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MAG5035

Meteorologist
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Posts posted by MAG5035

  1. Was going to call a final a bit ago but still getting quick bursts of moderate to heavy snow with the lingering scattered precip. 

    1 hour ago, CarlislePaWx said:

    For the few of you who melt down your snow, such as @Cashtown_Coop, I'd love to hear from you.  I think you'd all be interested to know that this storm had the highest SLR of any event this season.  I measured 2.8" of pure snow and it melted down to 0.20" of liquid.  This produced a ratio of exactly 14 : 1.  I don't think any other event this winter had a ratio that high.  Most of my other events were all around 10:1.  So, another anomaly from this storm.

    I was curious about this as well, as I did mention last night just a couple degrees colder on the low level temps might make a difference between 10:1 and <10:1 and higher amounts. There  definitely must have been some good snow growth with at least the front part of the event and those colder low level temps meant the flakes didn't get rimed or anything like that. This thing arriving a bit early helped too. 

    • Like 3
  2. On 2/20/2021 at 5:05 PM, MAG5035 said:

    This looks like a quick hitting advisory type event, like a 2-3" scattered 4" type deal for most with perhaps more frequent higher amounts (4-6") a better possibility in the Laurels, I-80 corridor, and Poconos. Also need to consider the possibility of a weak spot in the south central counties between I-99 and I-81 (Bedford, Fulton, Franklin, maybe southern half of Huntingdon, etc.) where could only be a 1-2" type snowfall. Low stays NW of PA on a general westerly flow so that typically invites the probability of some downsloping in that aforementioned area, and it has been showing up on most model guidance. Could only be 1-2" in the LSV as well, and I'll explain that below. 

    Timing and temps are another concern, esp LSV below the turnpike. This appears to be a late morning to late afternoon/early evening hit, so rates better be good there with marginal low level/surface temps. I often find that after about the 2nd week of February or so it's like flipping a switch with respect to solar input (ie the sun angle)...not yet with heavier and/or cold storms, but with clear days and light events with marginal temps (specifically ones in the middle of the day). NAM once again the warmest, bringing mixed up into the LSV. Showing ZR as primary p-type but I would imagine any icing would be limited in scope if it were in fact liquid precip. And considering how thermals have went in the other two events this past week (even though the M/D simultaneously got their 4-6" of snow and still had mixing all the way up through MDT with Thur), I'm inclined to seriously consider the NAM in that regard. So ideally, a good shot of heavy precip up front would at least secure getting a couple of inches. Ratios might be <10:1 as well. Kuchera maps have actually looked a bit worse than the 10:1 maps, and while Kuchera method applies a fairly simple algorithm for calculating the ratios it is generally picking up that the temps 850mb to surface are a bit marginal. 

    Bringing this post back up from yesterday as my thought's really haven't changed too much on it and neither has guidance. Still seeing the weak spot in the aformentioned part of the south-central between I-81 and I-99. Still should see at least a quick 1-2" up front there though.   

    Biggest thing is this does look to take the whole LSV as a period of snow up front and how aggressive the rates are is going to ultimately determine impacts and accumulations. Sped up a tad too, with this looking to get into the Sus Valley by mid-morning so if it comes in gangbusters it's obviously going to screw the roads up pretty good. A couple degrees colder in the low levels might be enough to realize 10:1 instead of <10:1 ratios so all of the Sus Valley looking pretty solid on that 2-3" scattered 4". The wave of snowfall is probably done in 4-6 hrs tops, with any lingering precip east of the mountains likely in the form of some scattered showers later in the afternoon. 

    • Like 2
  3. 19 hours ago, pirates21 said:

    Great pics. You should take a ride up top of Wopsy. Looks similar to Blue Knob. Really beautiful with the snow on ice covering everything. The large pine trees covered with snow and ice are gorgeous 

    I did just that not too long ago, it definitely didn’t disappoint haha. It really sticks out with the clear skies today, I wish I could load the full quality pics on here. It’s always wild the difference 4 miles and 1100’ of elevation makes. 
     

    Top of Wopsononock Mtn west of Altoona
     

    05A348F1-247B-4C0D-9CBA-6076194C4B24.thumb.jpeg.3d3c0b82d6c0a9e9e1a23a2345d45ad3.jpeg76E7E8DD-07E2-41C4-9F5A-E5704AC989AB.thumb.jpeg.2e6b29c3e9b485a76763dc05bbadfa47.jpeg36CD9C5E-9509-4E99-873D-BA0E8AEA2120.thumb.jpeg.3a92801fcda0ff80fb5266251eb12740.jpegBC1BBAE0-0FC1-4388-BDCF-71A2C7B4870B.thumb.jpeg.9afd145ecc179a73cc9d68c3a9d127b3.jpeg7D289DED-D098-4D8E-8372-5AA6A55A86C2.thumb.jpeg.48ace880256cbc9e9d04fb6a44434457.jpeg9FD908FC-28F5-4085-BD07-4443F9CFAA72.thumb.jpeg.225509594965b6e135fb81b306fb6234.jpeg


     

     

    • Like 5
  4. 3 minutes ago, Blizzard of 93 said:

    @MAG5035

    What do you think of the Monday snow potential?

    This looks like a quick hitting advisory type event, like a 2-3" scattered 4" type deal for most with perhaps more frequent higher amounts (4-6") a better possibility in the Laurels, I-80 corridor, and Poconos. Also need to consider the possibility of a weak spot in the south central counties between I-99 and I-81 (Bedford, Fulton, Franklin, maybe southern half of Huntingdon, etc.) where could only be a 1-2" type snowfall. Low stays NW of PA on a general westerly flow so that typically invites the probability of some downsloping in that aforementioned area, and it has been showing up on most model guidance. Could only be 1-2" in the LSV as well, and I'll explain that below. 

    Timing and temps are another concern, esp LSV below the turnpike. This appears to be a late morning to late afternoon/early evening hit, so rates better be good there with marginal low level/surface temps. I often find that after about the 2nd week of February or so it's like flipping a switch with respect to solar input (ie the sun angle)...not yet with heavier and/or cold storms, but with clear days and light events with marginal temps (specifically ones in the middle of the day). NAM once again the warmest, bringing mixed up into the LSV. Showing ZR as primary p-type but I would imagine any icing would be limited in scope if it were in fact liquid precip. And considering how thermals have went in the other two events this past week (even though the M/D simultaneously got their 4-6" of snow and still had mixing all the way up through MDT with Thur), I'm inclined to seriously consider the NAM in that regard. So ideally, a good shot of heavy precip up front would at least secure getting a couple of inches. Ratios might be <10:1 as well. Kuchera maps have actually looked a bit worse than the 10:1 maps, and while Kuchera method applies a fairly simple algorithm for calculating the ratios it is generally picking up that the temps 850mb to surface are a bit marginal. 

    • Thanks 1
  5. 2 minutes ago, Cashtown_Coop said:

    @MAG5035 Nice pics.   I went for a drive yesterday and at 1600ft ran into what I know now after looking at your pics rime ice on the trees.    It almost reminded me of hoar frost

     

    That looks like a lot of snow down there too at that elevation. Yea it was a combination of rime ice near the summit which is in clouds a good bit (over 3100' at the top) but alot of it was also the new snow sticking directly to the iced trees too. It looked like they had a significant amount of ice up there from that ice storm even for their standards, and since there was never any strong warm push at what is essentially the 925mb level at the top of the mountain there, most of it didn't melt. 

  6. 23 minutes ago, Blizzard of 93 said:

    @MAG5035

    What are your thoughts on round 2 tonight into tomorrow?

    It does seem like the stuff around is being somewhat under represented on the HRRR but it's still fairly patchy so I don't think we'll end up with as much as some of the models have tonight. I think for the most part an inch or less but perhaps we can get a band setup that drops some localized 1-2" amounts. The best action seems to be staying NW of I-81 for now as well, with it actually snowing half decently here currently. It's been snowing off and on enough this evening that it's got most of the streets and secondary rds icy again. 

    Board was cleared this afternoon right after it started snowing off and on after 2pm. 2.9" fell before, and just measured 0.7" so far since for 3.6" on the event. That makes a 44.1" current season total on those measurements. I generally consider the 45-55" range as average-ish for this end of Altoona right against the Allegheny Front so looking pretty good for Feb 18th. 

    • Like 1
  7. 51 minutes ago, pirates21 said:

    Starting to pick up pretty good over on the other side of the city Mag. I’m near 99. Covering cars now

    Yep same over here, a nice moderate pixie dust snow for now. Getting this early swath of snow to set over the area is gonna be a big part of hopefully getting pretty well into our forecast range of the advisory (3-7"). I think we're in pretty good shape. There's a patch of some more enhanced echoes on radar over JST that should try to shift this way here within the next hour or so. 

    • Like 2
  8. 11 minutes ago, Cashtown_Coop said:

    LWX 9pm update

    00Z IAD sounding showed a warm nose of 1.8C at the 809 mb
    level. This is around 1C warmer than what most of the 18Z models
    initialized. The 18Z Canadian Regional had the best
    initialization of the 18Z guidance with a warm nose around 1C
    with the 00Z NAM now having caught up to the warmer air aloft.
    Although, there is a lot of dry air at that level which would
    result in wet-bulb cooling once precip arrives, the trend in the
    models has been for a faster changeover to mixed precip Thu
    morning. Will be incorporating more of the 00Z NAM and 18Z
    Canadian Regional in our update tonight. These two models have
    verified the best with temps aloft this winter, especially with
    the mid December 2020 and Feb 10 mixed precip events.
    
    There has also been a trend toward a faster exit of the
    precipitation late Thu night across the region with precip only
    lingering across southern MD and in the upslope areas.

    Great catch. And the 0z sounding (weather balloon) is hard data too. This was my worry about the southern tier in terms of a getting a warm layer somewhere in between 850-700mb. Yea it will wet bulb down, but more robust WAA there is already being noted. Fortunately for our region I think this has been trending towards minimizing the threat for sleet/mixed (0z NAM didn't have it getting very far across the mason-dixon). But there's still a decent possibility of pingers at some point to consider in likely the bottom tier of LSV counties.

  9. 4 minutes ago, MAG5035 said:

    Boy I bet the DC metro folks are loving seeing the 0z NAM and some of the differences between other models this close to game time (||GFS vs GFS and Euro). 3k gives them almost nothing snowy and 12k NAM isn't much better and the 0z HRRR hits them good. My only worry for this region is some sleet mixing in at some point for a little bit in the southern counties. At least none of us are riding THAT edge for this event. 

    To clarify a bit, holy crap the NAM is sleeting on DC. 2.5-3"+ on both the NAMs lol. 

  10. Boy I bet the DC metro folks are loving seeing the 0z NAM and some of the differences between other models this close to game time (||GFS vs GFS and Euro). 3k gives them almost nothing snowy and 12k NAM isn't much better and the 0z HRRR hits them good. My only worry for this region is some sleet mixing in at some point for a little bit in the southern counties. At least none of us are riding THAT edge for this event. 

    • Like 2
  11. 43 minutes ago, Itstrainingtime said:

    For most of this season storms have been modeled too high with QPF only to see a reduction in the final 24-48 hours. I think there's a correlation to that being Nina influenced. That's a guess based on my perception, perhaps @MAG5035 could actually provide real analysis. We've been saying for a few days that 10, perhaps 12" was the max for this storm in a few lucky spots - this was never going to be a prolific snow maker. Flow is WAY too progressive to allow for monster totals. 

    I don't know if it's necessarily a Nina thing. Models being too high with QPF certainly isn't anything new.. especially on the high resolution short range stuff like the NAM and also the RGEM at times too. Pattern is progressive but we're also not phasing shortwaves or amplifying a big time low here in this alignment, and that's a good thing with where that 500mb trough is postioned currently with no NAO/AO blocking anymore. That's why the overrunning aspect of this wave is probably going to be the main part of the storm with the weak surface low and weak mid-level features. We've had a few of these type events this year too. 

    • Thanks 2
  12. A big key to what we're going to see snow wise with this system is what happens right up front late tonight into early tomorrow with that finger of early warm advection snows that develops and where it's placed as that probably will be the best snows ratio wise and could throw a stripe of a few inches right off the bat to whoever gets it.That's really been the name of the game with this system since last week, what it does on the front end... even with it being a much colder system overall than it was looking at that point. 

    At any rate, it seemed like a good bit of guidance today (especially the short term and high res stuff) places this early stuff closer to a JST-UNV-IPT line than say a Cumberland to MDT one and then the main surge of precip fills in the rest where it will probably be heavier overall in the southern tier. This is actually most important for that corridor (JST/UNV/IPT/FIG) because this may be a low end advisory or worse without it in the central counties.  I'd wager the folks that gets a good piece of the early stuff and transitions into the main surge without wasting a period of light or non-consequential rates are probably going to be the ones that see the best accumulations for the whole event. And if that actually does end up back as far as that JST-IPT corridor, I'd def be more worried about the implications of eventual mixing in the LSV counties. NAM and related near term guidance is the mixiest still, while generally everything else minimizes the mixing above the mason-dixon line. Still have the same concerns with the 500mb mean trough centered west over the central US as well as the mid-level features west of PA and associated WAA busting 0ºC somewhere in that 850-700 layer in esp the LSV. 

    The trend the last couple days has been a bit of a SE shift in the heavy swath and especially an overall toning down on QPF. I think this is basically a 4-8" for all the regulars in here. Clearfield and Williamsport should eventually at least get to 3-4" by the end of this event. Places like AOO/UNV 5-6" and the best chance of a consistent 6"+ swath likely resides closer to the turnpike. Below the turnpike in the southern tier/LSV has the best QPF for widespread 6"+ but that directly depends on if the mixing happens. If it does, I still think everyone gets 3-4". The upper end of this is probably 10".

    • Thanks 1
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