Wednesday Forecast

93 Comments

3:08AM

DAYS 1-5 (JULY 20-24)…
An area of high pressure will provide sunshine and dry air today and Thursday, with a range in temperature from almost a little bit of a chill to start this morning to a mid summer feel by Thursday afternoon. Add humidity and more heat to the mix Friday, along with an approaching disturbance from the northwest, and the result will be scattered showers and thunderstorms. This will move away for the weekend but this time don’t expect a refreshing air mass behind it. Expect more heat and humidity.
TODAY: Sunny. Highs 77-85, coolest coastal areas. Wind light variable with coastal sea breezes.
TONIGHT: Clear. Lows 53-58 interior, 58-63 coast. Wind light variable becoming light W.
THURSDAY: Sunny. Highs 77-85 coast, 85-90 interior. Wind SW 5-15 MPH.
FRIDAY: Partly cloudy. Risk of PM and nighttime t-storms. Humid. Lows 60-68. Highs 80-88 coast, 88-95 interior.
SATURDAY: Mostly sunny. Humid. Lows 62-70. Highs 85-95, coolest Cape Cod.
SUNDAY: Hazy sunshine. Humid. Lows 65-75, warmest urban areas. Highs 83-88 Cape Cod, 88-93 immediate shore, 94-99 elsewhere.

DAYS 6-10 (JULY 25-29)…
Hot and humid with showers and thunderstorms possible July 25. Less humid and a little less hot with fair weather July 26-27. Risk of showers/thunderstorms again July 28-29 with humidity increasing.

DAYS 11-15 (JULY 30-AUGUST 3)…
Less humid again early period then more humid with a few additional showers/thunderstorms in the early days of August. Temperatures above normal.

93 thoughts on “Wednesday Forecast”

  1. Thanks Tk. Is it to early for Hampton beach forecast as we arrive next Tuesday night through Friday afternoon than pool party on the 30th . Thank you.

    1. It’s too early for specifics, but not too early to say we’ll be in a similar pattern to the one we’re in now.

  4. Good morning and thank you TK.

    I looks to me as if models have backed off some on severe Friday. Some of that due
    to timing as it looks to have slowed down with main action over night Friday.

    HOWEVER, the SPC has all of NE in a slight risk of Severe Friday, so we aren’t
    out of the woods just yet.

  5. From NWS

    Friday…

    We still have concerns about severe weather potential Friday into
    Friday night. The timing is not set, but currently favoring a
    typical diurnal pattern. While much of the day will be dry, it will
    become hot and humid.

    Model soundings continue to suggest the presence of an elevated
    mixed layer. Still need to see if this layer will develop, and
    arrive into our region in time to make a significant impact. It
    appears there should be plenty of forcing mechanisms and instability
    to support at least scattered thunderstorms. The strength of these
    thunderstorms is still in question.

  9. While I’m down here, Tom and Sue and I are going to meet in Marshfield tomorrow around 4:00. We just put it together and know it is very last minute but we wondered if anyone else would like to join us.

  10. I guess it is now clearly evident that HHH will certainly dominate the rest of the season as TK predicted for the past several months now. 🙁

    I am now wondering if opportunities for thunderstorms will be increasing as well. I am also somewhat surprised that with so much heat across the nation that the tropics haven’t been active by now even though we are still aways to go from peak season.

    1. Philip, I recall responding to someone here with a statement regarding
      thunderstorms always crapping out before reaching the coast. His response was: “Wait until August”. My guess is thunderstorm chances will be on the increase.

      2. That should have said TK responding to someone. Sorry.
        Tired fingers do NOT type well and active brain thinks ahead. 😀

  12. Thanks TK
    Tweet from meteorologist Ryan Hanrahan for Friday.
    Steep mid level lapse rates, shear & strong vertical wind shear all point toward possible svr storms Friday evening

  13. Here is a little back and forth between Ryan and Meteorologist John Bagioni of Faxalertweather on twitter..
    John Hoping timing is not too late? Pretty classic EML signature.
    Ryan These steep lapse rate days with NW flow can continue severe 00z-06z a lot of times where typical events don’t.
    John Agree… my first quick thought was it was just a tad later than I like, but if steep lapse rates hold svr pntl still solid
    Ryan the 1500 j/kg of DCAPE is sort of eye opening to be honest on that NAM sounding.

    1. Thanks JJ. I always find Ryan Hannrahan’s tweets fascinating.
      He is presenting at the SNE weather conference.

      Please keep em coming.

    2. DCAPE = Downdraft CAPE. DCAPE can be used to estimate the potential strength of rain-cooled downdrafts with thunderstorms convection, and is similar to CAPE. Larger DCAPE values are associated with stronger downdrafts.

      Downdraft CAPE (DCAPE)
      Follow a moist adiabat down to the ground from the minimum theta-e value in the lowest 400 mb of the sounding, and then calculate positive and negative area. DCAPE values greater than 1000 J/kg have been associated with increasing potential for strong downdrafts and damaging outflow winds.

      Downdraft CAPE (J/kg)

      The DCAPE (Downdraft CAPE) can be used to estimate the potential strength of rain-cooled downdrafts within thunderstorm convection, and is similar to CAPE. Larger DCAPE values are associated with stronger downdrafts.

      And finally here is a link to a PDF that REALLY explains DCAPE. Enjoy.

      http://www.weather.gov/media/lmk/soo/DCAPE_Web.pdf

  14. If those things come together as he mentioned we could get nasty storms even past peak heating.
    SPC has all of New England in a slight risk for Friday.

  16. Taking a quick look at the 12Z NAM, it confirms what those tweets were about and it
    gets worse.

    Helicity, EHI, Supercell Composite and Significant tornado ingredients are
    all HIGH.

    And the Maximum RISK TIME is 6Z Saturday OR 2 AM.

    This would be HORRIBLE! Horrible! Frighteningly Horrendous!

    Waiting for other 12Z runs. This is at hour 66.

    Will post some charts soon. Want to check out another website to make sure
    what I am seeing isn’t some site bias. I was checking pivatol. Will check College of DuPage.

    1. COD has NO significant tornado parameter for 6Z, while Pivital has the index
      at 2, which is extremely high for our area.

      This is what I do NOT like about these models. Which one is correct?
      Which one to trust?

  17. Looking on cod.weather.edu site running the time you could see the disturbance going up over the ridge and coming into New England on that northwest flow.

  18. Something is wrong.
    On the COD site, EHI is very high, Helicity is very high. Cape is high.
    Yet significant tornado is non-existent. Looks like they may have had a glitch.

  19. 6Z charts

    Cape

    http://maps1.pivotalweather.com/maps/models/nam/2016072012/066/sbcape.conus.png

    1KM helicity

    http://maps1.pivotalweather.com/maps/models/nam/2016072012/066/srh01.conus.png

    3km helicity

    http://maps1.pivotalweather.com/maps/models/nam/2016072012/066/srh03.conus.png

    1km EHI

    http://maps1.pivotalweather.com/maps/models/nam/2016072012/066/ehi01.conus.png

    Significant tornado

    http://maps1.pivotalweather.com/maps/models/nam/2016072012/066/stp.conus.png

  20. on the cod site I clicked on significant tornado and for 0z it has values across SNE ranging from 0.8 to 1.6 with highest values southeastern CT RI and parts of southeastern MA

  21. Checking the cod site for the 12z NAM the supercell composite the values across SNE are highest between 0z and 3z.

  22. Who will hit 85 today?
    My guess is if anyone does, they’ll get to 89 or 90 tomorrow.

  23. 12Z GFS has MUCH less instability for Friday. Reaches Max between 21Z and 0Z.
    Hardly anything left at 6Z.

    Tells me there is plenty of uncertainty with this upcoming situation.

    1. From NWS

      Model soundings continue to suggest the presence of an elevated
      mixed layer. Still need to see if this layer will develop, and
      arrive into our region in time to make a significant impact. It
      appears there should be plenty of forcing mechanisms and instability
      to support at least scattered thunderstorms. The strength of these
      thunderstorms is still in question.

  24. Back on Monday there was uncertainty what was going to happen with thunderstorms that day. I would not be surprised if the same thing happens this time around.

    1. To be sure. We shall see. NAM is pretty robust.
      GFS, not so much.

      Let’s see what the Euro shows and the next SREF run.

  25. Friday reminds me of Monday but over a larger window of time.

    Next Monday may be similar.

  26. Thank you, TK.

    Per usual, your forecasts have been spot on. I had hoped you’d be wrong, but never ever bet against a top cat. Even my cat Mia knows this. She meowed it the other day.

    My wishful thinking perspective had me dreaming of a continuation of June right through July and August. We had a few June days in July, but it appears the heat’s on in full force the rest of the summer and I must admit it’s not easy to deal with without AC and the ability to properly ventilate (today’s a nice exception, and I’ve ventilated accordingly).

  27. TK do you see a mesoscale convective system with the thunderstorm potential Friday and next Monday.

    1. Trying to predict an MCS 3 days in advance is like trying to predict the final score of the Patriots Opening Night game against Arizona right now. Way too many details need to be worked out before you can make that kind of prediction.

    1. To add to what SAK said, and I totally agree with him…you can see patterns that “sometimes” produce them, and yes we’ve seen them occur in a similar pattern, but the large scale pattern is only the canvas upon which a much more complex picture is painted. You need things to be just a certain way to get one of those. We won’t know about Friday until maybe sometime tomorrow late-day at the earliest.

  29. Well, I’m looking but I don’t know if I’m going to get my 85 anywhere, except maybe Westfield and/or Hartford, but that’s further west than I expected. I’ve been looking at some of the unofficial stations just to see.

    Then of course you have the one out of Attleboro that currently reports a temperature of 82 with a MATCHING dew point of 82. Ummm, I don’t think so, unless the weather station has been dropped into someone’s heated back yard pool…

      1. They could be right, or may be off by 1 or 2. It’s really hard to get spot-on temps unless you have a proper instrument shelter. Otherwise you almost always get an outside influence, usually in favor of a warmer reading than actually is occurring.

      3. that 85 is not far from me and I am guessing it is inaccurate and IF
        the station is accurate, then it is sitting on top of Blacktop and near baking brick buildings.

        1. I was just trying to help find one. As you know I have tend to confirm Wunder stations before I trust them but since I didn’t want to drive to Brookline…… 🙂

  30. From NWS…

    All that to say, there is certainly potential for severe thunder-
    storms Friday afternoon and evening, as indicated in the Day 3
    SPC outlook. However, as indicated yesterday in this discussion,
    so much of severe weather comes down to the mesoscale which is
    rarely clear this far out. Timing of all these features and the
    development of the instability during the day Friday will all be
    factors in determining how widespread any severe weather is,
    should it develop. Those with outdoor plans on Friday should keep
    a close eye on the weather over the next day or so.

      1. Agree. Tough one. Could be, maybe not, but could be maybe, I don’t know, we’ll see. It’s one of those, but “should” it materialize, it could be a doozey.

        1. I know you realize this, but many don’t realize how much has to be just right for any one area to see maximum activity. It’s probably a good thing it happens less often than it does in any given spot. Convection, even organized, can be so momentary. You have your complexes that can sustain for a long while under the right conditions, but so many times the most severe of storms is so relatively short lived and so localized that the vast majority of the population will see little or nothing. But that doesn’t mean the forecast is a bust, unless they forecast widespread major activity and it was just isolated.

          1. Absolutely. Well said.

            Btw, Just had a chance to peek at the Euro and latest Sref. Not so impressive. So, who knows.

  31. Beauty of a day today. Love those low dew points!

    It’s still not a wet pattern that we’re in- in fact, it remains dry- however, I think we’ve at least transitioned to a more “active” pattern. More frequent shower/t-storm chances than we’d been seeing for most of the summer. Models/ensembles generally agree that this more active pattern will continue or even amplify some as we continue into August.

    1. Have you noticed though that even the more “productive” systems are producing isolated to scattered activity, and nothing sweeping or widespread as of yet?

      2. Yes. The biggest issue is that anything we get is convective. No widespread/uniform rainfalls, which while not as common this time of year still do happen, even outside of tropical systems. No sign of that changing.

        1. Convection can produce widespread rain, when you get sustained updrafts, clusters/lines that are larger than what we’ve seen, and lots of elevated rainfall even after the updrafts have weakened.

          The problem is, lack of an ingredient just about every time has prevented sustained updrafts, thus eliminating any real shot at more widespread elevated post convective rainfall.

  32. Smoke from wild fires must have returned.

    I don’t see any signs of high clouds on satellite and yet the sky is milky white instead of blue.

    Perhaps a very red sunset tonight.

    1. It is indeed high altitude smoke, and in some cases it’s mixing down a bit lower.

  33. TK – we are going on a cruise from NYC to Bermuda the first week of August (leaving July 31 and returning on Aug 7) . Going to actually be in Bermuda Aug 3-4-5. I realize it is still two weeks out but any initial thoughts on the weather pattern over the Atlantic that week? I took a look at the 12z GFS and lo and behold, I see a wave coming off Africa next Wednesday and developing into what looks like a tropical storm and passing east of Bermuda around the time we are there. High pressure is over the northeast Atlantic which would seem to help steer any systems up towards us.

    Thankfully we are talking about the GFS at hour 384 here but I will be watching…. I know I assumed a bit of risk booking this trip in hurricane season 🙂

    1. Enjoy! Love Bermuda. At which port will you be docking?
      Hamilton, St. Georges or Royal Naval Dockyard?

      Have you been before?

      1. Enjoy the cruise Mark. I have cruised there many times. Now a days the ships are so large that they aren’t able to dock in St. Georges. That is such a shame because it is such a quaint area of Bermuda. And it was always fascinating entering the harbor there as there is just a small cut that ship passes through to get to the dock.

        1. When I was there in 2008, we went to St Georges for a day and was surprised to see a smaller cruise ship docked there. The NCL ship we are taking is 4,000 passengers so no chance!

      2. Royal Naval Dockyard. We are taking the Norwegian Breakaway. I did take a cruise there 8 or 9 years ago and had a great time. We are docked there for three days so plan to do Horseshoe Bay beach one day, a catamaran/snorkeling trip another day, and then probably just a day of sight seeing. We will definitely stop at the caverns and Swizzle Inn for a rum swizzle or two or three…..

        1. I used to cruise on the Norwegian Majesty to St. Georges from Boston. I so enjoyed the smaller ships. The new ones have a million things to do and are beautiful but I would go back to the small ships in a heartbeat. Maybe I am just a little partial though since I met my husband on that ship. 🙂

  34. By the way, we did hit 85 today at Hartford/Brainard Airport. BDL and Westfield didn’t make it.

  35. I enjoyed every minute with the comfortable levels of humidity today.
    Keeping an eye on Friday to see what kind of thunderstorm activity we get.

  36. The current dewpoints in the Midwest are unbelievable

    Mid to upper 70s ….. in Minneapolis, the Dakotas and thunderstorms are erupting in that airmass.

  38. No surprise 18z NAM more aggressive than 18z GFS for Friday.
    Will be interested what the SPC does with the slight risk tomorrow. Two updates for Friday come tomorrow one past 1am the other around 1:30pm tomorrow.

  39. Quick peak at 0z NAM on the cod website and more than enough instability for strong to severe storms. Knowing NAM probably over done. Friday COULD be an interesting day around here.

  40. Mark…
    The overall pattern leads me to believe the weather will be typical for this time of year. Mainly dry, isolated showers, warm and humid. I don’t see much in any way of a tropical threat out that way around that time – though of course always worth keeping an eye on.

  42. Morning.

    Taking a quick look around at the model sites, I am less and less impressed with
    the severe parameters for tomorrow afternoon/night. In fact not only less chance of severe, but looking more and more like little to NO rain for the Boston area.

    I suppose things could still change. We shall see.

    SPC still has us in the slight chance of severe area.

    http://www.spc.noaa.gov/products/outlook/day2otlk_0600.gif?1469098917851

    NWS discussion same as it was yesterday.

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