Tuesday Forecast

136 Comments

7:08AM

DAYS 1-5 (JULY 17-21)
The big focus today is the thunderstorm threat as a cold front and accompanying vigorous disturbance pushes into a warm/humid air mass. We’ll watch for a couple to several lines and/or clusters of showers and thunderstorms. Any of the storms have the potential to become severe, with the greatest potential for this being north and west of Boston during this afternoon. Drier air arrives during midweek, and humidity then tries to make a comeback later in the week, as first high pressure brings a bit of air from Canada, and then moves offshore and grabs air from over the ocean and south of the region. Forecast details…
TODAY: Partly to mostly cloudy. Areas of fog early. Showers and thunderstorms likely from early afternoon on from west to east. Humid. Highs 76-83 coast, 83-89 interior. Wind SW 5-15 MPH but may be variable and gusty near any storms.
TONIGHT: Mostly cloudy. Showers and thunderstorms likely eastern and southern areas evening. Areas of fog. Humid. Lows 62-69. Wind light variable but may be gusty near any storms early, then N up to 10 MPH overnight.
WEDNESDAY: Mostly cloudy morning with possible showers, especially Cape Cod, then clearing. Less humid. Highs 75-82. Wind N 5-15 MPH.
WEDNESDAY NIGHT: Mostly clear. Lows 55-63. Wind light N.
THURSDAY: Mostly sunny. Highs 78-85. Wind light variable with coastal sea breezes.
FRIDAY: Mostly sunny. Lows in the 60s. Highs in the 80s but cooler some coastal areas.
SATURDAY: Partly cloudy. Lows in the 60s. Highs from the upper 70s to upper 80s, coolest coastal areas.

DAYS 6-10 (JULY 22-26)
Increased shower risk and more humidity July 22-23 with more southerly air flow as high pressure is offshore but fairly far north. During the remainder of the period, a pattern transition to ridge West, trough Midwest / Great Lakes, ridge off East Coast will be underway with higher humidity common, warm to at times hot, but almost daily opportunities for at least isolated showers and thunderstorms.

DAYS 11-15 (JULY 27-31)
The pattern that develops during the days before this likely continues during this period.

136 thoughts on “Tuesday Forecast”

  2. Thanks TK
    Down in Virginia on vacation and SPC has the area I am in under a marginal risk. Looks like some reading the discussions from NWS and SPC it could be an active day up there in terms of thunderstorm and flooding potential.

    1. Have a great vacation !

      Trof in the east should help keep the excessive heat away from Virginia.

  5. I find it interesting where the NWS has hoisted a heat advisory for today.

    On a day where a strong disturbance with favorable dynamics is approaching, I interpret where the heat advisory is translates to where the best surface heating should be available, as the heat advisory area kind of identifies the area of overlap with the highest temps and very high dew points.

    Might this heat advisory area be a general zone for where the storms might be at their strongest later today ?

    1. Ok, reading the text, I get the idea the heat advisory covers more real estate than visually shown, but perhaps the flood watch is overlapping some of that area ??

  7. Severe potential discussion from NWS:

    2) Severe Weather Potential:

    The severe weather threat has increased from yesterday, due to
    the better potential for heating during the morning hours with
    some sunshine. The Storm Prediction Center has placed most of
    our region in a Slight Risk for severe thunderstorms. The main
    threat will be damaging winds from wet microbursts. 850-700 mb
    winds increase to 30-40 knots this afternoon, which is strong
    enough to produce organized severe storms. Besides a line of
    storms, the SPC HREF model is also indicating the potential for
    some rotating supercell thunderstorms in north central MA near
    the NH border. Helicity values reach 200+ north of our CWA.
    We will need to be extra vigilant for the potential for an
    isolated tornado, especially in the Route 2 corridor this
    afternoon. Hail cannot be ruled out in the strongest storms, but
    strong winds are the primary threat. We have continued with
    enhanced wording of gusty winds and heavy rainfall in our zone
    forecasts. A Special Weather Statement will be issued that
    highlights the severe weather potential for today.

    1. Rotation “appears” to be getting stronger. Wonder if albany NWS will warn
      this storm??????

  10. I was surprised to see 80 with a 71 DP so early in Humarock. The breeze keeps it comfy

    81 with 74 DP in Sutton.

  11. Latest update from SPC removes 2% tornado chance for parts of northern MA and southern NH.

    2. I think they are wrong. Just looking at the surface observations.
      In North Central MA and Western MA, surface winds are SSE.
      Winds above are WSW. This represents shear with height and a chance for rotating storms in those areas.

  12. Still looks like a potentially active day with the possibility of strong to severe storms and flash flooding. SPC does have most of SNE in slight risk.

  13. Logan is up to 84 with dp 72 and BRIGHT SUNSHINE priming the atmosphere.
    CAPE will reach close to or exceed 3,000 joules in the area.

  20. Interesting to note some of the wording in the Watch:

    * Primary threats include…
    Scattered damaging wind gusts to 70 mph likely
    A tornado or two possible

    This, despite removing the 2% chance of tornado area.

    Hmmm, interesting indeed.

    1. The watch probability table has Low (20%) chance of 2 or more tornadoes, and Low ,(5%) chance of F2 or stronger tornado. FWIW

  22. I’m glad I’m not still in Alfred, ME today. That bow echo near the concord, NH area is headed right that way.

    Storm motion is still mostly NE.

    I’m trying to understand if I’m supposed to watch the stuff in NE PA …. or is what is WNW of us currently going to translate to the southeast or if new cells will be developing closer to southeast New England ????

    1. I’m just watching the line of storms.

      More will develop for sure. The fact that the watch extends more to the SE, suggests that storms will hold together at least to about Boston, give or take, perhaps even a bit farther SE before weakening.

  28. FWIW,
    Line looks quite unimpressive at this time.
    However, beneficial rain should result which is a good thing.

  29. I left Lowell at 12:30. The sun was out and the car thermometer read 94. Just 45 minutes later, I was home in Lunenburg and it read 70.

  34. just northeast of Springfield must be having some flooding issues.

    They have been under training red echos for a while.

  35. It is amazing how strong a 10 mph wind is. I’m on east side of house (WSW wind) but wind is blowing through the west slider (through house) and out the east slider and blew a deck chair over on east facing deck

    If that makes sense

  36. looking at zoomed in (400 %) weather underground radar, I think those storms to the north of Boston are sending an outflow boundary south, on which a few storms are popping.

  37. 12z GFS with some sort of east coast surface low at 111 to 114 hrs.

    850 mb temps associated with it have an 18C contour right over it ……..

  38. Thank you, TK.

    I know I shouldn’t complain, but the past two days have taken a toll on my body. I nearly passed out yesterday. Today’s no better. In fact, it’s worse. The weather has made me sick. I see the rain has arrived, but hopefully the humidity will diminish.

    2. So sorry to hear that Joshua. Hopefully, the cool air will arrive in your area soon. I’m getting small gusts of cooler air here and the line of storms isn’t even close

      1. Thanks, Tom, Vicki, and JP Dave, I didn’t use to get `sick’ from the weather, but I feel the humidity is doing a number on me. As I mentioned before, my mother and I share a similar constitution. She keeps asking me when the cooler air will arrive. I told her again the other day that it’ll come soon, and especially where she is – Vermont.

  39. A bit of thunder, some spitting rain and a bit of cooling.
    Down to 80.

    But regarding thunderstorms, WHAT A JOKE!!!!!!!!!!!!!!!!!!!

    2. Hmm as I said that, something seems to be happening. We shall see.
      Still not much thunder and/or rain here at all.

  40. I’m seeing some good sized clouds building to the north. Hang in there Joshua, Mrs OS and Philip and others impacted by extremes. Hope the other side of this brings you all relief.

  42. ok, the EURO has this too at hr 120. 18C, (850mb mini contour) right over the small low pressure area south of Block Island.

  43. I see what you have been saying JPD. Rain has pretty much stopped and radar now has very few oranges and yellows, just green for the most part. And as I am posting, sun is peaking out a bit.

  46. Short-lived heavy downpour in downtown Boston. Air is still humid but clearly unstable. I think more rain is coming and perhaps a few storms, too.

  50. Down to 72 here, downpour had stopped, but raining a bit more now.

    Picked up a quick 0.31 inch in that downpour.

  52. I’m baffled by the public.

    Everybody translates potential into certainty, and severe possibility into *I* am definitely getting it. Yes there was already wind damage in both Billerica and Wilmington. Severe storms have already occurred. It’s not over yet either. This is no disappointment. It’s called a verifying forecast.

    1. Well, let’s just say I am not easily impressed and so far what I have seen
      here just underwhelms me. Not talking about other areas. 😀

  53. Whole new batch of rain moving in from the SW.
    I do NOT hear thunder anymore and have not for some time now.

    up to 0.52 inch here so far with it raining again.

  55. Dark clouds here ns temp to 73.

    More fun. Someone just posted on FB that whales were seen off Humarock by cliff

    1. I’m in Hanover, seeing same dark clouds.

      Gusty sw wind at surface has stopped, probably shut off by the outflow boundary from the storms to the north. Perhaps that’s why those storms have weakened some and broken apart, as there is less heat inflow into them.

      I think down here south of Boston, we now watch the storms to our west and see if they survive the trek eastward.

  57. Tornado warning near Putnam, Ct

    https://www.weather.gov/wwamap/png/box.png

    Tornado Warning
    Tornado Warning
    CTC015-172030-
    /O.NEW.KBOX.TO.W.0006.180717T1959Z-180717T2030Z/

    BULLETIN – EAS ACTIVATION REQUESTED
    Tornado Warning
    National Weather Service Boston/Norton MA
    359 PM EDT TUE JUL 17 2018

    The National Weather Service in Boston/Norton has issued a

    * Tornado Warning for…
    Northern Windham County in northern Connecticut…

    * Until 430 PM EDT.

    * At 359 PM EDT, a severe thunderstorm capable of producing a tornado
    was located over Eastford, or 9 miles northeast of Mansfield,
    moving east at 30 mph.

    HAZARD…Tornado.

    SOURCE…Radar indicated rotation.

    IMPACT…Flying debris will be dangerous to those caught without
    shelter. Mobile homes will be damaged or destroyed.
    Damage to roofs, windows, and vehicles will occur. Tree
    damage is likely.

    * This dangerous storm will be near…
    Woodstock around 410 PM EDT.
    Thompson and Pomfret around 420 PM EDT.
    Killingly and Putnam around 430 PM EDT.

    PRECAUTIONARY/PREPAREDNESS ACTIONS…

    TAKE COVER NOW! Move to a basement or an interior room on the lowest
    floor of a sturdy building. Avoid windows. If you are outdoors, in a
    mobile home, or in a vehicle, move to the closest substantial shelter
    and protect yourself from flying debris.

    &&

    LAT…LON 4186 7220 4193 7221 4198 7189 4187 7187
    TIME…MOT…LOC 1959Z 260DEG 26KT 4191 7212

    TORNADO…RADAR INDICATED
    HAIL…0.00IN

    $$

    md

    Funny thing, while I see some slight rotation, the 2 storms I posted earlier
    had tighter/stronger rotation and they were not warned. hmmmmm

  58. Old salty. I asked daughter in Sutton to read here. She doesn’t have a radar. I’ll also call her if there is a tornado warned area for her. I just know you see them before NwS

  59. Tornado trying to spin up in northern RI right along an outflow boundary, really cool evolution to watch. Storm is severe warned with a “tornado possible” tag, might need an upgrade to a tornado warning.

  60. Thanks all. Talk about being torn. Land side of house is where I want to be watching for storm. Ocean side harbormaster has been out just down from us for an hour looking for something. Could be what we thought was whale was a shark. What we saw had a fin. So I run back and forth between sides.

  61. Well the harbormaster was called back with storm coming so I can now focus on the storm

    The south shore has a rumbly in its tumbly and the lightening cloud to ground is amazing

      1. That seems to be all she wrote

        The wall of rain coming across the river was absolutely amazing. By the time I got to the slider in my room the rain was coming halfway across the room it was so wind driven

  62. Bolt of lightning between windmill and pole. Just my iPhone.

    Tom I was wrong. It seemed to be more Scituate way than yours and mine

  64. Thought we were winding things down here in the Hartford area but another band of rain with torrential downpours has formed and is moving through. An additional band has come together in the Hudson Valley on its heels. Keep em coming!

  65. We may see a very quick fire-up of a line somewhere in eastern MA and adjacent southeastern NH between 9PM and 11PM.

    2. Was just commenting on that above. Additional lines of showers/storms keep forming and moving in from the west. Pouring here in the Hartford area again.

  66. The strong to severe storms that moved through earlier had plenty of cloud to ground lightning but not much wind. Certainly nothing severe in this area. Big story was the torrential downpours and street flooding. I was out earlier driving in it and it was slow going, white knuckle driving at times with all the ponding on the highways.

  69. Final tally: 2.55 inches here in JP.
    As far as thunderstorms go, completely underwhelming, however
    the RAIN certainly delivered. Some intense downpours and I was driving through them.
    Only a very occasional flash of lightning and rumble of thunder.
    Rain was truly welcomed. My grass and plants are saying AHHHHHHHHHHHHH!!!!!

Comments are closed.