Rain Blast Won’t Last

153 Comments

5:50PM

The focus of this update, even though it will contain a full forecast, is the potential severe weather event for Wednesday morning. I will keep it short and to the point. As broad low pressure passes north of the region across southern Canada and a strengthening second low passes northwest of southern New England, its attendant cold front will swing through the region from west to east in the early to mid morning hours of Wednesday, bringing an area of rain including some embedded heavy showers and thunderstorms.

Time-frame: 3AM-9AM for entire event, though the heaviest rain and strongest wind will be relatively short-lived for any given area. Areas west of Boston from western into central MA and adjacent CT/VT/southwestern NH will see activity in the 3AM-6AM window of time, while eastern MA including the Boston area as well as RI and southeastern NH gets it closer to the 6AM-7AM time. Cape Cod and the Islands will be last to see the activity arrive and depart.

Severe? The risk of torrential rain for at least a brief period of time as high. This would disrupt travel and cause localized flooding. The risk of strong and gusty winds of the straight-line variety is moderate. The risk of a brief tornado is low but cannot be ruled out completely.

What happens after? Once the action is out of here Wednesday morning, the rest of the day will feature sun and passing clouds, drying air, and a gusty breeze, though it will still be mild through the daylight hours as a secondary trough, behind which is the cooler air, will not arrive until later in the day.

Between broad low pressure in eastern Canada and a small high pressure area to the south will be a gusty and cool westerly wind but a nice day for Thursday. Low pressure passing south of the region later Friday to early Saturday will bring some cloudiness and a threat of some rain to at least southern MA and RI. Not sure how far north this gets yet. But I do think it gets out of here for later Saturday and Sunday which will be dominated by high pressure and nice Autumn weather.

Still looks like a warm-up early next week, though the tropical threat looks less. More on this later.

SOUTHEASTERN NEW ENGLAND FORECAST
EVENING: Lots of clouds, partial moonshine as it rises in the east. A shower far west to northwest of Boston. Temperatures in the 60s. Wind S 10-20 MPH.
OVERNIGHT: Heavier clouds arrive from southwest to northeast. Rain and embedded thunderstorms arriving west to east after 2AM, heaviest activity west of Boston after 3AM and Boston area northward and southward by the 6AM hour (see details above). Lows around 60. Wind S to SW 5-15 MPH, higher gusts.
WEDNESDAY: Cloudy start with rain and embedded thunderstorms ending in eastern areas by mid morning. Sunshine and passing clouds mid morning on though lingering clouds/showers Cape Cod mid morning. Highs 65-70. Wind SW 10-20 MPH, strongest gusts, shifting to W.
WEDNESDAY NIGHT: Mostly clear. Lows in the 40s. Wind W 5-15 MPH.
THURSDAY: Mostly sunny. Highs around 60. Wind W 10-20 MPH.
FRIDAY: Increasing clouds. Chance of rain south PM. Low 41. High 58.
SATURDAY: Decreasing clouds. Chance of rain south AM. Low 42. High 61.
SUNDAY: Mostly sunny. Low 40. High 60.
MONDAY: Partly cloudy. Low 45. High 65.
TUESDAY: Partly sunny. Low 55. High 70.

153 thoughts on “Rain Blast Won’t Last”

  5. I’m mobile so I haven’t figured out how to post a link. One day I will.
    In any case latest Hrrr kills us around 10z or 6am.
    Cape =2000+. Helicity 300+ reflectivity very strong.
    I wonder if Spc changes wording????

  8. Wow!!! Check out the nws discussion from taunton.
    IMPRESSIVE!!!!
    OK I am officially worried. I May have to get up really early.

  9. Whats the over and under for some unfortunate community getting a tornado tomorrow Am? I think there is at least one somewhere. WE SHALL SEE.

  10. Thanks tk 馃檪

    Not to worried about tornados, they haven’t bother me since we left Texas in 04, and that’s good 馃檪

  12. 6-10 & 8-14 SOLIDLY warm and wet.
    We will continue this regime for a while, then we’ll start to work back toward dry but remain mild when the jet streams split later this Autumn.

    1. The SPC bumped up the tornado risk for you guys in the 01z outlook, which is valid through 12z tomorrow morning. 5% tornado probabilities now. Stay alert!

      …DELMARVA/NJ TO SRN NEW ENGLAND…
      FORECASTER CONFIDENCE HAS INCREASED /INCLUDING COLLABORATION WITH
      WFO/S MT HOLLY…UPTON AND BOSTON/ FOR A SLIGHT RISK OF ISOLATED TO
      SCATTERED SEVERE STORMS NERN NJ THROUGH LONG ISLAND /INCLUDING NYC/
      INTO SRN NEW ENGLAND DURING THE LAST 6 HOURS OF THIS FORECAST
      PERIOD. THIS CONFIDENCE IS BASED ON THE CURRENT STRENGTH OF AN
      OBSERVED WLY 500-MB JET OF 80 KT AT JACKSON KY EARLY THIS EVENING
      PER THE VAD. STRONG DEEP LAYER ASCENT WITHIN THE EXIT REGION OF
      THIS JET WILL MOVE INTO NRN DELMARVA BY 06Z AND THEN INTO LONG
      ISLAND AND SRN NEW ENGLAND BY 12Z. THIS MIDLEVEL JET AND AN
      EXPECTED STRENGTHENING SSWLY LLJ UP TO 50-60 KT FROM THE
      MID-ATLANTIC STATES TO SRN NEW ENGLAND LATER TONIGHT WILL OCCUR AS
      THE CURRENT UPPER OH VALLEY SHORTWAVE TROUGH BECOMES NEGATIVELY
      TILTED OVER NY TO SRN NEW ENGLAND BY 12Z. THE STRENGTHENING WIND
      FIELDS WILL RESULT IN STRONG DEEP-LAYER SHEAR AND INCREASING
      LOW-LEVEL SHEAR FOR DISCRETE ROTATING STORMS AND BOWING SEGMENTS
      AND/OR QLCS DEVELOPMENT. 23Z RAP SOUNDINGS FROM THE VICINITY OF NYC
      AT 07Z INDICATED EFFECTIVE SRH AROUND 250 M2/S2 WITH SIMILAR VALUES
      INTO SOUTHEAST MA /NEAR NEW BEDFORD/ BY 12Z. THIS FACTOR SUPPORTS
      THE TORNADO THREAT…WHILE STRONG WINDS JUST OFF THE SURFACE WILL
      FAVOR THE THREAT FOR DAMAGING WINDS.

  17. From Taunton NWS office:

    IN ADDITION…THERE REMAINS AT LEAST A LOW PROBABILITY FOR AN
    ISOLATED TORNADO. LOW LEVEL HELICITY IN THE 0 TO 1 KM LAYER IS
    EXTREMELY IMPRESSIVE AND THE NAM SOUNDINGS ARE SHOWING SOME GOOD CAPES IN THE 0 TO 3 KM LAYER. SOME OF THE TORNADO PARAMETERS WE LOOK AT ARE QUITE IMPRESSIVE ANY TIME OF THE YEAR…BUT EXTREMELY UNUSUAL FOR OUR REGION DURING THE EARLY MORNING HOURS IN OCTOBER. WHETHER OR NOT THESE INGREDIENTS CAN COME TOGETHER WILL BE A NOWCAST/RADAR SITUATION…BUT IF THE MESOSCALE PROCESS WORK OUT AN ISOLATED TORNADO IS A POSSIBILITY.

      1. Taunotn NWS office

        THE THREAT REMAINS THE SAME THIS
        MORNING…LOCALLY HEAVY RAINFALL WITH HEAVY SHOWERS AND A FEW THUNDERSHOWERS. STRONG WINDS ARE LIKELY TO BEGIN MIXING DOWN WITH
        THIS RAINFALL AS WELL AS THE LLJ BEGINS TO SHIFT INTO NEW ENGLAND THROUGH ABOUT 12Z…AND A BRIEF TORNADO/WATERSPOUT IS POSSIBLE
        ESPECIALLY IN THE SOUTHEASTERN HALF OF THE REGION WHERE INSTABILITY IS MAXIMIZED. IN FACT SRN NJ OFFICE HAS ALREADY
        ISSUED A TOR THIS MORNING.

  19. I thought I saw some rotation in a storm out around Springfield. Didn’t last too long, but
    something was there.

  20. Thank you oldsalty for your continued dedication to keep us all informed with this pending quick storm .

    1. So far, convection is NOT living up to the hype. It’s just not.
      There is still a brief window in which something can happen, but so far, so good.

  27. From NWS

    US National Weather Service Boston MA
    32 mins 路 Edited 路
    [5A] Divergent signature (possible microburst) discerned via our radar (in an earlier scan) collocated with a wind gust of 55 mph reported at Westfield-Barnes Regional Airport. Receiving reports of downed trees & power lines. Looking for any additional information.
    With any heavy rain across the region, the threat for 50 mph winds or greater will exist during the morning commute! Please exercise caution and be safe if you need to travel the roads this morning!

    1. More from NWS:

      US National Weather Service Boston MA
      1 hr 路
      While a severe thunderstorm watch is not anticipated to be issued by the Storm Prediction Center, residents of Southern New England should be aware of the threats of heavy rain, frequent light, gusty winds exceeding 40 mph, and the possibility of a brief tornado.
      Main area of focus is noted in the scalloped brown lines within the image below from now into this morning.

  30. The line just exiting the Springfield area is the strongest so far this morning.
    That looks to Miss the Boston area to the North. Other elements just not very
    strong at the moment. Still watching.

  31. Watching the last line existing Springfield area. It looks to be filling in to the SW ALL
    the way back to Bridgeport, CT. We shall see IF this intensifies and becomes the
    main focus for convection.

  32. A good size thunderstorm warning box center of state – west of Worcester and moving northeasterly direction

    1. Yes, that is the one I mentioned above. Appears to have weakened some, but storms to the SW of there seem to be intensifying. See radar above. Tx

  33. I would expect a Severe thunderstorm warning to be issued for the Hartford CT area
    shortly as those storms are clearly intensifying. We shall see.

    1. Hmmm maybe not. On Taunton radar not impressive. On Long Island radar, impressive. Must be really LOW-topped. We shall see.

      Otherwise, activity is diminishing.

      I am about to pronounce a BUST, not that it is a bad thing with this
      situation. 馃榾 I’ll give it a bit longer.

    1. OS – I think I found the coffee – apparently I just dreamed that it was on here. Everyone to Hadi’s house!

      Very quiet here – had a 10 mph gust but that was about it. Of course I can’t see a thing and am anxious for that sun to come up.

  36. Latest from Taunton NWS:

    US National Weather Service Boston MA
    22 mins 路
    Convective indices centering in on SE New England in the last hour. Strong shear and building instability warrant continued monitoring for a potential severe weather situation incorporating the threats of strong to damaging winds, heavy downpours, frequent lightning and the potential of a brief tornado.
    Threats are presently materializing and will continue for the next few hours.
    If traveling in SE New England, which encompasses RI and SE MA, please exercise caution and maintain a situational awareness of the weather around you.

    https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-xfa1/v/t1.0-9/1601207_692151677545873_8503636146379662870_n.jpg?oh=9358b5e3c301d63de986914aa6749c86&oe=54C70810&__gda__=1420662592_581ad20efe1947960f00a00e8e375698

      1. Yes. I see some weak rotation with that one.

        Also, note: new line trying to get going just East of Worcester.
        Could this be the one? We shall see. Running out of time quickly.

        1. That line over SE MA looks to be intensifying.
          Is that the one? Looking more and more ominous in that area.

      1. It means NO severe thunderstorm watch, NO tornado watch.
        It’s up to us (NWS) to monitor for any rotation on individual storms.

  41. Keep in mind the conditions are ripe for development even at this early hour. It doesn’t mean we will see “the big ones” erupt everywhere. With luck, not much will happen other than downpours, a few rumbles of thunder, and a few wind gusts. Potential is still the same and things can come together quickly with little warning (such as what took place in Revere, we know that they could have gotten warning out sooner but the development of the low level rotation was rather quick). Should keep monitoring closely until this thing is out of here.

  44. Seeing lightning to our southeast.

    Western horizon is actually brightest, with some breaks in the cloud cover.

  47. Interesting little cell out around 495 in the Milford area. How big will it go?
    Looking a bit interesting toward Woburn. 馃榾

    1. If it holds it may come close, but looks like just SE of me in about 15 minutes. I can see breaks to the W-NW behind the line that’s over me right now. Just light to moderate showers but big drops.

    1. Yup, you are so correct.

      I headed out before 8AM and this is what greeted me:

      http://postimg.org/image/pewxp1nrv/

      Lower clouds and higher clouds moving in same direction. RISK OVER!
      DONE! KAPUT!

      A COLOSSAL BUST, which is this case was a very good thing.
      However, we could have used the rain. NO RAIN!!!!!

  53. BE CAREFUL comparing this to a situation like a winter storm.
    This is not a busted forecast, as it was a forecast for POTENTIAL severe weather. There was severe weather in the form of damaging wind in western New England. We are lucky that none of the cells did that here in the east. Unfortunately, many will focus on the fact it was over-hyped, when in fact, it was not. If nobody said anything other than “chance of showers and thunderstorms” and so much as one brief gust of wind took a tree down somewhere, they’d be all over the weather people about not warning them. Well, I’m standing my ground on this one if anyone even remotely accuses any of us of over-hype. Didn’t happen this time. Sorry folks. We’re right. 馃檪

    1. You can say to be careful all you want. In my opinion is was still a BUST.

      Of course I could see the “potential” as well as the next person.
      I would have forecasted the same thing. What is a met to do faced with
      the guidance? That is not the issue.

      It didn’t happen. No 2 ways around that.

      1. And it’s a very good thing it didn’t.
        We’re rather forecast the chance, and not have it happen, than the other way around. Every single time. 馃檪

        1. Agree.

          What I am getting at is that it is sad when it happens.
          Not that I wanted anything bad to happen, but when
          a forecasted event does not occur, the public gets complacent, sort of like the “crying wold syndrome”.

          Next time the public will say, yeah sure it will.

    2. Understood TK. We couldn’t ignore the strong signals for severe weather. However, the only thing I’ll say that was “busted” was the location of the severe weather. All indications were the severe weather would be in southern and eastern sections of NE, not western NE.

    3. Western Mass is a different world. It might just as well be on a different planet.
      Last night Mets were talking about the risk in Eastern MA.

  54. Tk, a post-mortem?

    In the end, what prevented the big convection?

    Was it just NOT enough instability? Ie CAPE values were TOO low?
    Did it just run into a drought area and lose it?
    Was it the Lunar Eclipse sapping the energy?
    Was it Charlie diverting energy to the Charlie Hole?

    Thoughts/Comments?

    Thanks

    1. ALL of the above. 馃檪

      Probably borderline CAPE. Wrong time of day.

      The jury is out on the Lunar Eclipse and the Charlie Effect. 馃檪

      Actually, I think we just lucked out. We had to rely on things coming together just perfectly. It may have come down to the lack of a forcing boundary at the surface to kick off a few severe cells.

      Whatever the reason, we should be thankful it did not do what it had the potential to do! 馃榾

    1. John,

      I did see some rotation on the storm out there about 5AM or shortly thereafter.
      We shall see. Earlier, NWS said it was a micro burst.

  56. I know we shouldn’t compare this situation to a winter storm, but isn’t it one in the same? We have had many potential snow storms showing strong signals to dump a lot of snow on our area, even hours before the event is to take place only for it to go out to sea or just not produce. In the end, everything just didn’t come together perfectly, much like this situation, no?

    1. Of course. Different, yet the same.
      To get a Dump of snow, EVERYTHING has to come together perfectly.

      1. True, but especially in eastern sections of NE, everything also needs to come together for severe weather. And to get a tornado, everything really needs to come together. What im getting at is, due to the rare nature of true severe weather in eastern MA compared to getting a sizeable snowstorm almost every winter, it it reasonable to say its more common to get a busted severe weather forecast than a winter storm forecast?

        1. In Eastern sections, yes. There is always something
          to bust a Severe Weather event forecast for Eastern sections. I can’t tell you how many times BOSTON
          was under a Severe Thunderstorm Watch to NEVER have anything even remotely resembling a severe thunderstorm happen. Even when Boston is WARNED for a severe thunderstorm, It often still doesn’t happen.

          From 495 Westward and sometimes inside of 495 yet West of 128 is OH so different.

          Very difficult to get Severe Weather on the coast.

          That’s what makes the Revere Tornado that much
          RARER.

  58. Bottom line is this is not a busted forecast.

    We forecast “potential severe weather” not “guaranteed severe weather”. Ask any professional and they will all give you the same answer.

    1. Tk, that is well understood.

      BUT we have to be careful of the Chicken Little effect. 馃榾
      We here on WHW know better, but the average Joe watching
      a news broadcast will form quite a different opinion.

  59. Conditions being favorable for the development of severe thunderstorms, the definition of a severe thunderstorm watch, IS NOT a guarantee such storms will indeed form. That is a pure fact.

    1. Of course it is. Who is arguing that?

      I was just saying that No matter how many times Boston is under a Severe watch, it virtually never materializes.

      Now a severe warning is supposed to be just that. I say supposed to be.

      I have seen many Severe Thunderstorm Warnings for Boston that plain and simply were NOT.

      Whenever I see one of those for Boston, I have to chuckle.

      In my life I have NEVER seen a T-storm in Boston with wind gusts
      >= 58 Mph OR hail >= 3/4 inch. Never ever ever. 馃榾 Largest hail I have
      ever witnessed in the City was pea to “perhaps” Dime on a stretch.

      Now this is for the City. I know there is a WORLD of difference for more inland locations.

      1. A lot of that warnings never materializing has to do with the local nature of storms in this part of the state and how warnings are mainly focused on counties. The severe thunderstorm could be over say Mattapan and someone in North Boston would be like, where’s the thunderstorm??

        1. And that is a whole other problem. Agree 100%

          Honest and truly, When I went to bed last night, I thought that there was a very very REAL risk. I was so worried, that I got up at 5AM (of course needlessly).

          So, in a sick way, Yes I am pissed that nothing materialized. Geez, I expected at least some Thunder and lightning and downpours. We didn’t even get that.

          NOTHING.

      2. It happens at the coast too. My friend’s neighborhood by the beach in Swampscott was torn up by a storm a few years ago. This summer an EF2 tornado formed almost on the coast. It’s just the local nature of this stuff.

        1. Of course it can happen at the coast, but it is very rare, indeed. And to happen in the City, even rarer still. 馃榾

  60. And the “crying wolf syndrome” the public seems to be afflicted with. Warranted at times, but the public needs to be better educated on how to read/listen to/understand and comprehend. The are failing at it. Miserably. Not necessarily all their own faults.

    1. Now, there’s a big surprise.

      HOWEVER, check out the CMC at 240 hours. Still has something
      Juicy. Not sure where it will go.

      1. Yes. I couldn’t tell you for sure IF it were EastHampton, but
        it was out that way somewhere. 馃榾

  63. Today is “Walk To School Day” and many communities have postponed it until tomorrow. Good move given the storm potential.

    However, it is interesting though how our grandparents had to walk 3 miles to school every day and in the winter in 3 foot drifts. 馃槈 馃榾

    1. And both ways were uphill 馃槈

      I don’t think they were faced with the traffic or the stranger danger that exists now. My grandson is supposed to walk. But he has to cross a main street where speed limit is 40 mph and there is no crossing guard. He was expected to do this from the age of 5.

      I wonder if the schools are not pushing this because they don’t want to pay for busing. Plenty of kids walk around here if they are within one mile which was the norm back in the stone-age when I went to school.

      1. Cuts cuts cuts, just wait many years down the road 馃檪 this is what the decisions of new englanders have made

    2. He did to us as well, Coastal. I kept wanting the others to stop talking so we could just listen to him.

  65. For the amount of days the blog has been tracking, I would have thought something would have happened, o well 馃檪

    1. I’m telling ya from living in Texas I no longer even pay attention to tstorms here anymore, 9/10 times it’s nothing 馃檪

    1. Just came in. Beautiful out. Nice and warm. Only thing I could notice was
      a “drying” out going on. 馃榾

  68. Wxrisk.com new ECMWF seasonal forecast came out today …NOV mild in the NE US DEC normal JAN FEB colder snowier possible big Winter storms

  69. Matt Noyes: Broadcast Meteorologist added 4 new photos.
    2 hrs 路
    Though we always defer to the National Weather Service storm survey team for official word, combo of photos and radar analysis from Easthampton, MA, where significant damage occurred this morning, suggest a downburst…photo from the air via Twitter use @PatBrough shows a wide swath of trees downed in one direction. Ground level damage photographs are, not surprisingly given the breadth of the damage, inconclusive for the most part. So…we turn to radar data. Excellent signature of dry air intrusion on the backside of storm cell at 4:49AM, and that dry air intrusion literally blasts a hole in the storm by 4:51AM. The velocity plot, showing wind direction and speed inside the storm, first leads us on…was it rotating? Red vs. green is suspicious…but street level mapping and quality radar data combine to show straight-line over damage area (red marker) by 4:51AM.

    https://scontent-a-lga.xx.fbcdn.net/hphotos-xaf1/t31.0-8/1412363_861700367182848_8019149691498487857_o.png

    https://scontent-a-lga.xx.fbcdn.net/hphotos-xaf1/t31.0-8/1412363_861700367182848_8019149691498487857_o.png

    https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-xap1/t31.0-8/10661875_861700370516181_4562940251594892026_o.png

    https://scontent-b-lga.xx.fbcdn.net/hphotos-xap1/t31.0-8/1939894_861700373849514_1240570469913019788_o.png

  70. I’ll settle a debate:

    New England is New England.
    Texas is Texas.
    They are in different locations, therefore have somewhat different climates.
    Severe storms are severe storms.
    New England gets fewer than Texas due to the difference in the length of thunderstorm season and the different locations.
    No brainer. It’s not a competition either.
    The end.
    Time to move on.

  72. Blog is updated!
    I’m heading to Topsfield Fair to enjoy the evening there, including catching the concert by America.

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