Tuesday Forecast Update

99 Comments

7:28AM

DAYS 1-5…
Low pressure passing north of the region through early Wednesday drags a warm front / cold front combo through southern New England from west to east and takes through early Wednesday morning to get all of its areas of showers and thunderstorms through the region. Though no severe weather outbreak will occur, a few of the heavier cells may produce strong enough wind gusts for minor wind damage, and also some torrential rain with local flash flooding. This most widespread rainfall will come in the late morning through mid afternoon hours from west to east followed by more scattered activity after. Upper level low pressure with colder air aloft will allow for a few diurnal showers and thunderstorms to form on Wednesday though most of the day will be rain-free. High pressure brings fair weather Thursday and Friday before another front slides through with a chance of showers/thunderstorms on Saturday.
TODAY: Cloudy. Numerous showers and a chance of thunderstorms developing from west to east by late morning, then becoming more scattered from west to east by later in the day. Humid. Highs 68-76, coolest immediate coast. Wind SE to S 10-15 MPH gusting above 20 MPH.
TONIGHT: Mostly cloudy. Episodes of showers and thunderstorms. Humid. Lows in the 60s. Wind SW 5-15 MPH with higher gusts.
WEDNESDAY: Variably cloudy. Lingering showers/thunderstorms Cape Cod early. Isolated showers/thunderstorms possible anywhere in the afternoon. Highs 77-84. Wind W 5-15 MPH.
THURSDAY: Mostly sunny. Lows 56-63. Highs 75-82.
FRIDAY: Partly cloudy. Lows 56-63. Highs 78-85.
SATURDAY: Partly sunny. Chance of showers/thunderstorms. Lows 60-67. Highs 80-87.

DAYS 6-10 (AUGUST 16-20)…
A couple episodes of showers and thunderstorms possible during this period but much of it will be rain-free with more humidity and near to above normal temperatures.

DAYS 11-15 (AUGUST 21-25)…
High pressure ridge becomes more established with late August heat and humidity possible and limited rain chances.

99 thoughts on “Tuesday Forecast Update”

  1. Thanks TK !

    The 00z EURO continues more of those signs of returning summer warmth in the long term.

    On this particular run, from days 5 thru 10, the 850mb temps are consistently 15 to 20C

    The GFS isnt as bullish.

    1. Tom,

      I quickly read your post and thought that at the bottom you said
      “The GFS is Bullshit” 😆 😆 😆 😆

  2. RE-POST

    Old Salty says:
    August 11, 2015 at 6:33 AM
    JJ You have posted all that I was going to post.
    Interesting.

    Here is the latest SREF HELICITY charts for this PM. 21Z seems most robust.

    http://www.spc.noaa.gov/exper/sref/gifs/latest/SREF_1KMHEL_SSB_MEDIAN_MXMN__f018.gif

    HRRR for 19Z

    http://mag.ncep.noaa.gov/data/hrrr/09/hrrr_east-us_01000_helicity_1km.gif

    HRRR 0-3KM helicity 19Z

    http://mag.ncep.noaa.gov/data/hrrr/09/hrrr_east-us_01000_helicity_3km.gif
    Reply
    avatarOld Salty says:
    August 11, 2015 at 6:35 AM
    On the other hand, last night’s 0Z Vorticity Generation Potential chart
    says what’s all the fuss. A general .2 on the index.

    http://www2.mmm.ucar.edu/prod/rt/wrf/wrf20/2015081100/vgp.hr21.png
    Reply
    avatarOld Salty says:
    August 11, 2015 at 6:39 AM
    However the LCL is VERY LOW.

    The LCL (Lifted Condensation Level) is the pressure level a parcel of air reaches saturation by lifting the parcel from a particular pressure level.

    3. Operational significance of LCL:

    Cloud bases: It determines how far air needs to be lifted to produce clouds.

    Tornado: In a supercell thunderstorm situation, a low LCL (closer to surface) increases the likelihood of tornadogenesissince the region of CAPE will be closer to the surface.

    http://www2.mmm.ucar.edu/prod/rt/wrf/wrf20/2015081100/lcl.hr21.png

    Also please note on the SREF, the significant tornado ingredients
    has nothing. The significant tornado parameter is 1 for only 1 or 2 ensemble members and is basically non-existent.

    Some conflicting parameters.

    IF we had this set up with the CAPE, LI and severity of the
    storms last week, there certainly would have been a tornado somewhere.

    Today, a remote chance I suppose, but the risk is very low imho.

    Will watch for any changes later.
    Reply

  4. Latest from Taunton at 8AM

    THIS COMBINATION OF STRONG DYNAMIC LIFT/INSTABILITY/HIGH
    MOISTURE SHOULD SUPPORT SHOWERS AND TSTMS. LOCALLY HEAVY DOWNPOURS AND STRONG WIND GUSTS /TRANSLATED DOWN FROM THE SOUTHERLY JET/ WILL BE A CONCERN THIS AFTERNOON AND EARLY TONIGHT. LOW LEVEL HELICITY VALUES OF 150+ ON ALL THE MODELS SUGGEST SOME TORNADO POTENTIAL AS WELL.

    1. From Upton NWS office at 7:34 AM

      THERE WILL ALSO BE BE A MINIMAL SEVERE WEATHER THREAT WITH THE WARM FRONTAL PASSAGE THIS MORNING AND EARLY AFTERNOON. GIVEN AFOREMENTIONED INSTABILITY AND STRONG 0-1 KM SHEAR WITH STRONGLY VEERING LOW LEVEL WINDS AND LOW LIFTING CONDENSATION LEVELS…STRONGER CELLS COULD PRODUCE DAMAGING WINDS OR A TORNADO.

      1. From the Weather Channel:

        Tuesday, August 11, 2015
        Scattered severe t-storms in south VT, south NH, MA, CT, RI, east NY, NJ, east PA, DE, east MD, east VA, east NC, central and east SC, east GA. TOR:CON – 2.

  8. Thanks tk:)

    Best kind of rain, a light to moderate garden variety rain that will soak into the ground. Perfect!!!

    1. It does look decent. Certainly much better than last week’s rain.

      We shall see IF there is any wind damage. So far, it just doesn’t look like
      that kind of system, although there is time for that to change.

  9. Next weekend begins the season of Fall/aeration and over seedings. I have 211 scheduled that will last through the end of Sept, I can add only about 50 more. 🙂

  10. Question for all.

    Is this batch that is just about upon us, just from the warm front.
    After this moves through, is it expected that the atmosphere destabilizes
    for more convection this afternoon? That was hinted in the Upton NWS discussion.

    This is coming through fairly late. I am skeptical. We shall see. 😀

  12. This appears to be the warm front. Later looks more hit or miss with any showers and storms. Will have to see if the atmosphere could recover and destablize for a couple stronger storms later.

    1. This is such a slug of rain, I don’t know about destabilization.

      If this were several hours earlier, yes. Now? Marginal.

    2. This rain won’t move out till 2-3pm, thinking by then it’s just to late for that to happen imho

        1. I am Wrong and Charlie is likely correct.
          Looking at HRRR, this slug of rains sticks around until
          after 2PM, perhaps until 4 or 5PM, then it gets hit and miss after that.

    1. If not rain, then clouds. So yes, likely, imo. TK can better answer that of course.
      Perhaps a viewing break or 2 here and there.

  15. GFS = too troughy in the medium range.
    ECMWF = too troughy in the short term.

    This simple fact is one of a few reasons that I have always thought today would be wetter than tomorrow when many outlets initially had it reversed.

    Guidance not Gospel.

  17. I guess there were a couple of rip current water rescues near Rexhame Beach in Marshfield yesterday per ch 7 news. I believe it, those were some of the biggest waves seen probably since winter or spring storms.

    1. According to the latest HRRR, any additional convection does fire
      in Western sections, but goes POOF as it moves Eastward into a region
      with little if any instability. And so it goes and so it goes.

      1. It appears most of the steady stuff moves offshore over the next couple of hours followed by hit and miss garden variety showers and storms. I’m not confident there will be enough instability behind the front for a widespread weather event in its wake.

        1. Certainly not in Eastern sections. There is a possibility
          in Western Sections. In fact the HRRR shows some
          rather robust convection out that way later on.

  22. Not sure if anyone has their radios on the past hour or so and noticed anything strange but a very strong E skip opening is in progress with FM stations from Florida, Georgia and other states down south being heard right now. For instance right now no sign on WAAF on 107.3 just WCGQ from Columbus Georgia.

      1. Actually not all that strange. From late April through August this type is fairly common. Some years more than others. I’ve logged over 2000 FM stations from around the country with this type of propagation. Still going strong more toward Memphis and Arkansas now. This type of propagation happens when a patch of the ionosphere gets really ionized. Locations in Memphis and Arkansas are more than likely getting us too…it’s a two way street. Another type of propagation involves tropospheric ducting which involves different layers of humidity, etc getting trapped at different levels of the atmosphere. FM signals can travel up to a thousand miles but usually more like 200-600. Eskip can cause signals to travel up to 1500 miles…

          2. Hey – I love seeing your name there. Certainly not shamelss self promotion at all. And very interesting read. Thank you.

  23. I am expecting a snoweir than normal winter starting in December. It could beat last years snowfall. Just a guess.

    I do look forward to the cool nights and crisp days of fall.

    1. Agree on looking forward to cool nights and crisp days.

      Can’t say I expect a snowier winter in 2015/2016 than 2014/2015. That would be unbelievable, given the records broken last winter. Maybe you mean a snowier December. I certainly expect that. In fact, I think the upcoming winter will feature 6 to 8 snowstorms, spread out over a 3-month period, but each storm will be relatively small (4-6 inches).

  24. ARGGGHHHH |On air radio station talent (DJ’s, etc) should not be allowed to interpret or ad lib the weather forecasts or try to figure out what the radar means…ARRGHHH. Ok I feel a little better now.

  25. Right now I am thinking 20-25 inches of snow for Boston for the upcoming winter. I hope I am wrong but I am not excited for a big snow season at the present time.

  26. 12z runs continue warm to hot theme in the medium range.

    Think 90F may start showing up on day 6 or 7 in tonight’s weathercasts’ 7 day forecasts.

  27. I was saying the other day were not going to go the rest of summer without another blast of heat and humidity. In terms of heat and humidity this has not been a bad summer so far.

    1. had a very brief glimpse of the sun about an hour ago here…still spitting out at times. The rain across southeastern sections of the state is moving slowly and the radar seems to be showing a little breakup of the line of storms that seemed to be forming in eastern NY.

  30. The line to the west will do a decent job holding together for a while then start to gust out as it accelerates eastward a little later. I’ll monitor to see what it looks like heading east. I expect it to be less intense but possibly wider in terms of coverage…

    Also there is some decent support for storms in eastern areas tomorrow afternoon. Will be re-evaluating this evening.

  31. Re-evaluation: Yeah, no. It’s not going to do a lot of surviving eastward…the line, that is. We may see brief intensification of a shower/storm cluster near or just south and east of Boston over the next few hours. Keep an eye out there.

      1. Not really. It’s just moving into an area that had little or no sun and is relatively stable. The other axis of instability is much further east. Ironically, some of it is over the Boston area now, popping showers and maybe even thunder in a few locations eventually, but this will be offshore by the time that line would get into the region.

        1. Absolutely spectacular complete double rainbow over Humarock. I am trying to get daughter to post on FB so I can share

    2. I gave a range of 0.25-0.75 widespread with pockets of 0.75-2.00 inches. Actually fell in the expected range in just about all areas.

        1. Coastal, since no ass would be .25″ to 2″, there most certainly is no ass covering here. Unless there are babies here of course . . . But I digress.

  34. Raining again in Boston. I think that in Boston we get to about .75 or so for today’s rainfall. Then we’ll add a little tomorrow. Better than nothing.

  35. Again today I fail to understand why they were talking-up severe storms from the offices in the Northeast as well as the SPC. I can see that there was the possibility of an isolated strong wind gust and some minor damage if things had set up just right, but that was a stretch. The risk of anything was minimal at best, yet they still managed to even be talking about tornadoes.

    It’s now safe to say that the NWS is a shell of its former self. I’m not sure the reason. What I am sure of is the public is going to not believe something when they actually should. That spells trouble.

        1. Snowfall contest summer edition. We should have predicted how many times this summer NWS would mention tornadoes…

          1. Who would have been responsible
            For the count???
            I love it. Probaby too late now.
            Next year perhaps.
            Modify to count number of days
            Mentioned in case some updates are missed.
            Spin ups count. What about rotation?

    2. They do that so everyone on here can pretend we are gonna get tornadoes, it’s like clockwork, no offense to anyone on here or Taunton. 🙂

          1. There were a few odd comments on here today. I thought maybe the blog had been hacked by a middle school computer wiz … 😛

  38. As expected, the line to the west indeed tried to expand its coverage while weakening. Now, it will shrink as it rains itself out. The stuff to the east is offshore. The exception is a little instability left in eastern CT to western RI where a few new cells may briefly flare up through midnight. This may reignite around Cape Cod overnight and exit in the early morning. Most of the rest of the region is essentially done.

    Precipitation amounts were pretty much as expected, though even heavier on parts of Cape Cod. Severe weather was non-existent. No surprise there.

    Now we’re heading for a period of above normal temperatures and below normal precipitation in the next 15 days. Time for the top soil to parch out again, except possibly in areas that are lucky enough to see some thunderstorm activity tomorrow and again Saturday. However, I’m having my doubts on that Saturday system now.

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