Wednesday Forecast

42 Comments

7:41AM

DAYS 1-5 (MAY 13-17)

A chilly start this morning – you felt it sting a bit if you were out there early. This, I can safely say, is the last “cold” morning of the spring, in terms of genuine chilly air with polar or arctic origin that isn’t modified enough not to have a bite. The upcoming weather pattern prevents another such event soon, and beyond that, climatology says “nope!”. Now this does not include the kind of chill you can get with a heavy overcast and a wind off the water. We haven’t actually seen much of that this spring, other than during some passing low pressure areas to the south, but we can still see some of that, but not in the next few days at least, as we experience a bit of a warm up through Friday. This will not come without a price though. First we do have a nice albeit cool and breezy day today, sunshine dominant but some clouds forming and passing by in the wind . Thursday’s going to be noticeably milder, but there will be some increase in high and mid level clouds as previously mentioned, due to the warming atmosphere. This will lead to a period of rain at night as a warm front approaches. Will this front make it all the way through the WHW forecast area? I think so, but it may take its time getting by the NH Seacoast, so if that area ends up somewhat cooler than my high temperature forecast for Thursday, or doesn’t reach those highs until late afternoon, don’t be surprised. Friday will be an active weather day at both ends, with early wet weather from the warm front, and mid afternoon to evening showers and thunderstorms with a cold front. Friday’s high temperatures and intensity of thunderstorms are both depending on how much sun we see during the middle portion of the day. More sun = warmer and stronger storms. Less sun = not quite as warm but less potent storms. Not looking for a widespread severe weather event but just something to watch. What about the weekend? Mostly good. A tad cooler but still very nice, and dry Saturday, with the coast likely coolest of all. Sunday probably clouds over, at least as a low pressure area approaches from the west, being in the Great Lakes at that time. A wild card is whether or not we bring lower clouds in off the ocean as the wind will be turning southeast to east by then. Wet weather may arrive before the day is over as well from the system to the west, but the bulk of it should hold off til night.

TODAY: Sun and passing clouds. Highs 55-62. Wind NW 10-20 MPH.

TONIGHT: Mostly clear. Lows 43-50. Wind W 5-15 MPH.

THURSDAY: Partly sunny. Highs 63-70 except 55-62 South Coast. Wind SW 5-15 MPH.

THURSDAY NIGHT: Clouding over. A period of rain likely. Lows 48-55. Wind SE 5-15 MPH.

FRIDAY: Variably cloudy. Risk of showers and thunderstorms. Highs 55-62 South Coast, 62-69 East Coast, 70-77 interior. Wind SW 10-20 MPH except may be lighter and still SE near the NH Seacoast for a while.

FRIDAY NIGHT: Lots of clouds and a risk of showers early then clearing. Lows 48-55. Wind shifting to NW 10-20 MPH evening, diminishing overnight.

SATURDAY: Sun and a few clouds. Highs 56-63 coast, 64-71 interior. Wind variable 5-15 MPH with sea breezes.

SATURDAY NIGHT: Partly cloudy. Lows 43-50. Wind variable under 10 MPH.

SUNDAY: Mostly cloudy. Risk of rain late-day or night. Highs 55-62, coolest coast. Wind SE-E 5-15 MPH.

DAYS 6-10 (MAY 18-22)

May 18 looks unsettled as low pressure sits south of the region before moving away – this would result in damp and cool weather but not sure how much rain at this time. Leaning now toward a slower evolution and departure of low pressure, so unsettled/chilly weather may linger into the middle of next week before brief improvement, but the end of the period while warmer may end up showery with a system from the west.

DAYS 11-15 (MAY 23-27)

Watching for high pressure in eastern Canada which may put a boundary between cool Canadian air and much warmer air to the south nearby. Don’t infer 5 unsettled days from this, but day-to-day weather can’t be determined with this pattern. Just expect variable conditions.

42 thoughts on “Wednesday Forecast”

  1. Predicted low at Logan: 37.

    Observed low at Logan: 37.

    Old record low of 38 from 1882: gone.

      1. Understandable that the BZ person may have thought that.

        At each ob time, the low appears to be 38F.

        But, at some point in btwn, it got down to 37F.

        Up top, last 6 hrs max and min temps are 44 and 37F.

        This happens a lot with high temps too and sometimes you see an official 90F day in the summer, yet the obs would make you think the high was 88 or 89F.

        https://r.search.yahoo.com/_ylt=AwrEzeaX67teyPkA2yFx.9w4;_ylu=X3oDMTByOHZyb21tBGNvbG8DYmYxBHBvcwMxBHZ0aWQDBHNlYwNzcg–/RV=2/RE=1589402648/RO=10/RU=https%3a%2f%2fw1.weather.gov%2fdata%2fobhistory%2fKBOS.html/RK=2/RS=D1P_Z8TdZm9c9GKtX7nwOcMivf4-

  8. The 12z NAM really lines up well with the Severe Weather Outlook JJ posted above.

    Best Cape (instability) is down by southwest CT and eastern NY state.

    Position of low shows warm sector makes it into eastern NY State and western New England. (Warm sector struggling to get into eastern areas).

    Looks like timing of cold front approach may be slowing a bit to 5 to 8pm ???

  9. Tom looks like what you would expect when it comes to strong to severe storms for this time of year with areas in Eastern NY and Western New England having the best shot at them. When this is suppose to happen is the two year anniversary when we had four tornadoes happen in CT. The one thing that looks different to me than the setup May 15, 2018 no elevated mixed layer appears present at this time.

    1. Exactly regarding the time of year.

      I believe you with comparison to the May, 2008 event. I have a lot to learn about severe weather.

      I don’t really know about elevated mixed layers and how they impact severe weather.

  10. Some of our big weather events here in SNE have come with an elevated mixed layer present. May 15,2018, The Springfield Tornado of June 1, 2011 and July 10, 1989 come to mind.

  11. The area under the marginal risk should just keep an eye on at this point. I know I will be as I can’t wait to start tracking thunderstorms.
    Ryan Hanrahan latest tweet for Friday for areas in that marginal risk
    Model sounding for Friday reveals potential for severe weather with strong overlap of instability and wind shear. Hail, strong winds and a tornado possible.

  12. Eric Fisher, on a tweet this morning ….

    what could go wrong department: sub tropical storm Arthur could form, linger offshore and prevent a bigger warmup next week.

    In 2020, in the what could go wrong department:

    It develops into the strongest subtropical storm ever in recorded history and makes a b-line straight into southern New England.

    1. Clarifying :

      the 3rd and 4th paragraphs are my take on what could go wrong with the disturbance offshore that the NHC has identified.

    2. The WPC, in its 3 ro 7 day outlook, predicts 55F, 54F and 58F for Boston next Monday thru Wednesday.

      The good weather news just keeps a coming !!!!!

      1. Meanwhile, the ice box of the nation, International Falls, has predicted for next Monday, 74F, 79F and 78F.

        I just love living in eastern New England in Spring …….

  13. Thanks, TK…

    Overnight low of 33.1 here. Up to a pleasant 54 right now.

    If Tropical Cyclone Nana forms and then dissipates later this year, will we sing,

    “Nana, Hey, Hey, Goodbye”?

    I am sorry.

  14. 12z NAM and 12z GFS ….

    I wouldn’t want to forecast temps for Logan and the north shore, maybe even the south shore on Friday.

  15. quite a lot of rain from the 12z GFS early next week. Some interaction with subtropical feature, I don’t think a lot of moisture entrained into mid-latitude low, but it captures the sub-tropical feature and sends it northeastward.

  16. Both 12z runs of the American models want to bring in mid 60 dew points for Friday across the interior of SNE. GFS increasing the CAPE ( Convective Available Potential Energy) for Friday parts of interior CT and MA. NAM has the best CAPE I-84 corridor points north and west. The NAM as always going bonkers with the supercell composite.

  17. I took a break from school work and took a ride.

    Beautiful out, nice sunshine, hot car, but ……. its still chilly out. The thermometer says 55F, but these 19F dewpoints just give the air a quite cool edge.

    The groundhog was wrong, he/she should have said 6 more weeks of winter beginning April 1st.

    1. Nice Tom. It is amazing how good a ride feels.

      Kids here are back in bathing suits and setting up slip and slide. Brrrtrr

  18. Looks like we’ll work some decent warmth into SNE for at least Friday, a little cooler at the coast. Saturday may be pretty nice as well, but that one’s dicier especially at the coast. Beyond that though… man, there are going to be some *ugly* days next week. Really just a question of how many, and how many are just “cool” vs. how many are downright cold and wet.

    For Friday severe potential, west will be the place to be. Doesn’t look like an outbreak day or anything like that, but probably some storms and a couple of stronger ones.

    1. This is the inverse narrative of the long range cold projections over the winter, as all the models have been trying to rush the warmth in too quickly. We’ll get there eventually, but not in the next 7 days. The sort of evolution that may spawn “Arthur” has been strongly supported by the large scale teleconnections for some time, and should’ve been a major red flag for the warm predictions. The last 7-10 days of the month look much more promising to me though.

      1. This is what I was referring to several days ago that the GFS had picked up on around the 18th-19th with 132 hours of measurable precip in SNE and temps in the 40s and 50s compared to the 70’s to near 80 the ECWMF was spitting out. Now it has flipped a bit with the ECMWF. Still cool, but drier than its European counterpart. I think next Monday-Wednesday are cool with Monday-Tuesday being the wettest, but once you get inland by Wednesday, I don’t see it being quite so miserable. Not great, but moderating temps and relatively dry. The ECMWF has been just plain bad with temps during any time period this spring and has hung on to precip far too long in the 120-168hr time frame for all of 2020.

        As I have written several times May would have more good days than April and May normal is way better than April normal. I still don’t see great consistent summer like weather, but this more zonal flow is going to better than most anything we “enjoyed ” in April. Further inland you are, the better the days will be.

        1. Agreed, I think we can limit the worst of the damage to Monday-Tuesday and trend better from there, slow at first but maybe more dramatically by the following week.

  19. I’ll gladly accept a few good soakers to keep the pollen counts down. May is a missrable month for me with allergies!

    1. Thanks Vicki for passing this along, we will have to keep our eye to the sky around 12:30!

      1. The flyover in MA didn’t come this way. I’m hoping you get to see. They are such a thrill. And amazing that they are doing this.

  22. TK – Has Logan ever broken (not just tied) a record low temp in this current century up until this morning?

    It seems during every season of a year Logan is breaking (if not smashing) record “high” temps without a problem. A definite sign of global warming/climate change obviously.

    1. Yes they have, but the last 2+ years that was sometimes (and sometimes often) because their thermometer was 2 degrees too warm, so a handful of those high temperature records are actually still not broken. So saying that is a definite sign of gw/cc based on one station would be an incorrect assessment. It is correct, however, if you look at MANY stations, that in the last 2 decades there have been more high temp records set than low temp records.

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