Tuesday July 21 2020 Forecast

47 Comments

7:39AM

DAYS 1-5 ( JULY 21-25)

High pressure builds from the Great Lakes to just south of New England through tonight, and while today will still be very warm to hot, it will be less humid and more comfortable. Cloudiness will make a come-back on Wednesday ahead of a warm front which will also bring a risk of showers, a slight risk of thunderstorms, and a return to higher humidity, which lasts through Thursday until a cold front passes by at night. It’s difficult to say where the warm front will be at any given time, but from later Wednesday through Wednesday night, we run the risk of an isolated severe storm or two near it and should keep a close eye out for this. Ahead of the cold front, expect a continued shower/thunderstorm risk during Thursday. Somewhat cooler and significantly drier air arrives behind that cold front for Friday. High pressure builds in with continued fair and pleasant mid summer weather for Saturday.

TODAY: Mostly sunny. Less humid. Highs 85-92 except cooler Cape Cod. Wind W 5-15 MPH.

TONIGHT: Mostly clear evening. Increasing clouds overnight. Lows 60-67. Wind variable under 10 MPH.

WEDNESDAY: Mostly cloudy. Risk of showers. Highs 77-84, coolest coast. Wind SE 5-15 MPH.

WEDNESDAY NIGHT: Variably cloudy. Risk of a few showers and thunderstorms. Humid. Lows 65-72. Wind SW up to 10 MPH.

THURSDAY: Variably cloudy. Chance of showers and thunderstorms. Humid. Highs 80-87. Wind SW 5-15 MPH, higher gusts.

THURSDAY NIGHT: Variably cloudy with a chance of showers and thunderstorms evening. Clearing overnight. Patchy fog lower elevations. Less humid. Lows 58-65. Wind NW 5-15 MPH.

FRIDAY: Mostly sunny. Highs 77-84. Wind NW 5-15 MPH.

FRIDAY NIGHT: Mostly clear. Lows 58-65. Wind N up to 10 MPH.

SATURDAY: Mostly sunny. Highs 80-87, cooler in some coastal areas. Wind variable up to 10 MPH with coastal sea breezes.

DAYS 6-10 (JULY 26-30)

A trough of low pressure may bring a passing shower or thunderstorm July 26. Fair July 27. Another disturbance brings a shower / thunderstorm threat July 28 before drier weather arrives again at the end of the period. Temperatures near to slightly above normal overall.

DAYS 11-15 (JULY 31 – AUGUST 4)

West to northwest flow aloft, a seasonably warm to occasionally hot mid summer pattern but no lasting or extreme heat expected. Occasional opportunities for showers and thunderstorms but drier than average overall for most of the region.

47 thoughts on “Tuesday July 21 2020 Forecast”

  5. Well, yesterday was certainly a bust. Now lets’ see what
    the next 2 days can produce. We shall see. I am not convinced
    at this is point. But, hey, lately or not so lately, I have been
    a true Mr. Negative. Sorry about that.

    Keeping my fingers crossed. My lawn is finally browning out.
    Not that I give 2 craps about it, just an observation. If it is meant to be green, it will be and if not, it won’t be. Simple as that.

  9. Warm front sometimes are sneaky so got to watch it just in case. Wed and Thurs could have isolated severe weather but neither day looks to be widespread severe weather. Of course if the isolated severe thunderstorm hits your neighborhood it doesn’t feel isolated.

  10. Quick peak at the HRRR that goes out 36 hours it wants to develop some isolated storms across parts of SNE Wednesday afternoon ahead of a line of storms approaching western parts of SNE in the 7pm – 8pm time period.

  11. Thank you, TK.

    Tomorrow is my oldests 40th birthday. Please don’t ask how I feel about that when I think I’m still 40. They were going to head to the beach. I’m wondering if that is a bad idea. Although I see your forecast is nothing really concerning.

    Thank you

    2. You’re a youngin. My oldest is just short of her 50th birthday.
      Try that on for size realizing you have a child that is 50 years old!!!

    1. Vaguely recall. My Dad was a weather buff. Gave me the gene or simply the bug. He would tell me about the weather almost every day, especially if something interesting happened. We were living in Needham, on the Dover line, very close to the Charles River. This is also near a spot where JP Dave fishes, I believe. I was 7 in 1972. Sometimes I wish I was 7 again. I often wish it was the 70s again.

      From 1971, Cat Stevens performing live Wild World, from one of the best albums ever – Tea for the Tillerman. Cat/Yusuf is 72 today.

      https://www.youtube.com/watch?v=P1b8z1h_rIs

      1. Yes, near there. Willow st where the pond empties under the road into the river. More so on South street right below
        the dam.

        1. Yes, exactly. It’s a beautiful area. Took my daughter and her British boyfriend there last September. It was late September so some foliage was appearing. Luke, my daughter’s boyfriend, couldn’t believe how beautiful the area is. He kept asking me, “so Boston is how many miles from here?” He couldn’t believe how rustic that area is, and yet so close to the big city. We toured through South Natick and Wellesley, too, that day. Splendid and spectacular. I told Luke, “your ancestors settled in a really nice place.” Then I ribbed him a little by saying “now you know why King George III wanted to keep it all.”

    1. SPC discussion for tomorrow

      Bowing line segments and clusters should be the dominant storm mode,
      with damaging wind gusts as the predominant severe threat.
      Deep-layer vertical shear decreases with southern extent, so the
      highest potential for more organized storms, and perhaps even a few
      supercells, exists from central PA into Upstate NY/Southern New
      England. In this area, the stronger vertical shear suggest slightly
      greater potential for hail and maybe even a tornado or two.
      Antecedent cloud cover and possibly a few showers could inhibit
      destabilization in the vicinity of the warm front, but the stronger
      shear still merits including this area in a 15% wind probability.

  14. The 2% tornado risk did not change with the latest outlook. The slight risk area has been expanded to include most of CT and good chunk of interior MA.

  15. Ryan Hanrahan talking about two windows for storms tomorrow.
    We’ll be watching the radar closely tomorrow for some scattered strong storms. There’s one window in the morning and another late afternoon/early evening.

    Eric Fisher’s take for tomorrow
    Highest risk for some strong to severe storms tomorrow looks to be across western MA/CT. Warmer with more instability.

    With a warm front nearby will be watching for rotating storms though overall wind fields look pretty weak. Still worth monitoring.

  16. I disagree with yesterday being a “bust”. A “bust” is a forecast that goes badly, or does not verify. My forecast yesterday called for “isolated to scattered showers and possible thunderstorms, favoring the I-95 corridor southeastward” for the afternoon. There were isolated small moderate to heavy showers southeast of I-95 (northeastern RI and adjacent southern MA). Coverage was extremely low. But this, however, was a verified forecast, not a bust. 🙂 The mention of I-95 was not a guarantee that thunderstorms would occur over I-95, or any other given location, but a general borderline of where I expected the potential for activity (SE) versus no potential (NW) during the afternoon hours. 🙂

        1. I would expect you to. I have no issue being criticized. It goes with the territory of trying to perform prediction or anything that is at least partially art (which this is, although much more science). 😉

  17. I reserve use of the word “bust” for short-term forecasts that turn out wrong. For example, when I was a kid (1970s) and I’d call the weather service at, say, 7pm, and I’d hear “winter storm warning in effect …” I’d be so happy to hear those words. But then when I woke up at 6am and peer outside and I’d only see rain and maybe the remnants of some slushy snow. Man, was I disappointed. I’d ask my father, what happened. He’d explain that the storm took a “left turn and dragged in too much warm air.” What would have been a nor’easter turned into a southeaster, if you will. That was a bust.

    1. The original term was coined by meteorologists to basically have a term to use when they messed up a forecast. 😉

  18. Generally in good agreement with the SPC outlook for tomorrow. Not an outbreak, but some storms or clusters of storms producing strong to damaging wind and perhaps an isolated tornado. As of now I think the best chance for a tornado would be over southeast NY or CT. But mainly a straight line wind threat.

    Tropical Depression 7 has formed over the open tropical Atlantic. It will become “Gonzalo” over the next day or two as it tracks towards the Caribbean. It’s very far from land, but most indications are that it will weaken after it gets into the Caribbean. As a fairly small/compact system though, it would not surprise me if it reaches hurricane intensity in the coming days.

    1. Love this and yikes. It’s been established here that I am just 40 so how do I recall 50 years ago.

  22. JPD…I meant to comment on your lawn post. Ours was brown but the rain a few weeks ago got it going a bit so we are watering and now it is as green as the dollar bills flying out the window to keep it that way 🙁

  24. Loved the Chicago link! I was a student at Tanglewood that summer — but they didn’t give us passes to this concert! Thanks for posting.

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