Tuesday Forecast

210 Comments

7:02AM

DAYS 1-5 (MAY 15-19)
A temperature roller coaster the next several days, but that won’t be the only ride we go on. Today we have a cold front slicing into a warm air mass and this will set the stage for showers and thunderstorms, some of which may be strong to severe. While I’m not expecting a widespread outbreak of severe storms, any of them can be strong and reach severe criteria, so we’ll have to keep a close eye on things this afternoon and early evening, the window of time in which they will be around. High pressure from Canada pushes everything to the south and introduces a much cooler northeasterly flow Wednesday, then sinks to the south and provides a warmer westerly flow on Thursday, only to see the cycle repeat with a cooler Friday, however this time the temperature change will not be accompanied by any thunderstorms. By late Friday into Saturday we will have to watch moisture to the south which may do anything from just glancing the region with rain to moving straight up and giving a significant rainfall. Enjoy the ride the next few days while those late week details get ironed out. Forecast details…
TODAY: Sunshine and passing clouds this morning. Variably cloudy with first isolated to scattered showers and thunderstorms then more general showers and thunderstorms this afternoon and evening, with any thunderstorms possibly strong to locally severe. Becoming humid. Highs 68-76 South Coast, 77-84 elsewhere. Wind SW 10-20 MPH, higher gusts possible.
TONIGHT: Mainly cloudy. Showers and thunderstorms possible early. Areas of fog. Lows 52-58. Wind NW to N up to 10 MPH.
WEDNESDAY: Mostly cloudy to partly sunny. Highs 57-65. Wind NE 5-15 MPH.
WEDNESDAY NIGHT: Partly cloudy. Patchy fog. Lows 48-54. Wind light variable.
THURSDAY: Mostly sunny. Highs 65-72 South Coast, 73-79 elsewhere. Wind W 5-15 MPH.
FRIDAY: Increasing clouds. Chance of rain late. Lows in the 50s. Highs in the 60s.
SATURDAY: Mostly cloudy. Chance of rain or showers. Lows in the 50s. Highs in the 60s.

DAYS 6-10 (MAY 20-24)
The battle of air masses will continue through this period with at least a few opportunities for showers or rain, and variable temperatures. Too early for detailed timing.

DAYS 11-15 (MAY 25-29)
This period should feature less wet weather and a trend to warmer weather.

210 thoughts on “Tuesday Forecast”

    1. I like the early thought on your long range (days 11 – 15), which is essentially Memorial Day weekend.

  5. Some text from NWS re: today’s threat

    Both the projected 0-1 km AGL and 0-3 km AGL helicity values
    raise some concern for potential tornadoes. Hodographs are
    largely linear in the 0-1 km AGL layer, and the LCL levels are
    somewhat marginal, too. Cannot completely dismiss this threat
    later this afternoon. Will need to be monitored closely.

  7. Latest from SPC brings the enhanced area just about to the coast:

    http://www.spc.noaa.gov/products/outlook/day1otlk_1300.gif?1526389065576

    Not much of a change in the tornado area

    http://www.spc.noaa.gov/products/outlook/day1probotlk_1300_torn.gif?1526389102942

    Depending upon what the SPC sees cooking this afternoon, it would not surprise
    me if a tornado watch is issued later for the 5% area. It “may” still be border-line
    for a Tornado watch issuance, but it is clearly on the table. We shall see.

    TO echo WxWatcher’s concern. The outlook keeps getting worse as each new guidance becomes available.

  11. Thanks TK
    Now with the latest SPC update a good portion of SNE in an enhanced risk for severe weather.
    From SPC regarding tornado potential today.
    when storm modes can be more favorably discrete or semi-discrete. A few tornadoes also may occur, whether from supercells or QLCS-embedded vortices.

  15. Your welcome JPDave.
    I believe the last time we had an EML present when we had thunderstorms was back in Feb 2016 when we had a severe weather outbreak in the night time hours. You don’t need a tornado to cause a lot of damage. If you get those straight line winds the damage left behind will be as if a weak tornado hit. I think the majority of the severe weather reports in SNE today will be wind damage.

    1. I agree, but we can’t rule out an isolated tornado somewhere and right
      now that somewhere could be almost anywhere, even right up to Boston.

      I have a sneaky feeling that a tornado watch will be issued. I could be 100% wrong, but I am feeling it. If not, then a severe thunder storm watch will
      almost certainly be issued containing some wording as to a possible tornado or 2.

  17. Still have the fog where I am and the cloud cover. As soon as it burns off and the sun comes out this atmosphere is going to destabilize and then its a wait and see game to see what happens when this front comes through with the thunderstorms.

    1. Bright and sunny here in Boston and the temp is climbing rapidly.
      temp up to 68 at my house in JP with DP up to 60.

  20. Just based on the outlook probabilities they’ve issued and their usual corresponding response, I think a tornado watch is more likely than not for this afternoon over the enhanced risk area. However, damaging straight line winds continue to look like the main threat. Tornado threat is much more isolated, and any tornadoes would be favored to be on the weaker side. Still looking like a very active day on tap.

    1. Your assessment appears to make good sense as per usual.

      I am looking at the 12Z NAMs.

      Regular NAM really shows the influence of the marine layer and limits
      decent Cape to about Boston and not any farther South. Super Cell composite
      much lower with this run.

      HOWEVER, the 3KM NAM seems to be painting a different picture.

      Waiting on a few more panels.

        1. Notice the very sharp cut off of the Cape South of Boston:

          http://maps3.pivotalweather.com/maps/models/nam4km/2018051512/009/sbcape.us_ne.png

          ditto Lifted Index

          http://maps3.pivotalweather.com/maps/models/nam4km/2018051512/009/sbli.us_ne.png

          Significant tornado parameter

          http://maps3.pivotalweather.com/maps/models/nam4km/2018051512/009/sbli.us_ne.png

          0-1KM helicity

          http://maps3.pivotalweather.com/maps/models/nam4km/2018051512/009/srh01.us_ne.png

          0-3km helicity

          http://maps3.pivotalweather.com/maps/models/nam4km/2018051512/009/srh03.us_ne.png

  21. 12z NAM with bullseye over my area for the supercell composite along with the Hudson River Valley.
    The sun is starting to come out now where I am but on a day like today the sun is what I like to call self destructing sunshine as this will destabilize the atmosphere further.

  23. From Eric Fisher.
    On track for strong to severe storms today…core of them 4-8pm Boston area. Think we may see an upgrade to ‘Moderate Risk’ western New England/Hudson Valley with midday update.

  24. If an upgrade to a moderate risk happens that would be the second time in less than two weeks that somewhere in the Northeast was placed under a moderate risk. Back on May 4th parts of Upstate NY got upgraded to a moderate risk.

  25. I will be keeping an eye to that sky this afternoon JPDave. The next update from SPC comes around 12:20 this afternoon and will see if an upgrade happens.

  27. JJ, it looks like we are just talking to each other. 😀
    Where is everyone on this potential severe weather day?

      1. I hear you. Meetings put me to sleep. Rarely does anything
        productive get accomplished. People just like to hear themselves speak and some people simply can’t shut the bleep up!!!!

        1. I’ve said before that you’d think differently if we conducted one of your meetings. We also have an approach where we use a polling approach (Turning Technologies) as part of the PowerPoint presentation. It is an awesome way to get everyone involved rather than just the ones who like to talk.

            1. Makes sense. We are an outside facilitator so presentation is our focus. It is probably why we get the positive feedback. We are engaged for specific projects and would not be used for every meeting. Although….no reason why someone within an organization cannot think outside the box.

  28. The LOL!!! was meant to go under the JPDave comment when he said JJ it looks like were just talking to each other. Did not mean for the LOL to go under your comment AceMaster.

  29. I’m listening and watching. And pushing out social media messages for work.

    Keep it coming JJ and JPDave! 😉

  30. I think the latest (14z) HRRR looks very reasonable for today’s evolution.

    Not sure about Eric Fisher’s moderate risk upgrade. It certainly would not be tornado driven. SPC would have to have high confidence in a widespread damaging MCS/derecho event in and around SNE, and I just don’t think we have that. Geographic threat area is too small. But we’ll see.

  31. Sun is just now struggling to break through the clouds/overcast in Sutton. Temp climbed to 67 with a 62 DP

  34. Have had a long and busy few months but I hope to be around the blog more this summer! As for right now, few discrete cells started popping up ahead of the fast moving blob in Western MA, something to watch. I do wonder if this first round takes away some of our instability.

      1. from Eric

        More
        A quick swipe of downpours will move across northern areas midday/early afternoon. *Not* associated with the stronger main line of storms later this eve.

  35. From NWS Upton NY
    Most significantly, per 12Z soundings across western PA and NY show an EML, with mid-level lapse rates according to sounding climatology near the climatological maximum for this time of year. Given strong west-northwest deep layer flow, these lapse rates will advect eastward, creating an environment not often seen in the Northeast, particularly this early in the convective season

  38. Ok, is the first batch across northern Mass a warm front ?

    Should we be focused on what looks like something trying to develop in central NY State ?

    2. Yes. That’s the show. Notice how this first batch is moving mostly north of the main risk area today, so destabilization will not be significantly impeded further south. I think it’s all systems go.

    1. yesterday in Chicago, 2 outflow boundaries met, one I think was from the upstream thunderstorms themselves and the other from the lake ……. some fairly nasty thunderstorms erupted when the boundaries collided.

    1. be back at 1:35 ish. 2 classes to go. 🙂 🙂 🙂

      2 step equations today with proper algebraic procedure.

  41. Good call by Eric moderate risk for parts of western CT southern Berkshire county Hudson River Valley
    http://www.spc.noaa.gov/products/outlook/day1otlk.html

    If you click on probabilities showing a 10 percent tornado chance Berkshires northern parts of Hudson River Valley and I have never seen a 60% percent wind chance here in SNE. The highest I have seen was 45% 60% covers Southern Berkshire Litchfield County Hudson River Valley and Northern parts of NJ

    1. They’re throwing around “derecho” very loosely, combined with those wind probabilities, I think they’re very confident in it.

  42. This is the fastest moving line I’ve ever seen. Made it from Western Mass to the coast in an hour.

  43. I posted the link earlier from SPC what each category means but a Moderate Risk which my part of CT is under means widespread severe storms are likely long lived and intense.

  44. First watch of the day is a severe thunderstorm watch for a good portion of PA and southern parts of Upstate NY.

  47. SPC placing areas in the northeast in moderate risk is not common. This is the second time in less than two weeks parts of the Northeast are under a moderate risk .

  49. This tweet from meteorologist Ryan Hanrahan here in CT. He does not hype things. Just waiting to see if a tornado or severe thunderstorm watch is issued for my area. Here is Ryan’s tweet.
    We have been upgraded to a rare “moderate risk” by the @NWSSPC. This has the potential to be a big day folks.

  50. Not impressed so far. Been cloudy more often than sunny and radar totally clear so far well to the west. Since I am not a fan of thunderstorms that’s fine with me if things don’t materialize.

    1. patience. Nothing was supposed to happen in our area just yet.
      It is beginning, trust me.

  52. Sun finally broke through and temp jumped – Clear sky with a bit of what appears to be haze …. 80 with a 64 dp

  53. From Eric Fisher
    They’re sending up an extra weather balloon today at 18z (2pm) from @NWSAlbany. Will be a nice window into what the atmosphere looks like this afternoon.

  58. It will be interesting what the weather balloons being launch show in the atmosphere. This launch happens at 2pm.

  60. Now keeping an eye on any discrete cells that pop. Looks like one south of Albany, NY has a severe thunderstorm warning on it.

  61. From Ryan Hanrahan
    Initially, the severe weather threat will include large hail – even very large hail. Over time the storm mode will shift to one that favors strong damaging winds. Isolated tornadoes remain possible in all storm modes.

  62. 81F at Logan.

    Except for extreme SE Mass and the immediate South Coast, I get the idea the surface winds aren’t southerly or 180 degrees. I get the sense they are closer to due SW and 220 degrees.

    1. Boston 230 degrees
      Springfield 220
      Hartford 215
      Providence 205
      Fall River 210
      Worcester 240
      Lawrence 230
      Norwood 225

      That should be enough.

  63. Have ways to get warnings as they are issued today. In most cases, tornado (as well as flash flood) warnings should be transmitted to your phone as soon as they are issued. But just make sure you have a way to get them.

  65. Some decent rotation in the supercell storm near Hudson, NY right now, moving towards southwest MA. That may get a tornado warning soon.

  66. Tornado Watch posted as far east as Worcester.
    Severe Thunderstorm Watch just up for Bristol County, MA

  67. TORNADO WATCH 96 REMAINS VALID UNTIL 9 PM EDT THIS EVENING FOR
    THE FOLLOWING AREAS

    IN CONNECTICUT THIS WATCH INCLUDES 3 COUNTIES

    IN NORTHERN CONNECTICUT

    HARTFORD TOLLAND WINDHAM

    IN MASSACHUSETTS THIS WATCH INCLUDES 4 COUNTIES

    IN CENTRAL MASSACHUSETTS

    WORCESTER

    IN WESTERN MASSACHUSETTS

    FRANKLIN HAMPDEN HAMPSHIRE

    THIS INCLUDES THE CITIES OF FITCHBURG, GREENFIELD, HARTFORD,
    NORTHAMPTON, PUTNAM, SPRINGFIELD, UNION, VERNON, WILLIMANTIC,
    AND WORCESTER.

  69. Severe Thunderstorm Watches out for all of Rhode Island, eastern Massachusetts (except the Cape and Islands) and southern New Hampshire

  77. The remarkable height of these storms (tops close to 50,000ft on the strongest ones) is largely a result of the remnant EML cranking up the instability. Updrafts can rocket up to and beyond the tropopause and overshoot well into the stratosphere. This setup is so unusual for the Northeast.

  79. I would be shocked if there is not a tornado on the ground with that storm we’ve been talking about. Tornado vortex signature on radar and some extremely impressive velocities.

  81. He posted earlier a link to SAK’s blog.
    One tornado warning storm looks to skirt the western part on the boarder between CT and MA. Second tornado they extended it to close to Poukipsee NY. I am watching that one closely to see what happens that one.

  83. The fact that NWS Albany extended that tornado warning means they believe it will maintain its strength. Reading these statements the one near the CT MA boarder baseball size hail and that other one tennis ball size hail the one tracking near Poukispsee.

  85. Northwestern part of Litchfield County in CT under tornado warning. There was a debris signature with that storm I just heard when it was in NY. Baseball size hail with this storm.

  86. Have not seen a cancellation of the Sox game yet but would not be surprised. At least a delay seems like a given.

    1. It would be awful to have a stadium full of people. My oldest and husband have a town meeting scheduled while I stay with granddaughters. I’d think they would postpone but doubt they will.

      Not sure if you saw my wish for a happy birthday, Longshot, in all of the comments. I hope you are having a great day.

  88. Eric Fisher
    ‏
    Verified account

    @ericfisher
    1m1 minute ago
    More
    We need to pay extra attention to storms as they approach the CT Valley…winds are more backed out of the south there (more directional shear for rotating storms)

    1. It seems to be traveling slightly southeast toward CT rather than along MA/CT border….maybe I am wrong??

  92. The circulation part where the tornado would be if there is one is in far northwestern CT.

  95. There extending severe thunderstorm warnings into my area with storms in Hudson River Valley of NY

  96. NWS Boston just issued their first tornado warning in a loooong time. Just outside of Hartford and Windsor Locks.

  97. Newly tornado warned cell just NW of Hartford, ct.
    Actually it is the previous cell and the rotation just regenerated.

  98. Storm is cycling. Even if no tornado we know the storm is producing hail and some pretty large hail

  101. I am south of that tornado warned storm thankfully. What I am watching is out over NY State and the NWS already extending thunderstorm warnings to my area. That storm looks intense which is tornado warned.

  102. JP, what does the storm just entering north central worcester county look like? It is warned, but I don’t like how it is looking.

    1. No rotation at all or at least none I can see with radarscope.

      Here is the display

      https://imgur.com/a/4ZM6ZG3

      If there were rotation you would see a fairly tight area with
      green on one side and red on the other.

      Doesn’t mean the storm isn’t dangerous, just that it is not rotating at
      this time.

  104. Just heard the first rumble of thunder of the year. Storms to the NW of Boston thankfully staying under severe limits.

  107. I don’t know if I should be happy or concerned that the sfc winds are turning more southerly.

    Marine layer influence vs better backing of winds …..

  109. It “may” be my imagination, but I am getting the distinct sense that
    the storm are starting to weaken just slightly as they march Eastward.
    Marine influence? I wouldn’t be surprised.

    1. The main line has not weakened much. The storms further north in MA are not doing much just because the environment there is less favorable, as expected. And the main line has a southward component to its motion, so most of the real action is not moving towards the Boston area. We’ve definitely seen the expected upscale growth into lines and clusters.

      1. I don’t think anyone in Eastern MA will see a severe storm.
        Getting totally unimpressed with radar from MA/CT border Northward. Any remaining “real” action will be in CT until
        even that fizzles.

  113. I am watching tv coverage and they have radar which has at BTI which is a tornado index that goes to 10 last scan showed a 5 for tornado warned storm heading this direction.

  117. All is pretty much as it was expected. HRRR was good today. The ONLY surprise was tornado parameters as far east in CT as they were. And it wasn’t a huge surprise. If anybody is disappointed in the forecast, they didn’t listen properly. 🙂

    You can be disappointed if you didn’t see a good storm at your location, but that’s just how it goes. We’ll be in this stuff around the region for a while. Front is slowing down and the elevated convection leftover from the CT storms will be riding up the boundary for several hours.

  118. got some small hail here in Billerica a little bit ago.
    continuous low frequency rumbling thunder. what I like to call rumble thunder.

  122. Niece in Marlboro who loves storms said it is scary intense there

    Occasional thunder here. Just regular rain

    1. Tom, we had two giant lightning strikes here (north of you?), right about when you posted this. And the local sirens went screaming toward something. Big rolling thunder and some more lightning flashes now.

  124. Was in meetings all PM at work!

    Storms just came thru Manchester CT. Got pitch black with some wind, heavy rain and lightning but nothing out of the ordinary. No hail or wind damage. Worst of it split to the north and south of here fortunately.

  126. 125,000 people without power in CT.
    Thankfully all I got was heavy rain and some lightning.

  127. Radar estimated a tornado warned storm in Oxford, CT which is south me had winds of 100mph.

  130. Today was one of those wonderful yet elusive days where everything in the forecast goes exactly to plan. The ingredients were there, and this time it all came together. If I had to nitpick one thing, it would be that the highest risk zone ended up being pinched a little further south than expected. Central MA was kind of a bust. But all in all a really impressive day of thunderstorm activity not often seen in the Northeast. Only one confirmed tornado on the SPC storm reports page right now, but it is likely several more will be confirmed in the coming days.

  131. The convective allowing models also by and large did a great job with this event over the past 24-36 hours. NAM, WRFs, HRRR. They nailed it.

  132. Periodic heavy rains in Boston’s Back Bay for a 90 minute stretch with some lightning and a few claps of thunder, but all in all nothing severe or out of the ordinary. Right now the rain is much lighter. What surprised me a little is the lack of wind. Maybe there will be more of that later on.

  135. On behalf of all of the lurkers – though we periodically pop up before we resubmerge – thanks to everyone for your great posts today. This blog is so informative and so helpful and as I’ve said before, due to the groups combined wisdom and insights I no longer dread storms. I even, dare I say, enjoy them a little?

    1. And people said they were done before the series even started. Hey, even if they eventually lose it, it’s already impressive.

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