Sunday August 2 2020 Forecast

156 Comments

8:34AM

DAYS 1-5 ( AUGUST 2-6)

While today will not be as sunny as yesterday was, we’re still not looking at a bad summer day, with partial sun eventually losing the battle to clouds, and only the minimal risk that a few showers work into areas outside of and around I-495 mid to late afternoon. This will be taking place as a warm front approaches the region. This front will cross the region tonight when there is a better risk of showers and even a few isolated thunderstorms. While our parameters are not ideal for severe weather, it’s important to keep an eye out for any isolated storm that can gets its act together, as they can produce isolated damage. The front will be by the region by Monday, which will be a very warm to hot and humid summer day with a southwesterly air flow. Other than the remote risk for a pop up shower or thunderstorm again mainly outside of I-495 later in the day, Monday should be a rain-free day. Then we can turn our attention toward Isaias, currently a tropical storm, and forecast by NHC to remain one for the duration of its run up the East Coast toward our region. We can discuss the impacts from Florida to the Mid Atlantic in the comments section of this blog over the next couple days. I will focus on its impacts here for the purposes of this discussion. Best guess now is we have a weakening tropical storm, getting ready to transition to post tropical, center passing west of the Boston area, possibly as far west as near the NY border with CT/MA very early Wednesday. Typically, this set-up would produce a couple periods of rain or showers, not too heavy, initially, with that timing most likely during the day Tuesday, and a band or 2 of heavier tropical showers (possibly some thunder), that timing likely Tuesday night into the pre-dawn hours of Wednesday. As always, the right flank of a system like this creates its own wind shear, and that can be enough for a brief weak tornado in some of the convective showers. This will be a very low risk but as you have heard many times, if it’s a non-zero risk it is worth paying attention to. Except for a gusty westerly breeze Wednesday morning, the system will be a memory by then, with a nice day behind the departed system. High pressure will build in with another nice day expected Thursday.

TODAY: Mostly cloudy. Scattered mid to late afternoon showers and possible thunderstorms, mainly west of to around the I-495 belt. More humid. Highs 78-85, coolest coastal areas. Wind SE up to 10 MPH.

TONIGHT: Variably cloudy. Risk of showers. Slight risk of a thunderstorm. Humid. Lows 65-72. Wind S up to 10 MPH.

MONDAY: Mostly sunny to partly cloudy. Isolated showers and thunderstorms possible late-day, mainly outside the I-495 belt. Humid. Highs 86-93, cooler South Coast. Wind S-SW 5-15 MPH.

MONDAY NIGHT: Variably cloudy. Slight risk of a shower or thunderstorm. Humid. Lows 65-72. Wind variable 5-15 MPH.

TUESDAY: Mostly cloudy. A few episodes of rain or showers likely. Humid. Highs 75-82, coolest coastal areas. Wind SE-S 5-15 MPH.

TUESDAY NIGHT: Mostly cloudy. Showers likely. Slight risk of thunderstorms that may contain locally strong wind gusts. Humid. Lows 65-72. Wind SE-S 15-25 MPH, higher gusts coastal areas, especially South Coast.

WEDNESDAY: Mostly sunny to partly cloudy. Moderately humid. Highs 83-90. Wind W-SW 10-20 MPH, higher gusts during the morning then diminishing during the afternoon.

WEDNESDAY NIGHT: Clear. Lows 60-67. Wind SW up to 10 MPH.

THURSDAY: Mostly sunny. Highs 80-87, coolest coast. Wind variable up to 10 MPH with coastal sea breezes.

DAYS 6-10 (AUGUST 7-11)

A frontal boundary to the south will get close enough for some cloudiness Friday but no more than a risk of showers near the South Coast. High pressure should win out for fair weather, seasonable temperatures, coolest coast, and moderate humidity over the August 8-9 weekend. A disturbance brings higher humidity and a risk of showers / thunderstorms August 10-11 but too far away to know any detail.

DAYS 11-15 (AUGUST 12-16)

A weak block may form in the atmosphere (low pressure to south, high pressure to north in upper levels). This promotes surface high pressure to the north with a general maritime air flow (northeast to east) at the surface. With time high pressure would probably drift southward and keep the region dry with a late-period warm-up.

156 thoughts on “Sunday August 2 2020 Forecast”

  1. Good morning and thank you TK. A couple of thoughts for today.

    WxWatcher was tracking a possible tornado near Reading, PA. Currently no warnings, however a cell near Allentown shows
    some signs of rotation:

    https://imgur.com/a/rWIBxQw

    Next, Isaias

    You mentioned the right front quadrant for possible brief
    tornadoes. Here is an excerpt for the SPC day 3 outlook:

    https://www.spc.noaa.gov/products/outlook/day3otlk.html

    If the track is far enough inland, convection
    within a strong low-level shear environment will support some
    tornado threat for at least coastal regions of the Mid Atlantic into
    southern New England. Some organized convection will also be
    possible earlier in the period downstream of Isaias, as tropical
    moisture streams northward into a region of moderate mid/upper-level
    southwesterly flow associated with the persistent upper trough.
    While this scenario is more uncertain, some threat for locally
    damaging wind or a brief tornado may evolve within this regime as
    well.

    Some portion of this region may eventually require Slight
    Risk-equivalent probabilities, once confidence increases in details
    regarding the track, timing, and intensity of Isaias as it
    accelerates northeastward.

    1. Regarding Isaias, it sure looks more healthy this morning to me.

      https://www.weathernerds.org/satellite/?initsatsrc=On&initsatname=GOES16&initsattype=swir&initcscheme=vis1&initimdimx=1050&initimdimy=764&initrange=30.750000000000:-86.500000000000:22.250000000000:-72.500000000000&initloop=True&initnframes=20&initlightning16=On&initlightning17=Off&initltngfed=Off&initltngtoe=Off&initinterstates=On&initwarnings=On&initlatlon=On&initascata=Off&initascatb=Off&initascatc=Off&initascatamba=Off&initascatambb=Off&initascatambc=Off&initsst=Off

  4. Latest HRRR model run lighting up like a Christmas tree with thunderstorm activity for a good chunk of SNE.

  5. Thank you TK. So 20 mph ish is all we see with exception of possible cell kick up? It’s early. I was Up good portion of the night so apologize if I am not reading correctly.

  7. Looking at those parameters that JpDave posted no surprise the SPC put out a 5% tornado risk for parts of SNE for today. To me 5% tornado chance in New England is an elevated tornado risk.

    1. Thanks Mark. Hopefully there will be minimal wind damage around here. It seems that due to COVID-19, work crews have to “socially distance” from each other and work in smaller groups which means it can take longer to make repairs and get power back again. Repairs can take hours or days as it is under normal circumstances.

  11. Latest SREF does show a low risk for tornadoes western parts of MA and CT when Isiasis affects us.

  13. JJ see previous blog near the botton where
    WxWatcher posted how he was the one to issue a TORNADO
    WARNING for the Reading, PA area. Pretty cool.

  14. I agree that was pretty cool. Thank you for pointing that out for me so I could go back and read WxWatcher’s post.

  15. Good morning, WHW, and thank you as always, TK!

    What a glorious night last night as Mrs. Fantastic and I watched our youngest (finally!) receive his high school diploma from Middleborough High. It was an intimate ceremony on the new football field (only two family members allowed per graduate),

    What a beautiful weather evening, too. It started at 6. It was warm, but not hot, a nice breeze. We had a gorgeous sunset and a inspirational full moonrise at the end.

    I had the deep honor of presenting David his diploma, something that the principal grants when a staff member has a child graduating. It will be something that I will remember and cherish for the rest of my life.

      1. Thank you! In his remarks, the principal teased the graduates that they really nailed “senior skip day” this year!!! 🙂

  16. This morning Dave Epstein was not very hopeful for much rain around here with the track now so far to the west.

    About 0.5-1.00”+at best and even less for the Cape. Yesterday the amounts were for a good 2-3”+ slug throughout.

    As Barry used to always say: “Everything fails in a drought”

    1. Thanks CF for sharing. I’m somewhat surprised though that ceremonies have been inside a stuffy gymnasium all these years up until now.

      1. The football field, where all the stands and seating are, are at the town field downtown. The field is not at the high school. With our brand new school, we have a new stadium on campus. Starting this year, graduation will be in the stadium. Check out the videoboard!!!

  18. Vicki to answer your question..
    based solely on how I think the system will track and the intensity it will be when it goes by us I would not expect too many wind gusts above 20 mph but there’s certainly can be some even without the help of convection. This is specific for your area but I would also expect opened higher elevations and coastal locations to have stronger wind.

      1. I do indeed. We will not see much rain in eastern areas from Isaias. And Barry’s quote has always been one of my favorites.

  19. The hurricane models continue to show slight strengthening btwn 24 hrs from now and landfall in the Carolinas.

    After that, there will be some interaction of the system and the 500 mb jet at which point the global models are showing some kind of interaction that either maintains Isaias strength or might even deepen it some. This isn’t something just one model is showing, but that has been a theme since yesterday.

    I have uneasy concerns about what Isaias may bring some area in New England, even if it’s only for a few to handful of hours.

  20. 12z NAM (which is still trash) is WAY too slow.
    06z GFS is too fast, but I expect the 12z to get a bit better with timing.

    Also think today’s storm threat will under-produce in western areas. Still have to watch tonight, but extremely low risk for any one area getting a t-storm tonight.

  21. Ok so the 12z GFS didn’t really slow Isaias down. The difference between forecast positions for Isaias for 00z Wed (Tuesday, 8PM EDT), is, oh, about 500 miles between the GFS & NAM. 😉

    People should never have to wonder again why SAK, JMA, WxW, and I talk about “the models” being so wishy-washy and sometimes just downright horrendous with these things (among other things). 🙂

    2. It had a nice convection flare. That will make it look larger because that moisture has to go somewhere once it gets to the top of the chimney.

  25. When I see the satellite of Isaias, the image that comes to mind is the leaning tower of Pisa.

    Looking straight on at Florida, its leaning to the right. The low level circulation is the bottom of the circulation and the mid level circulation is the top of the tower.

    And what a mid level circulation/vortex !!

  26. Sunsets now closing in on 8:00 and sunrises well after 5:30! Back to “dark” habits on both ends. 🙁

          2. I see a warning box west of Hartford but not East. The East cell looks to slide a bit west of here. I hope

  28. 12z EURO ….. projected pressure down to 989 mb just after landfall in the Carolinas. Trending a bit stronger with recent model runs.

    Lets see now what the pressure is on the next panel …….

    1. Thank you SAK. Where the system is expected to travel
      West of the Boston area, what are your thoughts on
      any “possible” tornadic activity on it’s East Side as it passes
      through our area?

      Many thanks

  31. https://www.tropicaltidbits.com/storminfo/09L_tracks_18z.png

    https://www.tropicaltidbits.com/storminfo/#09L

    Ok, so if we look at the spaghetti plots and notice the times, we fall between 48 and 72 hrs, nearly in the middle, so guesstimate 60 hrs.

    Link 2 : intensities and if we go to 60 hrs and go straight up, we have 2 models at 30 knots, 1 about 38 knots, 6 between 40 and 50 knots, 1 at 53 knots and 3 at 60 knots or higher.

    6 of the 13 are 45 knots (51 mph) or stronger.

    It does feel like the projected condition of Isaias has slowly been rising with each 6 hr successive model run since yesterday.

    1. I am more concerned with the front right quadrant. With low level shear, should we get any convection, there could be
      rotating cells. I suppose it depends upon the relative strength
      when it gets up here.

  32. Pouring buckets at the moment. My weather station measured an 8.11” an hour rain rate. Picked up 1/2” of rain in ten minutes.

  33. 12z UKMet has projected pressure for Isaias over NYC same as it is at landall in Carolinas …. 981/982 mb

    It deepens the low with the jet stream interaction. Over DC, the projected pressure is 986 mb.

  34. The soil is so hard packed and dry that it’s just pooling in large areas and not absorbing in quickly at all.

    1. This is an example of why it takes a series of rains over a relatively long period of time to truly end a drought. They never end with downpours.

  35. Quick peak at the SREF it is highlighting western parts of MA and CT Tuesday for a low tornado risk.

  37. I am watching the radar. The action right now is out Mark’s way.
    Will see if any other thunderstorms develop as the tornado watch for my area is up until 10pm.

    1. I don’t like the looks of 2 Cells near Hartford. One in Mark’s back yard and another approaching. Watch out Mark!

  38. Convection currently headed Eastwards is holding together well and if anything is intensifying, especially over N Central CT.
    Action seems to be heading ENE to NE on a bee line towards
    Boston. So far this looks to be more than I expected.
    We shall see if any of it makes it here.

      1. My display is showing a shit load of lightning in Central CT.
        It is Lightning Pro and has been pretty damn good since
        I have had it. I cannot tell you if it only records CG or not.

        1. There was a good cluster a while ago. It’s dropped off significantly to very little now.

    2. I am NOT saying we have adequate rotation for a warning or anything, but just saying that these 2 areas are worthy of
      watching, Vicki, these 2 “could” come over or near your area
      or possibly just South of you area.

      https://imgur.com/a/ooxQWfV

      1. Got it. I never question your seeing rotation but lately am curious how there isn’t a warning if any sign of rotation is seen. Or can’t it develop into more quickly

        1. Can’t cry wolf all of the time. The NWS must have some sort of formulae or algorithm comparing wind speeds
          toward and away from the radar. When it reaches a certain
          threshold, then I presume it is warned. Also, they look
          to see if any rotation is broad or tight. Tight might indicate tornado, whereas a broad circulation would not.
          Another way is to look at the DB echoes towards the radar and away from the radar.

          As of right now, it does not appear to be tight enough.

          It is tricky business.

          WxWatcher works at the Mt. Holly, NJ office, I am sure he could give you a more precise answer. TK , JMA , and SAK or more than qualified to chime in on this as well.

          I gave a layman’s answer for you.

          1. Thank you. Even when we had the confirmed tornado a mile-ish from here a couple of years ago, it was never warned. I lost some confidence then

          2. Your answer is generally adequate. There have been a lot of cells around here this year (overall pattern) with broad and weak rotation that could have been warned, but would have been warned unnecessarily so. The rotation was too broad and weak for anything. But the NWS is always monitoring for changes. Regardless, there are still going to be some misfires. They are fairly rare though these days. I still think their tendency is to over-warn, rather than under-warn, and then just hope complacency isn’t bred by more warnings that don’t result in something. 🙂

      1. And why am I not surprised you saw this Potential well before Warning.

        I’m hearing thunder here now.

  41. Tornado question. A dear friend was in the area of PA that WxW Warned. Thank you, WxW as her alarm did warn her. Her home is on a very wooded and hilly area. Her son had said that tornadoes need long flat surfaces so they would not get one. I had not heard this and am by no means questioning it….just curious. She did says thunder and rain were intense.

        1. I have to check but think the author of that book is the one who spoke at Todd Grosses weather spotter meet and greet. It’s on my computer which I won’t start up yet. I don’t have the book but will get it.

          1. It is quite a read. The author places the reader right
            in the thick of things. A frightening read to say the least.

  42. I’ve also been getting a number of warnings re lightning 6-32 miles away. Has to be Old Sally’s cell.

  43. I know it is still relatively early since the tornado watch is up
    until 10 PM, but I find it truly interesting that all of the action
    (so far) has been outside of the watch area.

    I presume this action is with the warm front, while any possible
    action related to the watch box will be from within the warm
    sector?

    1. Work for me. That is the one approaching here. I enjoy T and L but not so much rotation. Lots of rolling thunder with it

  45. The question of topography and tornado development has been carried more into myth rooting from a partial truth, a very generalized truth.

    Tornado alley is largely flat, plain land. A large percentage of the nation’s tornadoes occur there. Even the South & Midwest, the other 2 higher percentage areas for tornadoes, are relatively flat (with a few exceptions). But these areas see more tornadoes because they lie in regions that are more likely to have a mixing of ingredients (gulf moisture, jet stream energy, and frontal and other boundaries). You see less of this combo in the mountains of the west, and in the eastern US overall (though less-so) so these areas naturally have fewer. But it’s not strictly because of mountains / hills in any of these areas why there are fewer tornadoes. I hope that’s an adequate explanation. 🙂

    1. Excellent. Thank you, Brian. I’ll send this along too

      I’m still Smiling that our WxW was the one who issued the warning for that area.

      Re not warning. I’m a fan of erring on the side of caution since often folks need time to get to safety. I completely understand there is not an ounce of science in that. And I also understand that even if a life were to be saved, Many folks would find fault. So I do understand

      I Smile also when I think of at least three instances our Old Salty has warned us before the NWS warning was issued. As for all weather, I do come here first.

    1. For now, that makes sense. It’s just a watch, as it should be. Always enough unknowns in weather, and it’s summer, even in a pandemic there are plenty of water craft out and about and activity along the coast and on the islands. I agree with the watch.

  47. We received 2.04” of rain from that cell in about 45 minutes here in Coventry! I was in Franklin in SE CT at a softball tournament and by the time we got home it had just passed. My son said it poured here but not much wind and no thunder or lightning, despite the severe thunderstorm warning.

    1. Except at initial formation, these produced a low amount of lightning, but plenty of rainfall, for sure.

  48. Thanks TK! And well said in the topography explanation – long story short, no, terrain does not protect you from tornadoes.

    When the radar data becomes available online in another day or two, I’ll go back and grab a couple screenshots of the PA storm from this morning. As of now, no confirmation of any tornado (though it’s worth noting they sometimes take days to confirm especially in rural areas). We actually issued 3 TOR’s this morning, 2 of which were mine. The lowest radar elevation scan over that portion of PA is about 7000-8000 feet up, which is quite high. So you’re forced to make decisions based on a combination of the environment and what you can see up at those altitudes, and erring on the side of caution is generally a preferred approach.

    The flooding was the biggest story out there for sure though, many reports of water rescues and water into buildings. Not good given there is likely quite a bit more to come. What a time to be on a lengthy stretch of night shifts 😉

  49. Finally started getting thunder here from this final cluster in my area shortly after 5:30 p.m. … So the stuff was more potent and did make it further east than I had forecast. Bad forecast, but any rainfall is welcomed. 🙂

  51. Watching Ryan Hanrahan now, possible tornado touchdown under that warning in Litchfield County. There are several damage reports coming in from Sharon and Falls Village. Possible tornado now over northern Colebrook and Norfolk, about to move into Berkshire County.

    1. Rotation looks weak now but the dual pol radar loop he is showing sure looks like a tornado touchdown when it was over Sharon. Radar detected tornado debris in the air at that point.

      Fortunately a sparsely populated area.

    2. Ryan now showing a video someone captured from near Lime Rock park. No question a weak tornado touchdown.

  57. If this is a confirmed tornado by the folks from NWS out of Albany it would be the first tornado of the year in the state of CT.

  59. That very mountain near the video location had an EF-3 tornado cross it back on July 10 1989 during the CT tornado outbreak.

  60. Recall the other day I mentioned a short window for Isaias to restrengthen off the coast of FL. It certainly looks better on satellite this evening, though recon data indicates any strengthening remains slow at best. Still, it may try to regain Cat 1 hurricane intensity by morning. Either way, won’t matter much for New England impacts as extratropical processes will be dominant by the time Isaias makes it this far north. While heavy rain will be the biggest threat, I do have some concern for a period of 50-70 mph wind gusts especially along the coast as it moves overhead, thanks to some of those non-tropical processes kicking in.

  61. Getting some reports on the storm that looks like it produced a tornado in the Northwest Hills of CT and what it did when it crossed over the boarder and into Massachusetts.
    Tweet from NWS Boston/Norton Skywarn
    We are getting preliminary reports of a 12″ diameter tree down, and a utility pole snapped and second tree and wires down on East Otis Road in Tolland, MA along with trees down on Beech Hill Road in Blandford, MA. Monitoring for more reports. #mawx #wmawx #wmasswx

  65. Now it is just getting a survey team from NWS Albany to issue a report give a rating path length and width. This thunderstorm was moving in a northeast direction.

  67. Dewpoint is 74 here in Taunton; 76 in New Bedford. Yuck!
    77 in Marshfield, but isn’t that instrument in Marshfield suspect for being too high?

    1. You could cut the air with a knife outside right now. Dewpoint is 74 here as well with air temp of 75. Huge difference in airmass after the front pushed through.

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