Wednesday Forecast

205 Comments

7:20AM

DAYS 1-5 (AUGUST 31-SEPTEMBER 4)…
No big changes today. I’m aware of the model antics regarding the system formerly known as Invest 99L and currently known as Tropical Depression 9, and probably soon to be known as a tropical storm. I’ll keep an eye on it. First, a slow-moving cold front approaches today and passes through slowly on Thursday, followed by a cooler air mass and a little instability on Friday before high pressure takes over Saturday and probably holds through Sunday.
TODAY: Partly sunny. Isolated showers/thunderstorms late. Highs 77-88, coolest Cape Cod. Wind SW 5-15 MPH.
TONIGHT: Variably cloudy. Isolated to scattered showers/thunderstorms. Lows 60-68. Wind SW 5-15 MPH.
THURSDAY: Mostly cloudy. Chance of showers. Highs 73-80. Wind variable 5-15 MPH.
FRIDAY: Mostly sunny. Breezy. Lows 52-60. Highs 73-80.
SATURDAY: Mostly sunny. Breezy. Lows 48-56. Highs 75-82.
SUNDAY: Partly sunny. Lows 55-62. Highs 77-85.

DAYS 6-10 (SEPTEMBER 5-9)…
Staying with a dry forecast for Labor Day September 5 but keeping an eye on the tropical system. Isolated showers/thunderstorms possible September 6. Fair September 7-9. Temperatures mainly above normal.
Remainder of Labor Day Weekend September 4-5 looks dry with a warm-up. Isolated showers/thunderstorms possible September 6 with a cold front then fair and drier September 7-8.

DAYS 11-15 (SEPTEMBER 10-14)…
Dry pattern dominates. Temperatures above normal.

205 thoughts on “Wednesday Forecast”

  2. Thank you TK

    So you do not expect any problems on the cape Sunday?

    Lots of people have plans this weekend. As hard as it is, Hoping the general idea gets out there in time to work on plan B

  4. Good morning TK and thanks for the update.

    Not sure what to think of TD9.

    Just based on our drought alone would leave one to believe it WILL be a miss.
    But then again, anything “could” happen. I am leaning towards a miss, despite what
    the GFS and the CMC say. The Euro backed off on the left turn considerably. It’s still
    there but not nearly as pronounced and does not move as much Westward, basically
    causing a miss.

    So we shall see.

  6. Thanks TK.
    This tweet from meteorologist Ed Vallee at AccuWeather.
    Numerous members of Euro EPS are trying to “re-curve” #TD9 into Northeast. High uncertainty, but must be monitored.

    Here is something else we need to watch with regards to TD 9 from NYNJPA weather
    The short wave diving through the Northern Plains right now is what we need to watch for.

    If a part of the vorticity max brakes off & drops into the Tennessee River Valley, then TD9 develops into is tracking along the coast.

    HOWEVER, if the short wave stays over the Great Lakes and Canada, then TD9 just exits into the Atlantic Ocean.

    1. Short wave, short wave, who has the short wave.

      Just for fun, here is some decent information on “short waves” so we are
      clear on what is meant by this tweet: ( Click On the embedded links as well.)

      WHAT IS A SHORTWAVE TROUGH?

      METEOROLOGIST JEFF HABY

      A shortwave trough can be defined in several ways. The following are characteristics that most shortwave troughs possess:

      (1) Shortwaves are smaller than longwave troughs
      (2) Shortwaves have a counterclockwise kink to the height contours
      (3) They are associated with an upper level front or a cold pool aloft
      (4) Shortwaves generate positive curvature vorticity and positive shear vorticity
      (5) Shortwaves often represent baroclinicity in the troposphere (WAA and CAA)
      (6) Shortwaves are imbedded within the longwave trough / ridge pattern
      (7) Shortwaves are best located on the 700 and 500 mb chart / prog
      (8) Rising motion occurs within the exit sector of a shortwave
      (9) Their size and influence ranges from the mesoscale to the synoptic scale
      (10) Shortwaves move faster than longwaves (usually more than twice as fast).

      The link below has examples of shortwave troughs.

      http://www.theweatherprediction.com/charts/700/

  8. Posting the link to meteorologist John Homenuk twitter page and you could see with the GEFS the ensembles members are near the coast others over the ocean if you scroll down. I feel like were tracking a Noreaster here will all the different solutions. Nice pic to go with this tweet.
    Story of two model runs. Earlier GFS gave TD9 escape route east. New runs force it toward Northeast US. We will see.

    https://twitter.com/jhomenuk?lang=en

  9. Ryan Hanrahan communicates with this guy so I figured he is good. If I see some twitter chatter will post. I always like hearing different perspectives.
    My gut says fish storm.

    1. That’s my feeling. Much like how we get exciting about a possible big snow
      storm ONLY to see it pass harmlessly out to sea South and East of us.

      However, there remains some uncertainty here that must be monitored.

      We are now what 4 or 5 days out? Should be zeroing in on a correct or at
      least nearly correct solution.

      12Z runs should be interesting.

  15. 12Z NAM is interesting. Not sure what impact it would have for us just yet,
    BUT the NAM takes the system into the Pan Handle of Florida and across Southeast
    Georgia and then South Carolina. Looks like it would emerge on the coast of
    Northern SC or Se North Carolina, if not even staying inland longer????

    Here it is at 60 hours

    http://www.instantweathermaps.com/NAM-php/showmap-conusncep.php?run=2016083112&var=PCPPRSTMP_2m&hour=063

    We know that the NAM is not particularly good with hurricanes, but interesting
    none-the-less.

    1. WOW! It has it staying inland, but dropping so much rain, it appears
      to be maintaining intensity while over land. Interesting.

      Most models don’t have this track. I find it extremely fascinating that NAM
      chooses to do so. 😀

      1. It’s remaining INLAND the whole way up the coast and looking
        at the 250 mb chart, looks to get up here and perhaps WEST
        of the coastal plain. Perhaps well west like up the Hudson????

        1. NAM tends to do this in the winter as well with coastal storms. Tends to be more amped and further N/W with storm tracks than most other guidance.

          1. True, but this is quite an outlier now. Of course
            we don’t know how the other 12Z guidance looks yet.

            None-the-less, it’s getting interesting.

  17. While the models are busy playing with a shortwave regarding several days from now, TD 9 has quietly become stationary.

    1. This system has not behaved from day 1.

      If it stalls too long, all bets are off and there will be a whole new configuration
      of upper winds, so who knows where this thing goes. 😀

    2. Yep, so until it starts to move we don’t really have good initialization do we since that is what the previous model runs wouldn’t have taken that into account?

  20. This was a tweet yesterday from Ryan Hanrahan I found interesting
    Slower landfall in FL increases odds of blocking ridge building over Canadian Maritimes closing “escape hatch” and a stall off Mid Atlantic.

  23. Barry voiced his concern for strengthening potential as it meanders south of us once it gets over open waters off the Carolinas. Not many models have this more than an extratropical depression up here but there is potential

    1. Seems to have a digging 200mb trough. If it tightens up enough, that baby is coming up here. We shall see.

      1. Could still exit stage right. Several more frames to go before
        we know. Just don’t know how much that trough digs. If it doesn’t, then there remains an escape route to the East.

  28. So it was touched upon above but the system milling around in the gulf just a dozen hours longer changes everything, because the mid latitudes don’t wait for the tropical to make up its mind. They just keep right on moving so that the setup is different by the time it gets involved.

    1. TK, it looks like that drastic last minute turn to the Left corrected itself,
      but look how it resolved itself. Not sure which is worse.

  30. TK – just saw your comment re having backup plan. Thank you. Most do have one but unfortunately, as I believe SAK said, it is never a good thing when a good sized storm is around the ocean areas on a major weekend. Judging from what I am reading above, the timing stinks. I am hoping there is enough of a handle on this that the weather folks can get the word out in time…more than they did with Eduardo for instance and even Irene and Earl. I figure we are lucky here because we see the give and take and reasoning. The average person doesn’t have that. Although, in my silly opinion, they should all just be here.

    1. Thank you, JJ. And if it does emerge off NJ coast, it would be in too weak a state to develop into a hurricane. But would it be able to develop into a TS.

      I know this is all what ifs. I’m just curious about how any system would work under that scenario.

      1. Even though the water temps are above normal at that latitude, they are not warm enough to cause rapid intensification, or much intensification for that matter.

        1. About the only thing the water there “might” be sufficient for is “Maintaining” strength of an approaching Tropical
          system OR at least have it NOT be diminishing quickly.

          1. True, but if the newest data is correct, this thing will be over land for a long time, losing most if not all its tropical characteristics.

            1. Agree 100%. As depicted, it would be
              mostly an Extra-Tropical N’oreaster.
              How much wind depends on how intense
              it can get when it emerges off shore again.
              I’m thinking not so much. We shall see.

              I just want the RAIN!

              1. I’m with you on the rain. Sucks that it has to be during the holiday weekend, but its a small sacrifice.

      2. Usually, 82 degree water temp or higher to develop, intensify, and/or sustain a tropical cyclone.

        1. It is my understanding that the magic number is 80 degrees. If It’s coming up here and the water is 77
          it’s not going to destroy it. It will maintain or at least
          weaken very slowly.

          Now, if it hits 60 degree water, then it weakens rather rapidly.

  33. The longer it spends over land the less likely it will become anything tropical when and if it emerges back in my opinion. More likely it will be like a Noreaster in the winter.

  35. Looking at the pressure of some of the 12z model runs there not projecting a deep low pressure. We have seen more intense Noreaster’s than what is being projected.

      1. Starting to gain some symmetry on the northeastern side with some banding starting to move counterclockwise

    1. It just shows the location at that time. Does not show route to get there, which very well still could have been inland.

      HurricaneTracker App
      ‏@hurrtrackerapp
      Brand-new ASCAT satellite pass confirms we likely have a tropical storm. Recon is flying right now.

  38. I’d almost prefer this be a tropical system when it gets up here, at least the strongest winds would be on the east side away from us. If it becomes sub or extra tropical, the wind field will expand. With the poor health of many trees in the drought areas, we could see tree damage from even minimal winds.

  39. 2 thoughts ….

    Looking at the satellite picture, I think the mid level and surface circulation may be getting more closely aligned. I’m quite interested for the next recon plane’s pressure that they find.

    A tropical system doesn’t have to have a low pressure to cause havoc. Only need to look back a few weeks to Louisiana and what was an unnamed tropical system. Certainly, the atmosphere that system had to work with was more loaded with moisture than the one that will be in place along the east coast.

    As everyone else is …. looking forward to the EURO. 🙂

  45. Euro Also has Hermine making Landfall on the FL Panhandle, just about the same
    location as the NAM and the GFS. Will it also take the inland route? We’ll need about 1/2 hour to know.

      1. Then crosses into SC very much like the NAM, GFS and the CMC.
        Look at upper wind charts, it very much looks to get up here
        in some for or another.

          1. Then off shore. because of the 24 hour intervals
            on Tropical tidbits, can’t determine exactly
            where it goes off shore. I’m Guessing VA coast
            to perhaps the Northern part of NC.

  49. Oh boy ….. Do the warm 850mb temps right under the center at hr 96 mean it’s mostly still a warm core system ? It intensified from the Carolinas to NJ !

  50. This tweet from Ryan Hanrahan
    ECMWF brings Hermine up this way. Impact would be like a strong (rainy) nor’easter.

  51. To me and just my opinion it stays too long over the land and when it emerges offshore with that run of 12z EURO I don’t see how it regains strength to be a tropical system.

    1. Depends on where it emerges. Off the Carolinas and it could strengthen. Jersey shore? Nope. Also depends on forward speed. The slower it moves from wherever it emerges the better chance of regaining at least some tropical characteristics.

  53. Euro has it coming off shore at the NC/VA border between hours 78 and 84.
    Then it is over water the rest of the way.

    1. Yup, building 500 mb ridge right into the Maritimes ….. 588dm contour nosing up through central Nova Scotia, not going to move through that. 🙂

  58. I am in the GFS camp and staying there on this one. Was first to start seeing this possible impact from the start and has been ok with this system all along in not strengthening it at the start either. Location may not end up being good on these early runs but when is it ever 5 days out with a tropical system. Just my thoughts on not reading too much into the EURO solution.

    1. All good points. In the big picture, I don’t think the GFS and the EURO are that different. Just my take 🙂 🙂 🙂 🙂

    2. I’m In Camp: <B< FIIK

      If you don’t know what that acronym means, then I am sorry. (Hint: Part of it is
      “If I Know” 😀

    1. That doesn’t mean it’s the correct solution. It’s just a different solution.

      How many different solutions has the European model had with this system now? 🙂

      1. Of course. That is understood.

        It did offer some entertainment value for sure.

        Now what’s it gonna be?

        Seems like most everything is on the table.

        1. Tropical systems often do this. Add weak or changing steering currents and you just have to basically… “go with the flow”. 😛

          1. In this case, it might be “flow with the go”.

            I can’t wait to see exactly what really happens.

  65. At what point in time would forecasts on Hermine’s direction and strength start to have some confidence behind them? Thinking in terms of when to hop in the sailboat and start heading north out of Buzzards Bay. We were hoping to get a second visit to Martha’s Vineyard in this weekeend… we are often thwarted by the weather on this…

    1. Too important for me to weigh in with a take on this.
      I’d wait for a response from TK and/or SAK.

      Good luck

    2. 48 hours is a decent guess right now. Given the potential interaction, I’m going to guess that lead-time confidence is below normal throughout.

  66. Amy, even if the storm does not hit the islands Sunday/Monday, my initial guess is that there may be significant wave formations from a large ocean storm spinning well off the coast. The waves may be particularly large east and southeast of Outer Cape. But, I’m not an expert on these matters.

    2. That brings a question to mind. If waves are already increased from Gaston and Hermine comes on top of him, will they be even more pronounced. Or will there be sufficient time between the two?

  67. At this point, I do NOT want to see any rain until at least 1 second after MidNight.
    It’s 8/31 already, what’s a few more hours. Since we’ve come this far, let’s make
    this the direst Summer since records were kept in Boston (does not mean driest ever).
    But still, that is something. I wouldn’t want it ruined by .05 or .07 inch before
    Mid Night. There are some light showers roaming about out there.

    1. He came through for you! All tied up. The 8th inning has doomed the sox the 2nd half of the year so far.

      1. I was actually hoping for some reverse psychology here. I guess it
        back fired. 😀 😀 😀

        KISS this one good-bye

  71. Wave interaction is very complex, but we won’t have triple the wave height or triple the wave power because there are 3 storms out there. Just plan on rough surf and rip current risks for a while, as is the case when the tropics are on the active side. 🙂

    1. Agree, I didn’t mean to imply that it would be triple the wave height, just
      that it would add to the already roughness of the ocean.

      Not going to be mirror calm out there, that’s for sure. 😀

  72. 18Z NAM’s track is farther to the EAST. Surprise, surprise.
    AND it is about 10mb weaker than the 12Z run.

      1. It’s NOT a hurricane at this point, just a tropical storm.

        Here is another look with 10M winds

        http://www.instantweathermaps.com/NAM-php/showmap-conusncep.php?run=2016083118&var=PCPPRSTMP_2m&hour=084

        And 250 mb chart

        http://www.tropicaltidbits.com/analysis/models/namconus/2016083118/namconus_uv250_eus_53.png

        This would be more dangerous for us as it would be over
        water much longer.

        Here is my concern. What if over time, the track ends up
        just cutting across Northern Florida and emerging in the Atlantic. AND at the same time the upper winds have curved such that this thing could intensify over the Atlantic and take
        a complete water route up here.

        Things change awfully quickly around these parts. 😀 😀 😀

        Yes I know, it’s the NAM and 18Z to boot.

        Getting interesting just the same.

  75. Sox make it interesting. Horrific bullpen. Not a recipe for success in the post-season, but they might just get into the dance. Anything can happen at that point.

  79. Here’s an interesting look at the observations from the recon plane that has been flying through Hermine. The wind barbs are flight level winds. The orange dots with corresponding pressure values represent center fixes. The interesting thing here is that Hermine’s center, or at least its dominant center, has relocated southeast of the original center this evening. The two 1004mb points are actually the first two fixes; the two 1002mb points are the latter two. Overall, still not a well organized cyclone, but it is strengthening.

    http://imgur.com/a/Jzbvb

    3. Thank you WxW. I actually think I understood a good portion of that thanks to your great explanation.

    1. Thanks Tom. One reason not mentioned was the prolific rains
      produced out ahead of the system. That certainly won’t hurt in maintaining
      the intensity along with the issues mentioned.

      Really nice find Tom. Thank you again,

    1. Again, tons of rain out ahead of system. Almost as if over water while passing over the water logged land. 😀

  82. I think we break the record for the driest summer on the books (not ever, of course, but still). The rain to our west and south may not even make it here, and if it does it won’t be before midnight. Amazing. Just last year we broke the record for the most snow in one season. Now we break the record for the driest summer.

    2. We seem to be breaking the record every year since 2000 for rhe hottest year on record. Should otta make us think a bit.

  83. Something that interests me is that big high over eastern Canada. If that storm ever gets up here, it will have nowhere to go and may end up stalling for a bit.

  84. Raining here a bit. Does not look impressive on radar. I think we make this
    the driest Summer since records were kept at Boston.

    We shall see. My rain gauge has not tripped yet. Trips at 0.01 inch.

  87. Nice little late-night t-storms across part of southern MA. A decent amount of CG lightning as of 1:50AM.

  89. Believe much stronger Euro over very warm water off MA coast. 28C. euro 976 mb there. No matter what status, should be stronger there

  90. http://www.ssd.noaa.gov/PS/TROP/floaters/09L/imagery/swir-animated.gif

    I think the jet stream interaction has begun and is starting to help this thing breathe better. I believe its showing itself on the storm’s northern cloud shield with that expanding and fanning out of the cloud cover.

    Last pressure was down to 994 mb and the max flight level wind encountered was 66 knots.

    It isn’t the traditional symmetric looking storm, but I wouldn’t be surprise if we’re going to see a further pressure drop this morning somewhere into the 980’s and a rise of the corresponding sustained winds.

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