Tuesday February 21 2023 Forecast (7:24AM)

99 Comments

DAYS 1-5 (FEBRUARY 21-25)

Lots of unsettled weather in the forecast now as the pattern shifts away from what had been a mild and dry one to a colder, wetter one. Today, a low pressure wave passing just south of our region has spread a swath of rain (South Coast) and snow (elsewhere) across the region to start the day, resulting in some minor snow accumulating mainly on unpaved surfaces where it’s snowing. This will taper off as that wave moves away this morning. A cold front will sweep eastward across there region from late afternoon through evening with another period of precipitation, shorter duration but a little heavier, so some additional snowfall accumulation is likely in southern NH and northern MA, especially away from the coast, with more of a mix/rain situation in the I-95 belt and eastward from there. But this exits quickly tonight and with partial clearing, temperatures drop below freezing, so watch for icy conditions on any untreated surfaces, even where rain fell. Wednesday will be a dry day, but with clouds re-thickening as a small area of high pressure gives way to another approaching low. This is the start of a 1-2 punch of precipitation, the first Wednesday night into early Thursday, the second late Thursday to very early Friday. The precipitation profile will be complex as 2 low pressure waves moves just south of our region. The first one starts as snow most areas, mix South Coast, then transitions to rain South Coast but sleet and freezing rain elsewhere as the surface is cold but it warms up aloft. Expect some tricky travel in many areas and especially untreated surfaces for the Thursday AM commute. Another round of precipitation, again predominantly sleet and freezing rain except rain closer to the South Coast where it stays above freezing, comes at the end of the day Thursday into the early hours of Friday before tapering off. As the second low pressure wave moves away, an arctic cold front will come through the region on Friday morning, perhaps with a few snow showers at times during the day, even behind the front, but most notably a turn to much colder and windy weather through Friday evening. Bitterly cold Friday night and early Saturday and only a modest recovery keeping it well below freezing for high temps Saturday, but with less wind, and sunshine, so feeling more tolerable with a higher sun angle at this time of year. Next low pressure area wastes no time moving in so it may be snowing again by sometime Saturday night…

TODAY: Overcast through mid morning with a period of snow, accumulating a coating to 1 inch on unpaved surfaces I-95 northwestward, with mix/rain to the south. Mostly cloudy afternoon – rain/snow showers return from the west late-day, snow showers mostly north of I-90 with rain showers south. Highs 38-45 by midday but may fall a bit in the afternoon. Wind NE to E up to 10 MPH.

TONIGHT: Cloudy evening with snow showers of 1/2 to 2 inches north central MA and interior southern NH and up to 1/2 inch northeastern MA to NH Seacoast, with rain showers mostly south of I-90. Partial clearing overnight. Watch for black ice formation! Lows 23-30. Wind N under 10 MPH.

WEDNESDAY: Early sun, then clouding over. Highs 36-43. Wind N to NE up to 10 MPH.

WEDNESDAY NIGHT: Overcast. Snow/sleet/freezing rain likely, except possibly just rain South Coast. Lows 27-34. Wind N to NE 5-15 MPH.

THURSDAY: Cloudy. Sleet/freezing rain except South Coast rain early morning. Additional snow/sleet/freezing rain may return late in the day. Temperatures steady 27-34. Wind NE up to 10 MPH.

THURSDAY NIGHT: Overcast. Snow/sleet/freezing rain, maybe just rain for a while South Coast. Temperatures steady 27-34. Wind NE 5-15 MPH.

FRIDAY: Mostly cloudy to partly sunny with scattered to isolated snow showers. Temperatures steady 27-34 early, then falling to 15-22 by late-day. Wind NE backing to NW increasing to 15-25 MPH.

FRIDAY NIGHT: Clearing. Lows 5-12. Wind NW 15-25 MPH early, diminishing overnight. Wind chill below zero especially evening.

SATURDAY: Sun followed by increasing high clouds. Chance of snow at night. Highs 22-29. Wind N up to 10 MPH.

DAYS 6-10 (FEBRUARY 26 – MARCH 2)

Low pressure impacts with snow/mix and maybe some rain (precipitation types to be sorted out when storm tracks are better known) February 26, February 28, March 2). Temperatures near to below normal.

DAYS 11-15 (MARCH 3-7)

Additional unsettled weather including wintry precipitation opportunities around March 4 and March 6-7. Temperatures near to below normal.

99 thoughts on “Tuesday February 21 2023 Forecast (7:24AM)”

  6. Thanks TK.

    I will certainly go along with your opinion on the Wednesday-Thursday event, as I do always. 🙂

    A gazillion different snowfall maps in the coming days from the tv mets. Dr. S, start posting please, at your convenience of course. Thanks. 😉

  10. Thanks TK.

    Vicki – so glad your daughter has nothing seriously wrong with her and hope that with a neurologist they can solve the problem.
    Snowing here light to moderate with a light coating. Nice to see a pretty winter scene out our windows for a change!

  13. It’s beautiful this morning. I measured 2.25″ on both of my Official Snow Collection Surfaces – BBQ grill and picnic table bench. 😉

    1. Nice. No such luck here in the city, but at least it was
      snowing and it did manage to coat the ground. I guess that is something at least. 🙂

  14. On social media today again I see the focus on “snow amounts”. I still don’t get why this is such an obsession at the expense of knowing more important details like precipitation type, timing, and impact during event.

      1. Indeed.
        I mean sure inform about snow amounts too, that’s part of it, but DON’T skip important details. Thankfully our mainstream Boston media still does it right. Not sadly a lot more folks these days pay attention to the unqualified sources. 🙁

        1. I’ve been doing operational forecasting for nearly 25 years at this point. When a winter storm is coming, here is what DPWs and the like are most concerned about, in relative order:

          Timing of precipitation start
          Timing of precipitation end
          Timing of any changeover(s)
          Timing of the heaviest precipitation
          Temperatures during the event
          Amount of precipitation expected

          The amount is the least of their concerns.

          1. At least in my town, for both DPW and private services, amounts mean everything from a compensation and budgeting perspective.

            1. There are a few, but the vast majority, including Woburn, want SAK’s list before the final amounts. They want that, but it’s not as big a priority to most clients.

              My long time friend, who does snow removal for a huge business property owner, has always asked about those other details before final amounts.

              The rates, timing, and p-types are bigger concerns during the event.

              1. Exactly. They know they’re going to have to plow and/or salt/sand. What they are most concerned with is how long will they be out there (so they can plan properly), when will plows be needed more than sand/salt, when would be the right times to have sand/salt out there, when should they pre-treat the roads, etc.

                We had a blizzard that was hyped up big-time in late January, 2005. This was in the final days that I was at the company that TK and I worked out (before they got rid of the rest of us). We provided forecasts for Logan Airport at the time. After asking all of the questions about, here’s how the end of the conversation went:

                Logan: OK, what about amounts? I’ve heard all sorts of things. 1-2 feet? 1-3 feet? 15-25 inches? 10-20 inches? 2 feet or more? What’s the real story?
                Me: Let me ask you this, at what threshold do your operations change? If you’re going to get more than a foot, do you do things differently?
                Logan: Well, no, we’re going to be out there continuously once it starts snowing until it’s done, the amount really isn’t a big concern.
                Me: OK, then you’re getting more than a foot.
                Logan: OK, sounds good.

  15. Greetings all! No accumulation here at downtown crossing. Not to rub salt in a wound for JpDave and all the other avid snow lovers here, but I am delighted (as a snowphobic) to report that this is my first visit here this winter – there was no need before because no snow :-). Absent the likely cause (climate change and our rapid self inflicted destruction of our planet) I would say this winter is absolutely perfect for me so far! But I’m glad for everyone else that we have some upcoming action!

    Vicki – just seeing the comment above regarding your daughter – I hope everything is ok and that she’s healthy & safe!!!

    And hope everyone is having a great year so far!

    1. I just saw your comment, Mama. It is really nice to see you here. Kim is having a good day…hence my unleashed snarky comments. I’ve been holding it in for weeks and I think it exploded. Thank you

      I hope your family is well!!

  16. Worcester 18.9” Boston 7.9” (updated)

    I guess all I can hope for is that Logan can at least get into double digits for the season.

  17. Thanks, TK.

    I’ve given up paying a whole lot of attention to random social media comments. On the whole, I tend to have seen what Ace mentioned. Knowing start, stop, precip type, etc is sure very important. But with all of that, four hours of two inches has to be approached differently than four hours of 8+ inches.

    As far as our Mets, you know I agree. Their maps tend to be relatively similar, with exceptions of course.

    1. Still, knowing the rates, timing, start / stop, helps DPW and contractors plan more specific staffing.

      A lot of them get forecasts delivered to them in table form with all of the info, and of course a storm total too. But the hour by hour breakdown is most helpful for specific treatment and snow removal operations. 🙂

  19. I have to be away from blog for about 3 1/2 hours.

    I’ll check in late afternoon with an update on thoughts on upcoming events.

    Have a great afternoon. 🙂

  22. Do you think freezing rain will be much of a problem on Thursday in Natick area? Concerned about potential tree and utility issues. Thanks.

  23. Thanks TK.

    We had a about 0.5″ in Coventry this morning as well. Has now melted.

    12z GFS and Euro give VT, NH and ME a huge dumping of snow between the storms this week and early next week. They will be “rolling in the deep” if these model projections are correct. This refresher is much needed for the ski areas and should get most locations back to near 100% operational by end of next week.

    in SNE we will be closer to the boundary zone….less snow potential south coast and most potential as you get closer to the VT/NH border.

    12z GFS run total snow (Kuchera) thru 384 hours:

    https://www.pivotalweather.com/model.php?m=gfs&p=snku_acc-imp&rh=2023022112&fh=384&r=us_ne&dpdt=&mc=

    12z Euro run total snow (10:1) thru 240 hours:

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=sn10_acc-imp&rh=2023022112&fh=240&r=us_ne&dpdt=&mc=

    1. Note: probably some inflated numbers in that Euro snowmap across SNE as it is a 10:1 snow map. Those maps do not accurately account for sleet which may be the predominant precip type in many areas Thursday.

      1. With regard to ratios, I have been wondering what it would have looked like when Boston was -10F and there was abundant southern moisture available.

        30:1, 40:1, 50:1?

        1. Probably greater than 30:1 but it’ll be unlikely to really be tested outside of snow showers.

    3. If that boundary was setup further south, SNE would have the heavier snows. I wonder if that boundary is going to be “stuck” in the same position for the rest of the winter (March)?

      1. No, it wouldn’t, because the boundary has nothing to do with it. There is far too much warm air aloft.

        If the 700mb temp is around 0C (https://www.pivotalweather.com/model.php?m=ecmwf_full&p=700th&rh=2023022112&fh=48&r=us_ne&dpdt=&mc=&pwplus=1)

        and the 850mb temp is near or just below 0C (https://www.pivotalweather.com/model.php?m=ecmwf_full&p=850th&rh=2023022112&fh=48&r=us_ne&dpdt=&mc=&pwplus=1), you’ve got WAY too much warm air aloft for snow. You’ve got sleet at best, freezing rain at worst.

    1. No rain-snow lines. No forecasting complications. I imagine one of the easiest markets to forecast in, other than Southern California.

  25. The Wee hours of Thursday appears to be a battle of the Globals vs. the Short range and Hi res models.

    The former feature a longer period of snow and a prolonged
    period of sleet. The latter feature little or no snow and a short
    period of sleet.

    At this point, I would favor the Short range models and it would be more in keeping with this Winter so far to date.
    Just my lousy 2 cents for what it is worth.

      1. There are no models that show this as a completely rain event for Boston. And if any were I would discount them.

        They are not all rain for the entire event. They will have a variety of precipitation there as well even though they may luck out during the rain portion right in downtown and on the waterfront with temperatures above freezing.

        1. Although this might be a slippery mess for some, I am certainly not impressed by any of this. I just hope
          there is little or NO freezing rain.

    1. Well now we are bringing the colder air into what has been persistently mild and it isn’t always about the direct temperature but the contrast. Add to that the right atmospheric conditions and….

  30. From Ryan Hanrahan about that tornado warned storm in NJ

    Well this is how you get a tornado in February in New Jersey. 0-3km CAPE >100 j/kg and strong low level shear (0-3km helicity aoa 400 m2/s2). Not a big surprise to see some locally intense low-topped supercells.

  31. I don’t know if there will be a confirmed tornado in NJ today, but while having winter tornadoes in that area is rare, it’s not unprecedented. February tornadoes in NJ have occurred on 3 other known occasions between 1950 and the turn of the century, with the most notable being a mini outbreak of THREE tornadoes on February 2 1973. That is pretty remarkable. Pending today’s result, there have been no tornadoes in February in NJ this century yet. The last one was on February 12 1999.

  33. The tornado in New Jersey formed with air temperatures near 50 and dew points near 40. That is pretty wild. You’d think it would’ve been on a 60 or 70 degree day (which certainly happen there in February, as we’ve seen recently). Going to make a pretty awesome case study.

  34. The overall extent of high impact weather across the country right now is pretty astounding. Lot of the big cities in the East are being missed so the media coverage is somewhat muted, but there is a *lot* going on out there.

    https://www.weather.gov/

  35. Philip, forecasting in the Twin Cities can be difficult. It’s not at all like forecasting in Southern California.

    I concur that the Twin Cities area doesn’t have the same number of confounding or complicating factors as a coastal state like Massachusetts does (marine layer and all that). But, it’s not nearly as easy to forecast in Minnesota as it is, in, say, San Diego. Weather is very changeable in the Twin Cities, especially in spring and fall. On my many trips there I experienced all kinds of weather during 3-stay stays in April and May, for example. Also, sometimes Minnesota sits on the boundary between warm air to the South and cold air to the North, making forecasts quite tricky.

    1. I mean to comment on that earlier.

      Minnesota most certainly has rain/snow lines. Weather is not that clear-cut. And that area is very difficult to forecast, in some instances more difficult than New England.

      There’s a misconception that New England is the toughest place to forecast. Absolutely not. It’s not “easy” – far from that. But there are many other parts of this country that present equally tough or tougher challenges and more frequently than what we face here. Imagine trying to forecast a storied place like The Black Hills of SD. Let’s take a more populated area – Denver CO. Harder than New England. When I did ag weather the Texas High Plains were a royal PAIN IN THE BUTT to forecast. Busting temp forecast by 20, 30, degrees – not uncommon, especially if you don’t have a lot of experience. There are numerous others out there just as difficult if not more so than in this area. Some of the difficulty is a function of time of year and weather pattern as well…but that part is really no different than here.

    1. That one was still questionable anyway, given it’s beyond day 4. Don’t lock anything in (or out).

  37. Yet another dark day, like most days have been. This rain/ice stuff is just as depressing as the mild stuff. Sigh. 🙁

    The tv Mets keep emphasizing “no more 60s” but their extended forecasts don’t show 20s/30s either. Just lousy 40s, which doesn’t bring snow either. Oh well. 🙁

    Stupid La Niña!

  40. Golden Gate has been closed 3 times due to wind. Once in 1959, once in 1982, and once in 1983. The original construction was for safety in winds up to 68 MPH, which was probably not the greatest decision given the types of storms that can slam the West Coast, however in defense of planners, tech / material may have made it impossible to do “better” at the time it was constructed. I’m no expert on this – just an idea. But currently the bridge has been improved to withstand 100 MPH wind gusts.

    1. I saw the three times but wasn’t sure if it had been retrofitted, I thought it had been. But considering that was recent, in its existence to have only closed three times says a lot for the design back in 1937. My guess is the technology was not as sophisticated 86 years ago.

      1. Definitely improved since then on the tech end!

        I read briefly that the most recent upgrades were around 2019/2020. 🙂

    1. It drains the shallow surface cold layer a bit further south than the previous run during the daytime hours on Thursday, when there is no precipitation around.

      2. While the model doesn’t show any precip, I think there will be enough low level moisture hanging around. On all the local forecasts I’m writing tonight, I’m leaving in some occasional freezing drizzle and sleet through the daytime hours on Thursday.

    1. Apparently the Euro got a hold of my bag of conversation hearts and ate the whole thing……………..

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