Saturday July 29 2023 Forecast (7:56AM)

223 Comments

DAYS 1-5 (JULY 29 – AUGUST 2)

Boston can record an “official” heatwave with enough sun pushing their high temp to 90 today, but with highs of 91 & 90 the 2 previous days, this is hardly headline news. It’s July. What’s of more importance today is the threat of strong to severe thunderstorms with potential wind damage, instances of potentially large hail, and also areas of flash flooding possible from torrential rainfall. This is what the focus of today’s weather should be, not whether Boston’s high temp is 88, 89, 90, or 91. My prediction, by the way, is 89. So now that we have that taken care of, what’s the reason for the severe weather threat? Simple: Warm air, high humidity, cooling aloft, and an approaching disturbance and cold front. As higher dew points advect into the region this morning, some shower activity has been observed near the South Coast, but it looks like most of this will fade and move off to the east by mid morning and not really be a factor for a very long time. Much of the day will just end up rain-free, warm to hot, muggy, with a sun/cloud mix. While there can be a few isolated showers and thunderstorms popping up mainly from southern NH through the northern 2/3 of MA by mid afternoon, the “main event” looks a little later in timing, and its evolution may be a bit tricky. We probably see a fairly solid cluster or line of storms get going from NY to VT mid to late afternoon, then start an east southeastward march. But a dew point boundary and potential outflow boundaries from any advanced isolated cells make a region from around the Route 2 to I-90 corridors vulnerable to the eruption of new storms, and it’s entirely possible that this becomes the “new line” as the original one starts to weaken and “mush out” into a blob of more elevated convection. We’ll have to monitor the radar closely this afternoon to see how it goes. For this reason, I am leaning toward the Route 2 corridor southward as the most likely to see damaging storms with high winds and hail, as well as frequent lightning, which is not considered a factor in storm severity as far as warnings go. Any storm that contains lightning is a danger in itself, regardless of whether or not severe parameters are expected or achieved through hail 1″ or greater in diameter and wind gusts of 58 MPH or greater. The flash flood threat is greatest in areas that see torrential rainfall for more than just a few minutes, and in some instances where storms can train over the same region for a while it becomes a potentially bigger issue. In short, be on the look-out for storms and prepare to take action to protect yourself. Many outdoor activities on a summer weekend leave many vulnerable, so I can’t stress enough to keep an eye on the weather today! Regardless of the details of the event’s evolution, it will come to an end as storms exits via the South Coast and Cape Cod early tonight. While the South Coast & Cape are not immune to severe weather today, that region may be spared the worst with just a couple isolated stronger storms there in a more general area of showers – but like other areas keep an eye on trends. This is not strictly diurnally driven and sometimes enough of a boundary / lift of air in that region can keep storms going for a while. Tonight, a cold front sweeps through and the dew point which seems like it’s been 60+ forever will go to below 60 across the region, though it may take until mid or late morning Sunday to do so closer to the South Coast. Sunday will be a comfortable, rain-free day, but expect some diurnal clouds to pop up, more of the decorative variety. Monday’s weather looks fairly pleasant too. The dew point may tick back up a few degrees but really only to around 60 or just over it. This takes place ahead of a weak disturbance that may help initiate a quick shower over some locations during the afternoon or evening. This looks like a minor event, isolated in nature for showers, and favoring southwestern NH and central MA. Don’t cancel any Monday plans! We’ll welcome August with a sun/cloud mix but comfortable air Tuesday as a weak trough is still around but probably not enough for any showers. Wednesday, high pressure builds in surface and aloft with awesome weather!

TODAY: Variably cloudy. Isolated to scattered showers South Coast / Cape Cod until mid morning. Isolated to scattered thunderstorms possible mid afternoon and becoming more likely late afternoon mainly north of I-90. Widespread evening showers/thunderstorms. Any storms can be strong to severe with potential for damaging wind, large hail, frequent lightning, and flash flooding. Highs 85-92, cooler South Coast. Dew point upper 60s to lower 70s. Wind SW 5-15 MPH can be variable, strong, and gusty near storms.

TONIGHT: Variably cloudy. Showers/thunderstorms end by late evening, lastly near the South Coast / Cape Cod. Areas of fog forming. Lows 58-65. Dew point falling to upper 50s north of I-90 but still staying around or over 60 to the south. Wind variable becoming NW-N up to 10 MPH.

SUNDAY: A sun/cloud mix. Highs 77-84. Dew point upper 50s to lower 60s north to south, gradually decreasing during the day. Wind NW up to 10 MPH.

SUNDAY NIGHT: Mostly clear. Areas of ground fog in lower elevations. Lows 55-62. Dew point middle to upper 50s. Wind NW under 10 MPH.

MONDAY: A sun/cloud mix. An isolated shower possible by late-day mainly central MA and southwestern NH. Highs 78-85. Dew point around 60. Wind N up to 10 MPH with light coastal sea breezes.

MONDAY NIGHT: Partly cloudy early, then mostly clear. Lows 55-62. Dew point below 55. Wind variable under 10 MPH.

TUESDAY: Partly cloudy. Highs 76-83. Dew point below 60. Wind NW up to 10 MPH.

TUESDAY NIGHT: Clearing. Lows 56-63. Dew point below 55. Wind NW up to 10 MPH.

WEDNESDAY: Sunny. Highs 77-84. Dew point below 60. Wind W up to 10 MPH but local coastal sea breezes possible.

DAYS 6-10 (AUGUST 3-7)

Surface high pressure shifts to the east August 3 with fair weather and becoming slightly more humid. Trough / front from the west brings a shower/thunderstorm chance August 4. August 5-6 weekend looks mainly dry, less humid to start, more humid to finish, then some additional unsettled weather is possible by the end of the period with higher humidity. No significant heat expected.

DAYS 11-15 (AUGUST 8-12)

A weak westerly flow and weak trough much of the time in the region. This pattern is seasonable to cooler than normal with a couple shower chances, but not overly unsettled.

223 thoughts on “Saturday July 29 2023 Forecast (7:56AM)”

  2. https://www.pivotalweather.com/model.php?m=hrrr&p=scp&rh=2023072909&fh=16&r=us_ne&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=hrrr&p=stp&rh=2023072910&fh=15&r=us_ne&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=rap&p=stp&rh=2023072910&fh=15&r=us_ne&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=hrrr&p=sfcwind_mslp&rh=2023072910&fh=15&r=us_ne&dpdt=&mc=

    TK or others ……

    Links from 2 most recent HRRR’s and RAP

    This evening, right just S and SE of sfc low on front.

    Supercell/tornado parameters come up a bit.

    I don’t like this signal, is it a concern ????

  4. Good morning and thank you TK.
    Anticipation, that’s the word for today.
    I hope no one sustains any damage.

    Tk, I guess you believe that there is not enough tornado threat to even mention.

    Tornado parameters almost not there at all. None-the-less with some of the boundaries you mention, we could get some isolated turning of the winds and a resultant tornado. Need to watch.

    btw, Pete was not on last night, by Tevin Wooten sure mentioned tornadoes. He was quite concerned. I like Tevin. I think he is polished and knows his stuff. We are fortunate to have him.

  5. I know I’m overreacting, but I am concerned.

    Sfc ripple moving across southern New England in an environment with all the qualities TK listed in his discussion above. Flash flooding and other hazards.

    I’ll be glad when we’re past this particular weather feature.

  7. I’m a bit unsure of the south of route 2 corridor. The route 2 to I90 corridor is mentioned. But the most damaging storms are expected south of route 2. Is that expected to also be south of 2 but north of 90. And I absolutely understand that nothing is a given. Just trying to figure if my area is part of the most damage potential

    1. Expect possible severe anywhere south of rt 2. look at spc slight area. it looks to go right down rt 2

    2. Basically the belt from about 10 miles north of Route 2 to about 10 miles south of I-90 is my greatest concern for severe storms in the classic sense right now but this could evolve to be a slightly different scenario as the day goes on.

  8. SPC update soon, but in the last iodate they painted quite a swatch of 2% tornado chances.

    1. I’m with you. I agree with JPDs anticipation but am uneasy when it comes to damaging storms.

  14. Well, my interest starting early this afternoon will be locating and trying to guess the general track of this 1002-1005 mb sfc low.

    My takeaway from these short range models is that the thunderstorms in the sfc lows vicinity, especially JUST S and SE of its track are a little worrisome.

    In the meantime, the family wants to go to the beach 🙂 🙂 🙂

    1. Well, the beach can’t be far from home, so go, BUT HAVE your phone with you and eyes glued to radar. 🙂

    1. SREF significant tornado ingredients

      https://www.spc.noaa.gov/exper/sref/gifs/latest/SREF_prob_combined_sigtor__f012.gif

      https://www.spc.noaa.gov/exper/sref/sref.php?run=latest&id=SREF_prob_combined_sigtor__

      5% you say, so not to worry. Well, let me add, Over the years whenever this model has 5% painted over any part of New England, more times than not a tornado results. Even Thursday, it had 5-15% over VT and NH and we know what
      happened in NH.

      So, there is “some” risk. How much is to be determined.

  17. Excerpt from Norton NWS discussion, re: tornadoes

    We can`t rule out a brief tornado as well, but
    low-level wind shear conditions favorable for tornadoes aren`t
    as prominent as they were on Thursday.

  18. Tom Posted a bunch of links, but I want to point out a couple
    from the 12Z HRRR

    First here is a composite radar for 7PM this evening

    https://www.pivotalweather.com/model.php?m=hrrr&p=refcmp&rh=2023072912&fh=11&r=us_ne&dpdt=&mc=

    Same time period, here is the significant tornado parameter

    https://www.pivotalweather.com/model.php?m=hrrr&p=stp&rh=2023072912&fh=11&r=us_ne&dpdt=&mc=

    Sounding for just west of Boston at this time

    https://i1l.pivotalweather.com/sounding_images/hrrr_2023072912_011_42.34–71.22.png

    So, in short, yes there is some risk and we need to be on the lookout!

  20. Thanks, TK!

    I totally agree, JPD…I just came back from my morning coffee run and it’s hard to breath because of the humidity this morning!

    And, thanks, JPD and Tom, for the hourly updates about the potential severe weather later. Looks like it could be a very bumpy ride down here this evening!!!

    1. Sure does. Stay tuned.

      I can’t believe how humid it is!! Filthy!!!!
      I may head into Ac’d room with my laptop. I am hesitant because
      I have all my special weather links here on this desktop computer
      and I am old school! I need a mouse. I can’t use a laptop
      very efficiently!!! I hate them!!!!

  21. Thanks TK.

    Any chance of seeing dew points in the 40s to near 50 anytime soon? I know it’s rare before Labor Day but one can dream, right?

  22. On the topic of what are good ideas not to do during lightning.

    A friend was on the floor comforting her dog during the storms night before last. One foot was resting on a floor electric heater. Lightning struck nearby and she got an electric shock up her leg and her heel went numb. She said her heel remained numb for about an hour.

    1. Wow! Things like this happen all of the time.

      I only experienced it once when Our TV picture tube blew out.
      (this was like 50 years ago!)

      1. Ugh. That had to have been scary. My mom and a friend had their TVs blow out also. I would never have thought of a floor register.

  23. Thanks for all the comments today. I don’t understand them all but I get enough to know if I should worry. Be very happy when humidity and storms are over.

  27. I heard a morning dj say that the Patriots start their season in 6 weeks. With all this heat & humidity I hope I don’t have to crawl into a hole until then.

    I always hear heat combined with humidity. Can you ever have “cold” with humidity?

    1. I’ve actually answered this question for you several times. When it is snowing the humidity is often 100% with saturated air.

      Humidity is not reserved for warm or hot weather only.

      There is always moisture in the air to some degree. But pretty much any time it is precipitating it’s about as humid as it can get.

  32. Wouldn’t you know it, Logan has a sea breeze and a decent one at that.

    My question is: With WARM SSTS (relatively speaking) off of the coast and wicked humid Warm to hot air with plenty of lift arriving, wouldn’t it be possible that in this case the sea breeze, coupled with SW inland just a bit and a decent thunderstorm updraft, that rotation could occur. ie tornado.

    Just a thought to throw out there.

  33. Activity beginning to show on radar for Western MA.
    Almost time to really start watching. 🙂

    1. Nothing on radar anywhere near the coast.

      What beach are you at? Rex?

      Enjoy! How’s the water? Should be at least in the low
      70s.

      Boston Buoy is at 70. 🙂

      1. We are at a beach btwn green harbor and Duxbury beach that we call Avon St beach.

        It’s a nice low tide beach which is about 2-3 hrs from now.

        Seabreeze here too, thank goodness !

        I know the waters warm, but it feels chilly probably because it’s so uncomfortable out 🙂

  36. Brutal run today. I mean nauseatingly so. I know it’s not that hot but it’s very humid, the air is heavy and hard to breath in. I don’t know what the heat index is but as the British say “I feel quite poorly” now, in a daze and dizzy. I’ll recover but this isn’t pleasant.

    Nonetheless, the headlines continue to baffle me a bit. I guess they’re not reading my Forbes piece on cold being more dangerous than heat. Today I read about the airlines “buckling under the heat” and being “hit hard by the heatwaves.” I am quite sure that cold and snow impact airlines’ pocketbooks MUCH more than heat does. Cold and snow are very expensive for airlines to do with, from de-icing to ensuring runways are clear to managing all the delays that occur.

  40. The seabreeze just stopped and it’s sweltering.

    Small cells popping, don’t look like they are moving much. Localized flash flood issues.

  41. For all intents and purposes summer ended in the UK and elsewhere in Northwestern Europe in late June. See latest forecast. And this is NOT that unusual. Spring tends to be `their’ season. Generally tranquil, often sunny, fewer spells of rain, not very windy. It’s really quite beautiful between mid March and to mid June, much of the time. And then summer arrives. Often summer happens on a Thursday, as they British and Dutch will say. The occasional bright and sunny day is overshadowed by a veritable parade of low pressure areas traversing the Atlantic with light to moderate rain showers, intermittent sun at times but often cloudy, fairly windy, and temps in the 60s and low 70s. I would say that about 60% to 75% of summers are this way. The remaining 25% to 40% of summers are drier and warmer, though practically none of the summers there would remind you of the weather here. https://www.youtube.com/watch?v=1tNvKoy1gg4

      2. broke out the laptophttps://www.spc.noaa.gov/products/watch/ww0568.html

        poring buckets here

        trmp dropped from 89 down to 78

  48. I went out to do the yard work at 10 and my dad is like it’s too hot. I told him need to be done by 1 🙂 bc it’s going to pour and boom it opened up.

    My poor wife broke her foot playing against me in pickle-ball 🙂 and then I left her for a month so lots of work for me before we are off on a family vacation to Tremblant and Lake Placid

  51. I’m with my youngest. The txt alert she has on her phone sounds exactly like a weather warning. It’s driving me nuts

  53. Curious to know about where we stand in the total rainfall count for July. Is the July 1921 record in jeopardy? I don’t think so, but haven’t been keeping tabs.

  54. Will cooler temps help mitigate the storms later? Now roughly 77 in Natick and perhaps less humid. Seems like this should make a difference?? Thanks.

  56. So basically the activity in the Boston area was what the HRRR had predicted, except that forecast had the activity too early (mid to late morning) vs. the actual time it occurred. Still, had the right idea, just the wrong timing.

    Main event to come later…

  57. Keene, NH ….

    Another interesting cell, this time not directly overhead, but just a bit northwest of them.

  58. Storm just went severe passing just to my south over Andover CT. Just had a downpour with thunder and lightning here in Coventry but nothing too crazy. Sun breaking out again now.

    The humidity today is unbearable. We’ve had a lot of humid days over the past 5 weeks but today feels the worst yet.

  59. The chilly air several thousand feet above the ground was dragged to the surface by downpours and took Logan’s temp from the high (so far) of 86 down to 75. With a break coming up, their wind, which had been onshore for a while, can go back to southwest and they can (and very well may) shoot back into the 80s. It would take a remarkable jump to get them to 90 (and an official heatwave). 15 degrees is going to be hard to do without full sun and not that strong a gradient wind. I think they get 9 or 10 degrees back before the heavier overcast & rainfall/storms arrive later.

  60. Just saw the warning box in your area, mark, and came here to see if all is ok. Glad it is. And I agree about unbearable.

  61. I might have posted this on yesterday’s blog about either way here it is again… The CFS is going quite cool for New England for the month of August, and for that matter on the cool side for much of the lower 48.

    CPC 6-10 and 8-14 support this idea for the first couple weeks of the month. Below normal in New England.

    https://photos.app.goo.gl/oRVGXpMi1RgSKG2T9

  63. new cell just popped between Framingham and Needham. likely to pass just North of me. Will watch it.

    1. If I’m seeing correctly, one just popped as it passed Ace’s area

      They seem to be just appearing

  65. In Baltimore now to see Yankees take on the Orioles. Severe thunderstorm warning here until 545. The warning south of me 80mph wind gusts with destructive damage attached to that warning. Hopefully this is out of here by first pitch at 715

  66. As TK noted above, the CPC has New England very much on the cool side for the first half of August but poor Texas and Florida DO NOT get a break, continued well above normal under their heat domes.

  67. Another downpour but no thunder or lightning as of yet. Radar doesn’t look particularly active.

    1. this makes 2 with heavy downpours and counting. it looks like it’s going to storm off and on for at least 4 or 5 hours, perhaps longer.

  70. Franklin, Providence, Taunton, Dighton …. Just to name a few towns, untouched by rain, temps in the mid 80s, dps 75-76F.

    I’d figure, even 90 min -2 hrs from now, there should be plenty instability left in that area of Mass, northern RI, etc to keep the storms going and that chance for 70 mph wind gusts that the watch highlights.

    It is brutal outside, here as well. Spend 2 mins outside and then walk back in and the house feels like a freezer at first.

  71. As Philip rightly noted, NO thunder or lightning in Boston. Just very heavy rain.

    I am now really wondering about the July 1921 record being within reach. This is an absolute deluge, on top of one earlier this afternoon.

  72. Courtyard is filling with water, like it did 2 years ago. This happens when there’s a clog or it’s not draining properly but also when the water table is already very high. Same thing is happening in the trash area and back street.

  73. I wonder, as the disturbance and the cold front approach, if this line of heavy showers along the Pike into Boston is the outflow boundary/warm front trying to lift north one last time ?

  74. As soon as I mentioned no thunder it started to thunder. Pouring buckets of rain now. Insane amount.

      1. More intense now. It’s like Calcutta in a monsoon. Seriously it is coming down. As Hadi would say during a snowstorm it’s “puking,” but instead of snow it’s rain.

        1. New cells keep back building to your west-southwest.

          Hoping the line will edge a bit northward so you can get out of this particular deluge.

        2. Even more intense now. Rain is about as heavy as it can get. My life vest is on and I’m ready to row.

  75. The echoes in far northwest mass are moving southeastward, so the process is really starting to unfold.

    These cells should make good ESE distance in the next couple hrs.

    We’ll see what amt of instability remains when they encounter it.

  76. Very dark here in Sudbury and starting to rain. No thunder or lightning – yet. We haven’t had much rain or storms here today so far but I bet it will be a noisy night around here. Depending on movement of storms.

  77. Thank goodness the rain let up.

    I’m tending to the drains in the courtyard. Someone put a large hose on one and a flower pot on the other.

    1. Hadi, what’s your total so far? My rain gauge is KAPUT!
      And I am not fixing or replacing it as I Had to move my station into the shade where I can’t get anything close to decent
      rain measurements. 🙂

  80. Nothing even remotely severe as of yet. I am wondering if all of this action will prevent anything severe from erupting later.
    I am not feeling it for severe at all. We shall see. Just as well
    IF nothing severe develops.

  81. The storm in far north central Mass, just west of Fitchburg has decent straight line winds with it.

    Almost looking like a bow echo extending from a small low in extreme southwest NH

        1. I’m in Lunenburg. We got a quick 1″+ in about 30 minutes with less intense rain now. There have been no significant winds.

  83. Just had another bout of torrential rain and thunder here in Coventry and the main line hasn’t even arrived yet. Wettest month since I have lived here hands down!

    1. Up to a staggering 14” of rain on the month of July here. That’s a third of our annual rainfall in one month!

  84. About a week ago I almost bought tickets to tonight’s 7:05 Fisher Cats game in Manchester. I glad I decided against it.

    We have some lightning in the area now.

  85. 75 mph wind gust and 200k without power in Georgetown with that line of severe storms moving through the mid Atlantic earlier

      1. Yes, in that vicinity.

        It’s where you go from a straight NE to SW line of storms, but then, right there, the storm is almost in a semi circle and then it resumes a straight line again.

  88. They weren’t strong this morning in all the links I posted, but I do feel like where the line is now is where the models had some low values for supercells/tornado parameters.

    Eastern CT, southern Worcester CT, north and central RI and interior south shore MA for this general time frame.

  91. Pouring buckets again now along with thunder lightning and wind as the main line is passing through. Insane!

  94. Just some heavy rain here, nothing torrential or flooding rains , just some thunder in the distance with steady heavy rain., another nice drink for the flowers and garden. .49” so far. I have to admit that I thought today we would have seen some intense storms in this area.

  100. I see strong winds NW of Bridgewater and SE of Brockton, but I won’t necessarily see a couplet.

      1. Nope I’m on farmers porch , family down basement. Vivid lightning, nothing too crazy

  103. I can see some strong SW winds near Hanson.

    The little notch doesn’t look as pronounced but the winds near Hanson look strong.

  104. In this setup, the cool air is charging in, but it doesn’t necessarily move in, in a straight line. Depending on storm formation on the line, I think you can get these eddy’s, much like you might see in the Gulf Stream, where some cool air surges ahead here, but then further up the line, it’s not as far ahead, and the warm air hangs in a bit back and that can briefly cut off and circulate.

  105. NWS says tree damage in Easton.

    Dopplar shows strongest wind probably near Duxbury and Duxbury beach.

  106. Listen to NWS and not me, but I think all is ok.

    Wouldn’t be surprised to see that some wind damage has occurred north of plympton, maybe Duxbury and Kingston area, something like that. But, it looks to have moved east and southeast of us.

  108. I hope the folks in P-Town and the outer Cape are ready the next few minutes.

    Quite a shot of wind coming through off the frictionless ocean to boot.

  109. 13.72” for the month here mark, pretty amazing rain totals for July without any tropical Storm influence. Let’s hope we can get a few week respite before we have any potential tropical system come this way. The lawn and flower garden are absolutely flourishing with this weather pattern though.

  112. Tom you can come out of the basement now. 😉

    And by the way thank you for your welcome on the other medium. 😉

    I’m still sitting in North Pembroke at the moment but I’m about to head back…

        1. Well I figured in a tornado warning he would just move the bed to the basement to beat extra safe. 😉

  114. According to AJ Burnett, Logan’s rain gauge received 1.75” ( or thereabouts) in 15 minutes.

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