DAYS 1-5 (APRIL 25-29)

Low pressure moves quickly northeastward, passing southeast of New England today and this evening, bringing some rain, but not as much as it would have had it phased with some energy to its north. But I guess we’ll take what we can get in this deficit situation, although the heaviest will end up falling where it is least-needed, and the areas that need it most will miss out on the higher amounts. Once this gets by us, drier air comes back in overnight and Monday on a gusty north to northwest wind, and fair weather lasts through Tuesday, though that day will be more tranquil as a weak area of high pressure moves across the region. I’m now more accepting of the idea that high pressure is not going to prevent any further unsettled weather through midweek. It won’t be nearly as dominant as previously (and erroneously) indicated by guidance. We will find ourselves in a bit of a battle ground between warmth to the south and cool air to the north, which is definitely not atypical of this time of year either. A warm front will slide into the region late Tuesday night and early Wednesday, and may not completely make it all the way while its parent low pressure area, will be moving rapidly east southeastward and will drag that boundary back across there region as a cold front during Wednesday, a day that will feature lots of clouds and an opportunity for rain showers. There’s a bit of a dilemma for day 5 of this forecast (Thursday). One medium range model takes that system far enough south so that a bubble of Canadian high pressure has enough influence on our region to provide a nice day Thursday, while another model moves the disturbance much more slowly, keeping the frontal boundary and shower chances in the region. For now, I’ll lean toward the drier solution…

TODAY: Cloudy. Rain arriving southwest to northeast during the morning, tapering to drizzle late in the day. Areas of fog. Temperatures steady 47-54 or may fall slightly. Wind S up to 10 MPH this morning shifting to E 5-15 MPH with gusts up to 20 MPH near the coast during the afternoon.

TONIGHT: Lots of clouds with a few patches of drizzle and maybe a rain shower early, then clearing. Lows 37-44. Wind shifting to N 10-20 MPH and gusty.

MONDAY: Sun and passing clouds. Highs 54-61. Wind NW 10-20 MPH with higher gusts.

MONDAY NIGHT: Clearing. Lows 38-45. Wind NW 5-15 MPH.

TUESDAY: Sunny start then some high clouds filtering the sun at times. Highs 65-72. Wind W 5-15 MPH.

TUESDAY NIGHT: Variably cloudy. Brief light rain possible mainly northern MA and southern NH overnight. Lows 48-55. Wind S up to 10 MPH.

WEDNESDAY: Mostly cloudy. Chance of rain showers. Highs 67-74. Wind W 5-15 MPH.

WEDNESDAY NIGHT: Mostly cloudy with a chance of rain showres evening. Clearing overnight. Lows 45-52. Wind N 5-15 MPH.

THURSDAY: Partly sunny. Highs 58-65, coolest coast. Wind NE 5-15 MPH.

DAYS 6-10 (APRIL 30 – MAY 4)

Since we already have uncertainty as to the position of weather systems and the resultant weather here just 5 days into the forecast, going forward from there will be fairly low confidence as well, as one will impact the other to some degree. Today’s guidance is somewhat similar to what was indicated yesterday, which was a notable shift in the overall set-up from what was being shown previously, so this forecast, while low confidence, will be based on that idea being at least somewhat in the ballpark of accuracy. We’ll be near a boundary with cool air in eastern Canada and a warm US Southeast (where have we heard that before?) and this will bring a few opportunities for unsettled weather, which we can hope will bring us some beneficial rainfall. As far as day-to-day timing of such possibilities, that will have to be fine-tuned as we get closer to this time frame.

DAYS 11-15 (MAY 5-9)

Adjustment to this forecast period based on the above idea, and thinking that the overall pattern will leave us near the aforementioned boundary, with no real indication of a major change in the pattern from the 6-10 day period. As always, will be paying attention to the guidance trends and overall pattern in general to bring these days into better forecast focus once it is possible to do so.

C-19 Chat Post – April 25 2021

DAYS 1-5 (APRIL 24-28)

Short discussion today so you can get outside to enjoy the one nice day in the weekend split! High pressure is now offshore of the Middle Atlantic and will provide our area with a very nice spring today today before low pressure spoils the second half of the weekend with overcast and wet weather. The pluses about the low pressure area will be that any rainfall we get helps, though this still does not look like a system that will reach its maximum potential as it will be moving quickly and not really linking up with energy passing north of here until they are both well beyond the region. Monday will be our blustery day behind the low and ahead of approaching high pressure. High pressure sits atop the region Tuesday with fair weather. There’s a little question in the forecast today as to whether or not that longer stretch of dry weather takes place without interruption. I hesitate to buy into it too quickly but it is showing up on a few sets of guidance, and that is a frontal boundary from the north approaching by Wednesday, which would be at least clouds and possibly a shower threat. I’m only going to nibble on this a bit for today’s forecast then re-evaluate. If something like that did happen it would be an example of guidance often being questionable beyond day 3, and is also typical for springtime anyway.

TODAY: Sun and high clouds. Highs 67-74, cooler Cape Cod and a few other coastal areas. Wind W 5-15 MPH.

TONIGHT: Increasing clouds. Lows 47-54. Wind S up to 10 MPH.

SUNDAY: Cloudy. Rain arriving southwest to northeast during the morning, tapering to drizzle late in the day. Areas of fog. Temperatures steady 47-54 or may fall slightly. Wind E 5-15 MPH with gusts around 20 MPH.

SUNDAY NIGHT: Clearing. Lows 37-44. Wind N 10-20 MPH and gusty.

MONDAY: Sun and passing clouds. Highs 54-61. Wind NW 10-20 MPH with higher gusts.

MONDAY NIGHT: Clearing. Lows 38-45. Wind NW 5-15 MPH.

TUESDAY: Sunny. Highs 65-72. Wind W 5-15 MPH.

TUESDAY NIGHT: Partly cloudy. Lows 48-55. Wind W 5-15 MPH.

WEDNESDAY: Partly sunny. Highs 67-74. Wind W 5-15 MPH.

DAYS 6-10 (APRIL 29 – MAY 3)

A considerable shift in guidance between yesterday and today regarding the weather for the last couple days of April and first few days of May. Previous indications were for high pressure to sit over the region with dry and warm (cooler coast) conditions to end April then low pressure to evolve and sit south of the region with a cooler more general easterly flow developing but a struggle for any rain to get this far north. Today’s guidance likes the idea of a frontal boundary nearby with a battle between 2 high pressure areas, one to the south, one to the north, more cloudiness here, and at least some risk of a couple episodes of wet weather for the last couple days of April, and this pattern remaining in place into the first few days of May as well. I’m not sold on this yet, even though it shows up on more than one model. Leaning toward scenario number 1 for this update. Re-evaluation tomorrow.

DAYS 11-15 (MAY 4-8)

It goes without saying since I am not making any big changes in the 6-10 day forecast period that I will leave this section alone for now as well. Expecting low pressure to the south but whether it comes far enough north for occasional wet weather is not certain. This forecast will also have to be re-evaluated for the next update.

C-19 Chat Post – April 24 2021

DAYS 1-5 (APRIL 23-27)

Alright, you got by the “retro-winter” day yesterday with temperatures in the upper 30s and 40s, gusty wind, and snow showers around. Today will be a piece of cake, despite still being on the windy side. With much more sunshine today, but still a few passing clouds later, after a cold morning we’ll see a decent temperature recovery so that some areas reach 60 this afternoon. This will be occurring as low pressure pulls further away in eastern Canada and a high pressure area slides across the Mid Atlantic region, then offshore by tomorrow when we warm up even more. Low pressure will be approaching the region quickly though and will impact Sunday, making it a weekend split for weather. But the trends on recent guidance have done with this system what a lot of systems have done, and the indication is that this low will have a slight disconnect with energy it could phase with to its north, and be moving rather quickly, not quite maximizing its potential for precipitation. We’ll still get some beneficial rain from it, just not as much. Either way, that system is gone by Monday, a day which will be about half way between yesterday’s weather and today’s weather, cool and breezy, but not too cold, and without the snow showers – just dry weather with a sun/cloud mix. By next Tuesday, we’ll be in what will be the start of a new blocking pattern when things slow down again, once again with high pressure on top of us – the start of a dry & warmer stretch of weather…

TODAY: Sun & passing clouds. Highs 55-62. Wind W 10-20 MPH, gusts up to 30 MPH.

TONIGHT: Mostly clear. Lows 38-45. Wind SW 5-15 MPH.

SATURDAY: Sun and high clouds. Highs 65-72, cooler South Coast. Wind SW 5-15 MPH.

SATURDAY NIGHT: Increasing clouds. Lows 47-54. Wind S to SE 5-15 MPH.

SUNDAY: Cloudy. Rain likely. Temperatures steady 47-54 or may fall slightly. Wind E 10-20 MPH and gusty.

SUNDAY NIGHT: Cloudy with lingering drizzle and possible rain showers early, then breaking clouds overnight. Lows 37-44. Wind N 10-20 MPH and gusty.

MONDAY: Partly sunny. Highs 54-61. Wind NW 10-20 MPH with higher gusts.

MONDAY NIGHT: Clearing. Lows 38-45. Wind NW 5-15 MPH.

TUESDAY: Sunny. Highs 65-72. Wind W 5-15 MPH.

DAYS 6-10 (APRIL 28 – MAY 2)

A weak blocking pattern is expected with high pressure parked over the East Coast, resulting in fair and warmer than normal weather April 28-30, with some coastal areas being cooler each day. Low pressure may position itself south of New England by the first couple of days of the new month, turning the wind more easterly here which would cool things down somewhat, but not quite sure how quickly this evolution will take place yet.

DAYS 11-15 (MAY 3-7)

A general blocking pattern should remain in place, but slow movement of weather systems will occur and we’ll watch for low pressure to the south should it come far enough north to finally produce some rainfall again…

C-19 Chat Post – April 23 2021

DAYS 1-5 (APRIL 22-26)

Happy Earth Day 2021! Take care of our planet! It is our only home…. Well, this year’s edition of Earth Day here in southeastern New England may as well be on a day in late February or early March for how it’s going to feel. The last couple days’ taste of the warmer side of spring, ending with yesterday’s showers and thunderstorms, is now a memory as we’ve had a strong cold front pass by, opening the door to a strong shot of polar air from Canada on gusty northwesterly winds. The mechanism pulling this air into our region at the surface is the pressure gradient between the now stronger low pressure wave that went by us yesterday as it travels through eastern Canada and a high pressure area sliding southeastward from the Ohio Valley toward the Middle Atlantic States. Other than a narrow ocean-effect band of stratocumulus clouds just north of the tip of Cape Cod, and some strips of similar clouds from the mountains making it into southwestern NH, central MA, and one closer to the South Coast, much of the region is starting out with sunshine despite the blustery and cold conditions, but there is plenty of even colder air aloft and not only will we have additional cumulus & stratocumulus clouds coming in from the northwest today, but additional clouds will fill in any clear spaces as the sun heats the ground below. This is a process we see on a fairly regular basis here in the Northeast, and it most frequently happens in spring and sometimes autumn. There will be enough instability that a few rain and even snow showers may fall from some of these clouds as we go through the day and into early this evening, before they finally start to break up and dissipate. Friday’s weather will still feature a gusty breeze, though less strong that today, and we’ll have more sunshine as a downsloping westerly wind will dry the air and warmer air above leads to less cloud development. As high pressure moves offshore during Saturday we’ll see the wind flow go from west to southwest and we’ll warm nicely, except for typical cooler South Coast regions. But with things on the move with this week’s zonal pattern, the next low pressure area will be making a run at the region by Sunday, which looks like a wet, windy, and chilly day, but any rain is needed, as we remain in a significant deficit. This system will move beyond the region by Monday, a day that will be breezy and drier but on the cool side as well…

TODAY: Sun/cloud mix morning. Mostly cloudy afternoon with a passing rain or snow shower possible, favoring southern NH and northern MA. Highs 43-50. Wind NW 15-25 MPH, gusts 30-40 MPH.

TONIGHT: Variably cloudy. Slight chance of a rain or snow shower early. Lows 28-35. Wind W 10-20 MPH and gusty, diminishing overnight.

FRIDAY: Partly sunny. Highs 55-62. Wind W 10-20 MPH, gusts up to 30 MPH.

FRIDAY NIGHT: Mostly clear. Lows 40-47. Wind SW 5-15 MPH.

SATURDAY: Sun and high clouds. Highs 65-72, cooler South Coast. Wind SW 5-15 MPH.

SATURDAY NIGHT: Increasing clouds. Lows 47-54. Wind S to SE 5-15 MPH.

SUNDAY: Cloudy. Rain likely. Temperatures steady 47-54 or may fall slightly. Wind E 10-20 MPH and gusty.

SUNDAY NIGHT: Mostly cloudy. Lingering drizzle and possible rain showers early. Lows 40-47. Wind N 10-20 MPH and gusty.

MONDAY: Partly sunny. Highs 52-59. Wind NW 10-20 MPH with higher gusts.

DAYS 6-10 (APRIL 27 – MAY 1)

Zonal (west to east) flow pattern starts to transition to blocking again… Similar to a recent blocking pattern, we’ll be on the dry side of it with high pressure dominating our weather with mild to warm days which will feature coastal sea breezes at times.

DAYS 11-15 (MAY 2-6)

A general blocking pattern should remain in place, but slow movement of weather systems will occur and we may end up with low pressure south of our region and an increased chance for cloud cover and eventually rainfall. Low confidence outlook at this time.

C-19 Chat Post – April 22 2021

DAYS 1-5 (APRIL 21-25)

The changeability of New England’s spring weather can be showcased in many ways. Yesterday in speaking with a friend on social media, I noted that one such example of the upcoming swings will be that some locations that reached or exceeded 70 yesterday may see a snow shower Thursday evening with wind chill in the 20s, only to be back near 70 again Saturday. When the first bubblings of the coming summer’s heat start to build in the South, and winter’s lingering cold and snow cover try to hang on in Canada, they often meet somewhere between, and our region is definitely somewhere in between. We live in a meteorological battleground, and while this can be seen numerous times throughout the year, it’s often most vividly displayed in the springtime. And here we are now. This next showcase of variability will be started as a frontal boundary, the one that entered from the west as a cold front that promptly came to a halt over the region and slid back to the north as a warm front, becomes the atmospheric running board for a low pressure wave today. This low will track just northwest of the WHW forecast area, across northern New England. On our side of the boundary resides mild air, for now, and the low pressure areas and the contrast across the front from our mild side to a much colder air mass on the other side, will result in a more widespread ribbon of showery rainfall that will be preceded by isolated rain showers. Once the main shower area gets here it may have a thunderstorm or two embedded in it, but mainly this will just be a gusty rain shower episode later today into this evening. The snow that has been falling across much of the Midwest behind the front is going to head across northern New England, giving the mountains a bit of snow for a little more spring skiing, and while that area will miss our area, the cold air behind the front will not miss. We’ll see a significant temperature tumble from today’s mild readings to air that feels more like February or March on Thursday, which is ironically Earth Day. Not a great day for an Earth Day picnic – sorry! Blustery, chilly, sun to start then lots of clouds. Some of those clouds may even produce a rain or snow shower, favoring the hilly terrain west and north of Boston, by later Thursday. The gusty wind will be the result of the air pressure difference between departing low pressure in eastern Canada and a high pressure area sliding southeastward from the Ohio Valley to the Middle Atlantic States. This high will move across the Middle Atlantic and offshore during Friday and Saturday. During that time we will see the wind relax and shift to the west Friday and southwest Saturday, resulting in a warming trend with dry weather. Another low pressure area will be trekking eastward in a now zonal (west to east) flow pattern, and it’s destined to bring our next shot at much needed rainfall for the second half of the upcoming weekend. More details on this system as we get a little bit closer to the event…

TODAY: Partly sunny through early afternoon with isolated rain showers. Mostly cloudy mid through late afternoon with widespread rain showers and possibly a thunderstorm arriving from west to east. Highs 55-62 South Coast, 63-70 elsewhere. Wind S increasing to 10-20 MPH, gusts to 30 MPH.

TONIGHT: Cloudy with numerous rain showers evening. Clearing west to east overnight. Lows 32-39. Wind shifting to NW 15-25 MPH, gusts 30-40 MPH.

THURSDAY: Sunny start, then lots of clouds. A rain or snow shower possible mainly hills north and west of Boston by mid to late afternoon. Highs 43-50. Wind NW 15-25 MPH, gusts 30-40 MPH.

THURSDAY NIGHT: Variably cloudy. Slight chance of a rain or snow shower early. Lows 31-38. Wind W 10-20 MPH and gusty.

FRIDAY: Partly sunny. Highs 50-57. Wind W 10-20 MPH, gusts up to 30 MPH.

FRIDAY NIGHT: Mostly clear. Lows 40-47. Wind SW 5-15 MPH.

SATURDAY: Sun and high clouds. Highs 65-72, cooler South Coast. Wind SW 5-15 MPH.

SATURDAY NIGHT: Clouding up. Lows 47-54. Wind S to SE 5-15 MPH.

SUNDAY: Cloudy. Rain likely. Highs 50-57. Wind E 10-20 MPH and gusty.

DAYS 6-10 (APRIL 26-30)

Zonal (west to east) flow pattern starts to transition to blocking again… Drier/breezy/cool April 26 as low pressure departs and high pressure builds toward the region from the west. High pressure may sit over the area for several days thereafter ending April with a dry stretch, temperatures trending milder but coolest along the coast much of the time.

DAYS 11-15 (MAY 1-5)

Favoring continued blocking with the region staying mostly dry with near seasonable temperatures, but it won’t take much to completely change this outlook, so it’s low confidence.

C-19 Chat Post – April 21 2021

DAYS 1-5 (APRIL 20-24)

Very pleasant spring days start and end this 5-day forecast period. In between, we have some spring volatility to go through. First, we begin with high pressure centered to the south of New England and a nice mild air mass in place today. But a cold front will be charging eastward trailing from low pressure moving across southeastern Canada. But this front is running out of steam and will be sputtering out as it moves into New England this afternoon and early evening, only bringing us some clouds and the slight chance of a few rain showers into the region, especially northwest of I-95. This frontal boundary will then pull back to the north as a warm front early Wednesday as low pressure forms in the Upper Ohio Valley and western Pennsylvania and then travels northeastward into northern New England. This will bring one more push of mild air into our region Wednesday but with an increased rain shower threat as this frontal boundary gets pulled eastward from this second low pressure area. The front by then will have quite a sharp temperature contrast across it, with snow on the back side. But that snow is destined for northern New England, not the WHW forecast area in southeastern New England. However once the rain showers (and possibly a thunderstorm) cross this area later Wednesday, the cold air behind the front will waste no time getting in here, along with plenty of wind. So as we observe Earth Day on Thursday, we will do so with a cold air mass in place, a gusty wind, and probably sun followed by lots of clouds. I do think rain and snow showers will be confined mostly to the mountains west and north of this area, but can’t rule out one or two wandering into this area later in the day or during the evening. By Friday, the cold relaxes a little as the wind goes more westerly around northern side of high pressure which will be sliding eastward across the Mid Atlantic States. By Saturday, this high will be offshore and we’ll be in a warmer southwesterly air flow with the timing of the next trough slow enough that while we may end up seeing cloudiness moving in, it should stay rain-free, making it quite the nice start to the weekend.

TODAY: Sunny start, then a sun/cloud mix. A passing rain shower possible mainly west and north of Boston during the afternoon to early evening. Highs 57-64 South Coast region, 65-72 elsewhere. Wind SW 5-15 MPH with higher gusts.

TONIGHT: Variably cloudy. Slight chance of a rain shower, mainly southern NH and northern MA early. Lows 41-48 I-95 belt northwestward, 49-54 elsewhere. Wind SW 5-15 MPH shifting to W-NW then becoming variable.

WEDNESDAY: Variably cloudy with isolated rain showers through mid afternoon. Mostly cloudy with rain showers and possible thunderstorms arriving west to east later in the day. Highs 63-70 except 55-62 South Coast. Wind SW 10-20 MPH, higher gusts.

WEDNESDAY NIGHT: Mostly cloudy evening with rain showers ending west to east. Clearing overnight. Lows 32-39. Wind NW 15-25 MPH, gusts 30-40 MPH.

THURSDAY: Sunny start, then lots of clouds. Highs 43-50. Wind NW 15-25 MPH, gusts 30-40 MPH.

THURSDAY NIGHT: Variably cloudy. Slight chance of a rain or snow shower. Lows 31-38. Wind W 10-20 MPH and gusty.

FRIDAY: Partly sunny. Highs 50-57. Wind W 10-20 MPH and gusty.

FRIDAY NIGHT: Mostly clear. Lows 40-47. Wind SW 5-15 MPH.

SATURDAY: Increasing clouds. Highs 65-72, cooler South Coast. Wind SW 5-15 MPH.

DAYS 6-10 (APRIL 25-29)

Expecting mostly zonal (west to east) flow in the large scale pattern… Significant rain event is possible for April 25 due to passing low pressure along with below normal temperatures. Turning mostly dry as high pressure builds in for several days after, a warming temperature trend but very likely cooler at the coast most of those days.

DAYS 11-15 (APRIL 30 – MAY 4)

Pattern may evolve into a blocking set-up again with trough western US, ridge east central US, and trough off the US East Coast. The idea in this pattern would be for cool / dry overall. Not high confidence, but something to watch as several influences still have to be considered.

C-19 Chat Post – April 20 2021

DAYS 1-5 (APRIL 19-23)

As we begin another week we find ourselves in a continued active weather pattern. We have milder to warmer air moving into the region today into Tuesday. But it is still cold enough aloft for an unstable atmosphere, and this will be aided further by a small but potent disturbance moving eastward into southern New England later today through this evening, triggering the development of a few showers and possible thunderstorms. Not expecting widespread activity or any severe weather with this though. Tuesday, low pressure moves rapidly eastward across southeastern Canada and sends a cold front toward the region. We’ll warm up nicely ahead of this front, which will barely make it across part of the region before it comes to a halt and is pulled back to the north as a warm front ahead of another approaching low pressure area. This low will also pass north of our area Wednesday, pushing a sharper frontal boundary into and eventually across the region, maybe needing to wait for an additional low pressure wave to form and move along it. This day will bring our best chance of widespread rainfall over the next 5, in the form of a solid band of rain showers ahead of the front, maybe with an embedded thunderstorm. The snow that will be on the back side of this front as it is travelling through NY will be destined for northern New England, not the WHW forecast area. But we will be visited by the cold air behind the front, along with wind, for Wednesday night through Thursday. We may see a decent amount of cloud development Thursday due to even colder air aloft, but right now I’m leaning toward any disturbance passing by to not be enough to produce the rain and snow showers I had previously mentioned, so going with a dry forecast. High pressure builds across the Mid Atlantic States by Friday, so we’ll still be breezy here between it and low pressure in eastern Canada, but not as windy as Thursday, and a little less chilly as well…

TODAY: Partly sunny. A late day shower or thunderstorm possible mainly west of Boston (eastern CT, RI, central MA most likely locations). Highs 54-61 South Coast, 61-68 elsewhere. Wind SW 5-15 MPH.

TONIGHT: Partly cloudy. Chance of a shower or thunderstorm early evening. Lows 40-47. Wind SW 5-15 MPH.

TUESDAY: Partly cloudy. Highs 57-64 South Coast region, 65-72 elsewhere. Wind SW 5-15 MPH with higher gusts.

TUESDAY NIGHT: Partly cloudy. Lows 41-48 I-95 belt northwesward, 49-54 elsewhere. Wind SW 5-15 MPH shifting to W-NW for a while overnight.

WEDNESDAY: Partly sunny early then becoming mostly cloudy. Numerous showers arriving west to east and a slight chance of a thunderstorm. Highs 62-69 except cooler South Coast. Wind SW 10-20 MPH.

WEDNESDAY NIGHT: Rain showers move out, partial clearing follows. Lows 32-39. Wind NW 15-25 MPH.

THURSDAY: Partly sunny then mostly cloudy. Highs 43-50. Wind NW 15-25 MPH.

THURSDAY NIGHT: Variably cloudy. Lows 30-37. Wind W 10-20 MPH and gusty.

FRIDAY: Partly sunny. Highs 50-57. Wind W 10-20 MPH and gusty.

DAYS 6-10 (APRIL 24-28)

A zonal (west to east moving) weather pattern is expected to be dominant. Iffy on timing of low pressure and a rain chance in the April 24-25 window, leaning toward late April 24 to early April 25 but subject to change. Drier, chilly behind that, then moderating temperatures by later in the period as Canadian high pressure eventually sinks southeastward to the Mid Atlantic.

DAYS 11-15 (APRIL 29 – MAY 3)

Idea for now is that a zonal pattern will continue, but again we’ll need to watch for rapid reconfiguration of the pattern including the possibility of a return to blocking. Will monitor for the interaction of the former western Pacific typhoon energy with the jet stream heading into North America.

C-19 Chat Post – April 19 2021

DAYS 1-5 (APRIL 18-22)

It’s been a “slow improvement” weekend as we were expecting, and today will definitely be better than yesterday, but don’t expect full sunshine. With cold air aloft and yet another disturbance to pass by, we’ll still see lots of clouds at times, and possibly another passing rain shower or two. But overall, not a bad mid April day in comparison to the last couple of days. Still on track for the early-week warming but there are a couple of forecast wrinkles to deal with today. First, a small but vigorous disturbance which I hadn’t sniffed out as of yesterday’s update reveals itself to be a shower and thunderstorm threat late Monday afternoon or early Monday evening as it works on some moisture and instability in the region. This small feature will be moving fairly quickly eastward and has the ability to trigger a shower or storm in a few locations especially near and south of I-90, favoring eastern CT, RI, and adjacent southern MA, late in the day Monday. And then a low pressure area moving rapidly eastward across southeastern Canada will send a cold front toward the region Tuesday. It will still be mild ahead of this front, but I’m not quite sure yet how far east that boundary comes. So the mild day may be replaced by a chilly evening or nighttime for areas at least north and west of Boston. We’ll have to monitor that front. I do think that any rain shower activity with that initial front will stay to the north of us. Stronger low pressure trailing this one moves eastward and its center will also pass north of us by Wednesday evening, but this time there will be more moisture available, so I’m expecting a decent round of rain showers sometime Wednesday between the middle of the day and the evening. This day will still be mild ahead of the cold front, but a sharp temperature drop is likely to occur with the passage of that front, setting us up for a blustery and chilly Earth Day on Thursday, possibly with lots of cloudiness on the back side of what will then be pretty strong low pressure in eastern Canada. We may even see some scattered rain and/or snow showers on that day…

TODAY: Variably cloudy – times with more sun, times with more cloudiness. Chance of a passing rain shower but dry conditions most areas most of day. Highs 53-60. Wind W 5-15 MPH.

TONIGHT: Variably cloudy. Lows 40-47. Wind W 5-15 MPH.

MONDAY: Partly sunny. A late day shower or thunderstorm possible mainly southwest of Boston (eastern CT, RI, south central MA most likely locations). Highs 54-61 South Coast, 61-68 elsewhere. Wind SW 5-15 MPH.

MONDAY NIGHT: Partly cloudy. Chance of a shower or thunderstorm early evening mainly southwest and south of Boston. Lows 45-52. Wind SW 5-15 MPH.

TUESDAY: Partly cloudy. Highs 57-64 South Coast region, 65-72 elsewhere. Wind SW 5-15 MPH with higher gusts.

TUESDAY NIGHT: Partly cloudy. Lows 41-48 northwest of Boston, 49-54 elsewhere. Wind SW 5-15 MPH may shift to NW north and west of Boston.

WEDNESDAY: Variably cloudy. Rain showers arriving from west to east during the day. Highs 61-68 except cooler South Coast. Wind SW 10-20 MPH.

WEDNESDAY NIGHT: Rain showers move out, partial clearing follows. Lows 32-39. Wind NW 15-25 MPH.

THURSDAY: Partly sunny then mostly cloudy. A chance of rain and/or snow showers. Highs 41-48. Wind NW 15-25 MPH.

DAYS 6-10 (APRIL 23-27)

A zonal (west to east moving) weather pattern is expected to be dominant, but with the mean trough position being in eastern Canada and the Great Lakes to northeastern US with the tendency for temperatures below normal. Best chance of wet weather comes from a disturbance about April 24.

DAYS 11-15 (APRIL 28 – MAY 2)

The idea is for a similar pattern to continue, mostly west to east flow, but we do have to watch for rapid evolution of blocking pattern at any time. For now, overall idea is below normal temperatures and drier than average. Added pattern volatility potential from the interaction of a former western Pacific typhoon as its post-tropical remains interact with the jet stream heading into North America.