Saturday June 21 2025 Forecast (7:50AM)

157 Comments

DAYS 1-5 (JUNE 21-25)

High pressure controls our weather today with lots of sun, a pleasant breeze at time (maybe a coastal sea breeze), low humidity, and seasonable warmth. You’ll start to notice some cloudiness appearing in the northwestern sky toward the end of the day. Remember the MCS (mesoscale convective system) that has been talked about here on the blog for days? That formed last night in the Upper Plains and began its trek eastward, which it does today moving through the Upper Great Lakes. It then takes a turn southeastward on the “ring of fire” eastern side of a high pressure ridge. This propels it, likely in a decaying but still somewhat potent state, into and across New England during the first 8 to 10 hours of Sunday. While this system looks like its greatest impact will be north and west of the WHW forecast area, a round (or two) of gusty showers and thunderstorms can occur in this area from around sunrise to late morning on Sunday. This type of a set-up, even with a weakening system, can produce areas of wind damage. Hail and frequent lightning can also occur with any remaining or re-developing stronger thunderstorm cells, so we’ll have to watch for that. Residual cloudiness in the wake of the system can limit the sun for a few extra hours, and rain-cooled air will also be present, and this will have an impact on Sunday’s high temperatures, which would have been hotter otherwise. My forecast will adjust for these limiting factors, and while by late-day it may feel hot and humid in much of the region, it will still be limited from its original potential. Monday and Tuesday we have a better upper level pattern set-up for significant heat, but a weak surface pressure gradient will allow for a pretty widespread coastal sea breeze to develop on Monday, keeping coastal communities from getting too hot, while it will be hottest inland. Tuesday, the sea breeze potential is weaker, so the region overall will see its hottest day of the stretch. A back-door cold front will put an end to the heat by Wednesday, accompanied by some clouds, but no more than an isolated shower or thunderstorm as it looks this far in advance.

TODAY: Sunshine dominates. Highs 80-87, 75-82 some coastal areas. Dew point sub-60. Wind W to N up to 10 MPH with coastal sea breezes.

TONIGHT: Clouds increase. Lows 61-68. Dew point approaches 60. Wind variable to S up to 10 MPH.

SUNDAY: Mainly cloudy through mid morning including scattered to numerous showers and thunderstorms, a few of which can be strong. Partly sunny late morning to mid afternoon with an isolated thunderstorm possible. Mostly sunny late-day. Highs 83-90 except 75-82 some coastal areas. Dew point 60+. Wind variable, mainly S 5-15 MPH early but can become strong and gusty near showers and thunderstorms, then variable to mainly N 5-15 MPH by late morning on, diminishing late in the day.

SUNDAY NIGHT: Mostly clear. Patchy fog. Lows 62-69. Dew point 60+. Wind SW up to 10 MPH.

MONDAY: Mostly sunny. Highs 86-93 inland, 78-85 coast. Dew point 60+. Wind variable up to 10 MPH with coastal sea breezes developing.

MONDAY NIGHT: Mostly clear to partly cloudy. Lows 65-72. Dew point 60+. Wind variable to SW up to 10 MPH.

TUESDAY: Mostly sunny. Highs 91-98 but considerably cooler South Coast, and possibly cooler eastern coastal areas. Dew point 65+. Wind W up to 10 MPH with an immediate coastal sea breeze potential.

TUESDAY NIGHT: Mostly clear to partly cloudy. Lows 70-77. Dew point 65+. Wind W up to 10 MPH shifting to N.

WEDNESDAY: Partly sunny. Slight chance of an isolated shower or thunderstorm, favoring inland locations. Highs 78-85. Dew point 60+. Wind NE 5-15 MPH.

DAYS 6-10 (JUNE 26-30)

June 26-27 features a broad scale but weak maritime air flow with varying amounts of clouds, a few chance for showers and thunderstorms, and mild temperatures with moderate humidity. Warmer weather in the June 28-30 period with an isolated shower or thunderstorm possible but mainly dry weather. More details to come…

DAYS 11-15 (JULY 1-5)

Overall trend is upper level west to northwest flow but surface high pressure mostly dominant. While there may be a brief shower or t-storm threat a time or two, this pattern is mainly dry and seasonably warm overall.

157 thoughts on “Saturday June 21 2025 Forecast (7:50AM)”

  1. The MCS produced wind gusts as high as 94 mph as it moved across North Dakota overnight. When I got to the office at 3am, the MCS was moving across eastern North Dakota and western Minnesota. Just 5 hours later it’s crossing Lake Superior and the Upper Peninsula of Michigan. It is moving rather quickly.

    1. Will there be anything left when it gets here, if it even gets here?
      That is the question. And if so, where does it primarily hit?
      And how much debris cloudiness is left around tomorrow.
      Would be nice IF it prevented 90 degree readings.

  2. Good morning and thank you TK.
    I see latest model trends coming back closer to your forecast highs. Although a few 100 degree reading appear here and there, none are showing for Boston. Interesting.
    I wonder how potent the sea breezes will be. Very likely preventing Logan from a true Heat wave. Could it prevent Logan
    from ANY 90 degree days??? Will be fund to watch that for sure.

    I’ll bet anything I see 90+ here Sunday, Monday and Tuesday.
    Will be posting.

    Took 2 more ACs down from the attic yesterday and cleaned them all out while it was dry. Now I just have to place them in the windows. Will do today or at lunch tomorrow. Have not yet decided. We like the natural air coming in the house and detest blocking windows. House feels so NICE this morning!! DRY and COOL!!!! The new AC we already have installed has been working very well.

    1. I’d wait. Do it in the rain-cooled air behind the showers tomorrow if you can do it around the end of whatever we get. Today, the air is rather refreshing.

  3. Thanks TK.

    Jacob has 101 for Tuesday. We’ll see if Logan gets there.

    I bet JPD easily gets to 100 along with other Boston neighborhoods. Logan Airport is a strange location weatherwise regardless of the season.

  5. The next several days should re-teach some lessons on the “rip-&-read” use of 2m forecast temps on models.

    1. you have been preaching that for a long time. As we get closer, models appear to be adjusting.

      btw, Last evening Eric had 101 for Logan. Did he seallow it hook line and sinker???? Or does he genuinely believe that? I suppose it is still possible, We shall see.

  6. At the summit of Mt Major in NH. Gorgeous day! Perfect view of Lake Winnipesaukee. Haze way off in the distance, but can see for miles.

    About to take the trek down.

  8. Thanks TK !

    The 00z Euro has 99F at Logan, under 100F, but its projected dp is now 67F. When it projected 101F on the 12z yesterday, it projected a 64F dp.

      1. Awesome for you both. Took me five. A friend who typically does better than I didn’t get it. A few others didn’t either.

  10. I wrote a new blog post for the company blog this morning:

    https://www.hometownforecastservice.com/heat-humidity-and-a-snowstorm/

    For the record, I agree with TK (as usual), that it will likely not reach 100. It is extremely tough to get to 100 in this region, especially this early in the summer.

    # of times reaching 100 before July 1:

    Boston: 3, all exactly 100 (6/6/1925, 6/26/1952, 6/30/2021)
    Blue Hill: 0 (highest is 99 on 6/4/1919)
    Providence: 0 (highest is 98 done 4 times, last 4/19/1976)
    Worcester: 0 (highest is 98 on 6/26/1952)
    Hartford: 2, both exactly 100 (6/26/1952 and 6/30/1964)
    Bedford: 0 (highest is 99 on 6/26/1952)
    Norwood: 0 (highest is 98 on 6/29/2021)
    Lowell: 5 (101 – 5/22/1992, 100 4 times – 6/26/1952, 5/21/1975, 6/22/1983, 6/10/1984)

      1. Yup remember that time. It was 93 in Boston on the 18th. We have a photo of our Daughter in her Easter outfit repleat with a beautiful coat. She was dying it was so hot!!!! Hmmm I just looked, Easter Sunday was April 18th that year and that WAS the hot day here. I wonder if there was a back door and Providence got nailed the next day, the 19th and boston did not.
        Boston was down to 82 on the 19th while Providence hit 98.

  12. Current location of our MCS that we have been tracking

    https://radar.weather.gov/?settings=v1_eyJhZ2VuZGEiOnsiaWQiOiJsb2NhbCIsImNlbnRlciI6Wy04NS44MTMsNDYuMTZdLCJsb2NhdGlvbiI6bnVsbCwiem9vbSI6Ny4wMjY4NzU3MjE4MDM4MjEsImZpbHRlciI6IldTUi04OEQiLCJsYXllciI6InNyX2JyZWYiLCJzdGF0aW9uIjoiS0FQWCJ9LCJhbmltYXRpbmciOmZhbHNlLCJiYXNlIjoic3RhbmRhcmQiLCJhcnRjYyI6ZmFsc2UsImNvdW50eSI6ZmFsc2UsImN3YSI6ZmFsc2UsInJmYyI6ZmFsc2UsInN0YXRlIjpmYWxzZSwibWVudSI6dHJ1ZSwic2hvcnRGdXNlZE9ubHkiOnRydWUsIm9wYWNpdHkiOnsiYWxlcnRzIjowLjgsImxvY2FsIjowLjYsImxvY2FsU3RhdGlvbnMiOjAuOCwibmF0aW9uYWwiOjAuNn19

  13. Although we didn’t know it at the time, the Bruins made a historic change to the organization on this date in 2003. After taking Defenseman Mark Stuart with the 21st overall pick in the draft, in the 2nd round at #45 overall, they drafted a 17-year old kid from L’Ancienne Lorette, Quebec. He had played 1 full season for the Acadie-Bathurst Titan of the the QMJHL, racking up 23 goals and 50 assists in 73 games, then adding another 6 goals and 9 assists in 11 playoff games. Most observers figured he needed at least 1 or 2 more years of junior hockey before going back, but he surprised everyone making the Bruins as an 18 year old after a spectacular training camp that fall, scoring 16 goals and adding 23 assists in 71 games as a rookie.

    It was 22 years ago today that the Bruins drafted future Hall-of-Famer Patrice Bergeron.

      1. Yeah right, and only ONE lousy Stanley Cup (2010-11) to show for it. 😉

        I bet at some point soon the Florida Panthers will equal the same number (6) of Cups as the Bruins did in their entire 100+ year history. They’re one away from “half” of the Bruins total already.

          1. I have always disliked the Bruins Organization, although the players seem to be very nice. Years ago met several at a Bruins charity event and they were all super nice.

        2. Edmonton won 5 in 7 years in the 80s, and hasn’t won any since then. The Islanders won 4 in a row in the early 80s ad haven’t won since then. Even the Canadiens, winner of 24 Stanley Cups, hasn’t won one in 32 years. Just because a team has won the last 2 in a row does not mean that they are going to keep winning them. In fact, the odds are strongly against them winning again.

  16. The 12z HRRR supports TK’s thinking that rain cooled air with further cloud debris keeps temps just short of 90F tomorrow.

    What a warm overnight it has Sunday night, mid 70s so far up to 2am and not just the heat island of the cities, combined with low 70s dps.

    1. Will be interesting to see how it shapes up.

      NWS hints that thunderstorm chances increasing with the MCS for SNE. We shall see.

  17. Thanks Tk . Big job in Carver next Saturday the 28th so I’m hoping for no rain.

  22. Congratulations Captain on your retirement! 🙂

    Did your fellow teachers give you a formal retirement party? I certainly hope so! 🙂

    Enjoy! Now EVERY day will be a “snow day”. ❄️ 😉

  23. The MCS is overplayed on the HRES stuff. The idea of a single system on being on a NNE trajectory and then diving south into stable, drier air, and becoming more energized does not pass the reality test to me.

    Boston won’t hit 100. If anywhere hits 100 in SNE its the Hartford to Amherst corridor.

      1. ha ha ha. Even though I have asked and been assured that the Norwood sensor is AOK, I remain skeptical. Norwood stands out with consistently higher temperatures.

        THANK YOU JMA!!!!

        1. Norwood has been a hot spot for years. Geography.

          Believe me, when there is a sensor that’s off, I notice it, and point it out.

          I’ve been following this stuff too long not to notice. Trust me. 🙂

    2. Yes this is why I mentioned remains / decaying stage. It to me looks like a slightly lesser version of 7/15/1995.

  25. Talk about a roller coaster. 12Z NAM has Boston at 73 Monday PM. Wow! Of course, doesn’t mean it is correct, but would not surprise me in the slightest. And if so, NO 90 here in JP either. Perhaps 80 or so. We shall see. Would be nice, if you ask me.

  27. Ocean temperature (Boston buoy) down to 57,2 as a result of upwelling from yesterday’s wind. Get a sea breeze with that temperature and we’ll feel it. 🙂

    1. As I said, Monday is a prominent sea breeze day. Those cooler water temps are a factor.

      Most people won’t even think of it when setting up a forecast a few days in advance. This is where experience and taking EVERYTHING into account and not just looking at model output comes into play. SAK and I learned this – had it drilled into our meteorological brains – from the best in the business during our post-college days.

      1. Indeed. I for one, am very tuned into that ocean temperature after living with an East wind every Spring for, well I don’t want to say how many years, but a LONG TIME!!! And yes even in the Summer and although it is Summer officially, that ocean is still plenty cool.

  28. Thanks, TK.

    I read some Bruins talk above. I do NOT think of the Bruins’ run with Bergeron et al. as a failure at all. They were a very competitive team throughout the entire period. I never just view championships as THE barometer of success. Making it to the finals 3 times during that period is great. And having a perennial competitor is, too.

    Perhaps my time living overseas has `tainted’ my perspective. I love the fact that European fans of their clubs are never opportunistic. That is, they root for them no matter what, win or lose. AND, winning it all is not considered the only metric of success. I must say that this American obsession about being number one or bust is off-putting.

    1. This was the early morning forecaster’s take on the MCS potential from NWS Boston…

      “The main forecast issue for tonight revolves around the track of what is currently a severe mesoscale convective system (MCS) seen in early-Saturday-morning satellite imagery over NE MN. This feature and its convectively-augmented shortwave disturbance is rotating around a building heat ridge over the mid-MS Valley with a plume of mostly capped but extreme convective instability over the
      mid/northern MS Valley associated with the northeastward advection of an elevated mixed layer coming off the Rocky Mtns.

      Models over the last few days have hinted at this for the past few days, although the track of this feature is still a bit
      uncertain. There is a pretty apparent split in outcomes between the global models and the convective-allowing models; the global models (GFS, ECMWF, NAM- 12) all take this feature across far northern New England or adjacent Quebec late tonight with little to no impact to SNE. On the other hand, the majority of the CAMs have trended further SW, essentially backbuilding the southern end of the MCS into the considerably more unstable air, with a potential MCS moving over parts of or all of SNE during the pre-dawn to early Sunday morning hours (approx 3 to 8 AM). Although surface based instability progs at that time of day are essentially nil, steepening lapse rates aloft support nearly 1500 J/kg of MUCAPE with increasing effective shear to around 40-45 kt, a shear/instability space which could support embedded elevated supercells above more stable sfc layer.

      There still is quite a bit of uncertainty regarding this feature`s
      track and how strong it may become, were it to affect our area. The outcomes here range from passing us by to the north, to an overnight to early-day MCS capable of hail, wind damage and torrential rain. I ended up following the trends in the CAMs, which increase PoPs into the 15-25% range for the southern coast, and increasing to around 30-50% for northern MA. After coordinating with the neighboring WFOs, also included enhanced wording for gusty winds, hail and heavy downpours. While not set in stone, there has been an uptrend in at least some overnight/early-Sunday impact from this convective complex. Stay tuned on this situation.”

      Some of that’s a big technical, but you can get the general idea from the rest of the wording. Also there are a couple formatting glitches – I tried to fix most of them.

  30. Thanks TK. Hope you and others are right about temps coming up being overdone. Love to see the numbers roll back. Some channels had Tuesday hitting 103.

      1. Pete brought it up too. I actually watched EVERYONE last night just to see how the news directors were directing things. 🙂

  32. The hype in most cases not all never happens. When I was in Sarasota last week some of the seabreeze storms were 60k into the atmosphere. For them no big deal. Around here the mediia would have said ” Maybe 100.000k height into the atmosphere”.

  33. At the beach, very gentle seabreeze. Guessing it’s about 75F at the beach. It was 80F leaving the house.

  34. Maybe I misinterpret and again, I agree the media oversensationalizes, but I don’t think putting 100F or 101F on the 7 day for Tuesday is overhyping. Had they put 104, 105F+, then that to me is overhype in this specific scenario.

    98F vs 101F to most people is going to feel very hot.

    1. I shy away from the term “hype”.

      What I did state is that I do not agree the air temps will max out there on Tuesday. And then gave my educated reasons for the opinion.

  35. Our “soggy Saturday” streak ends today at #13!

    I suppose if it wasn’t for all those wet Saturdays, we still might very well have been in drought mode. Done with that for awhile. 🙂

    Thanks for reminding us SAK!

  37. Logan has an ESE seabreeze at 13 MP with temp at 79. Don’t expect it to stay that high for too long. I would expect it to drop to the low to mid 70s, if not lower. Watch Logan prove me wrong.

    brrrr Boston Bouy water temperature now down to 56.5!!!!

    Is this June 21st? or April 21st?? Good Grief, that is COLD WATER!!!!!!!

    No wonder there is a seabreeze and Logan will probably be in the 60s or lower 70s tomorrow while Springfield is 95. Wouldn’t that be a hoot????? Then on Tuesday Logan back up to 95-100!!!!
    WOW!!! Gotta love it! Crazy crap for sure!!!!!

    1. I meant Monday for the big Logan Sea Breeze, although they will probably have one tomorrow as well, perhaps not as potent.

      It’s only 81 here, but with that high sun angle, it is getting warm in the house. We have 1 AC cranking and doing its job beautifully.

      I wish I could jump To Wednesday and skip the heat!!!!!

      1. FWIW Eric predicted a high of 88 for Logan on Monday.
        That may be just a wee bit high. We shall see.

        1. I don’t think a high of 88 is a bad prediction for Monday. It could end up several degrees lower, depending on arrival and strength of sea breeze, but that’s really fine-line kind of stuff.

          1. I agree. Waiting to see how strong it becomes and how much the ocean surface water warms up tomorrow., I assume it will some. That will be a factor as well,

  39. SPC thoughts for tomorrow
    if convection
    moving into the Northeast by Sunday morning is less robust,
    convective re-intensification may be more likely farther north into
    southern New England. A more focused severe threat would be highly
    dependent on the placement and evolution of earlier convection/MCS
    morphology across Ontario during the late Day 1 period, which
    currently has low predictability. Despite weak vertical wind shear,
    of concern is the eastward advection of a modest EML into the
    Northeast, which may boost MLCAPE well over 3000 J/kg (perhaps over
    4000 J/kg locally). Higher severe probabilities may be needed if
    confidence in the placement and/or timing of more organized
    convection increases.

  40. 12Z Euro has it 85 Degrees at 12Z Monday or 8AM. That doesn’t bode well at all.

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=sfct_b-imp&rh=2025062112&fh=72&r=us_ne&dpdt=&mc=

    and up to 102 for Boston by 2PM and who knows what happens 2-5 PM????? Could go even higher.

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=sfct_b-imp&rh=2025062112&fh=78&r=us_ne&dpdt=&mc=

    So, 3 days out. Is the Euro still Over doing it. I know it tends to do that 7-10 days out for sure, but does it still do it at 3 days out.

    This doesn’t look good.

      1. So, even a few days out. Wow! One would think that they could perform better than that.

        850 MB temps to be around 22C which “could” equate to a high temperature of 99.

        I know you said 96 for Boston. Not enough Mixing to attain the 99?? Curious.

        Wind looks to be W to WNW, perhaps allowing for some down slope heating. We shall see. And dp only 67 to 68 or so which could allow for slightly higher temperatures.

        In short I am WORRIED about Tuesday!
        If we lose Power, we’re COOKED, almost literally!!!
        We’d have to drive around in the car or find a motel room.

  44. Thanks, TK!

    While listening to my “Patriotic/Summer” playlist on my deck and celebrating the first day of “Sum-mah” and retirement, this song by The Cars came up in rotation:

    Speaking of “Sum-mah” (“It turns me upside-down!”):

    https://www.youtube.com/watch?v=E0Kv6vxZwL8

    Uh Oh, It’s Magic! 🙂

    1. If I am correct about where the sensor is, an ESE wind actually blows along the length of a runway before reaching the sensor. That probably makes a difference.

  47. Didn’t catch this earlier. Bemidji airport in Minnesota recorded a wind gust to 106mph when the MCS came blasting through early this morning.

    KBJI 210555Z AUTO 33034G92KT 3/4SM +TSRA OVC003 17/17 A2967 RMK AO2 LTG DSNT ALQDS P0088 60097 T01720172 10255 20172 402860125

    1. Impressive … it’s funny, somebody on the net (not the blog) kind of accused me of hyping up the MCS when I should be focused on the heat. Gave me a good laugh.

        1. It may trend a degree or two high at times, but NWS says that’s “acceptable error”.

  49. I have between now and about 1AM to make the decision to keep the windows open overnight. I see mixed guidance all over the place. My gut so far says, NOPE to any rain in Boston, but that could be dead wrong and requires further monitoring.

    Waiting on 18Z runs. HRRR should starting coming out in 10 -20 minutes or so and NAMs about 35-40 minutes. We’ll see what they have to say.

    2. hmmm after 1 line fizzling, HRRR sends another. Looks like it wants to rain on Boston in the morning like 10-11Z.

  50. 84 here in Quincy. Not bad given the proximity to the ocean. Don’t know the wind direction.

  51. Mansfield airport is 85 as it is here, yet Norwood, only a few miles away is at 88. Seems odd to me.

  52. Just checked Norwood. It’s at an airport. Correct? Its temps are pretty much in line with sensors around it. Did anyone write or call nws?? Someplace I have the email of the person I spoke to a couple of years ago re Logan sensors?

    1. Found address. His explanation then was exceptionally detailed. I’m happy to write again if no one else has

  54. When will we know where the MCS will definitely hit? How much lead time will there be? Thanks.

  57. Being near the shore, it’s cooler of course. Still sticking with an over / under of 96F for Tuesday and I took the under. My friend took the over. A bottle of Cabernet is at stake!

  58. Tk I know you’re a big fireworks fan but, hingham is doing a drone show this year. Ever seen one of those?

    1. I haven’t seen one in person. They have grown a bit in popularity, but are far, far more expensive than fireworks. They will not be replacing fireworks anytime soon in a general sense.

  59. Beautiful night sitting on the back deck , very pleasant with a very , very slight breeze @ 73

  62. The warm air advection at 700 mb tomorrow is super strong, at 850 mb, there’s some, but not as strong.

    HRRR has a lot of cloud debris to our southwest but not a ton in New England.

    If cloud debris holds off, with the warm advection, I think high temps might be closer to 4pm, as opposed to 2-3 pm.

  63. What a warm evening tomorrow night is shaping up tomorrow night.

    00z or around sunset, mid 80s, low 70s dps and heat indices near 90F around sunset.

    1. No, it really wouldn’t. We’ve seen plenty of backdoor fronts bring in much cooler air with significant warming aloft. This is the same thing on a much smaller scale.

  68. Once again WBZ late night radio is playing the AccuWeather forecast from the overnight before. This is now the second time, at least for me. Who knows how long they’ve been doing it?

    This WBZ/iHeart collaboration is awful radio!
    I wish some local rich benefactor would buy WBZ radio and bring it back to its late night “talk” roots. I bet it’s totally automated with no radio personnel other than a security person or two.

    I just had to rant this early in the morning.

    1. That may not be WBZ’s fault. It could be Accuweather. It could be a comms problem between them. Trust me, I deal with similar issues ALL the time at work.

  69. So, we all got a good laugh at the NAM yesterday when it had the MCS make a hard right turn and send a squall line through central NY instead of around here. Well, guess what? The squall line is going through central NY this morning with just some showers out ahead of it across New England.

    1. NAM wins that one. 🙂

      HRRR was decent with the size and placement of the system, but the NAM definitely won the surface convection forecast.

    1. Unless you are in Binghamton, the only thing bearing down on us is an area of light to occasionally moderate rain showers.

    1. Pretty much as expected. I stressed this would be a decaying system moving through here, but to watch for stronger storm pockets (that happens to be in NY State right now).

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