Saturday Forecast

64 Comments

8:37AM

DAYS 1-5 (JUNE 30-JULY 4)
Not much new on this update, just a few tweaks. A disturbance passing through Maine should keep its showers and storms northeast of the WHW forecast area today and tonight but will watch it and alert in comments section later if something does end up a little closer than expected, and that would be southeastern NH or northeastern MA if it did happen, and sometime tonight. This disturbance, and the outflow from the storms associated with it, will push a boundary with a little more momentum into eastern areas during Sunday, sparing the coast the highest heat. This will penetrate inland some distance, but the impact is much less by the time we reach this time of year than it would have been earlier in the spring, and with the heat already in place, we’re starting at a much higher level before knocking things back. This air will hang around into Monday but the air mass will warm under the early July sunshine so don’t expect refreshing ocean wind everywhere, although the coast may still be quite comfy Monday, despite the air being rather humid. The hottest days of this period for the region overall should be Tuesday and Wednesday. There is only the slightest risk of an isolated thunderstorm Wednesday but the chance is so remote I hesitate to even mention it. I believe warm air aloft should keep it stable enough to overcome a little surface convergence and the heat/humidity at the ground. But where it is the holiday itself, the forecast is high stakes and will of course be closely monitored.
Forecast details…
TODAY: Mostly sunny. Highs 76-82 Cape Cod, 80-87 South Coast, 86-93 elsewhere. Wind W to SW up to 10 MPH.
TONIGHT: Mostly clear. Lows 66-75, warmest in urban areas. Wind light SW.
SUNDAY: Mostly sunny. Highs 78-85 shoreline and 86-95 elsewhere but falling back through the 70s immediate coast and through the 80s for up to 25 miles inland from east-facing shores during the late morning and afternoon. Wind SW up to 10 MPH shifting to E and NE.
MONDAY: Sunny. Lows from the upper 60s to upper 70s, warmest urban areas. Highs from the upper 70s to lower 80s immediate coast, ranging up from middle 80s to middle 90s further inland.
TUESDAY: Mostly sunny. Lows from the upper 60s to upper 70s, warmest urban areas. Highs from the upper 80s to middle 90s, coolest coastal areas.
WEDNESDAY – INDEPENDENCE DAY: Partly cloudy. Lows from the upper 60s to upper 70s. Highs from the upper 80s to middle 90s but cooler in some coastal areas.

DAYS 6-10 (JULY 5-9)
Currently expecting hot and humid weather but no storm threat July 5, and similar but with an isolated storm threat July 6 and 7. Better risk of showers/storms July 8 with a cold front and the hot weather pattern is broken, at least temporarily, by the end of the period.

DAYS 11-15 (JULY 10-14)
Less heat, back to more seasonable temperatures as the ridge backs up further west and a couple disturbances move through with shower and thunderstorm chances.

64 thoughts on “Saturday Forecast”

  1. Thank you, TK…..we found summer and it feels awesome. Gonna be hot for the kids in the bounce house at the bday party today. Not that kids ever notice heat or cold or anything in between.

  3. 85 at Logan as of 9AM, BUT the wind has gone CALM already.
    Hmmm, Wonder what that means.

    I hope it generates a nice fresh sea breeze that penetrates 10 miles inland.
    Doubt it, but here’s hoping. 😀

    1. 86 with 67 DP here, JPD, and an ESE wind of 1 mph. It has the direction down….now Mother Nature has to just pick up the speed. Got my fingers crossed for you JPD

      1. Tk seems to see some break by Sunday also. And Saturday is move in day so I’m hoping for a bit cooler then also

  5. Good morning from near Sanford, ME where it’s 86F with a dp of 65F, not much wind.

    Will be on the lookout for an MCS later tonight.

    May have had a big storm miss to our northeast around 5pm last night. At the time, I couldn’t confirm with radar, but there was a beautiful anvil which lead me to reason there was a pretty good storm to our northeast.

    Stay cool everyone !!

  6. Thank you, TK.

    France v. Argentina is already an instant classic and it’s not nearly over yet (2-2 with a half hour to go). Defensively Argentina is weak, but they certainly have enough firepower to overcome it. The Frenchman Mbappe (19 years old), is the fastest striker I’ve seen in a long time.

  8. Its a nice sunny day for a pool party . Then heading on up to Appledore Island Maine for the Month. One of my friends up there said its 72 degrees at the moment.

    1. Funny thing is, the NAM radar reflectivity map is totally and completely
      EMPTY. ZILCH! NADA! NOTHING!

  11. The 12Z GFS would keep the HEAT going ALL he way until a WEEK from next Thursday!!!!

    Holy Crap. Hopefully this model is way out to lunch. We shall see.

  12. Surprised the SPC went with a marginal risk tomorrow for interior parts of SNE. I think that cap going to be strong enough to prevent thunderstorms. I agree with the outlook they have today for northern New England.

  13. Logan has ESE wind at 14 mph. NOT NOT NOT feeling it here 6 miles away.
    Logan is reading 84, We’re reading 95, but I have to say 2-4 degrees of that is due
    to heat generated from the asphalt roof under the porch deck upon which the unit
    is mounted. The fan generally works to keep the readings decent, except when
    there is High angle bright sun with not a whole lot of wind like today.

    I’d say we are really at 91 or 92.

  14. Logan has now dropped to 79 refreshing beautiful degrees. Send some this way!!!!!

    I’m going out it in a few and will get a feel for myself.

    ACs cranking here, of course not in this room. 😀 😀 😀

  15. Yesterday was one of those days that will be counted as 90 at Logan even though it never got there. Their 1 to 2 temp error on the sensor there really needs to be addressed. The real high was probably 88.

  18. 18Z regular NAM has ABANDONED the cooling boundary for tomorrow, Sunday.
    Has coastal boston temps into the mid 90s. Waiting om 3KM NAM.

  19. Logan has SE breeze with temp 77. It is nearly 20 degrees hotter here
    with a nice West to SW breeze. No hint of sea breeze here. a mere 6 miles away.

  20. 18Z 3KM NAM still drops temps to mid 60s along the coast tomorrow PM
    after it getting to near 80.

    1. Come to my house. It is brutal in the house, unless snug up to one of the ACs.
      True, I have seen it worse, but it’s not nice.

  23. So, which model do we believe for tomorrow????

    Waiting on the 18Z RDPS. The 12Z RDPS had a blast furnace for us tomorrow with
    temps 103-105. Most models now favor the heat tomorrow and either do not have
    the cooling or delay it till the damage has been done.

      1. NWS was expecting convection fire near the Quebec / Ontario border…just checked and didn’t look like much. Also what was over the NB/Maine border didn’t look all that impressive.

        1. Yup, it has to have an effect.

          18Z GFs squarely in CAMP HEAT with 100+ temps across
          SNE tomorrow!!!

  24. 18Z RGEM/RDPS is coming out now. So far it seemed to have NAILED
    today’s temperature profiles, including the very near the coast sea breeze.

  28. GROSSORAMA SWEATORAMA words that come to mind with those temperature links you posted if your not a fan of the heat.

  29. Nice to see the GFS & RGEM temp forecasts still suck 24 hours away from the forecast time.

  31. From today’s Wall Street Journal (Czerski writes about what she calls “everyday physics”)

    A Crash Course in Summer Thunderstorms

    By Helen Czerski
    June 27, 2018

    The thunderstorms of July are just around the corner. The first flash of lightning may offer the dazzle and the peril, but the thunder announces the scale of this atmospheric drama: a gigantic boom that fills the sky and your ears. I find the thunder far more interesting than the lightning. The richness of that sound has quite a story to tell.

    As a thundercloud begins to darken and swell, its chilly innards host a churning jumble of ice particles. Fountains of air surge upward inside the growing thundercloud and push the tiniest ice crystals upward, but the larger ice pellets continue to fall, so there are constant collisions.

    The consequence of the collisions is that electrons get knocked off the crystals and join the pellets, and so the negative electric charge that all electrons carry starts to accumulate at the bottom of the cloud. This charge eventually finds a path to the ground: a narrow channel of conductive air extending downward from the cloud that meets other delicate electrical tendrils snaking up from the ground.

    At the instant of connection, a vast electrical current can flow, dumping so much heat in the channel that air is converted to a plasma. The temperature soars to an astonishing 52,000 degrees Fahrenheit within a few millionths of a second. The hot plasma blazes white, and we see it for the tiniest fraction of a second: a lightning bolt.

    If you’re standing a mile away, that light reaches you five millionths of a second later, and then it’s gone. But in the air around the channel, things are just getting started. The hot tube of plasma expands rapidly, shoving into the air around it so hard that it creates a sonic boom. Sound travels far more slowly than light, so if you’re a mile from the base of the lightning bolt you’ll have to wait a whole five seconds before the first sharp crack finally reaches you.

    But the thunder doesn’t stop. The lightning bolt probably extends a couple of miles upward, and the sound from higher up takes longer to reach you. As the thunder rolls on, you’re hearing the same plasma explosion, but it’s traveled from farther away. That lets you pick out what the air itself is doing to the sound: filtering out the highest notes. The pitch drops as time passes, because the lower notes are the only ones left after a longer trip through the air.

    Listen to the rumble: You’re hearing the shape of the lightning bolt. Lightning doesn’t travel in a perfectly straight line. Instead, it looks more like straight sections that are linked at different angles. It can zigzag all over the place on its way to the ground, and lightning scientists have a great word for the amount of zigzagging: tortuosity. The rumble comes and goes because it’s the sum of the sound from all of those sections, frequently overlapping as they reach you. Then you’ll also start to hear echoes as the sound reflects off nearby buildings, walls and hills, extending the rumble for even longer.

    But if you’re more than about 16 miles from the lightning strike, all of this acoustical complexity may never reach you at all. Air temperature usually drops as you go higher up, and sound travels more slowly in colder air. If sound is traveling horizontally, that means the sound closer to the ground will be going faster than the sound higher up, and so the rumble bends away from the ground. If you’re too far away, it will pass over your head, never reaching your ears.

    So the sound from each lightning strike carries with it the imprint of the atmosphere around the lightning bolt. I’ll be looking forward to the summer’s thunderstorms, and as I hear the thunder I’ll be watching the sky, imagining the dance of the sound waves creating this fabulous symphony.

  32. Some storms firing near Montreal and also in Northern NH and North Central Maine…not a lot but they are there.

  33. SAK & I have been telling people for months (even a couple years), not just on here, but around social media, how bad those 2m air temp forecasts are but they always draw people in. Not once have the astronomical heat #’s on those forecasts verified. That tells you something. 🙂 2 words: Model bias. A benefit of being an old school forecaster is this was drilled into our heads by our mentors and we never forgot it.

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