Wednesday Forecast

122 Comments

7:25AM

DAYS 1-6 (MAY 25-30)…
It’s all about the wind direction. Upper level high pressure builds in and remains in general control of the large scale pattern in the Northeast for the next several days, but our resultant weather here in southern New England will have everything to do with the wind direction, which will be governed by the position of surface features, particularly high pressure, as well as a frontal boundary that will be seemingly indecisive about where it wants to be. First, we start on the damp and cloudy side today as there has been little wind to clear out the low level moisture overnight, but this will change quickly during the day as a drying and warming westerly wind takes over, erases the cloudiness and replaces it with sunshine and the feel of summer, even for much of the coast as the wind comes off the land. Thursday, a weak front will have dropped through from the north in the pre-dawn hours, and a light north to east wind will mean cooler conditions for north-facing and east-facing shores while interior areas are still quite warm. On Friday, winds flip to southerly and many areas are warm, except the South Coast which will be modified from wind off ocean water just to the south of New England. As we enter the Memorial Day Weekend, it will be the same story. Saturday looks like the hot day with a stronger westerly wind in control, the front will come back a little stronger from the north at night as a more reinforced high pressure area builds in eastern Canada. This front may ignite some thunderstorms as it presses toward and through the region, but should push far enough to the south that high pressure noses in with not only cooler but dry air for Sunday into Monday, although some cloudiness may be around at times. It may end up warmer later Monday as the high pressure area sinks far enough through the region so that the wind starts to come back around to southwest or west. Note that I extended the typical “DAYS 1-5” to a “DAYS 1-6” for today’s blog so we could include the entire Memorial Day Weekend forecast in this section.
TODAY: Early low clouds dissipate, then mainly sunny. Highs middle 80s to near 90, except cooler Cape Cod and a few immediate eastern coastal areas. Wind W 5-15 MPH, higher gusts.
TONIGHT: Partly cloudy. Lows in the 60s. Wind W 5-15 MPH shifting to N.
THURSDAY: Mostly sunny. Highs 70s coast, 80s interior. Wind N 5-15 MPH shifting to E.
THURSDAY NIGHT: Variably cloudy. Scattered showers and a slight chance of thunderstorms. Lows in the 60s. Wind E 5-15 MPH shifting to S.
FRIDAY: Partly sunny. A little more humid. Highs 70s South Coast and Cape Cod, lower 80s interior.
SATURDAY: Partly cloudy. Chance of late-day showers/thunderstorms. Humid. Lows in the 60s. Highs middle 80s to lower 90s except cooler some immediate coastal areas and Cape Cod.
SUNDAY: Partly sunny. Lows from the upper 50s to middle 60s. Highs middle to upper 60s coast, 70s interior.
MONDAY – MEMORIAL DAY: Partly sunny. Lows middle 50s to lower 60s. Highs upper 60s to lower 70s coast, middle 70s to lower 80s interior.

DAYS 7-10 (MAY 31-JUNE 3)…
Scattered showers/thunderstorms possible May 31 as a front pushes through the region. Fair and cooler June 1-3.

DAYS 11-15 (JUNE 4-8)…
Passing disturbances during this period will bring a few episodes of showery weather and changing temperatures.

122 thoughts on “Wednesday Forecast”

  3. Thanks TK. Great looking weekend! Latest HRRR has Boston Logan hitting 91 today. Might be a little overdone, but 90 should be a common number later on.

  4. Thank you…Absolutely spectacular morning. Filtered sun and temp at 62.4. First time I have had every window wide open and it feels amazing. A special cousin of Mac’s is visiting today from Seattle (in town for her daughter’s college graduation). She is a huge weather nut and we will surely show her how spectacular New England springs can be.

  6. It is amazing that we will be going from St. Patrick’s Day to 4th of July within 24 hours.

    Only in New England! šŸ™‚

      2. What revised format? Looks the same to me?
        What am I missing? Am I that foggy in the morning?
        I guess so. If you mean the photo, indeed that is really nice.

        Good morning and thank you TK.

          1. Yes I saw that. I wouldn’t qualify that as a format change. It is simply logical. But, I guess that is the way I am wired or not wired?

        2. I’m foggy also I guess. I thought it was photo which, knowing me, could have been there for quite a while. I focus on the wording and forget to look at the photos.

  7. Hmmm

    0Z Euro shows it quite toasty today through Saturday, with today approaching 90,Thu & Fri low-mid 80s and Saturday into the lower 90s.

    1. There was a reason I advised you to be careful of Euro temps more than a few days out. Like snowfall numbers, they are not good.

      1. Yes, I completely understand. I have learned this over time.
        It just needs to be factored in along with all of the other information.

        1. It’s funny how a model that is generally superior in predicting the overall pattern can fail so often at the fine details.

          1. Such is life in the model world.
            At least you have the experience to know these
            things and factor it all in. I could see a less
            experienced Met falling for the Euro hook line and sinker. In fact I see some experienced Mets doing
            the same thing. šŸ˜€

            This is what separates you from the rest of the field and puts you in elite company.

            You have a remarkable sense of what is going on in the atmosphere. Way more than your average met. I put you on par, if not better, than Harvey, Eric and Barry.

  9. Quickly reading the discussion from NWS out of Taunton looks like weak shear will be the limiting factor for thunderstorm development. Certainly there is enough CAPE present.

      1. I guess so. Here is the discussion:

        While most of the day will be dry, a few showers and
        thunderstorms may develop Saturday afternoon and evening with a
        pre-frontal trough and CAPE values between 1000 and 2000 J/KG.
        This will be mainly to the northwest of a Boston to Providence
        line. Forcing will be rather weak, so areal coverage of any
        activity that develops may remain limited. Severe weather threat
        also looks rather low at this time with rather weak 0 to 6 km
        shear, but too early to rule out a strong thunderstorm or two
        given decent instability.

  10. I was talking about Saturday.
    Parts of the region are in the hazardous weather outlook for Saturday with a low risk of a strong thunderstorm.

    1. 73 inland, with light and variable winds.

      The West wind is “supposed” to kick in a bit later.
      Will never make the 80s near the coast if it does not.

      Meanwhile, Boston Buoy sits at:

      Water Temperature (WTMP): 54.3 Ā°F

      As of 10:50 AM

      Last night Eric reported sea temperatures of 52-56 across the region.

  12. Thank you, TK, for your forecast, diligence, and accuracy.

    I think a SE wind will play games with us at the coast this week, especially on Friday. I did not expect it to today, but it appears that Logan Airport says it is. Today may be one in which Roslindale or Brighton (both are Boston neighborhoods) get to 90F while Logan remains stuck near 80F. This theme may continue later this week as well, although I can envisage Friday being a day in which a larger portion of the coastal region gets impacted by the ocean, limiting the heat.

    1. Such is life in Coastal New England. šŸ˜€
      We cherish the East wind in summer and Loath it in Spring. šŸ˜€

      1. Indeed. The outer Cape and the islands will struggle to get out of the 60s all week: For example, Provincetown is 58F right now, and Nantucket 64F. I’m sure it’ll still feel nice there with ample sunshine.

  13. For a small state Massachusetts has rather remarkable variation in weather. One could even say climatic variability, as the coast and islands are so very different from the interior. The Bay area in California reminds me a bit of this contrast. SF can be 15-25 degrees cooler than Oakland on any given day, and then as you move further inland the difference can be as much as 35 degrees. We’re only talking about a 10-20 mile stretch.

    2. The bay area of CA was an excellent example. That Pacific Ocean is quite
      cool at their latitude and often the wind is straight off of that ocean.

      There is some saying about enjoying a fine San Francisco Winter’s day during July. šŸ˜€

      1. Yes. Mark Twain put it well. In 2010 I was there with my daughter. We visited Yosemite. It was close to 100F. On the east side of the Hayward bridge it was 79F, west side 67F. Near Golden Gate Bridge 55F. I bought a scarf for my daughter at a local department store as she was “freezing.”

  15. 12z runs of American Models differ quite a bit for Saturday in regards to instability
    GFS CAPE
    http://www.instantweathermaps.com/GFS-php/showmap-conussfc.php?run=2016052512&time=INSTANT&var=CAPE&hour=081
    LIFT
    http://www.instantweathermaps.com/GFS-php/showmap-conussfc.php?run=2016052512&time=INSTANT&var=LFTX&hour=081

    By comparison the NAM less with the instability and more instability at 15z where GFS has the greatest amount of instability at 21z
    CAPE
    http://www.instantweathermaps.com/NAM-php/showmap-conussfc.php?run=2016052512&time=INSTANT&var=CAPE&hour=075

    1. That GFS is rather robust for almost all of SNE. Pretty impressive actually.
      Now we have to see if that verifies or not. šŸ˜€

      I’m afraid we need to keep an eye on this.

      I want to take a look at the 12Z Euro coming out in about an hour or so. šŸ˜€

  16. I’m at 83 with a dew point of 52. Not what I consider anything special. We’ll see what happens with the rest of the day. Certainly not a “torch”.

  17. We are heating up pretty fast here in the CT Valley – already up to 86 in Hartford so should be able to attain 90 fairly easily. Though it is very tolerable out with the low dewpoints.

    It is looking like our backdoor cold front isn’t going to have as much punch as it previously appeared. Models seem to be getting weaker with it in successive runs and GFS/Euro both have it basically washing out near us on Monday/Tuesday. I see NWS has bumped highs back up into the 80’s across interior areas Sunday, Monday and Tuesday.

  19. …and people were in a panic about a return to a terrible pattern this week. šŸ˜‰

    “Guidance not gospel.” šŸ˜€

  20. Hmmm
    As of 1 PM, still 67 at the Pit (airport).

    Boston, Logan International Airport, MA
    (KBOS) 42.36056N 71.01056W
    Fair
    67.0 Ā°F
    Last Updated: May 25 2016, 12:54 pm EDT
    Wed, 25 May 2016 12:54:00 -0400
    Weather: Fair
    Temperature: 67.0 Ā°F (19.4 Ā°C)
    Dewpoint: 57.9 Ā°F (14.4 Ā°C)
    Relative Humidity: 73 %
    Wind: East at 9.2 MPH (8 KT)
    Visibility: 10.00 miles
    MSL Pressure: 1014.9 mb
    Altimeter: 29.97 in Hg

    Just got back from Lunch. 77.5 at my house. It was difficult to determine the wind
    direction, but I’d say we had a light breeze drifting in from the SE, NOT E or NE, but
    SE. Same thing here at the office. Best I can tell, temp is about the same as at home.

    Another fine example of the airport NOT being representative of the vast majority of the city. šŸ˜€

    1. Wood Island is indeed not representative for the city as a whole. This said, I’m close to South Station and my estimate is that it’s around 71F here. A little more than a mile from here – outside my apartment – it’s probably 75F or warmer. Don’t know this for sure, but on my walk home from work I almost always feel a significant difference. In winter, there’s often more snow accumulation where I live than at my office.

        1. 86 with comfortable dew point is unbearable?
          I think you are messing with us. šŸ˜€

  23. JPDave curious with the 12z EURO shows for instability and see if the GFS is alone and out to lunch on this one or this some support. Certainly the humidity for thunderstorms Saturday will be present.

    1. I’ll share when it is available. I am impressed by the numbers of the GFS, however, that doesn’t always translate to reality. šŸ˜€

  24. The key with the CAPE values its POTENTIAL energy available which does not mean those values will be realized. Right now I am thinking non severe thunderstorms potential favoring the interior.

    1. True, but if you go to Pivotal Weather and check out some other
      Severe parameters, there “may” be something here.

      I’ll explain more later. šŸ˜€

  26. I look forward to hearing more later. This looks to be our first watcher for thunderstorms in the warm weather season. We had thunderstorms back in February which some became severe here in SNE with some wind damage reports.

    1. Here is what I meant:

      http://maps1.pivotalweather.com/maps/models/gfs/2016052512/078/sblcl.us_ne.png

      You will note that the LCL level “just” West of Boston is depicted to be
      400-500 Meters, which as you read below you will see can be quite serious.

      Explanation

      Mean Parcel LCL

      The Lifting Condensation Level is the pressure level at which a lifted parcel of air reaches saturation when lifted dry adiabatically. On a Skew-T, the mean parcel LCL is identified by using the average temperature and dew point in the lowest 100mb. The intersection of a line drawn parallel to the mixing ratio line from the dew point, and parallel to the dry adiabat from the temperature, is the LCL. The location of the LCL roughly approximates the height of the cloud base when air parcels undergo forced ascent.

      As a forecasting parameter, low LCL heights (in meters) are associated with the development of tornadoes. Statistically, the most destructive tornadoes form when LCL heights are extremely low — in the four- to six-hundred meter range. On average, both the potential and intensity of tornadoes tends to decrease as the height of the LCL increases.

      Now to be sure, this is NOT the only parameter to be considered, BUT in combination with the CAPE and LI depicted by the GFS, these LCL numbers
      are somewhat alarming.

  27. Here is the 12Z Euro Total Totals Index:

    http://imgur.com/Mtn3RDJ

    Although it is possible for some strong to “possible” severe, this index most likely
    represents garden variety.

    Here is an explanation of total totals

    TOTAL TOTALS INDEX

    TT = Td850 + T850 – 2(T500) or (Td850 – T500) + (T850 – T500)

    cross total + vertical total
    where TT is the total totals index (Ā°C), Td850 is the dew point temperature (Ā°C) at the 850 mb level, T850 is the temperature at the 850 mb level, and T500 is the temperature at the 500 mb level.

    Guide: TT > 44 = possible thunderstorms, slight chance of severe TT > 50 = moderate chance of severe thunderstorms TT > 55 = strong chance of severe thunderstorms

    The total totals index (TT) is an index of atmospheric instability composed of two indices: the cross total and the vertical total. The cross total is a measure of how buoyant the air parcel is due to less dense, moist air in the lower levels. It is defined as the difference between the 850 mb dew point temperature and the 500 mb temperature. The vertical total is a measure of how buoyant the air parcel is due to warm air at lower levels. It is defined as the difference between the 850 mb temperature and the 500 mb temperature. The sum of the cross and vertical totals is the total totals index. The vertical total deals with the thermal difference while the cross total takes into account the amount of moisture present. Hence, the three main factors in obtaining high total totals index values are the following: a high 850mb temperature, a high 850 mb dew point temperature, and a low 500 mb temperature. Note: The total totals index has not been calculated for Fig. 1.

    Also, not particularly impressive CAPE values either.

    http://imgur.com/oqFxn06

    If it were more interesting, I’d share some more charts.

    Let’s see what it looks like as we get closer.

    Right now the GFS seems to be on an island by itself.

  28. 2PM Logan obs

    Boston, Logan International Airport, MA
    (KBOS) 42.36056N 71.01056W
    Fair
    73.0 Ā°F
    Last Updated: May 25 2016, 1:54 pm EDT
    Wed, 25 May 2016 13:54:00 -0400
    Weather: Fair
    Temperature: 73.0 Ā°F (22.8 Ā°C)
    Dewpoint: 59.0 Ā°F (15.0 Ā°C)
    Relative Humidity: 62 %
    Wind: Southeast at 5.8 MPH (5 KT)
    Visibility: 10.00 miles
    MSL Pressure: 1014.2 mb
    Altimeter: 29.95 in Hg

    Note: due to sea breeze, dew point stands at 59. Somewhat HIGHER than inland
    locations.

    1. Inland locations are sporting SW winds.

      I’m guessing Logan switches to a land breeze soon with the temperature
      jumping into the 80s somewhere, but I highly doubt Logan pushes 90.

      We shall see.

      1. Not sure who indicated 90 for Logan. That, if it happens , will be Valley locations of interior. Logan breaks 80 late today.

        1. No one here. It’s just that the Magic temperature of
          90 has been bandied about that is all. I was just re-iterating that Logan would never make 90. šŸ˜€

          Perhaps on Saturday. We shall see.

        2. One of the local weather folks yesterday made a comment that we could see our first 80 and 90 degree day.

          This is Vicki’s fact-based, informative minute that doesn’t mean a thing since she has no idea who the weather person was.

        3. Todd Gross called it the “six o’clock jump” when he was on air back on in the day.

          Do you know what Todd is doing these days TK?

  29. 89 in Hartford but with a dew point of 42 and relative humidity of 20%. It is dry out there. The heat index is actually about 3 degrees lower than the air temp. That will change come Friday and especially Saturday.

  30. Looks as if Sue and WeatherWiz share the honor of hitting the first 80 degree day at Logan on the nose. Both had May 25. Well done!

      1. That is PATHETIC!!! Meanwhile at nearby and I do mean nearby
        BlueHill, it is 84. That means it must be really close to 84 at my house. Wow!

          1. Never surprised when temperatures at the PIT
            behave like that.

            Watch it do the Philip (Todd Gross) Jump
            at 6PM.

  32. Iā€™m at 85.8, off a high of 86, so that might be it for the day.

    Dew point back down to 50. I recorded 58.4 at 9:10 am this morning and has been dropping since.

    BTW, I posted this just now and got back “Your comment is awaiting moderation”
    Silly me mistyped my email address. At first I thought what bad thing did I do? šŸ™‚
    I posted this same post and got

    1. WP is picky. One character different and it will send it to moderation. Also, I would not suspend someone without warning them. This blog is not known for over-moderation. If someone gets booted, they earned it. šŸ™‚

  33. Off today my wife had an appointment in town earlier . Sitting on back deck and its 84. This is my kind of day . I love the heat but I would take this all year .

    1. Yes, John, I know it’s your kind of weather. Enjoy! This is just a start. You’ve got the entire season in front of you.

  34. I am enjoying this since the humidity is in check. Too bad everyday can’t be like this during the summer.

  35. I made a prediction of 88F for Logan today. Ain’t going to make it. I did think some seabreezes would knock off the temps at the immediate coast this week, but not today. I was thinking later in the week.

  37. Logan up to 75 at 3:54 PM, but wind is due East at about 7 mph.

    Still could get the 5 or 6 PM Jump.

    1. While Bradley is at 87 as is Westfield MA
      Norwood MA is at 89 and Bedford, MA at 87.
      Taunton at 87 and Lawrence at 88. Close all around.

      1. This covers it for most of Massachusetts:

        AN AIR QUALITY ACTION DAY MEANS THAT GROUND LEVEL OZONECONCENTRATIONS WITHIN THE REGION MAY APPROACH OR EXCEED UNHEALTHY STANDARDS.

        What is causing this. We hardly ever see this.

        MAZ002>005-008>014-017-018-026-2603 00-
        WESTERN FRANKLIN MA-EASTERN FRANKLIN MA-NORTHERN WORCESTER MA-
        CENTRAL MIDDLESEX MA-WESTERN HAMPSHIRE MA-WESTERN HAMPDEN MA-
        EASTERN HAMPSHIRE MA-EASTERN HAMPDEN MA-SOUTHERN WORCESTER MA-
        WESTERN NORFOLK MA-SOUTHEAST MIDDLESEX MA-NORTHERN BRISTOL MA-
        WESTERN PLYMOUTH MA-NORTHERN MIDDLESEX MA-
        INCLUDING THE CITIES OF…CHARLEMONT…GREENFIELD…ORANGE…BARRE…
        FITCHBURG…FRAMINGHAM…LOWELL…CHESTERFIELD…BLANDFORD…
        AMHERST…NORTHAMPTON…SPRINGFIELD…MILFORD…WORCESTER…
        FOXBOROUGH…NORWOOD…CAMBRIDGE…TAUNTON…BROCKTON…AYER
        347 PM EDT WED MAY 25 2016

        …AIR QUALITY ALERT IN EFFECT FROM 11 AM TO 11 PM EDT THURSDAY…

        THE MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION HAS ISSUED
        AN AIR QUALITY ACTION DAY FOR GROUND LEVEL OZONE…IN EFFECT FROM
        11 AM TO 11 PM EDT THURSDAY.

        AN AIR QUALITY ACTION DAY MEANS THAT GROUND LEVEL OZONE
        CONCENTRATIONS WITHIN THE REGION MAY APPROACH OR EXCEED UNHEALTHY
        STANDARDS. FOR ADDITIONAL INFORMATION…PLEASE VISIT THE
        MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION WEBSITE AT…

        http://WWW.PUBLIC.DEP.STATE.MA.US/MASSAIR
        /ALL LOWERCASE LETTERS/…OR CALL 1-800-882-1497.

  40. Gradient sharpening up right on time. Wind gusts to 20 in Woburn out of the west.

    Y’all do realize the sun sets after 8 now and Logan often maxes out early evening in the spring, yes? šŸ˜€

    1. Of course. I am waiting for that jump.
      It will go from 75 to about 83-85 I am guessing.

  41. NWS

    — Changed Discussion —
    4 PM Update…Temperatures have climbed in to the mid to upper 80s
    away from the immediate coastline this afternoon. The sea breeze
    along the immediate east coast of Massachusetts should push back out
    to sea in the next hour. This will allow temperatures to make a
    last ditch effort to get up to 80 at Logan Airport. Once the sea
    breeze moves off, the temperature jump should occur rather quickly.

  42. Logan just can’t be compared for averages, records etc vs what used to be. It’s a bunch of baloney imo. It’s 88 here in JP and 5 miles away its 70.

    1. We knew the jump was coming. Jumped more than I thought, that is for sure.
      It now has reached Joshua’s prediction for today. šŸ˜€ šŸ˜€ šŸ˜€

  44. Made it to 89 here in Wrentham, looks like that’s all we’ll get. Too warm for my liking, but the low dew points make it manageable. We’ll see if Logan bounces up to 90 between hours. Doubt it, but the morning HRRR runs don’t look so bad now, do they šŸ˜‰

  45. Sue let me be first to congratulate you…..oh wait, I was. Hehehehe.

    Seriously though….well done. !!

  46. That’s called being lucky – my Logan prediction of 88F. Even a blind squirrel finds a nut sometimes. Just like my Providence snow total prediction.

  47. Question. Air quality tomorrow is warned to be poor 11-11. Doesn’t seem hot enough. Is it heat? Smoke from fires? Something else ? Combination?

    1. Stagnant air …… Upper ridge centered above, not much wind at all levels in the column, so it won’t take much to accumulate pollutants.

    2. I’m guessing it’s for ground level ozone. The UV from the sun oxidizes nitrogen oxides into O3. If there’s not a lot of wind to move it out, it can build up during the heat of the day. Once the sun starts to go down, it dissipates pretty fast.
      Could also be smoke left over smoke from Canada.

  48. Hmmm…

    The 8 pm National Hurricane Center advisory now calls for a 60% probability for development in the next five days for an area of showers and storms The area is forecasted to move northwesterly to approach the southwestern part of the US during the weekend.

    My Bonnie Lies Over the Ocean????

  51. Thanks for the congrats Vicki! I chose today because it is my favorite aunt’s birthday. šŸ™‚

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