Thursday Forecast

79 Comments

7:25AM

DAYS 1-5 (JULY 18-22)
Not time for a heatwave yet. Patience! First we have this marine-cooled day to get through, and then, Friday through Sunday will produce a heatwave for many, but possibly not all. With a lower launching pad and marine air to warm-up, Friday may fall shy of 90 in some locations, including Boston. No guarantee but we’ll watch to see how it pans out. While we have a northeast to east air flow at the surface today we still have some tropical moisture riding up over a boundary to our south and that will create a shower and thunderstorm risk today as well, but it won’t be a widespread heavy event, just more scattered activity and favoring areas to the south of I-90. This moves out tonight, and a southwesterly air flow arrives Friday, bringing in the heat and humidity, although as stated, it may struggle to heat up too quickly at first. But that’s splitting hairs. After today, whether a particular area is in the upper 80s or lower 90s Friday, with high humidity, it will feel quite hot. The heat peaks Saturday then eases ever-so-slightly Sunday, almost unnoticeable. We may get the dew points down a little over the weekend because of a downsloping west wind, but that will be compensated by the higher air temperatures. Another thing we have to watch out for in this pattern are nocturnal thunderstorm complexes, or the remains of them, from the Great Lakes area. One or two of them may make a run at New England, but the first indications are that one would cross far southwestern New England while dying, not impacting the WHW forecast area, early hours of Saturday, and another one may visit northern New England Saturday night or early Sunday, again not impacting southeastern New England directly. A surface boundary (weak cold front) getting closer to the region later Sunday may trigger a few showers and thunderstorms as we break the heat Sunday night. This should push through the region by early Monday but still may be close enough with some cooler air aloft to trigger a few showers during Monday. That day will also be decidedly cooler than the weekend, back to more seasonable warmth.
Forecast details…
THURSDAY: Mostly cloudy. Episodic showers and a chance of thunderstorms, favoring areas near and south of I-90 in southern MA, eastern CT, and RI. Moderately humid. Highs 70-77. Wind NE to E 5-15 MPH.
TONIGHT: Variably cloudy. Areas of fog. Humid. Lows 63-70. Wind light SE.
FRIDAY: Partly sunny. Very humid. Highs 81-88 Cape Cod, 88-95 elsewhere. Wind SW 5-15 MPH.
FRIDAY NIGHT: Partly cloudy. Humid. Lows 72-79. Wind WSW up to 10 MPH.
SATURDAY: Mostly sunny. Humid. Highs 92-99, hottest Merrimack Valley, except 84-91 South Coast and Cape Cod. Wind SW 5-15 MPH.
SATURDAY NIGHT: Partly cloudy. Slightly less humid. Lows 74-81. Wind light W.
SUNDAY: Mostly sunny morning. Party sunny afternoon. Moderately humid. Highs 90-97, cooler Cape Cod. Wind W 5-15 MPH.
SUNDAY NIGHT: Variably cloudy. Scattered showers/thunderstorms possible. Moderately humid. Lows 63-70. Wind W 5-15 MPH, higher gusts.
MONDAY: Partly sunny. Isolated showers and possibly a thunderstorm. Less humid. Highs 80-87. Wind NW 5-15 MPH.

DAYS 6-10 (JULY 23-27)
With upper level high pressure having pushed back to the west we’ll see a more seasonable temperature period. The very start of the period may feature some cloudiness as a disturbance passes, but much of the time should be rain-free. We may have to eye some tropical moisture from the southwest by the very end of the period that would at least make it more humid, and possibly increase the shower risk.

DAYS 11-15 (JULY 28-AUGUST 1)
Near to above normal temperatures expected with a couple opportunities for showers and thunderstorms as we go down July’s home stretch and arrive at August.

79 thoughts on “Thursday Forecast”

  5. Thanks TK !

    Looking at the radar, the lower top, yet still heavy showers over Boston and Attleboro are not really moving.

    1. Depending on how long they stay in place, may need some very small, localized flood statements/advisory etc …..

  7. Interesting conversation on the last blog regarding NWS warnings. If you’d like to learn a little more, read on through this lengthy post for some insight.

    There are three ways a storm can be considered severe. These are the same criteria everywhere and have been for many years as TK said on the last blog. It can produce straight line winds in excess of 50kt (58mph), quarter size diameter (1″) or larger hail, or a tornado. The latter two are easy. Hail is easily measured, and anything quarter size or larger will certainly cause damage in terms of car dings or worse. Likewise, a tornado, of any strength, is capable of causing damage. Both severe hail and tornadoes are infrequent in the Northeast US. The challenge comes down to straight line winds. Given the sparsity of the observation network, even in a densely populated area like the Northeast, it is quite difficult to physically measure a 58mph wind gust, even in a bona fide severe storm. This is problematic for NWS offices, as severe t-storm warnings need to be verified, and it’s not fair to let warnings for legitimate severe storms count against offices as unverified just because no gusts to 58mph were measured.

    The solution, then, is to use damage reports as a proxy for severe wind. For most offices, a downed tree will “verify” the warning, though different offices can interpret this a little differently. You only need one severe weather report anywhere in the warning box to consider the warning a “hit” (and to be fair, severe wind is often a highly localized phenomenon). But were the winds really 58mph? For a healthy, full grown tree, the answer is usually yes. But what if it’s a small tree, or a rotting tree? What if it’s just a large limb? There’s a gray area. We have so many trees in the East, that it’s pretty easy to get reports of downed trees on marginally severe storms. And if you get a tree downed and there’s no warning, that’s a missed event, and you don’t want that. So you have to warn more. This isn’t an issue in the Plains, where there aren’t any trees. Their warnings tend to be much more selective, issued on storms we’d rarely see in the Northeast and that would cause chaos if we did. And some of them still don’t verify because there’s no trees to take down and no anemometers to measure.

    FWIW, at Mount Holly, in an area not too different from SNE, I see a similar number of complaints of over-warning as I do under-warning. Not that most of the complainers have the first clue what they’re talking about, but it’s still good to know the perception, and the fact that it’s a fairly even mix tells me we’re probably doing a decent job with an imperfect solution to an unsolvable problem. But you’ll never make everyone happy, and there’s always going to be both false alarms and missed events. It’s inevitable.

    Preliminarily, looks like Boston verified 11 of 16 severe t-storm warnings with 4 missed events yesterday. At Mount Holly, looks like we hit 12 of 13 with 5 misses. If you’re interested in playing around with these numbers, you can experiment with the site below. Again, these #’s are unofficial/preliminary but should be close to reality as offices go through and do their official verification.

    https://mesonet.agron.iastate.edu/cow/

    4. Thx WxWatcher. I agree its an inexact science up here with all of the trees. You and your co-workers don’t have it easy with crafting messages and information that the large majority of the public can relate to. Thanks again…

  8. Good morning and thank you TK.
    Some prettty decent wind here in the city to go along with the rain.

    It’s almost as if Barry is regaining a circulation as that rain is rotating in from
    the ocean with a NE wind. Raining pretty hard at the moment.

    https://radblast.wunderground.com/cgi-bin/radar/WUNIDS_map?station=BOX&brand=wui&num=20&delay=15&type=N0R&frame=0&scale=0.47608695652173916&noclutter=0&showstorms=0&mapx=400&mapy=240&centerx=394.7488584474886&centery=325.06849315068496&transx=-5.251141552511399&transy=85.06849315068496&showlabels=1&severe=0&rainsnow=1&lightning=Hide&smooth=0&rand=26057595&lat=0&lon=0&label=you

    1. It isn’t that Barry is regaining a circulation, it’s that there is a small synoptic scale low pressure area forming along the boundary which the short-range guidance has been indicating.

  11. Thank you, TK.

    I realize there’s still a lot of humidity in the air, but the northeast wind feels refreshing. I feel alive today, which was not the case yesterday. I’d like to bottle up today’s air and periodically spray it around during the next few days.

    I am headed to London to visit my daughter at the end of the month. It’ll be a brief, 3 day visit, as unfortunately I don’t have more time to spare. Still, it’ll be good to see her. I haven’t seen her in nearly 8 months. After a very warm June, London had a more `normal’ July. Temperatures are in the low 70s, generally, with occasional light rain showers, but not every day.

    London (Westminster area) on a fine summer day in 1970, as John Cleese is in charge of the Ministry of Silly Walks:

    https://www.dailymotion.com/video/x2hwqki

  12. It’s 4 or 5pm on what has been a sunny, warm to hot day.

    You get to the car and it’s roasting.

    You turn on the A/C and it doesn’t help much. The vents through which the cool air travels are hot. All the car’s seats and inner materials are hot. Even 5 to 10 minutes later, when the AC has finally cooled, its struggling to cool off inside the car because everything is still giving off warmth.

    5 hrs later, it’s 10pm and you need to run an errand. Car starts and the AC is ice cold and the car cools off quickly.

    I know this sounds ridiculous. Run the AC today. Get your houses or individual rooms in houses as cool as you can. Get ahead of the incoming heat. Turn the AC on Friday, when the house temp is 78F and the outside temp is zooming through the 80s and it’s not going to cool as much as you’d like.

    Consider it. Yes, its spending extra money and it’s missing out on nice fresh air. But, it might give a better chance to stay cooler on Saturday and Sunday, when your AC will be fighting a losing battle.

      1. Another thing I’ve found is to lower the blinds on the sides of the house that face toward the sun….helps here.

    2. Excellent advice, Tom. And Keith also. We do put blinds down and close curtains on sun side.

      I have yet to figure out if it is spending more money. If the AC doesn’t have to work as hard tomorrow because it is cool today, do you think that may even out?

  14. At work just now..

    “Bri, how hot is it really gonna be Saturday? I saw a 107 on the news and it was all red.”

    Thanks media.

    1. I’ve seen the maps ….

      In fairness to the media, the titles of the maps have said Heat Index and the mets during the presentation have said “heat index”.

      There has to be some responsibility of the public to raise their paying attention skills. Otherwise, I think the only other solution is for the media to only present what the listening public is capable of comprehending. I’d rather see the former, hoping that it might inspire those paying attention to raise their listening and comprehension skills a bit. ……. just my opinion 🙂 :).

      2. Excellent comment, Tom. I am very against dumbing down to the lowest common denominator. I had noticed the confusion with heat index. It is odd because folks seem to fully understand wind chill.

  15. Thanks TK!
    Does anyone know of a site other than lightning maps.org where I can find accurate archives of last evenings lightning strikes?

    1. My pleasure. To be fair I guessed at what I thought I’d been told about balls traveling better. You might want to check that 🙂

      I don’t even listen to Ted’s HOF speech with out some tears.

  17. Tom I do agree that people should be paying a little more attention to what the maps actually say but I have noticed that many of them are not. They are just seeing colors and numbers.

      1. Right now – in my house. I turned AC down which was a wise suggestion from Tom. I’m digging out as I type!

        1. I’ll grab my shovel from storage, bring the wood in for the fireplace, and get cocoa for hot chocolate at the store. M.L.’s “we’re gettin’ a foot” got me excited.

  19. For what it’s worth, NWS point hourly forecast is forecasting a high of 96 for Boston Saturday.

  20. Hey “Cathy”, the last time I checked, 2019 minus 2017 is not 4 1/2.

    I know you’re having fun trying to get back on the blog as a woman in her 60s, but can’t you even keep your lies straight? Thanks for the amusement though. I get to see the messages which are good for a laugh. Too bad they never see the light of day on the blog itself though. Awww… 😉 But have fun if it gives you something to do.

  22. Oh I meant to bring up earlier, don’t be surprised if Boston area and other locations in eastern MA and possibly RI as well as NH Seacoast start overcast first thing tomorrow. The wind at that time will still be NE to N and may hold a marine layer in place. It won’t be until between 7 and 9 that the wind will flip to SW and then anything left from the marine layer will be obliterated.

  23. I just heard on a Boston radio station “the heat index for Saturday is forecast to be 112°”
    The way it was being presented might lead a casual listener to hear “its going to be a hundred and twelve degrees on Saturday!!!!” I understand how someone could hear it that way. I wonder though, is there a discernible difference between how 96° vs 105° “feels “ to most people?

  24. Vicki…
    You had asked last night if I saw your post about the CBS Apollo 11 special. I am so glad you and your grand saw and loved it!!!! I thought it was very well done. I am enjoying all of these specials on Apollo 11. Like all of us who were alive and old enough to remember the first Moon landing in 1969, I remember exactly where I was that night. I saw the broadcast on an old black and white set. The transmission from the Moon was not that great in the first place. It was very hard to make sense of the picture.
    50 years later, it is great that the images have been cleaned up and digitized and/or they are movie quality!

    1. We sure did enjoy. I’m so happy you posted that it would be on. I also saw on an old black and white. My dad was working…he was dispatcher at BPD. My mom, brother and I sat glued to the TV. I have goosebumps even now

  25. Philip…You had asked the average number of 100+ degree days in Boston a couple of days ago
    Like Sue, I found a website with Boston’s high maximum temperatures each summer. (I have WAY too much time on my hands.)

    There have been 24 100 or greater degree days in Boston history.

    The data is mostly accurate. There were two 100+ degree days in 1944 (101 on August 12 and 100 on August 13). It was 100 twice in 1952 (June 26 and July 23). It was 101 on July 4 and 5 in 1919. And, in a toasty July, 1911, it was 100 or greater four time, 102 on July 3, 104 on July 4 (Boston’s all-time highest max), 101 on July 6 and 100 on July 11. That must have been BRUTAL!!!

    Not listed is 101 on July 10, 1880 and 102 on September 7, 1881.
    No, I was not there. 🙂

    Here’s the website:

    https://www.currentresults.com/Yearly-Weather/USA/MA/Boston/extreme-annual-boston-high-temperature.php

    1. Great info! See what I’m about to share from SAK. He included some data, including for Lowell MA.

  27. TK, I absolutely love how today feels, too. Oh my goodness, I really feel alive. I do realize that feeling will diminish rather quickly starting tomorrow. Well, maybe. I think tomorrow will still feel coolish in the morning as you point out, especially at the coast. I actually don’t think Boston will make it to 90 tomorrow. Perhaps 86. Saturday and Sunday, different story, but I hold out hope that the oppressive heat will be short-lived.

    1. My current thoughts for Logan’s high temp are 89, 96, 97 Friday-Sunday. Sunday’s may have more to do with wind direction than anything.

      1. That helps. Oldest was to attend a horse show Sunday. They will not take horses in that heat. Even in Plymouth

  29. We were wrapped in blankets at baseball tonight. Will be a different story at Saturday’s game.

  30. The more recent guidance is a little more “dramatic” about putting our temps from much above normal Saturday-Sunday to right about average Monday-Friday with especially low humidity around Tuesday-Wednesday, although the GFS doesn’t do that until Wednesday after having a day more likely today on Tuesday after a very showery Monday. It’s a little more excited about activating the front that comes through Monday, slowing it down and running moisture along it. It then brings the heat back next Saturday-Sunday (27th-28th).

      1. No, I was talking about what the guidance was doing. I’ll still be applying meteorology when I make my next update. The only change I’ll probably make is increase the risk of thunderstorms for Monday.

  31. The 00z NAM has a large part of central New England not getting below 80F for lows overnight Saturday night. And then by 12z (8am) Sunday, the 85F contours re-appear.

  32. The NAM’s interesting in the way it tries to evolve the 500 mb ridge late in the weekend.

    I thought in the medium range (a few days ago), the whole ridge was going to head west and the top of the ridge in the east was slowly going to erode away.

    Now, in the last 12 to 24 hrs, it’s like part of the ridge heads west, but part also holds on off the east coast, not allowing the ridge to erode as quickly Sunday, allowing Sunday to also be brutally hot, perhaps hotter than Saturday.

    I wonder if this trend continues …..

    1. Now that I re-examine the 12z Euro and 18z GFS, there is some similar idea on those runs as well. Piece of 500 mb ridge at 591 dm hanging off the southeast coast late in the weekend, slowing the erosion of the ridge in the northeast.

      1. All of the models have been a little higher with their 500mb height forecast for off the Southeast Coast. In turn what that’s starting to do is keep the front that approaches Sunday around for a good part of next week (as evident on the latest GFS run). In fact the GFS would like to put wetter/cooler weather from late Monday through Thursday, although I think that is overdone and not moving things far enough to the southeast.

        The GFS wants to keep most of SNE in the 60s to lower 70s Tuesday, everyone in the 70s Wednesday, the the coast still in the 70s with 80s interior Thursday. Not saying I buy this, but that’s what the model likes at the moment.

  33. New post!

    And no, the clouds and “coolish” start to today is not a surprise if you were paying attention. 😉

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