DAYS 1-5 (MAY 27-31)

As many of us pause to remember the fallen at parades / ceremonies today, we’ll do so under an overcast with some areas of fog and light drizzle, and a few passing showers which can be around through the middle of the day. The warm front responsible for this will approach the region during the day, but not likely pass by until the evening, at which time a cold front from the west will be approaching steadily. This will send a swath of widespread showers and embedded thunderstorms across the region during this evening, ending from west to east by shortly after midnight. This is slightly faster than the timing I was expecting on yesterday’s update, but still slowly enough that we get through the daylight hours in most of the region before it arrives. Use caution if planning to travel during the evening as visibility will be lowered and there can be ponding of water on many roadways. Behind this system, expect a fair and warm day on Tuesday. An upper level trough will move through the region via the Great Lakes at midweek, presenting a cooling trend and additional shower activity, mainly Wednesday night and Thursday, based on current expected timing. This feature will move along so that we end up with a nice day on Friday to end the month of May as high pressure builds in.

TODAY (MEMORIAL DAY): Cloudy. Foggy areas, patchy drizzle, and a chance of brief passing showers through midday. Widespread showers return to western areas by evening. Highs 65-72, coolest South Coast / Cape Cod areas. Wind SE up to 10 MPH through midday, increasing to 10-15 MPH later.

TONIGHT: Cloudy. Widespread showers and embedded thunderstorms evening, ending west to east overnight. Lows 55-62. Wind S to SW 5-15 MPH, higher gusts possible.

TUESDAY: Sun/cloud mix. Highs 68-75 South coast, 76-83 elsewhere. Wind SW 5-15 MPH, higher gusts.

TUESDAY NIGHT: Clearing. Lows 52-59. Wind W 5-15 MPH.

WEDNESDAY: Sunny start, cloudy finish. Highs 66-73. Wind W up to 10 MPH shifting to S.

WEDNESDAY NIGHT: Cloudy. Showers likely. Lows 55-62. Wind S 5-15 MPH.

THURSDAY: Mostly cloudy with showers likely in the morning. Sun/cloud mix with a chance of an additional passing shower during the afternoon. Highs 65-72. Wind shifting to NW 5-15 MPH.

THURSDAY NIGHT: Clearing. Lows 48-55. Wind NW 5-15 MPH.

FRIDAY: Mostly sunny. Highs 65-72. Wind NW to N 5-15 MPH.

DAYS 6-10 (JUNE 1-5)

We may have to watch for a weak disturbance around June 2 with a passing shower, otherwise most of the first weekend of June looks dry and mild. Another shot at unsettled weather comes toward the end of the period.

DAYS 11-15 (JUNE 6-10)

Pattern looking a little unsettled early portion of this period before fair weather returns. Temperatures variable, averaging fairly close to normal.

DAYS 1-5 (MAY 26-30)

As we move to the middle day of the holiday weekend, we observe early this morning some showers and even an isolated thunderstorm having moved across southern New England, now (as of 8:30 a.m. writing) exiting the MA South Shore, with a few lighter showers near the South Coast. Aside from a quick pop-up shower potential in the mid to late morning as a weak boundary settles through this area, a good part of today will be rain-free. But later today, with a disturbance about, a little more moisture, and some solar heating, and the weak surface boundary lifting back to the north, we can and probably will see the development of some pop up showers and thunderstorms by later afternoon to early evening. These don’t look widespread, rather scattered, but can be heavy, at least briefly, where they occur. While this is going on we’ll have a more notable air flow off the Atlantic and this should keep the lower levels stable enough so that development is far less likely east of I-95. As we move through tonight and Monday, clouds will be the rule as we are in a southeasterly to southerly air flow as low pressure moving into the Great Lakes sends a warm front into and across the region. While occasional showers can accompany this, I do not expect a widespread day-long rain, and many of the outdoor activities for Memorial Day will take place with mainly rain-free conditions. At the end of the day and especially at night, a more pronounced and widespread band of showers and embedded thunderstorms will arrive from west to east with a slow-moving cold front, which will take until Tuesday morning to clear through the area. Some significant rainfall is likely with this, but this will followed by drying and not much cool air behind the front, resulting in Tuesday becoming quite a nice late spring day. Heading into midweek, we have a trough back to the northwest associated with the Great Lakes low pressure area that will swing through with another episode of shower chances from late Wednesday into Thursday. Timing and details of this part of the forecast need to be tweaked and fine-tuned the next few days.

TODAY: Variably cloudy. An additional shower possible east of I-95 and south of I-90 into mid morning. Isolated to scattered showers and a slight chance of a thunderstorms mainly I-90 northward later in the afternoon. Highs 68-75 coast, 75-82 inland, but coastal areas will cool down during the afternoon. Wind S to SE up to 10 MPH.

TONIGHT: Mostly cloudy. Fog patches South Coast. Lows 55-62. Wind SE up to 10 MPH.

MONDAY (MEMORIAL DAY): Mostly cloudy. Isolated to scattered showers. Rain-free most of the time. Highs 65-72, coolest South Coast / Cape Cod. Wind SE to S 5-15 MPH.

MONDAY NIGHT: Mostly cloudy. Showers likely. Chance of thunderstorms. Lows 55-62. Wind S to SW 5-15 MPH.

TUESDAY: Beginning-of-day clouds with showers and thunderstorms exiting west to east, then a sun/cloud mix. Highs 75-82. Wind SW 5-15 MPH.

TUESDAY NIGHT: Clearing. Lows 52-59. Wind W 5-15 MPH.

WEDNESDAY: Sunny start, then a sun/cloud mix. Highs 66-73. Wind NW 5-15 MPH.

WEDNESDAY NIGHT / THURSDAY: Variably cloudy. Chance of showers. Lows 52-59. Highs 64-71. Wind S to W 5-15 MPH.

DAYS 6-10 (MAY 31 – JUNE 4)

This stretch from the final day of May into the first few days of June looks mainly dry with high pressure in general control. A trough approaching around June 2 may be obliterated by the block or deflected to the south. Early hints of some unsettled weather around the end of the period though. Temperatures near to below normal.

DAYS 11-15 (JUNE 5-9)

Pattern looking a little unsettled early to middle portion of this period before fair weather returns. Far too soon for any details. Temperatures variable, averaging fairly close to normal.

DAYS 1-5 (MAY 25-29)

Memorial Day Weekend is upon us and the weather these 3 days will be different daily, but the weekend as a whole will be largely rain-free for any given location. Today is the slam dunk for the pick of the 3 days in terms of favorable weather for outdoor activity. Governed by high pressure, we’ll see plenty of sun, filtered at times by filaments of high clouds. A little bit of thin high altitude smoke from western US fires can add a hazier look to the sky. But it will be a nice day – quite warm / not too hot / and manageable humidity. Also, the active post-frontal breeze we saw yesterday will be less so today as high pressure builds over the region, diminishing the northwesterly air flow we have and making for a lighter, variable wind. This will, however, allow for the development of coastal sea breezes, which will keep it cooler in those locations versus inland areas. Toward day’s end, if you’re watching the sky you’ll see high and mid level clouds starting to be more obvious, and as we get into tonight, these will increase from west to east as a disturbance approaches, via the Great Lakes. Once triggering numerous showers and thunderstorms, this system will be much weaker as it crosses our region during the overnight hours, with just the chance for a few isolated / widely scattered showers and a low risk of a thunderstorm. Sunday, we’ll develop a more southerly air flow as a weak low pressure area crosses northern New England with a trough extending southward. Eastern coastal areas can develop more of a southeasterly sea breeze due to a weak pressure gradient, and this air flow will already be an ocean breeze for the South Coast, so all coastal areas will again be cooler than inland areas on Sunday. With the weak trough and a bit more moisture, solar heating can help trigger a few showers popping up, mainly away from the coast, during the afternoon and early evening hours. During Sunday night and certainly on Monday (Memorial Day), with upper level and surface low pressure moving into the Great Lakes and a warm front moving into the region, we’ll see a more regionwide southeasterly air flow and it will become mainly cloudy. I do think that rainfall generated by the approaching / passing warm front will be limited to just patches of light rainfall, favoring areas north and west of Boston, and that the cold front associated with the low, while approaching from the west, is slow enough that its associated shower and thunderstorm activity holds off until night. This front can produce a fairly healthy amount of rain in just a handful of hours as it goes by with widespread showers and embedded thunderstorms mainly in the overnight hours, but should exit early in the morning Tuesday, leaving us with a sun/cloud mix and a warm day as there is not much cool air to be delivered by the front itself, which will be washing out. A narrow area of high pressure provides dry weather for us Wednesday, but expect some fair weather clouds to pop up in response to a cooling trend aloft as upper level low pressure to the north has us in its influence.

TODAY: Sunshine, filtered at times by high clouds and high altitude smoke, then interrupted at times later in the day by a few thicker cloud patches. Highs 75-82 except cooler coastal areas. Wind NW to N up to 10 MPH morning, becoming variable with coastal sea breezes midday on.

TONIGHT: Partly to mostly cloudy. Isolated to widely scattered showers and a slight chance of a thunderstorm, mainly north of I-90, late evening / overnight. Lows 55-62. Wind variable up to 10 MPH becoming S.

SUNDAY: Variably cloudy. An isolated shower possible early morning I-95 and I-90 east and south. Isolated afternoon showers and a slight chance of a thunderstorm mainly west of I-95. Highs 68-75 coast, 75-82 inland, but coastal areas will cool down during the afternoon. Wind S to SE up to 10 MPH.

SUNDAY NIGHT: Mostly cloudy. Fog patch potential South Coast. Lows 55-62. Wind SE up to 10 MPH.

MONDAY (MEMORIAL DAY): Mostly cloudy. Brief rain possible mainly north and west of Boston through midday. Isolated afternoon showers possible mainly west of I-495. Highs 65-72. Wind SE to S 5-15 MPH.

MONDAY NIGHT: Mostly cloudy. Showers likely. Chance of thunderstorms. Lows 55-62. Wind S to SW 5-15 MPH.

TUESDAY: Beginning-of-day clouds with showers and thunderstorms exiting west to east, then a sun/cloud mix. Highs 75-82. Wind SW 5-15 MPH.

TUESDAY NIGHT: Clearing. Lows 52-59. Wind W 5-15 MPH.

WEDNESDAY: Sunny start, then a sun/cloud mix. Highs 66-73. Wind NW 5-15 MPH.

DAYS 6-10 (MAY 30 – JUNE 3)

A trough will swing through the region May 30 bringing scattered showers. Fair weather is expected to return behind this system for the final day of May, which should then extend into and just beyond the first weekend of June as we see high pressure in control. Temperatures near to below normal early in the period return to near normal later in the period.

DAYS 11-15 (JUNE 4-8)

High pressure gives way to a low pressure trough bringing a few episodes of unsettled weather early to middle portion of this period. Temperatures variable, averaging fairly close to normal.

COMMENTARY

The “unofficial” start to summer aka Memorial Day Weekend is upon us. Weatherwise, it’s very much still springtime here in New England, but many people think of this weekend as the season opener and Labor Day Weekend being the closer. So be it, and we treat the forecast with the scrutiny of a mid summer one, keeping in mind that it’s not mid summer. But we should also not forget, going into this long weekend, that Memorial Day itself is an important day to remember those who served who did not come home. I feel it’s important to not lose sight of this, and remember them.

DAYS 1-5 (MAY 24-28)

High pressure will control the weather today and Saturday with fair weather, lower humidity, and above normal temperatures. The position of the high to the southwest of our region today, combined with a low pressure area moving across southeastern Canada, means a warm southwesterly to westerly air flow for all, with a cooling influence confined mainly to the South Coast, especially Cape Cod. The high center shifts more over our region on Saturday, allowing a more widespread sea breeze to develop. Some filaments of high clouds will be around today and a few fair weather clouds can pop up today and again mainly away from the coast Saturday, otherwise sunshine will be fairly abundant for both days. Saturday night, a weak disturbance will slide across New England from northwest to southeast, and this will bring some clouds in, and may produce a couple isolated showers, maybe even a thunderstorm, sometime from late evening to overnight (early Sunday) favoring areas north of I-90. During the day on Sunday a weak boundary associated with this feature will hang around mainly south of I-90 where some pop up showers can occur. But for the most part, the region will have a rain-free day on Sunday with just some varying cloud cover. On Memorial Day Monday, expect more substantial cloudiness as upper and surface low pressure move into the Great Lakes, and a warm front approaches and moves through our region. We’ll have to watch for a swath of light rain accompanying the warm front, but some indications are that this will stay mainly to the west and north, and a cold front following it will hang back long enough that much of the area gets through most of Monday either free of rain, or with just a few quick passing showers, with a more widespread shower area arriving at night. This system will be over the region Tuesday, which looks unsettled, with showers and thunderstorms around.

TODAY: Mostly sunny. Highs 77-84, cooler Cape Cod. Wind W to SW 5-15 MPH.

TONIGHT: Mostly clear. Lows 54-61. Wind SW under 10 MPH becoming variable.

SATURDAY: Sunny to partly cloudy. Highs 75-82 except noticeably cooler in all coastal areas. Wind variable up to 10 MPH with coastal sea breezes.

SATURDAY NIGHT: Partly to mostly cloudy. An isolated shower or thunderstorm possible late evening / overnight, mainly north of I-90. Lows 55-62. Wind S to SW up to 10 MPH.

SUNDAY: Variably cloudy. A few showers are possible, mainly I-95 southward. Highs 68-75, cooler some coastal areas. Wind variable up to 10 MPH with coastal sea breezes.

SUNDAY NIGHT: Variably cloudy. Lows 53-60. Wind S up to 10 MPH.

MONDAY (MEMORIAL DAY): Mostly cloudy. Brief rain possible mainly north and west of Boston through midday. Isolated afternoon showers possible. Highs 65-72. Wind SE to S 5-15 MPH.

MONDAY NIGHT: Mostly cloudy. Showers likely. Chance of thunderstorms. Lows 55-62. Wind S to SW 5-15 MPH.

TUESDAY: Variably cloudy. Chance of showers and thunderstorms. Highs 65-72. Wind SW to variable 5-15 MPH.

DAYS 6-10 (MAY 29 – JUNE 2)

Weaker upper level through around can still produce a few showers, but drier more often than not, during the May 29-31 period. Cautiously optimistic for a fair weather weekend on June 1-2. Temperatures near to slightly below normal.

DAYS 11-15 (JUNE 3-7)

Fair weather early period. Better chance of unsettled weather mid to late period. Temperatures near normal.

DAYS 1-5 (MAY 23-27)

We hold onto the warmth for the next few days, but the temperature will be down a few notches in the region today with lots of cloudiness and a couple / few rounds of showers and thunderstorms moving through with a trough and eventually the passage of a cold front. Dew points will be up today so you’ll notice the humidity which helps drive the showers and storms too. There are three distinctive time frames for activity in the region overall. Number 1 is now, with scattered showers and storms, focus near and south of I-90 heading into southeastern MA via RI. By the time many of you read this, batch number 1 will be heading out to sea via the MA South Shore (mid morning). The next batch will be a fairly widespread swath of showers and embedded thunderstorms that moves more in a southwest to northeast fashion across the region over a few hours’ time from late morning to early afternoon. If there is a “round 3” it’s with the cold front itself from northwest to southeast between 4 p.m. and early evening, but the coverage on that looks quite limited, and there may be only a few isolated cells. Nevertheless, keep an eye out, just in case. Any storms can produce gusty winds and a few can produce hail. While severe weather is possible, its occurrence would be fairly isolated. It all goes quiet tonight and lower dew point air arrives overnight. The rain I was concerned about has shown a southward trend and I’m now calling for a 100% dry day on Friday, both in terms of no rainfall and also lower humidity, with abundant sun to be had. Many areas will still break 80 for high temps, but it will be rather comfy. Saturday will be similar – lots of sun / a few more clouds than Friday, but fairly low humidity and will be the warmest day of the 3-day Memorial Day weekend as high pressure controls the weather. As we progress through the weekend we’ll see slight cooling trend for Sunday and Monday as an upper level low pressure trough moves into the region. A weak disturbance passing through the region on Sunday may trigger a couple showers, but for the most part this will be a rain-free, nice day, with some varying cloud cover, so keep any outdoor plans and just keep an eye on the sky / radar. Memorial Day itself is when we see a greater chance of wet weather impacting most of the region. It looks like an area of surface low pressure will move into the Great Lakes that day with a warm front extending eastward from it, lifting into New England with lots of clouds and scattered rainfall areas. This may be limited and have no major impact on parades and ceremonies that take place during the morning and midday hours. The warm front may not make it all the way through the region before a cold / occluded front arrives from the west later in the day with a greater threat of showers and possible thunderstorms, but this may hold off until the end of the day or even the night, allowing a good portion of Monday to be rain-free. Fine-tuning to come on this part of the forecast…

TODAY: Variably cloudy. Early to mid morning showers and thunderstorms mainly south of I-90. More widespread showers and embedded thunderstorms late morning to early afternoon. Isolated showers / thunderstorms later in the day, favoring areas north of I-90. Highs 80-87 except cooler (mainly 60s) South Coast with a sharp gradient between. Wind SW 5-15 MPH, but variable and potentially stronger winds around any thunderstorms.

TONIGHT: Variably cloudy. Lows 55-62. Wind shifting to NW 5-15 MPH.

FRIDAY: Early clouds South Coast, otherwise sunshine dominates the day. Highs 77-84, cooler Cape Cod. Wind NW 5-15 MPH.

FRIDAY NIGHT: Patchy clouds. Lows 53-60. Wind NW to W up to 10 MPH.

SATURDAY: Sunny to partly cloudy. Highs 76-83. Wind W 5-15 MPH.

SATURDAY NIGHT: Partly cloudy. Lows 53-60. Wind W to SW up to 10 MPH.

SUNDAY: Partly to mostly cloudy. Chance of a shower. Highs 68-75. Wind SW 5-15 MPH.

SUNDAY NIGHT: Variably cloudy. Lows 53-60. Wind S up to 10 MPH.

MONDAY (MEMORIAL DAY): Mostly cloudy. Patchy rain possible morning and midday. Showers and thunderstorms return later in the day west to east. Highs 65-72. Wind SE 5-15 MPH.

DAYS 6-10 (MAY 28 – JUNE 1)

A trough moving through the region brings the chance of additional showers and thunderstorms on May 28. An upper trough flattens out but still can produce a couple showers May 29 or May 30 before high pressure builds in with fair weather May 31 / June 1.

DAYS 11-15 (JUNE 2-6)

A passing disturbance may bring a shower chance early in the period, a second disturbance brings a chance mid period, and a third late period. No major temperature extremes indicated.

DAYS 1-5 (MAY 22-26)

Summer preview, day 2, today, with high pressure off to the south and a warm southwesterly air flow in place (South Coast / Cape Cod cooler as usual). Today we see more sun than yesterday, and late-day showers and thunderstorms that develop to the north and west will do so further upstream and not make their way into southern NH and northern MA as they did last evening – even more significant than I had expected them to. Thursday, a cold front moves into the region, but slowly enough that we get another 80-degree plus day for much of the region. But that warmth does add fuel for the storms that while may not be widespread, can be heavy in some areas, along with the slight potential for isolated severe storms – wind damage primary threat / hail secondary threat. Any activity moves out in the evening, but the front responsible for them will be a little sluggish, and a follow up low pressure wave can cause another swath of showers especially for the South Coast region sometime during the first 12 hours of Friday. Some guidance has this occurring further south and Friday completely dry. This is a possibility as well. Final fine-tune on next blog. Either way, drier air arrives Friday and for the start of the Memorial Day Weekend on Saturday, with temperatures closer to seasonable, though still a little above normal. When we get to Sunday, a weak disturbance from the west may trigger a few showers, but otherwise that day looks mostly fair. Plenty of time to focus in on that potential as we get closer to it.

TODAY: Early clouds exit Cape Cod. Fog / stratus patches southwestern NH, north central MA, and eastern CT vanish by mid morning. Plenty of sun. Evening cloud patches arrive from the west. Highs ranging from 58-65 Cape Cod / Islands / immediate South Coast to 85-92 I-95 belt westward, with a sharp gradient between. Wind SW increasing to 10-20 MPH.

TONIGHT: Partly cloudy. Lows 55-62. Wind SW 5-15 MPH.

THURSDAY: Variably cloudy. Scattered showers and thunderstorms, primarily in the afternoon, with some strong to locally severe storms possible. Highs 80-87 except cooler South Coast / Cape Cod. Wind SW 5-15 MPH but locally variable, stronger, and potentially damaging winds in any storms.

THURSDAY NIGHT: Clouds linger. Chance of showers mainly South Coast. Lows 55-62. Wind shifting to NW 5-15 MPH.

FRIDAY: Clouds and a rain chance South Coast early, otherwise a sun/cloud mix. Highs 66-73. Wind NW 5-15 MPH.

FRIDAY NIGHT: Clearing. Lows 48-55, coolest interior valleys. Wind NW up to 10 MPH.

SATURDAY: Sunny to partly cloudy. Highs 66-73. Wind W 5-15 MPH.

SATURDAY NIGHT: Partly cloudy. Lows 50-57. Wind SW up to 10 MPH.

SUNDAY: Partly to mostly cloudy. Chance of a shower. Highs 68-75. Wind SW 5-15 MPH.

DAYS 6-10 (MAY 27-31)

Memorial Day (May 27) watch for low pressure to approach with a chance of showers before the end of the day. Additional showers and potential thunderstorms May 28 as a trough / cold front move across the region. Generally fair weather with high pressure in control May 29-31 based on current medium range expectations.

DAYS 11-15 (JUNE 1-5)

Weak upper low trends to hang around Great Lakes / Northeast with a couple disturbances bringing shower chances and variable temperatures with no extremes.

DAYS 1-5 (MAY 21-25)

A summer preview takes place the next couple days with high pressure off to our south and and upper level high pressure ridge on the East Coast. This allows Boston to hit 80 for the first time this season (average first date May 4, so behind that by quite a bit), likely today, definitely tomorrow. A prevailing southwesterly wind flow will be, of course, a cooling influence for the South Coast and Cape Cod. Other than fog patches and low clouds in some areas for a while this morning, and a repeat of this tonight / early tomorrow morning, the weather will be generally fair regionwide both days. One other potential exception is with a disturbance moving into northern New England from the west this evening with showers and thunderstorms, a couple of these can migrate as far south as southern NH, so keep an eye out for that. Wednesday’s shower and thunderstorm activity with an approaching cold front should stay well to the west and north of our region. That cold front does move across the region on Thursday. Trends have been a little faster and weaker for the front, so while there is a chance of the development of some showers and thunderstorms that day, they may be earlier and less widespread, with the main focus / trigger having gone by before prime heating time. Will keep an eye on that. A later arrival and efficient heating ahead of the front would increase the potential for heavier showers and stronger thunderstorms. Still eyeing the potential for a follow up low to bring at least a chance of rain for a portion of Friday. As we get into the start of the Memorial Day Weekend on Saturday, we will be in a west southwesterly air flow with a weak upper trough in the region. This will be why I can’t make Saturday’s forecast “sunny”, but I’m also thinking it won’t be that bad. With a disturbance maybe moving in quickly from the west I’m going to add the chance of a shower, but don’t cancel any plans now.

TODAY: Areas of low clouds / fog into mid morning otherwise filtered sun with variable high clouds, then more abundant sun during the afternoon before other clouds arrive from the west later in the day. The slight chance of an evening shower or thunderstorm across portions of southern NH. Highs range widely from near 60 Cape Cod to 80-87 I-95 belt westward. Wind SW 5-15 MPH.

TONIGHT: Variably cloudy. Areas of fog overnight. Lows 53-60. Wind SW diminishing to under 10 MPH.

WEDNESDAY: Fog / low cloud areas early, otherwise mostly sunny. Highs range from near 65 Cape Cod / South Coast to 83-90 I-95 westward. Wind SW increasing to 10-20 MPH.

WEDNESDAY NIGHT: Partly cloudy. Lows 55-62. Wind SW 5-15 MPH.

THURSDAY: Variably cloudy. Chance of showers and thunderstorms. Highs 75-82, cooler South Coast. Wind SW 5-15 MPH shifting to W.

THURSDAY NIGHT: Clouds linger. Lows 50-57. Wind NW 5-15 MPH.

FRIDAY: Cloudy. Chance of rain. Highs 58-65. Wind NE 5-15 MPH.

FRIDAY NIGHT: Clearing. Lows 48-55. Wind N up to 10 MPH.

SATURDAY: Variably cloudy. Chance of a shower. Highs 63-70. Wind W 5-15 MPH.

DAYS 6-10 (MAY 26-30)

Leaning fair May 26 then unsettled May 27 (Memorial Day) as another disturbance arrives from the west. Additional unsettled weather May 28 before a drying trend. Temperatures slightly variable but overall close to normal.

DAYS 11-15 (MAY 31 – JUNE 4)

Weak upper low trends to hang around Great Lakes / Northeast with a couple disturbances bringing shower chances and variable temperatures with no extremes.

DAYS 1-5 (MAY 20-24)

This work week’s weather pattern will be quite different from the one we saw last week. Today, high pressure builds to our south and will strengthen there into midweek, while an upper level ridge builds along the East Coast. The transition today may seem a bit slow to get started as the region starts the day blanketed by clouds along with some patches of fog, but improvement will come as the clouds begin to erode, though they may hang on longest over Cape Cod. Tuesday and Wednesday will present the feel of early summer away from this ocean influence, and sunshine will be abundant both days. Tuesday and/or Wednesday you may notice some cloudiness in the western and northwestern sky later in the day, and this will be the result of upstream showers and thunderstorms generated by the sun’s heating and some instability closer to a frontal boundary moving into and through the Great Lakes region. We won’t hear from that front until Thursday when it moves into and across New England, bringing the chance of showers and thunderstorms. It’s a bit early to call how widespread and heavy these may be, so check updates over the next few days as I fine-tune this part of the forecast. Friday’s forecast is a bit of a question mark. The pattern reminds me of one that leaves Thursday’s cold front just to our south and allows a wave of low pressure to ripple along it. This may result in the chance of some rainfall on that day. If it doesn’t materialize and the front chugs further offshore and high pressure is strong enough, all bets are off on the rain chance and Friday is fair and pleasant. I am leaning toward the wet forecast right now, but don’t be surprised if this changes…

TODAY: Fog patches until mid morning, otherwise a sun/cloud mix, with clouds most dominant over Cape Cod. Highs 55-60 Islands / Cape Cod, 60-65 South Coast and immediate eastern coastal areas, 65-70 I-95 belt, 70-75 west of I-95 belt. Wind variable up to 10 MPH becoming SE.

TONIGHT: Clear. Lows 51-58. Wind SE to S under 10 MPH.

TUESDAY: Sunshine dominates, but some clouds arrives from the west late. Highs range widely from near 60 Cape Cod to 80-87 I-95 belt westward. Wind SW 5-15 MPH.

TUESDAY NIGHT: Partly cloudy evening, then clear. Lows 52-59. Wind SW 5-15 MPH.

WEDNESDAY: Sunny until late day when a few clouds return from the west. Highs range from near 65 Cape Cod / South Coast to 83-90 I-95 westward. Wind SW 10-20 MPH.

WEDNESDAY NIGHT: Partly cloudy. Lows 55-62. Wind SW 5-15 MPH.

THURSDAY: Variably cloudy. Chance of showers and thunderstorms. Highs 68-75, cooler South Coast. Wind SW 10-20 MPH.

THURSDAY NIGHT: Clouds linger. Lows 50-57. Wind NW 5-15 MPH.

FRIDAY: Cloudy. Chance of rain. Highs 58-65. Wind NE 5-15 MPH.

DAYS 6-10 (MAY 25-29)

Outlook is for fair weather 2/3 of the Memorial Day Weekend with the next shower threat potentially on May 27, but may hold off until the day after. Fair weather returns end of period. More seasonable temperatures but somewhat variable.

DAYS 11-15 (MAY 30 – JUNE 3)

Last couple days of May look fair, early part of June maybe a shower threat. Temperatures variable, but close to normal overall with no major extremes.

COMMENTARY

Horrible forecast yesterday. No excuse, but the reason for me (and according to NWS discussion, others as well), extremely poor performance by short range guidance in picking up conditions that produce more widespread and persistent rainfall than they were indicating. A forecaster from NWS Boston noted that even the “best performing” piece of guidance was inadequate and far under-forecast the scope of the rainfall. Ouch. I gave a couple of forecasts to people for outdoor events that were less than accurate, to put it nicely, though the events worked out fairly well anyway. Still, not a good feeling when that happens! But, we move forward…

DAYS 1-5 (MAY 19-23)

Since the synoptic conditions haven’t changed all that much today from yesterday, today’s short term forecast is a little less optimistic than I indicated just 24 hours ago. No I don’t think we’re in for a repeat of the rainfall, but an overcast morning with drizzle patches and areas of fog may only improve very slightly, and I can’t rule out pop up showers at any time, as low pressure sits to the south and a fresh feed of Atlantic moisture remains in place. Finally, this begins its exit this evening as high pressure starts to shift in from the southwest and overtake our weather. While some lingering cloudiness is likely to be around Monday, expect a much nicer day overall with fair weather and it turning considerably warmer than the weekend was. This trend will continue for Tuesday and Wednesday as high pressure sits just to our south and puts us in a warm southwesterly air flow. This will give us a preview of summertime with many areas going over 80 for high temps. This, of course, will be a lot harder to achieve closer to the South Coast and over Cape Cod where a southwest wind is a direct ocean wind and the cooler water will have a significant modifying influence. Thursday, the temperature forecast will depend on the speed of an incoming cold front, which will bring the chance of showers and thunderstorms, along with associated cloudiness. Details TBD.

TODAY: Cloudy. Areas of drizzle/fog. Chance of a shower. Highs 56-63, coolest coast. Wind E to SE 5-15 MPH.

TONIGHT: Breaking clouds. Patchy fog. Lows 49-56. Wind SE to S up to 10 MPH.

MONDAY: Variably cloudy South Coast to MA South Shore / more sun elsewhere. Highs 62-69 South Coast to MA South Shore, 70-77 elsewhere. Wind S to SW 5-15 MPH.

MONDAY NIGHT: Partly cloudy. Lows 51-58. Wind S to SW up to 10 MPH.

TUESDAY: Sunny. Highs ranging from near 60 Cape Cod to 81-88 Merrimack Valley, interior MA, southern NH. Wind SW 5-15 MPH.

TUESDAY NIGHT: Clear. Lows 52-59. Wind SW 5-15 MPH.

WEDNESDAY: Sunny. Highs ranging from near 60 Cape Cod to 81-88 Merrimack Valley, east central to central MA, southern NH. Wind SW 10-20 MPH.

WEDNESDAY NIGHT: Partly cloudy. Lows 53-60. Wind SW 5-15 MPH.

THURSDAY: Variably cloudy. Chance of showers and thunderstorms. Highs 68-75, cooler South Coast. Wind SW 10-20 MPH.

DAYS 6-10 (MAY 24-28)

Models may not yet see what turns out to be a rain threat from passing low pressure on May 24, followed by fair weather to at least start and get into the Memorial Day Weekend, with the potential for the next shower threat around Memorial Day itself, unless a slower pattern holds it off til the end of the period. Will monitor the trends. Temps will be typically spring variable.

DAYS 11-15 (MAY 29 – JUNE 2)

Last few days of May look fair, early part of June maybe a shower threat. Progressive pattern – variable temperatures not straying too extremely.

DAYS 1-5 (MAY 18-22)

A little weather toll booth stop today – a day that I thought would remain dry just a couple days ago, but for most places won’t be 100% dry after all. That said, we’re not looking at a Saturday wash-out either, just some scattered showers and patches of drizzle as low pressure offshore sends some moisture back our way via the Atlantic. This threat will last into tonight and even the very early portion of Sunday before it’s gone again, but there will also be plenty of precipitation-free time during this as well. It’ll remain on the cool side with the air flow off the Atlantic this weekend. The first few days of the upcoming week we will see a transition to fair, warmer weather as high pressure becomes established to our south and the next frontal boundary stays well to the west and north of our region.

TODAY: Cloudy. Patchy drizzle / isolated to scattered showers. Highs 56-63, coolest coast. Wind E 5-15 MPH.

TONIGHT: Cloudy. Patchy drizzle / chance of a shower. Lows 48-55. Wind E to SE 5-15 MPH.

SUNDAY: Mostly cloudy to partly sunny. A shower or patch of drizzle early. Highs 60-67, coolest coast. Wind SE 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 51-58. Wind S up to 10 MPH.

MONDAY: Variably cloudy South Coast to MA South Shore / more sun elsewhere. Highs 62-69 South Coast to MA South Shore, 70-77 elsewhere. Wind S to SW 5-15 MPH.

MONDAY NIGHT: Partly cloudy. Lows 51-58. Wind S to SW up to 10 MPH.

TUESDAY: Sunny. Highs 78-85 except 70-77 South Coast / Cape Cod. Wind SW 5-15 MPH.

TUESDAY NIGHT: Clear. Lows 52-59. Wind SW 5-15 MPH.

WEDNESDAY: Sunny. High s78-85 except 70-77 South Coast / Cape Cod. Wind SW 10-20 MPH.

DAYS 6-10 (MAY 23-27)

Not high confidence on any details, but the general idea is that a cold front brings a shower or thunderstorm chance May 23, a follow up low pressure area brings a chance of rain May 24, then fair weather follows for the first couple days of the Memorial Day Weekend (May 25-26) before a trough brings a shower threat sometime on Memorial Day itself (May 27).

DAYS 11-15 (MAY 28 – JUNE 1)

Unsettled weather early period, then a progressive pattern brings drier weather back, but watch for another front with shower / t-storm chance later in the period.

DAYS 1-5 (MAY 17-21)

We’ll remain in a general easterly air flow off the Atlantic through the weekend, with varying amounts of clouds dominating over clearer sky, but very little threat of wet weather. It is only sometime tonight and into Saturday morning that some moisture from the east can result in areas of drizzle and/or a few showers. Much of the time from today through Sunday will be free of any precipitation threat. It will be on the cooler side though, especially the closer to the coast you are. This weather pattern comes about as we see a block with high pressure to the north and low pressure to the south. But the pattern breaks down early next week and high pressure moves over us on Monday, then south of us on Tuesday. This is when we see fair weather and a warming trend.

TODAY: Clouds dominate / intervals of sun. Highs 58-65, coolest near coast. Wind E up to 10 MPH.

TONIGHT: Mostly cloudy. Periods of drizzle and possibly a shower, especially eastern MA and NH Seacoast. Lows 47-54. Wind E up to 10 MPH.

SATURDAY: Mostly cloudy with patchy drizzle and maybe a shower in the morning. Clouds break for sun at times during the afternoon. Highs 60-67, coolest coastal areas. Wind E to SE up to 10 MPH.

SATURDAY NIGHT: Variably cloudy. Lows 49-56. Wind SE up to 10 MPH.

SUNDAY: Variably cloudy. Highs 60-67, coolest coast. Wind SE up to 10 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 51-58. Wind S up to 10 MPH.

MONDAY: Partly cloudy. Highs 68-75, cooler South Coast. Wind S 5-15 MPH.

MONDAY NIGHT: Partly cloudy. Lows 51-58. Wind S to SW up to 10 MPH.

TUESDAY: Mostly sunny. Highs 75-82, cooler South Coast. Wind SW 5-15 MPH.

DAYS 6-10 (MAY 22-26)

Above normal temperatures middle of next week followed by a cool-down. Unsettled weather chances go up in the May 23-24 window followed by improvement heading into the Memorial Day Weekend later in the period.

DAYS 11-15 (MAY 27-31)

Drier with warming weather early period, unsettled mid period, cooler late period as we have more west to east progression of the pattern.

DAYS 1-5 (MAY 16-20)

Low pressure to the south brings wet weather through midday today, then a drying trend begins as the low starts to pull away and drier air arrives from the north. A blocking pattern then puts high pressure north of our region but close enough to keep the weather dry from Friday through Monday with a generally cooling easterly air flow, starting to transition to a warming trend by early next week as the high center slips southeastward. After today’s heavier overcast, we’ll see varying amounts of clouds Friday through the weekend as additional unsettled weather is held at bay not too far away to our south and west, but by Monday the sun should increase.

TODAY: Cloudy. Rain and drizzle around through early afternoon, then ending from north to south. Highs 55-62, coolest coast. Wind E 5-15 MPH.

TONIGHT: Mostly cloudy. Lows 45-52. Wind E up to 10 MPH.

FRIDAY: Mostly cloudy. Highs 58-65, coolest coast. Wind SE up to 10 MPH.

FRIDAY NIGHT: Partly cloudy. Lows 46-53. Wind variable under 10 MPH.

SATURDAY: Partly sunny. Highs 60-67, coolest coast. Wind SE up to 10 MPH.

SATURDAY NIGHT: Variably cloudy. Lows 49-56. Wind SE up to 10 MPH.

SUNDAY: Variably cloudy. Highs 60-67, coolest coast. Wind SE up to 10 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 51-58. Wind S up to 10 MPH.

MONDAY: Partly cloudy. Highs 68-75, cooler South Coast. Wind S 5-15 MPH.

DAYS 6-10 (MAY 21-25)

Blocking high pressure holds early in the period with fair, warmer weather (cooler some coastal areas), then a bout of unsettled weather around mid period then a cool-down as fair weather returns at the end of the period, based on current expecting timing.

DAYS 11-15 (MAY 26-30)

Drier with warming weather early period, unsettled mid period, cooler late period as we have more west to east progression of the pattern.

DAYS 1-5 (MAY 15-19)

Frontal boundary to north, low pressure to south. These players result in a kind of disorganized unsettled weather day. Patchy rain is around, more to the west, this morning and should diminish with time, but can’t rule out a few stray showers wandering northward in a southerly air flow today. Tonight, low pressure to our south gets closer and the wind turns more easterly. This is when that low’s rain shield works northward into the region, only to start getting eaten away at and pushed back to the south by blocking high pressure to the north during Thursday. This period of time will show a cool-down with a broad scale onshore flow more established. The weather for Friday and the weekend depends on the magnitude of the block and the ability of high pressure to keep additional moisture at bay. Today, I continue to lean to the drier forecast, similar to that of yesterday. But this is not a super high confidence forecast, so monitor updates.

TODAY: Mostly cloudy. Patchy rain morning. Isolated showers afternoon. Highs 60-67 South Coast, 68-75 elsewhere. Wind S 5-15 MPH.

TONIGHT: Cloudy. Rain returns, especially South Coast to I-90 belt. Lows 50-57. Wind SE 5-15 MPH.

THURSDAY: Mostly cloudy. Rain most likely in the morning I-90 belt southward, then diminishing. Highs 57-64, coolest coast. Wind E 5-15 MPH.

THURSDAY NIGHT: Mostly cloudy. Lows 45-52. Wind E up to 10 MPH.

FRIDAY: Mostly cloudy. Highs 58-65, coolest coast. Wind SE up to 10 MPH.

FRIDAY NIGHT: Partly cloudy. Lows 46-53. Wind variable under 10 MPH.

SATURDAY: Partly sunny. Highs 60-67, coolest coast. Wind SE up to 10 MPH.

SATURDAY NIGHT: Variably cloudy. Lows 49-56. Wind SE up to 10 MPH.

SUNDAY: Variably cloudy. Highs 60-67, coolest coast. Wind SE up to 10 MPH.

DAYS 6-10 (MAY 20-24)

Fair, milder weather early to mid period. Shower chance increases later in the period with a cooling trend.

DAYS 11-15 (MAY 25-29)

Improving conditions, cooler start then warming trend.

DAYS 1-5 (MAY 14-18)

A spring blocking pattern is going to create better weather than we might have otherwise during the next 5 days. Now don’t get the idea that we have 5 straight top-ten days ahead. We don’t. And we’ll see a variety of weather. Follow along to gain and understanding of how I think this will play out…

A bit of an atmospheric chess game will work out mostly in our favor, keeping the weather on the drier side more often than not in the days ahead. First, a warm front is passing by first thing this morning, having produced lot of clouds and a few scattered showers overnight. But today, we’ll have a late spring feel in much of the region, even a little preview of summer, as the temperature surges well into the 70s to around 80 for highs, away from the cooling influence of a southwest wind off the Atlantic which will prevent much of the South Coast from even reaching 70. A cold front will be approaching the region tonight, but the short range guidance has been steadily trending this feature weaker and slower and I believe this will be the case. The front never really truly moves through the region at all. We get more clouds tonight and a few showers may wander into the region into the early part of Wednesday, favoring northern portions of the WHW forecast area, and then that should be about it for that front for us as it pretty much washes out. Our cool-down will result from low pressure forming and moving out south of our region later Wednesday through Thursday, turning our wind more easterly off the Atlantic. But the blocking in place wants to force this system further south, another trend I’ve been following over several days on medium range guidance, now pretty much confirmed by short range guidance. So the forecast for this feature is for some rain to occur near the South Coast Wednesday night and part of Thursday, but the majority of the region to miss out on the rain from it. This low sits off to our southeast then on Friday and Saturday, far enough way to keep rain away, but close enough to exert influence on the next approaching low, slowing it down and keeping it further south and west, hence a now mainly dry forecast for both Friday and Saturday. This part of the forecast, of course, is lower confidence than the next couple days, so check updates going forward.

TODAY: Lots of clouds early, then mostly sunny to partly cloudy. Highs ranging from near 60 Cape Cod to around 80 from Metro Boston west and north. Wind SW 5-15 MPH.

TONIGHT: Partly cloudy early, then mostly cloudy with isolated to scattered showers late evening and overnight. Lows 54-61. Wind SW 5-15 MPH, higher gusts possible.

WEDNESDAY: Mostly cloudy. A few showers possible in the morning favoring areas north of I-90. A bit of rain possible near the South Coast late in the day. Highs 60-67 South Coast, 68-75 elsewhere. Wind S 5-15 MPH.

WEDNESDAY NIGHT: Cloudy. Chance of rain near the South Coast. Lows 48-55. Wind SE 5-15 MPH.

THURSDAY: Mostly cloudy to partly sunny. Chance of rain near the South Coast early. Highs 58-65, coolest coast. Wind E 5-15 MPH.

THURSDAY NIGHT: Partly cloudy. Lows 45-52. Wind E up to 10 MPH.

FRIDAY: Variably cloudy. Highs 58-65, coolest coast. Wind SE up to 10 MPH.

FRIDAY NIGHT: Partly cloudy. Lows 46-53. Wind variable under 10 MPH.

SATURDAY: Partly sunny. Highs 60-67, coolest coast. Wind SE up to 10 MPH.

DAYS 6-10 (MAY 19-23)

Fair, milder weather early to mid period. Shower chance increases later in the period as an evolving zonal flow allows a trough and front to move in from the west.

DAYS 11-15 (MAY 24-28)

Early-period unsettled weather potential, then improvement following. Temperatures start cooler, then moderate.

DAYS 1-5 (MAY 13-17)

Like last week, we have a warm-up to start the week off today and Tuesday. Today we moderate over yesterday quite nicely as we’ve lost the clouds and will turn the wind around to southwest with high pressure to our south. Tonight, a warm front will cross the region with clouds and maybe a few showers – much of the region probably staying dry or just seeing brief rain. Tuesday warms even more over today behind the front, with more sunshine and a slight up-tick in the humidity that those sensitive to it may notice. A cold front approaches at night, but most of the energy for its showers will stay to the north, with just perhaps a few wandering into the region overnight and early Wednesday as the front moves in and washes out. While this is happening, low pressure organizes to our south. The trend on this from guidance has been for it to occur further and further south, to the point where the primary rain threat from the low is confined to the South Coast. It looks like that at this point and my hints of a mostly cloudy but largely rain-free forecast for Wednesday as discussed on yesterday’s blog are carried over and solidified today. There’s a little uncertainty on medium range guidance for late week with a few different scenarios depicted, but the one I am leaning toward carries the surface low out to sea Thursday while an upper level disturbance brings a sun/cloud mix and maybe a shower. And Friday, another trough approaches from the west with an increase in clouds. Further refinement of this later-week outlook will take place on the next update.

TODAY: Cloud patches early to mid morning in some locations, otherwise a fair amount of sun then some additional clouds arriving later in the day. Highs 56-63 South Coast and Cape Cod, 63-70 elsewhere. Wind SW 5-15 MPH.

TONIGHT: Mostly cloudy. A passing shower possible. Lows 50-57. Wind SW 5-15 MPH.

TUESDAY: Partly to mostly sunny. Highs 65-72 South Coast, 73-80 elsewhere. Wind SW 5-15 MPH.

TUESDAY NIGHT: Partly cloudy early, then mostly cloudy with scattered showers late evening and overnight. Lows 54-61. Wind variable 5-15 MPH.

WEDNESDAY: Mostly cloudy. A few showers possible in the morning favoring areas north of I-90. A bit of rain possible near the South Coast. Highs 58-65, coolest coast. Wind variable to SE 5-15 MPH.

WEDNESDAY NIGHT: Variably cloudy. Lows 45-52. Wind N 5-15 MPH.

THURSDAY: Partly sunny. A possible shower. Highs 56-63. Wind NE 5-15 MPH.

THURSDAY NIGHT: Partly cloudy. Lows 45-52. Wind N up to 10 MPH becoming variable.

FRIDAY: Increasing clouds. Highs 58-65, coolest South Coast. Wind variable to S up to 10 MPH.

DAYS 6-10 (MAY 18-22)

My outlook continues to largely ignore medium range guidance in anticipation of some errors, so after an early unsettled start for the weekend of May 18-19 it should improve with a milder finish than it starts out. Fair weather early next week, maybe unsettled by middle of next week with milder weather.

DAYS 11-15 (MAY 23-27)

Upper level low pressure may bring cooler and somewhat unsettled weather early to mid period – details TBD. Improvement may follow for Memorial Day Weekend which is May 25-27. Low confidence based on how far in the future this is, so follow updates.