Monday August 3 2020 Forecast

7:29AM

DAYS 1-5 (AUGUST 3-7)

August in New England. The sun angle may not be as high as it was in June and July, but we’re still in the midst of summer and we get some of our best “summer weather” around this time of year. And some of that will indeed take place during this 5 day period, but there will be a couple of “less-nice” days as well. We start with a hot and day today in a humid southwesterly air flow ahead of a trough, that will pass by and dry the air out a bit with a wind shift to west. Humidity will start to rise again later tonight and Tuesday as another trough approaches from the west – the very trough of low pressure that will steer a weakening Tropical Storm Isaias up (mostly just inland) along the East Coast today and Tuesday, the center passing just west of the WHW forecast area, probably between the Connecticut & Hudson Rivers Tuesday night. This track keeps much of the rainfall in advance of the system light and patchy with only an embedded heavier shower possible during the day, and the main storm impact will be a band or two of showers / downpours (possible thunder) Tuesday evening, also when the strongest wind will occur. We’re not going to see any widespread damaging winds from this – it will be too far west and too weak, but gusts in the 40 to 50 MPH range are definitely possible, favoring the South Coast. This system exits overnight, and by the time the sun comes up it’ll be a memory except for a gusty westerly breeze, transporting some drier air into the region behind it. Wednesday will be a very nice summer day, despite some forecasts you may have seen to the contrary. High pressure builds in for a nice Thursday too, but this high will be centered a bit north of the region and during Friday, a frontal boundary and weak disturbance to the south will be close enough for some cloudiness, but probably no rain except possibly a few South Coast showers.

TODAY: Mostly sunny to partly cloudy. A very slight risk of isolated showers or thunderstorms central MA and southwestern NH. Humid. Highs 80-87 South Coast, 87-94 elsewhere. Wind SW 5-15 MPH, higher gusts.

TONIGHT: Partly to mostly cloudy. Risk of a shower or thunderstorm late evening and overnight, favoring areas southwest and west of Boston. Humid. Lows 67-74. Wind S 5-15 MPH, higher gusts possible.

TUESDAY: Mostly cloudy. Episodes of showers, a few of which may be heavy. Slight risk of a thunderstorm. Humid. Highs 78-85. Wind S 10-20 MPH, gusts 25-40 MPH possible especially by late in the day favoring the South Coast.

TUESDAY NIGHT: Mostly cloudy evening with showers likely, a few downpours probable, and a risk of thunderstorms. Clearing overnight. Humid. Lows 67-74. Wind S 15-25 MPH with gusts 35-45 MPH favoring the South Coast and higher elevations evening, shifting to SW 10-20 MPH with higher gusts overnight.

WEDNESDAY: Sun and passing clouds. Less humid. Highs 81-88. Wind W 10-20 MPH and gusty early, diminishing to 5-15 MPH.

WEDNESDAY NIGHT: Clear. Lows 62-69. Wind W up to 10 MPH.

THURSDAY: Sunny to partly cloudy. Highs 80-87, but turning cooler in some coastal areas during the afternoon. Wind variable up to 10 MPH with coastal sea breezes.

THURSDAY NIGHT: Increasing clouds. Lows 60-67. Wind E to SE under 10 MPH.

FRIDAY: Mostly cloudy. Slight risk of showers South Coast. Highs 77-84, coolest coast. Wind SE up to 10 MPH.

DAYS 6-10 (AUGUST 8-12)

High pressure drifts back to the south providing fair weather for the August 8-9 weekend. High pressure then shifts south of the region with an increase in humidity and a slight risk of showers and thunderstorms August 10-12, maybe highest around the end of the period as a frontal boundary arrives.

DAYS 11-15 (AUGUST 13-17)

Weak blocking pattern – high pressure north and low pressure south, probably with this region influenced more by high pressure with dry weather, but a more persistent northeast to east air flow keeping heat at bay. Still not the highest amount of confidence on this forecast. A high pressure area that shifts to the south, which may happen later in the period, could quickly open the door to a shot of heat.

179 thoughts on “Monday August 3 2020 Forecast”

  1. Good morning and thank you TK.

    So now, with Isaias, has any tornado threat totally disappeared?
    Or at least diminished as Isaias transforms to Extra Tropical?

    It would appear that helicity values for tuesday/tuesday night
    have all but gone poof.

  2. Happy birthday, Old Salty and Rainshine! And also Tom and my Rilyn Mac!! It sure is a busy day for special birthdays.

  3. NWS Boston take on the tornado threat for tomorrow.
    Another concern during the evening into overnight Tuesday will be the potential for isolated tornadoes. Timing of course would change if the storm`s arrival time changes. Several hundred J/kg CAPE will provide plenty of instability together with a ton of 0-6 km effective shear for sustained updrafts. Add on top of it some serious low level spinning (0-1 km shear of 50 kts and 0-1 km SRH over 500[!] m2s2) and we`ll have to keep an eye on any storms that get going.

  4. Thanks, TK and SAK.
    Sure to be checking in a lot today and tonight.

    Happy Birthday, JPD, Rainshine, Rilyn Mac and Tom Brady!
    Enjoy your special day!!!

  5. Thanks TK !

    Happy Birthday Rainshine, JpDave and Rilyn Mac !!

    Tom Brady ………. who ???????? 🙂 🙂 🙂

  6. Quick peak at the latest SREF most of MA at some point tomorrow is in that low risk tornado category. I would think when the SPC updates the outlook for tomorrow around 1:30pm today the 2% tornado area will still be there.

  7. With this tweet from Ryan Hanrahan I got my flashlight ready and will be charging my cell phone tonight.
    While the heaviest rain threat is west of Connecticut there is still the potential for a period of damaging winds Tuesday evening. Most of our models maintain a fairly tight inner core of the system. Tree damage/power outages expected particularly CT and LI.

  8. I know the NAM is not reliable for tropics …….

    current 12z NAM op run´s pressure projection is down another 3 to 4 mb at landfall in Carolinas vs last night´s 00z NAM op run.

  9. Wow!!! the dew point has come down about 10 degrees!!!!!
    Most noticeable! Very thankful for that!
    Looking at surface map, a cold front (read dp front) has
    passed the area. YEAH!!!

    1. I noticed that as well heading out for my mid-morning coffee break. Coming into work earlier it was A-W-F-U-L!

      I woke up this morning soaking wet as I don’t have AC, just a typical high speed fan.

      Happy Birthday JPD! 🙂

    2. thank goodness, that was real soup and warmth yesterday evening into a good part of the night.

      I think we might get another mid 70F dewpoint surge tomorrow /tomorrow night as Isaias passes well to our west.

  10. According to WBZ radio this morning, we can expect a widespread 2-4” of rain from Isaias. This was out of the mouth of the Accuweather.com met, not the newscaster. And it continues well into Wednesday.

    TK – Your emails to WBZ radio have really set them straight. 😉

    1. that is pure BULLSHIT!
      Perhaps in the berks, but over most of SNE and MA,
      NO WAY!!! That is irresponsible!!! PATHETIC!!!

  11. Putting a Tropical Storm Warning up for eastern New England is an absolute joke.

    A. It will probably be extratropical when it gets here.
    B. We may see gusts to Tropical Storm force along the coast, but sustained winds of 39 mph more? Not likely.

    1. It also projected a min pressure of 995 at 11am, recon found 1002. Recon also hadn’t found flight-level winds above 50 knots for a couple of hours. At this point, ignore the models (actually, we’re way past that point). Use the actual data, which tells us this is weakening, not strengthening like NHC seems to think.

  12. Thank you TK!
    A big happy birthday to JP Dave, Rainshine, And Rilyn Mac!! JP Dave trying real hard to get you a storm for your birthday, but unfortunately this gift maybe on back order until later in the season. Let’s see if Mother Nature can deliver.

    1. I believe JPD would much prefer a raging 2-3 foot blizzard instead. Too bad his birthday isn’t in the dead of winter. What a gift that would be! 🙂

  13. Outside putting away most of the bulky chairs and a table. It is really hot.

    The drought is region wide by the drought monitor I have seen. We are parched in Marshfield with many, many yellow lawns where the blades of grass crunch under your feet.

  14. If my eyes don´t deceive me, the center of Isaias has had a slight eastward component to its largely northward motion. With the shape of the Carolina coastline, the slightest eastward track component can translate to dozens of miles for location of landfall.

    Also, feel like the radar is showing some moderate convection wrapping around the circulation in the last few hours.

  15. SPC for tomorrow

    https://www.spc.noaa.gov/products/outlook/day2otlk.html

    https://www.spc.noaa.gov/products/outlook/day2probotlk_1730_torn.gif

    …SUMMARY…
    A few tornadoes will be possible from the Virginia Tidewater into
    New England Tuesday into Tuesday night, in association with Isaias.
    Scattered severe thunderstorms capable of producing large hail and
    damaging winds may also occur across portions of the northern and
    central Plains.

    …Eastern North Carolina to New England…
    Latest forecast from the National Hurricane Center indicates that
    Isaias should be located over far northeastern NC and southeastern
    VA at the start of the period Tuesday morning. Isaias should
    accelerate northeastward along the Mid-Atlantic Coast and into New
    England through the period as it becomes absorbed within an
    upper-level trough over the eastern CONUS. A rather strong low-level
    flow field (60-70+ kt at 850 mb) will be present in the eastern half
    of Isaias’ circulation, which will aid in substantial low-level
    hodograph curvature/enhancement.

    The best prospect for weak destabilization (MLCAPE 250-1000 J/kg)
    should exist along/near the Mid-Atlantic to southern New England
    Coast, where surface dewpoints should increase into the low to
    perhaps mid 70s through Tuesday evening. Given the very favorable
    low-level shear, primary concern will be a few tornadoes with any
    low-topped cells in outer rain bands along/east of the center of
    Isaias’ circulation. Confidence has increased enough in the Isaias’
    track and potential for modest diurnal destabilization along/near
    the coast to include 5% tornado probabilities and a Slight Risk from
    the VA Tidewater region northeastward into southern New England.
    Eventually, the strong low-level shear should become displaced to
    the north of even weak inland destabilization across NH and ME by
    late Tuesday night. This should result in a gradual lessening of the
    isolated tornado threat with northward extent across New England.

  16. “Data from the reconnaissance aircraft and NOAA Doppler weather radars indicate that maximum sustained winds remain near 70 mph (110 km/h) with higher gusts.”

    It does? Is there a top-secret recon plane in there that isn’t sending data out for the public to see? Someone at NHC has a future career as a fiction writer.

  17. I watched webcams from Folly beach, Sullivans Island, Isle of Palms and the surf is up but not terrible. Wild dunes and the Battery were off line when I checked. That said, it is low tide and waves are up some. I’m assuming the Battery is flooded; however, if it is not yet, it will be. Residents are asked to stay home after 6 pm but not mandatory.

  18. Isaias looks quite healthy on radar this afternoon after some struggles this morning. Would agree with SAK that 70mph sustained is probably a bit generous at the moment. But I’m worried. You’ve got basically all the models showing 70+ mph wind gusts all the way up the mid-Atlantic coast into New England. Some reliable models showing 80-100+ mph. You can’t ignore that, not given the sort of baroclinic properties and highly anomalous (for the season) upper jet at work here. Though I’m certainly working under the assumption that 90-100 mph won’t happen, or would be extremely isolated. Not to mention the rain which at least for my region looks like a very big deal.

    This also isn’t going to look tropical for much longer. The intensity may fluctuate, but do not mistake structural evolution for weakening over the next 24 hours.

    1. A different take ….. I don´t know what to think now ……. I´ve been kind of concerned about this one, but I have interpreted the general feedback I´ve received today to be different than what you wrote here. (Perhaps I have interpreted the other feedback incorrectly.)

      Oh well, I secured the front yard in case and plan to secure the back yard tomorrow morning.

      Good luck down in NJ area !

      1. Thanks! I’m obviously a lot more focused on impacts here than in SNE, and I suspect we’ll probably get it worse than you guys up there, but I still think there will be issues into MA/RI/CT as well.

        One of the things we often think in terms of is the “reasonable worst case scenario”. At least for my region, I could see that as being widespread 70-80 mph wind gusts for multiple hours, causing widespread tree damage and several hundreds of thousands of power outages. And again, not to mention the rain.

      2. Tom I was thinking the same. I wasn’t moving anything in the yard and I do fully understand that you are at the coast and I’m well inland. I find myself wondering if I need to rethink moving a few things.

        1. Long story. Didn’t have username and email saved and when I entered them, well you see where the smiley faces ended up.

          Did I ever tell you that I HATE WORD PRESS!!!!!!!!(@()#(!@#()*!()@*#)(!@*#(!(#*(!*!@()*

    1. You had mentioned the Charleston radar. There´s a nice radar shot on Mike´s tropical weather page and the center is now fully surrounded with convection. Much more in the northern semi-circle, but some in the southern semi-circle too.

        1. I do believe we now have an eye or at least a semblence
          of one. They’ll know it when that sucker comes ashore.

        2. Wonder if the orange/red echos around the circulation are a western eye wall trying to form or just being closed to the radar, so it’s got the intensity more correct due to its closeness ????

  19. 97 the max at my home today at my conservative, shielded sensor. We’ve had very hot days here the last couple of weeks!

  20. We had 40-50 mph gusts in that wind storm weeks ago. It rearranged even our heavy Outdoor furniture a bit but not more. I’m a bit worried that things are changing as time passes Today and wonder if sustained wind at those Speeds is likely This far inland now??

      1. Tk did say 40-50 gusts and I know it said favoring south coast. That doesn’t mean limited to. But you don’t think the gusts will translate to anything remotely sustained?

  21. I hope that next recon plane arrives at Isaias soon …… looking at an improving representation on Charleston radar, the central dense overcast looks a bit more symmetric in the north half of the system, I believe the next pressure readings will show a decent drop ….. perhaps mid 980s ????

    1. Nothern eye wall looks decent, however, the southern one
      leaves much to be desired, but at least it is there. It didn’t used to be there. 🙂

    1. And your thoughts? Similar? or not?
      Wind and rain doesn’t bother me, but the prospect of
      tornadoes does. Is this tornado talk real or hype?
      thanks

  22. Can’t an extratropical storm cause just as much damage as a cat 1 hurricane given the right conditions?

  23. Hope I replied to all birthdays. In case I didn’t – Happy Birthday to all today. And I know I haven’t been posting here lately (got on FB in April) so a little caught up (addicted?) to that. But I have been looking at WHW off and on but not posting. My bad. But with tropical storm coming our way, wanted to see what TK and you guys think might happen. Still trust WHW more than tv meteorologists. So came on today to see comments re: storm. Not just because my birthday! And, as always, thank you TK for your wisdom and for your work in keeping WHW going.

  24. Buoy 41004, 41 NM southeast of Charleston has, as of 6:20 pm, a pressure of 29.23 in = 989.8 or 990 mb.

    The buoy looks like its close to the right side of the center of circulation as the winds have veered to SSE and eased to 15.5 knots.

  25. This tweet from Eric Webb goes along what Tom just mentioned.
    Pressure continues to fall like a rock at this NOAA buoy offshore the SC coast. Now reporting 989-990mb w/ 30 knot wind actual pressure is likely around 986-987mb & #Isaias almost certainly is a hurricane (again). Recon are currently en route to confirm

    1. around 4pm on TWC, they mentioned that particular buoy and I´ve been checking it periodically since then.

  26. Two Tornadoes confirmed in Litchfield County in CT yesterday.
    From Ryan Hanrahan
    @NWSAlbany confirms 2 tornadoes touched down in Litchfield County last night. An EF-0 in Sharon and an EF-1 in Falls Village.

  27. Interesting excerpt from the latest Norton NWS office
    forecast discussion. Still seems to be quite a bit of concern
    re: possible tornadoes tomorrow.

    3. Severe Weather/Tornado Threat. It`s the eastern side of the
    storm again. Huge helicity values 300-600 m2/s2 develop late
    afternoon/early evening. Bulk shear values are 50kt+. Plus some
    of the hi-res convective allowing models show bands of
    convection that suggest embedded small supercells. Pretty
    classic of landfalling tropical systems. SPC has increased the
    severe risk to “Slight” for tomorrow. Seems reasonable. Have a
    feeling we`ll have several short lived and small, but still
    damage causing tornadoes anytime from mid afternoon to late
    evening.

    1. Yeah, the simulated radar I saw on 6pm weathercasts was that classic, thin, curved, right quadrant tail, containing spaced supercells. That might be interesting ……..

  28. Oh yes, first pass approaching center from west southwest quadrant and they encountered 65kt flight level winds.

    Lower pressures being measured as well.

  29. Buoy 41004´s pressure bottomed out at 29.20 inches or 988.8 (989mb). Pressure rising now with a WSW wind as center has moved just pass.

    1. yup. And because it tracked the way it did, it has another 2 hrs over water because of that concave shape of the coast just to its north and northeast. Will it continue to intensify to landfall. I think it might because you can see the srong ventillation on its north side, being aided by the beginning interaction with the jet stream.

  30. For the Carolinas does it really make a difference from a strong tropical storm or very low end category one hurricane.

    1. Probably not, but ……. I do wonder with a bit more increased energy now and possible help from the jet stream, how that will play out in the next 24-30 hrs ….

      1. Isaias with the help of the jet stream when the center passes just to the west of CT MA to me will have some steroids in it’s system. Hurricane Center has it as strong tropical storm when it makes its approach to SNE.

    1. Are these storms related to the tropical system or the humidity front that went thru New England this morning ?

      1. Mainly related to the approaching trough in concert with that frontal boundary! Dew points actually mixed out quite a bit today even here (it did not feel very tropical at all outside) and that low level dry air combined with strong lift enhanced downburst potential.

  31. To answer the question posted above I do not think this will quite measure up to the analog storm that my colleague mentioned.

    1. Do you mind taking a minute to answer mine to SAK if you have a minute. As I read, I am worrying a bit more about not preparing some things that I should have. Hopefully, I’m over worrying but would like to be sure. Thank you, Sir

      1. I don’t expect the inland winds to be too serious.. maybe 15-30 sustained gusts around 40-45 during a relatively short peak wind period in the evening.

    1. thats cause they got nutty flight level winds in the right quadrant, so much so, that it didnt believe them.

        1. And if thats true, then we have to consider that the normal over land weakening may not occur as quickly as would be expected..

  32. 00z hurricane models updated. 24 hrs from now, they project Isaisas to be somewhere around Albany to NYC. Intensity wise, at 24 hrs, 7 of the 13 models are at 55 knots or greater.

  33. I am rooting for a big forecast bust here in CT tomorrow. I did move my deck furniture in just to be safe.
    From Ryan Hanrahan
    Evening update – worst of the weather expected 2 p.m.-10 p.m. with a slightly faster storm. Low tide arrival should mitigate surge threat. Heaviest rain stays just west. Tornadoes possible with any storm that develops. Widespread power/tree issues possible w/ gusts to 70.

  34. SREF upping the tornado potential for CT and most of MA with the exception of eastern areas of MA late tomorrow afternoon. Instead of the low chance for a tornado it is showing an elevated tornado risk in the areas I mentioned. The rest of SNE in the low tornado risk.

  35. Per Eric Fisher, 96 mph gust at Frying Pan Shoals off NC/SC border.

    If this deep trof for summer weren´t there, I wouldn´t be as worried. But, it is there and there are some in the weather world commenting on its impact to temper the weakening of this system compared to perhaps what would be expected.

  36. Recon plane making third pass in northeast quadrant. Nearing circulation. Last flight level wind was 96 knots ……..

  37. This area of thunderstorms still damaging winds as it was doing where it was earlier in NJ
    From Ryan Hanrahan
    The terminal doppler at JFK is showing 60 mph winds moving into Stamford and Darien. Damaging winds incoming for Fairfield County – Milford and New Haven you’re in line for this too.

  38. It is heading off in a northeast heading and Ryan Hanrahan was just on an put a storm track on these thunderstorms and around 10:40 it will get near my area. Will see if it holds together.

  39. Vicki there was no mention here of any thunderstorms tonight in CT. Our meteorologists really concerned about the damaging wind and tornado potential tomorrow along with the possibility of widespread power outages.

    1. Oh dear. Thank you. I’m also worried. And wish I’d followed Toms lead and prepared outdoors today. We will be at it early in am. Please be safe

  40. Looking forward to the 11pm NHC advisory.

    At 8pm, they project a ´strength´ of 65mph at the time the storm is around NYC

    What will they project now in that general vicinity ??

    Also, the percentage chance for tropical storm wind gusts have gone way up from like 30% to 70% chance. Even higher your way, JJ

  41. Low tide at the Battery (NY) tomorrow afternoon at 3:45pm : 0.3 ft

    High tide at the Battery (NY) tomorrow evening at 10pm : 5.5 ft

  42. Tom 80% chance for tropical storm force winds for CT. You don’t see percentages like that this high too often here in New England when it comes to these tropical systems.

  43. Tomorrow night Hurricane Center has 60mph winds near Albany, NY. The only good news is for the shoreline in CT this is coming at low tide unlike with Irene which came during high tide.

  44. Ocean Isle Beach, NC is the landfall location for Hurricane Isaias. It had winds of 85 mph pressure 988mb.

  45. I cannot say enough how good Pete’s explanation of the strongest winds was on his 11PM forecast. He basically said what will be coming from me on my morning update. Too tired to do it now. 5 more hours…

    1. Just listened to Pete. He is always exceptional. So winds and not gusts up to 55. So far. He qualified that of course. West wind impacts our house the most.

  46. Up to take some tums as my stomach is churning big time Had a peek at Spc. ALL of Ma and most of NE in the 5% tornado area I believe we see a tornado watch hoisted for our areas. We shall see. This was my main concern all along.

    1. looked at sref. it and Hrrr show main tornado threat west and sw of boston.
      Close and tricky, so we shall see .
      spc may err on side of caution and bring the watch, if there is one, right to the coast .
      Will see what new runs show. tons of low level shear with this system.

  47. I am really thinking that IF there is a tornado watch it will
    be in NJ, NY and far Western MA and CT. We shall see.

    1. They really think that the main threat is well to the East
      of the center. Interesting to follow future Meso Scale
      discussions and watches.

  48. From NWS Tropical Storm warning for Boston:

    * TORNADO
    – LATEST LOCAL FORECAST:
    – Situation is unfavorable for tornadoes

    – THREAT TO LIFE AND PROPERTY THAT INCLUDES TYPICAL FORECAST
    UNCERTAINTY IN TRACK, SIZE AND INTENSITY: Tornadoes not expected
    – The tornado threat has decreased from the previous
    assessment.
    – PLAN: Tornadoes are not expected. Showers and thunderstorms
    with gusty winds may still occur.
    – PREPARE: Little to no preparations needed to protect
    against tornadoes at this time. Keep informed of the latest
    tornado situation.
    – ACT: Listen for changes in the forecast.

    – POTENTIAL IMPACTS: Little to None
    – Little to no potential impacts from tornadoes.

    * FOR MORE INFORMATION:
    https://www.weather.gov/box

    Here is the link: https://forecast.weather.gov/wwamap/wwatxtget.php?cwa=box&wwa=tropical%20storm%20warning

    Have to scroll down for Boston as there are many regions listed.

    This is from the Norton NWS office:

    Tornadic wind… Strong 0-3Km helicity values of 400-600 move into
    Wrn MA/CT…generally the area west of Worcester…18Z/2 PM to 01Z/9
    PM. The system does have a history of generating tornadic
    circulations in storm rain bands as it moved into North
    Carolina. Isolated tornadoes will be possible, mainly this
    afternoon and evening.

  49. So, some mixed messages. I’d lean more towards our own
    NWS office and NOT the SPC. I think at the moment
    I am somewhat relived here in Eastern MA.

    To the West may be a different story.

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