Friday July 16 2021 Forecast (8:11AM)

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DAYS 1-5 (JULY 16-20)

This short-lived stint of heat and humidity will last one more day before a cold front puts an end to it, kind of. Ahead of that front is a trough, which may trigger a few showers and thunderstorms as it approaches the region today, and the front itself will quietly amble its way overnight into but once again probably not all the way through the region, and will be sitting around the South Coast region basically from Saturday through Monday, bringing the temperatures down, but allowing the humidity levels to stay on the higher side (noticeable but not oppressive) and as we have seen so many times recently, disturbances coming along this boundary will bring us chances for some rainfall. Timing the rain chances is rather difficult, but right now Saturday evening / night looks like the wettest part of the weekend, but shower chances will probably continue Sunday and into Monday as well. I’d love to say with confidence that Tuesday would be drying out with high pressure moving in, but we may actually have an upper low moving in with another risk of shower and thunderstorm activity. As bad as this sounds, this is the signal of a change in the pattern which is eventually going to bring us into a drier regime. More to come on that, but first the detailed forecast for this 5-day period…

TODAY: Mostly sunny to partly cloudy. Scattered to broken linear showers and thunderstorms forming early afternoon southwestern NH and central MA moving east southeast, peaking in the I-95 and I-90 areas mid afternoon before weakening while traveling toward the South Coast by late afternoon. Highs 84-91, cooler some coastal areas. Wind SW 5-15 MPH but some coastal sea breezes developing.

TONIGHT: Partly cloudy. Patchy fog late. Lows 66-73. Dew point middle to upper 60s. Wind SW under 10 MPH becoming variable.

SATURDAY: Variably cloudy. A possible morning shower, then scattered showers and thunderstorms in the afternoon. Highs 78-85. Dew point upper to middle 60s. Wind variable to N, shifting to E, up to 10 MPH.

SATURDAY NIGHT: Mostly cloudy. Chance of showers. Areas of fog. Lows 61-68. Dew point lower to middle 60s. Wind E up to 10 MPH.

SUNDAY: Mostly cloudy. Chance of showers. Areas of fog mostly in the morning. Highs 72-79. Dew point middle to upper 60s. Wind variable 5-15 MPH.

SUNDAY NIGHT: Mostly cloudy. Possible showers. Patches of fog. Lows 61-68. Dew point 60s. Wind variable up to 10 MPH.

MONDAY: Variably cloudy. Chance of showers and possibly a thunderstorm. Highs 76-83. Dew point 60s. Wind variable 5-15 MPH.

DAYS 6-10 (JULY 21-25)

A little more confident that we enter a pattern where we’ll be in low pressure troughing aloft more often than not, but also with systems moving along as they come through the trough, with limited time for precipitation. This pattern is cooler and somewhat drier.

DAYS 11-15 (JULY 26-30)

Current thinking is that the pattern of DAYS 6-10 will continue here as well.

44 thoughts on “Friday July 16 2021 Forecast (8:11AM)”

  6. Latest from the SPC for today.

    https://www.spc.noaa.gov/public/cwa/images/BOX_swody1.png

    From Norton NWS office:

    2) Afternoon/Early Evening Strong to Severe Storms

    The very warm and humid weather will support a moderately
    unstable air mass, with most-unstable CAPE values around
    1500-2500 J/kg per the 00z HREF; will note the NAM/RAP have
    considerably larger instability values than that but they also
    show dewpoints in the upper 70s which seem far too high even
    when accounting for evapotranspiration.

    Still, models simulate t-storms developing on the
    aforementioned wind shift boundary roughly between 2-4 PM from a
    rough BAF-FIT-LWM line, then trudging SE through the the late-
    afternoon to a roughly HFD-PVD-PYM line between 5-8 PM. The net
    storm coverage is in some question and varies across models, but
    anticipate initial cells congealing into a line or line
    segments capable of gusty to locally damaging straight line
    winds. While PWAT values aren`t overly high at around 1.5
    inches, I did note that the upshear component to Corfidi vectors
    are very small (less than 5 kt!). This could lead to potential
    for backbuilding and possible localized street flooding if
    storms re-develop. SPC has maintained a MRGL/5% severe risk to
    address the severe potential.

    1. Yes they have been hit pretty nastily.
      When you have a pattern that is anomalous it tends to have several significant impacts hemispherically. We’ve seen this before.

  10. Thanks TK.

    VERY much looking forward to DAYS 6 – 15 and getting us out of this awful summer pattern.

    TK – Will the HOT & WET pattern return at some point?

  11. Thanks TK. In good agreement with your thinking at the moment. Another few days of humid and unsettled. Then a pretty lengthy stretch of lower humidity, limited rain, and near to slightly below normal temperatures from about the 20th through at least the end of the month. Then the current pattern reloads heading into the first or second week of August. My thinking at least!

    3. So Hampton beach from the 23 – 31 might not be ideal beach weather as it won’t be hot

      1. The good news is the 23rd to the 31st of July, climatologically, is about the warmest time of the year. So, slightly below average to average temps could mean 80F -82F by day, comfortable nights, along with not so many cloudy days as there have been. If it works out that way, then you might be pleasantly surprised. Lets see what the models show around July 20th-21st. Right now, given past performance, the 23rd is too far out to be confident on whats in the medium range.

  15. I liked Dave Epstein’s midday summary for the weekend:
    “Mostly it’s not going to be miserable.”

  16. Radar getting active. Lightning strikes with the cell on the CT/MA state line in the northeast corner of CT.

    1. I just saw. Thanks. It’s warned. Im
      Watching clouds build to my south. Some to my north also.

  17. It sounds like I could be driving into some nasty thunderstorms tomorrow evening as I am returning from Virginia. I just saw the SPC has my area in the 2 percent tornado risk.

  18. Heavy downpours here. Just a few rumbles of thunder, yet the strongest winds of any thunderstorm here so far this year! It looked awesome out there. Winds well over 40 mph for sure.

      1. Same cell dumped over the Charles in the Natick, Dover, Needham area. Not going to help the already flooded river and then add tomorrow’s crap to it(!@(#*(!@*#(*!@(*@()

        1. Do not need more here either. Water levels are dropping some which is good. We had one small dam break

  20. Storm now several miles off shore, certainly providing plenty of thunder still in Marshfield.

    Picked up my wife and niece from the beach, it was a mass exodus with lightning bolts hitting the ocean, as they looked north.

  21. 0.54 in about 11 minutes. Thunder and lightning literally on top of each other and us and are house shaking. JPD thanks for warning on wind. I was tempted to leave umbrella up since we are not in warned area but thought better of it.

    This is most severe so far

  23. Storm just arrived in pembroke . Thunder shook the house !! Just in time to put my Omaha birthday steaks on the grill from my parents. I think I’ll be hungry later these suckers are small .

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