Wednesday April 14 2021 Forecast (7:52AM)

55 Comments

DAYS 1-5 (APRIL 14-18)

A weak area of high pressure provides a decent mid April day today before things go downhill. However, this downhill slide provides us with the best chance for widespread beneficial precipitation for a while, and we need that. It also brings the chance of some very late season (nearly post season) snowflakes for some areas. It all takes place as low pressure moving eastward from the Midwest redevelops south of New England Thursday night into Friday and matures rapidly. The upper level low pressure system associated with this system will contain plenty of cold air aloft and will be moving right across our area. This is a springtime set-up in which the cold air above can be drawn to the surface by the falling precipitation, which begins as rain everywhere. We’ll see a change over to snow at least in the higher elevations of southwestern NH and central MA, possibly northern RI. How far east and how low in elevation this at least mix and possible change can occur is still a little fuzzy and something we’ll have to watch closely as the system evolves. As it stands now, this should be a system that brings steadiest precipitation from mid evening Thursday to mid morning Friday, with the greatest chance of accumulating snow occurring west of the I-95 belt and north of I-90 during the darkness of the early morning of Friday. This system will also produce some gusty wind from the east during the time its producing its heaviest precipitation, which will then switch to north as it stacks with its upper level low and gradually pulls away during Friday. By Saturday, this system will be far enough away that we’re dry again, other than the chance of some lingering low level moisture enough for some drizzle/showers near the coast in the early morning, and perhaps a pop up shower during the day as a considerable amount of cloudiness will be present. A small area of high pressure will have arrived by Sunday which will make the “pick-of-the-weekend” for outdoor activity an easy one…

TODAY: Most clouds early to mid morning southwestern NH, central MA, and RI, with more sun to the east. Mostly sunny to partly cloudy all areas this afternoon. Highs 54-61 coast, 62-69 inland. Wind variable up to 10 MPH with coastal sea breezes.

TONIGHT: Variably cloudy. Patchy fog. Lows 45-52. Wind S to SE up to 10 MPH.

THURSDAY: Cloudy. Rain arriving in central MA and RI by late in the day. Highs 50-57, coolest coast. Wind SE 5-15 MPH.

THURSDAY NIGHT: Overcast. Rain, possibly heavy at times, changing to snow in higher elevations of southwestern NH, central MA, and mixing with or changing to snow in higher elevations of northern RI where some accumulation is possible. Rain may mix with snow eastward toward the I-95 belt overnight. Lows 35-42. Wind E 5-15 MPH but gusting over 20 MPH coastal areas.

FRIDAY: Cloudy with snow/mix/rain inland areas, rain coastal areas, tapering to snow/rain showers and areas of drizzle. Highs 38-45. Wind E to NE 15-25 MPH, strongest coast with gusts 30-40 MPH possible.

FRIDAY NIGHT: Mostly cloudy with rain showers and areas of drizzle. Temperatures steady 38-45. Wind NE to N 10-20 MPH with higher gusts, especially coastal areas.

SATURDAY: Cloudy start with lingering rain showers and/or drizzle eastern coastal areas, then mostly cloudy to partly sunny with a slight chance of a passing light rain shower. Highs 45-52. Wind N to NW 10-20 MPH with higher gusts possible.

SATURDAY NIGHT: Variably cloudy. Lows 37-44. Wind NW 10-20 MPH.

SUNDAY: Partly cloudy. Highs 55-62. Wind variable to S up to 10 MPH.

DAYS 6-10 (APRIL 19-23)

An area of high pressure slides offshore with fair, mild weather April 19. Next trough of low pressure moves in from the west with some unsettled weather April 20-21 before fair weather returns later in the period.

DAYS 11-15 (APRIL 24-28)

Unsettled weather threats most likely early and again late in this period with fair weather in between. Temperatures near to possibly below normal.

55 thoughts on “Wednesday April 14 2021 Forecast (7:52AM)”

  3. Thanks Tk . I have a job going in Duxbury Saturday morning it sounds like I’ll be able to get it in .

  4. Good morning and thank you TK.

    Delightful surprise yesterday with it making it to 63 at my house in JP. I don’t care what it was at the stinken airport!

  5. Thanks TK
    The NAM continues to be the most bullish model when it comes to snowfall. Is out to lunch or on to something??? I am thinking out to lunch.

  7. Question to the Mets here.

    How well do the models handle Dynamic Cooling?

    My gut says not all that well, due the number of times I have seen
    an unforecasted change to snow due to DC.

    Most Curious and thanks

    I am thinking that IF not for the ocean being 44 and the wind forecast to be ENE, even Boston would Snow. But the aforementioned conditions could keep the boundary layer just warm enough to prevent snow.

    Here’s hoping that the track changes just enough such that surface winds are more NE-NNE. That would do it.

  10. Tom,

    It seems it was your birthday yesterday. I neglected to pass along warm birthday wishes to you. Hope you had a great day!

  11. re: Dynamic Cooling

    IF I read the NWS discussion properly, they tend to use
    the 0C isotherm as the threshold for dynamic cooling
    to be possible.

    So that would be freezing or below at about 2,500 feet give or take.

    Well according to the 6Z NAM, 925 0C line is over or just East of Boston. Hmmm, interesting

    https://maps1.pivotalweather.com/maps/models/nam/2021041406/054/925th.us_ne.png

    GFS,on the other hand has that line more N&W

    https://maps1.pivotalweather.com/maps/models/gfs/2021041406/054/925th.us_ne.png

  12. Thank you, TK.

    No matter what happens Thursday into Friday there will be significant precipitation. We need it desperately.

    1. I do! Look at the set up. Look at the upper air configuration and the 850 and 925 mb temperature profiles.

  16. Will see if the NAM is on to something. For the valley and shoreline of CT to get that amount of snow for the time of year would be impressive.

  21. I should know this but sadly do not recall. Which one has had the best track record with amounts?

    Thank you

  23. Eeeerily similar discussion regarding snow same time last year almost to the day. I was making a snowman with my kids on April 18th

  25. Storm track just not quite far enough south for coastal plain snow. Wasn’t the April 1,1997 track off of southern New Jersey?

    1. It’s not really so much about the surface low position for these. It’s much more about the strength and positioning of the upper low.

  26. Philip just reading about the April Fools storm of 1997 the low pressure moved of the NJ coast on March 31st and began to rapidly strengthen.

  27. Be careful not to look at model guidance the way you would in January for a snow event. This is still an April event, regardless. I’ve chosen today not to waste too much time scrutinizing the individual models. Most of them are not going to do well here.

    Experience and a dash of the blend of models will serve a forecaster well I believe.

    What this isn’t: April 1997.
    What this also isn’t: April 1987.
    What this is sort of like: A displaced version of April 17-18 2020.
    Probably similar to others, but again I don’t try to find too many analogs because it takes away from trying to forecast the current event when you get too hung up on past events beyond the basics. 🙂

      1. As in OUT TO LUNCH! 🙂

        If this were Winter, I’d be really angry, Now, I don’t give a rat’s ass. I just want it out of here, so we can go back to some nice weather.

        1. Well at least there is that, and you don’t have to worry about finding a rat’s patoot! 😉

  29. I recall seeing snow on the side of I-95 on April 18th, 2020. I found that a fairly remarkable sight. And it was 10:30am. It didn’t accumulate in Boston, but it certainly did a little outside of Boston.

    Of course, I wish this was April 6-7 1982. But then again I’m kind of crazy (about snow and cold).

  30. I won’t feel bad if I miss out on the snow. If this was December through March I would feel different.
    I didn’t think the Red Sox were going to be in first place at any point this season. 8 wins in a row after an 0-3 start.

  32. As I hunt for a mosquito somewhere in the house that I missed, I am chanting ….snow….feet of snow….snow

  34. HELLO NAM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    https://maps1.pivotalweather.com/maps/models/nam/2021041506/036/ref1km_ptype.us_ne.png

    https://maps1.pivotalweather.com/maps/models/nam/2021041506/084/snku_acc.us_ne.png

    https://maps1.pivotalweather.com/maps/models/nam/2021041506/084/snodpc_acc.us_ne.png

    3KM NAM

    https://maps1.pivotalweather.com/maps/models/nam4km/2021041506/060/snku_acc.us_ne.png

    I must say that ALL other models keep the snow much farther to the West of Boston. So, is the NAM onto something OR is it far more likely the NAM is OUT TO LUNCH?

    I will say this: At the 11PM Broadcast, Harvey seemed a bit nervous about a possible more Southern track that could bring the snow farther East. To me, more reasonable than the absolute that this will be a rain event.

  35. oops just posted on COVID.

    repeating

    WSW out here in hillbillyville.

    Let’s see if it gets converted to warning which means maybe advisory pushes to north side of 495 near rte 2?

    Gut tells me 3-6″ maybe out here. I’m at ~900′ ish.

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