cloudy. Lows in the 40s. Highs in the 60s.

7:29AM

SOUTHEASTERN NEW ENGLAND DISCUSSION…
No big changes to this forecast other than to slow the timing down of the wet weather system for next week a little. Onshore flow continues today but with sun, especially inland, though ocean clouds win the battle late in the day after flirting with the coastline most of the day. By tonight and Saturday, it’s overcast as low pressure approaches from the west, but its rain will first arrive well to the west and hold off from reaching the eastern areas until late in the day and evening. Some drizzle and areas of fog may occur before that due to low level moisture from the ocean. The cold front from the west clears the whole mess outta here by Sunday morning and Sunday will be a great Fall day. Nice weather with a warming trend for next week as the flow turns southwest. Another front crosses the region Wednesday with showers.

SOUTHEASTERN NEW ENGLAND FORECAST…
TODAY: Sun inland, clouds/sun coast, then clouds advancing inland late. Highs from near 60 coast to near 65 inland. Wind NE up to 10 MPH.
TONIGHT: Cloudy. Areas of fog and drizzle overnight. Lows in the 50s. Wind light E.
SATURDAY: Cloudy. Areas of fog and drizzle. A band of rain arriving from west to east late afternoon into the night with a slight risk of embedded thunderstorms. Highs in the 60s. Wind SE 5-15 MPH increasing to 10-20 MPH with higher gusts late.
SUNDAY: Mostly sunny. Low 50. High 60.
MONDAY: Partly cloudy. Low 45. High 65.
TUESDAY: Partly sunny. Low 55. High 70.
WEDNESDAY: Mostly cloudy. Chance of showers. Low 55. High 65.
THURSDAY: Partly cloudy. Low 45. High 60.

12:05AM

SOUTHEASTERN NEW ENGLAND DISCUSSION…
A few days ago, it looked like “a few showers”. But in reality, for at least parts of southern New England, it evolved into a somewhat beneficial rain, all due to low pressure spinning offshore. It’s not a strong storm, but this interaction of upper level energy, surface low pressure, and moisture has delivered some wet weather, not nearly enough to break the minor to moderate drought but helpful to that end. What would be better is more regular rain events. We’ll have some of that, as the overall pattern is evolving to feature a significant trough of low pressure in the Midwest, putting the East Coast including New England on the east side of it, often in an upper level southwesterly flow, combining moisture from the south with disturbances from the west. One such system will cross the region this coming weekend, with another threat early next week. Right now, the former looks more significant and the latter a little less productive. Though some chilly shots of air will be diving out of Canada into the central US in this upcoming pattern, it’s not a particularly chilly pattern for New England, as cool air masses arriving behind departing low pressure systems are often modified by a long trip over a landmass holding leftover Summer warmth.

SOUTHEASTERN NEW ENGLAND FORECAST…
OVERNIGHT: Overcast. Rain likely. Lows in the 50s. Wind NE to N 10-20 MPH.
THURSDAY: Cloudy with rain becoming spotty and diminishing north to south during the morning. Breaking clouds in the afternoon. Highs in the 60s. Wind N 10-20 MPH.
THURSDAY NIGHT: Clearing. Lows 48-55. Wind N 10-20 MPH.
FRIDAY: Sunshine but increasing high clouds late day. Highs in the 60s. Wind E 5-15 MPH.
SATURDAY: Cloudy. Patchy fog and drizzle with a chance of light rain morning and midday. Showers developing from west to east afternoon and evening. Rain and a chance of thunderstorms at night followed by rapid clearing southwest to northeast overnight. Low 56. High 68.
SUNDAY: Mostly sunny. Low 52. High 65.
MONDAY: Partly cloudy. Low 53. High 71.
TUESDAY: Mostly cloudy. Chance of showers. Low 54. High 67.
WEDNESDAY: Partly cloudy. Low 50. High 65.