Friday April 30 2021 Forecast (7:09AM)

DAYS 1-5 (APRIL 30 – MAY 4)

The story’s the same. We’ll be dealing with a frontal boundary in the area for days to some. But today as the third in a series of disturbances in this stretch moves away from the region, it’s going to be intensifying significantly, and resulting in quite a bit of wind. This air coming from the west will dry us out after yesterday’s wet weather. Yesterday’s rainfall amounts were heaviest north of I-90, but this was an area that needed it more than areas along the South Coast, so in general this was quite good. After a milder day today due to the air flow coming from land, a cold front will pass through the region this evening, shifting the wind to northwest, and a secondary trough will follow that, with a band of rain and even some snow showers as it will be getting marginally cold enough at the surface and definitely cold enough aloft to support this. No snow accumulation will occur, but technically there may be some areas that see very early May flakes with this happening after midnight. During the day Saturday it will start out quite windy and chilly with a sun/cloud but the wind will relax. But already by afternoon we’ll be seeing high and mid level clouds racing back in from the west ahead of that frontal boundary which will already be heading back in this direction as a warm front ahead of another low pressure disturbance. This races by Saturday night and pulls the front back south again, maybe with a few showers around, but not cold enough air for any mix/snow this time, and then the front sits right in the area Sunday into early next week, with the last few days of this forecast carrying a fair amount of uncertainty, dependent on the position of the boundary and the timing of disturbances moving along it…

TODAY: Variably cloudy. A passing rain shower possible. Highs 58-65. Wind W increasing to 10-20 MPH but gusting 30-40 MPH at times by afternoon.

TONIGHT: Variably cloudy. A passing rain or snow shower possible overnight. Lows 35-42. Wind NW 15-25 MPH, gusts 35-55 MPH, strongest in highest elevations.

SATURDAY: Partly sunny. Highs 55-62. Wind NW 10-20 MPH, diminishing and shifting to W.

SATURDAY NIGHT: Mostly cloudy. Light rain possible overnight. Lows 44-51. Wind variable 5-15 MPH.

SUNDAY: Mostly cloudy. Slight chance of rain. Highs 57-64. Wind variable 5-15 MPH.

SUNDAY NIGHT: Variably cloudy. Slight chance of rain. Lows 47-54. Wind variable to W 5-15 MPH.

MONDAY: Variably cloudy. Highs 55-62 southern NH and northeastern MA, 63-70 elsewhere. Wind variable 5-15 MPH.

MONDAY NIGHT: Variably cloudy. Chance of rain showers. Lows 48-55. Wind variable 5-15 MPH.

TUESDAY: Mostly cloudy. Chance of rain. Highs 55-62. Wind variable 5-15 MPH.

DAYS 6-10 (MAY 5-9)

For now it looks like a similar pattern with a boundary hanging in the New England area, variable temperatures and episodes of unsettled weather but not possible to time individual rain threats and specific milder or cooler days.

DAYS 11-15 (MAY 10-14)

Overall pattern similar to start then may break down into a more conventional west-to-east moving weather pattern with time.

Thursday April 29 2021 Forecast (8:27AM)

DAYS 1-5 (APRIL 29 – MAY 3)

A frontal boundary will be spending most of its time in or at least close enough to have significant impact on the weather in the southeastern New England region (aka the WHW forecast area) during this entire 5-day period. It’s already played havoc with my own forecast made just yesterday morning, within hours of me posting it, when it became sunnier and warmer than I thought just a few hours in advance. I don’t think too many people will complain about a nicer spring day than had been expected, so there is that! My idea had been that today would turn out like yesterday did, and yesterday would have been more like today is likely to be. I don’t think I’m going to get surprised with nice weather today though, as the overcast will be hanging around and there will be an increasing chance of rain showers as we go through the day, so that by later this afternoon wet weather is pretty widespread across the region. This in response to the third in a series of disturbances / low pressure waves riding along the frontal boundary, which separates Canadian coolness from springtime warmth to the south. Model indications have been that if we’re going to bust into the warmer air on the other side, that we may have to wait until Monday, but yesterday that was a day 6 forecast, and do I need to repeat how those can go? Today’s guidance is not so sure about the Monday warmth, with some models “deciding” that the frontal boundary is going to stay down to the south. From a pure temperature forecasting standpoint, this could make a difference of at least 20 degrees in the temperature at some locations. Just for an example, a warm push on Monday with a west or southwest wind could drive Boston’s temperature toward 80, while being on the other side of the boundary with an east or northeast wind could hold them closer to 55 or even lower, depending on cloud cover. So not only does the forecast challenge include timing and coverage of any precipitation, but also taking into account temperature and wind direction based on the forecast position of that front. Rewind a bit to Friday. After today’s general onshore flow keeps it cool, we get “milder” for a while as the wind flow shifts to a strong land breeze during Friday, with many areas breaking 60 for high temperatures. But did you notice I said “precipitation” and not just “rain” earlier? Yes, there is a reason. On Friday, when the third disturbance pulls away from the region, it will be intensifying and there will also be a lot of cold air aloft with an upper level disturbance that still has to make its way through the region. A lobe or two of energy rotating around the back side of the departing low will create some showers, and these can fall as rain, mix, or snow during the late night hours of Friday and early morning of Saturday. This will likely be dependent on elevation and/or intensity of precipitation. So while it’s highly unlikely anybody will see accumulating snow, it is distinctly possible that parts of the region may see very early May flakes. During the day Saturday we’ll see nothing more than a passing additional rain shower in a few locations, otherwise it should be dry but breezy and rather chilly for the start of May. Many times when we have a day like that, the next day is likely to be tranquil and somewhat milder as high pressure builds in. Nope. Not this time. This is such a fast-moving pattern right now and the frontal boundary is not getting that far south of us Saturday that it’s ready to be pulled back northward Sunday by another approaching disturbance. It’s going to be tough to time this one for a couple days, until we get closer. Some guidance has it moving more rapidly than other guidance. But the idea is that Sunday will likely feature a fair amount of cloudiness and possibly the threat of some light rainfall at some point. And this leads us to the day 5 dilemma for Monday. A faster-moving disturbance would drag the boundary back to the south during Sunday and yet another approaching disturbance from the west could push it back to the north Monday, at least giving us a shot at getting into the warm air. A slower-moving disturbance would drag the front back to the south as it departed Sunday night into Monday, making it more likely we’d be on the cooler side for Monday. This is one of those times when I am just going to say I have no idea how this is really going to play out yet, so I’ll write the forecast below to cover this uncertainty as best I can and then re-evaluate for the next update. That’s about all I can do from a forecasting standpoint right now…

TODAY: Cloudy. Isolated to scattered rain showers through early afternoon. Scattered to numerous rain showers becoming widespread by late day including a slight chance of thunderstorms. Areas of fog. Highs 48-55 eastern coastal areas and Cape Cod, 56-63 elsewhere. Wind E up to 10 MPH.

TONIGHT: Cloudy, areas of fog, widespread rain showers with a chance of thunderstorms evening. Mostly cloudy with scattered rain showers overnight. Lows 45-52. Wind E up to 10 MPH evening, N 5-15 MPH overnight.

FRIDAY: Variably cloudy. A passing rain shower possible. Highs 58-65. Wind NW 10-20 MPH but gusting 30-40 MPH at times.

FRIDAY NIGHT: Variably cloudy. A passing rain or snow shower possible overnight. Lows 35-42. Wind NW 15-25 MPH, higher gusts.

SATURDAY: Sun/cloud mix. A brief rain shower possible. Highs 52-59. Wind NW 10-20 MPH with higher gusts.

SATURDAY NIGHT: Mostly cloudy. Light rain possible overnight. Lows 40-47. Wind variable 5-15 MPH.

SUNDAY: Mostly cloudy. Slight chance of rain. Highs 52-59. Wind variable 5-15 MPH.

SUNDAY NIGHT: Variably cloudy. Slight chance of rain. Lows 43-50. Wind variable to W 5-15 MPH.

MONDAY: Partly sunny. Highs 60-67 southern NH and northern MA, 68-75 to the south except cooler parts of South Coast. Wind variable to SW 5-15 MPH.

DAYS 6-10 (MAY 4-8)

Oh goodie! More uncertainty as it appears we’ll have a frontal boundary in our vicinity much of the time. Best chance of “warm” is very early in the period, otherwise leaning cooler with episodes of unsettled weather.

DAYS 11-15 (MAY 9-13)

Overall pattern similar, frontal boundary tends to hang nearby with episodes of unsettled weather and variable temperatures averaging not that far from normal.

Wednesday April 28 2021 Forecast (7:40AM)

DAYS 1-5 (APRIL 28 – MAY 2)

The frontal boundary that I’ve talked about for several days now made its first announcement of arrival with a very nice sunrise on Tuesday morning, and continued to show itself with a fair amount of mid and high level cloudiness yesterday morning and early afternoon, which then thinning out for a very nice latter portion of the day. But overnight, those clouds came back, and this time they brought with them areas of showers, and even some thunder (especially across far southern MA, parts of eastern CT and RI. This was not a surprise as it was evident there would be enough instability for this potential, and it was realized. There are still a few showers in the region early this morning, and a few more may travel through the area during the course of the morning before we see less showers and just a dominant overcast. But as that frontal boundary sits over the region, another couple of low pressure disturbances will move along it as it wavers around. The next disturbance will come through tonight, with another round of showers and the potential for thunder, with that potential highest near the south of I-90. The most pronounced low pressure wave of the series will be the one that moves across the region Thursday night and Friday. Most short range guidance indicates that the center of this low may track just to the north of the WHW forecast area, perhaps across southern VT and central NH into Maine before departing. However even if this happens, the surface front may never really get pulled all the way north before the trailing cold front portion from that final low pressure wave comes through, resulting in an occlusion of the front. The best chance for getting into the warm sector will be closer to the South Coast. Regardless, this system will bring fairly widespread shower activity late Thursday into Friday, before a drier northwesterly air flow arrives. But there will be a price to pay for the trend to drier, and that will be pretty decent shot of cold air from Canada, along with wind. In fact, the air will be cold enough so that when a trough passes by sometime in the morning of May 1, the showers it creates may be in the form of snow in at least parts of the region. The rest of Saturday should be dry with only a minimal risk of a pop up rain shower, but with that gusty wind and sun/cloud mix ongoing. No break Sunday as we’ll likely find ourselves right back in cloudiness and eventually the potential for some wet weather as a warm front approaches.

TODAY: Mostly cloudy. Scattered rain showers this morning and again late-day. Highs 55-62, coolest from the NH Seacoast to Cape Cod. Wind variable up to 10 MPH becoming E 5-15 MPH.

TONIGHT: Mostly cloudy rain showers likely. Chance of thunderstorms, especially I-90 southward. Lows 48-55. Wind variable up to 10 MPH.

THURSDAY: Mostly cloudy. Best chance of a rain shower early morning and late afternoon. Highs 55-60 eastern coastal areas, 60-65 most interior areas, 65-70 possible interior locations south of I-90. Wind E to variable up to 10 MPH.

THURSDAY NIGHT: Mostly cloudy with rain showers likely and a slight chance of a thunderstorm. Lows 50-57. Wind variable 5-15 MPH.

FRIDAY: Mostly cloudy with rain showers likely. Chance of a thunderstorm early. Highs 58-65. Wind variable 5-15 MPH becoming NW 10-20 MPH by later in the day.

FRIDAY NIGHT: Variably cloudy. A passing rain or snow shower possible overnight. Lows 35-42. Wind NW 15-25 MPH, higher gusts.

SATURDAY: Sun/cloud mix. A brief rain shower possible. Highs 52-59. Wind NW 10-20 MPH with higher gusts.

SATURDAY NIGHT: Partly cloudy. Lows 38-45. Wind W 5-15 MPH.

SUNDAY: Mostly cloudy. Slight chance of rain. Highs 52-59. Wind variable 5-15 MPH.

DAYS 6-10 (MAY 3-7)

The region may warm up briefly with a southwesterly air flow on May 3, but the predominant pattern will be cooler with occasional episodes of showers during the balance of the first week of May as a frontal boundary sits in the region once again.

DAYS 11-15 (MAY 8-11)

Overall pattern similar, frontal boundary tends to hang nearby with episodes of unsettled weather and variable temperatures averaging not that far from normal.

Tuesday April 27 2021 Forecast (7:27AM)

DAYS 1-5 (APRIL 27 – MAY 1)

The high and mid level clouds have already arrived ahead of an approaching frontal boundary. This boundary is going to tease the forecasters over the next few days with challenging wind direction and temperature forecast, and even present a challenge trying to figure out when the best chances of passing areas of rain will be. This is how I think it goes, and the overall idea is very similar to what I put forth on yesterday’s blog. For today, already there is more cloudiness than I had expected, but I do think some of that will thin out and we will still end up with a fair amount of sun at times, but it may vary from place to place and time to time. It will be a dry day, however, on the mild side, and less windy than yesterday was as that departing low is now far enough away and high pressure slides southwest of the region. Impulses of energy in the form of waves on the frontal boundary will bring increased rain chances that I think time for mostly the pre-dawn hours of Wednesday and again Wednesday evening, and a couple more times between Thursday evening and Friday afternoon, although tweaks will be needed most likely. There may be enough instability for a couple thunderstorms thrown into these rain chances too, though nothing widespread or severe is expected to occur. So our last 4 days of April will feature “disorganized” weather, for lack of a better term, and it won’t be until we get to Saturday, the first day of May, that it currently looks more clear cut: Gusty wind, cool air and a sun/cloud mix behind departing low pressure, with upper level disturbance still crossing the region and possibly triggering a few passing rain showers. Mother Nature, I challenge you to change this day 5 forecast on me! 😉

TODAY: Variably cloudy but some sunshine. Highs 64-71. Wind W 5-15 MPH.

TONIGHT: Mostly cloudy. A few passing rain showers possible and a slight chance of a thunderstorm. Lows 45-52. Wind variable up to 10 MPH.

WEDNESDAY: Mostly cloudy. A few rain showers possible. Highs 55-62 southern NH and northern MA, coolest coast, and 63-70 to the south. Wind variable becoming mostly E 5-15 MPH.

WEDNESDAY NIGHT: Mostly cloudy rain showers likely and a slight chance of a thunderstorm evening. Partly cloudy overnight. Lows 48-55. Wind variable up to 10 MPH.

THURSDAY: Variably cloudy. Best chance of a rain shower early morning and late afternoon. Highs 58-65 coast with coolest Cape Cod, 66-73 interior. Wind variable to W 5-15 MPH.

THURSDAY NIGHT: Mostly cloudy with rain showers likely and a slight chance of a thunderstorm. Lows 50-57. Wind SW 10-20 MPH.

FRIDAY: Mostly cloudy with rain showers likely and possibly a thunderstorm. Highs 60-67. Wind SW 10-20 MPH may shift to NW.

FRIDAY NIGHT: Variably cloudy. Lows 40-47. Wind NW 15-25 MPH.

SATURDAY: Sun/cloud mix. A rain shower possible. Highs 53-60. Wind NW 10-20 MPH with higher gusts.

DAYS 6-10 (MAY 2-6)

I don’t think we get a forecasting break during the first week of May, as our region will likely still be near a frontal boundary for much of if not all of the time. Early guess, warm front approaches with clouds and risk of light rainfall May 2, high pressure builds in with a dry and mild interlude next day, then we go back into the in-and-out-of-clouds with occasional brief wet weather chances, but nothing that’s really going to produce beneficial rain.

DAYS 11-15 (MAY 7-11)

I’ve been looking for indications of change, but still not seeing it. Still leaning toward the idea of weak systems with limited rain changes, but no long stretches of fair/warm weather.

Monday April 26 2021 Forecast (7:16AM)

DAYS 1-5 (APRIL 26-30)

Plenty of springtime variety is on our weather agenda for these final 5 days of April. We should still get our warm-up, I think, but it will last a fraction of the time that our guidance was trying to tell us just a few days ago. That will come at midweek at least in theory, but before that, we have a blustery Monday and a tranquil Tuesday. Today’s gusty breeze comes courtesy the circulation around the low pressure area that went by us yesterday without much fanfare. Since then, it has started to strengthen as it merged with energy to its north. Now, as a much more formidable storm system its need for air intake is greater, hence the increased wind between it and high pressure to our southwest. The low moves away enough and high pressure edges closer to get rid of the wind or at least reduce it down to a lighter breeze during Tuesday. You’ll notice high clouds starting to move in during the day and much more cloudiness will follow this at night as a warm front moves into the region. There should be enough moisture with this front to result in the possibility of a few rain showers and maybe even a thunderstorm near this boundary. Now I said the warm front will move into the region, but that does not necessarily mean it will move through the region. There’s a distinct possibility that the boundary never quite clears the region and becomes stationary or even drifts back to the southwest, and what it does is crucial to the temperature forecast here. While one can look at the guidance and come up with a forecast that is warmer Wednesday and cooler Thursday, it could very well end up the opposite with the warm up delayed on Wednesday if the boundary struggles to come through, and a warmer Thursday as a slightly stronger wave of low pressure tracks north of our region. Just yesterday, I was thinking that this entire boundary may have pushed far enough south for high pressure to the north to give us a dry Thursday. There are forecasts that have just as much chance of being correct for showery weather Thursday while the scenario I can see happening brings us drier, warmer weather for a brief time that day before the front comes back to the south, and during Friday with wetter weather. Even that timing is far from clear-cut with some guidance slower and other guidance faster. The best way to go in this situation is just to forecast the front to be nearby with unsettled weather, then fine-tune the forecast in subsequent updates, and that’s exactly what I am going to do…

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

MONDAY NIGHT: Clearing. Lows 36-43. Wind NW 5-15 MPH, higher gusts.

TUESDAY: Sunny start then some high clouds filtering the sun at times. Highs 64-71. Wind W 5-15 MPH.

TUESDAY NIGHT: Mostly cloudy. A few passing rain showers possible and a slight chance of a thunderstorm. Lows 45-52. Wind variable up to 10 MPH.

WEDNESDAY: Mostly cloudy. A few rain showers possible. Highs 55-62 southern NH and northern MA, coolest coast, and 63-70 to the south. Wind variable becoming mostly E 5-15 MPH.

WEDNESDAY NIGHT: Mostly cloudy with a chance of rain showers evening. Partly cloudy overnight. Lows 48-55. Wind variable up to 10 MPH.

THURSDAY: Partly sunny. A few rain showers possible. Highs 58-65 coast, 66-73 interior. Wind variable to W 5-15 MPH.

THURSDAY NIGHT: Becoming mostly cloudy with a better chance of rain showers. Lows 50-57. Wind SW 10-20 MPH.

FRIDAY: Mostly cloudy with rain showers likely and possibly a thunderstorm. Highs 60-67. Wind SW 10-20 MPH may shift to NW.

DAYS 6-10 (MAY 1-5)

Still not going to be the highest confidence forecast here coming out of an already uncertain end-of-April forecast, but best call at this time is that we see low pressure depart and high pressure approach but an upper low still crossing the region May 1 with a sun/cloud mix and maybe a pop up shower along with breezy and cool conditions, then dry and milder weather May 2. Once again we likely deal with a boundary in the region heading into early next week with uncertain temperature, cloud, and rain threat forecasts, but the potential for unsettled weather definitely there.

DAYS 11-15 (MAY 6-10)

Still not a strong indication of any big change, likely a flip floppy outlook period due to uncertainty of where we sit in regards to a boundary that seems to want to hang out with us for a while. While unsettled weather is often possible in this pattern, I like the idea of leaning drier than average with variable temperatures, but no huge temperature departures from normal.