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Everything posted by MAG5035

  1. Yea this wasn't really looking like much more than a 6-12" type event at any point in the heavy axis, other than like the 18z NAM. Another thing I didn't mention on my long post earlier going over the mid-level lows was that we're not really deepening the coastal storm. It's just an overrunning wave attacking a cold high pressure with overrunning WAA precip in either one or two separate heavier precip areas depending on the model. And the weak 850mb low never goes to the coast nor strengthens much, with the parent low staying west of here. So you don't develop the anomalous easterly flow you want to look for to start getting the widespread big amounts and intense banding.
  2. Temps already back to 24°F here with some fluffy upslope snow showers starting to get things covered up again. Spent enough time above freezing this morning that ice is mostly off the trees. Was hard to measure. I called it about a half inch of sleet which combined with the freezing rain made quite the ice layer on the snow. Actual ice accrual on trees and such looked fairly similar to the mostly ZR event I got at the end of December (which I measured 0.2”). Snowpack avg depth after the ice is about 8-9” with as low as 4” and as high as over a foot.
  3. The bigger concern I have for especially the LSV wrt to some mixing later in the storm deals with the mid-level features at 850 and 700mb. The 850 low and 700.. trough are based west of the area. Fortunately these features are weak because a more dynamic phasing storm would assuredly be cutting west given 500mb positioning of the mean trough still over the middle of the country into Texas. Here's the 500mb mid-storm via the Euro. You wouldn't think at first glance CTP (or southern PA here in the Euro's case) is in the midst of getting a significant snowfall but thats the magic of when the features below 17k feet (500mb) are at least somewhat favorable and there's cold air. This isn't the first time we've played this game this winter either. Now going to show what the latest 3k NAM had with it's mid level features. The NAM is definitely on the most amped side of guidance, but same general idea is applying to the other guidance as well. 850mb heights/wind 850 temps First off, you can see the big difference between this one and the last storm... where the 50-60kt+ jet is nosed over SE VA and the Delmarva instead of right directly over PA like last night. There is some southerly flow into PA (enhanced a bit on the west side of the Laurel's) but not the major jet that torches the layer. That big arrow i drew doesn't show it well but the streamlines show that flow turning back a bit toward a due southerly flow over the Delmarva keeping the 0ºC line somewhat close. But overall, that level is okay for us but we don't want to slow down and amp this storm up much more or your going to direct that southerly flow more towards southern/southeast PA. Now 700mb winds/heights 700mb temps This is the level (and possibly somewhat between the 850 and 700mb) that I'm most concerned about for mixing here in our region. You can already see why the NAM has so much sleet as a pretty strong 700mb jet runs through the Mid-Atlantic into PA.. There's going to be some significant WAA in that layer either way (which could cap snow ratios to a degree) but that 0ºC line is teetering near the LSV at 48 when the bulk of the precip is happening. Above 0ºC 700mb air does work into roughly the SE quarter of PA by hr 54. Now as I said..the NAM is generally the most amped with the features I pointed out right now, but consider where we ended up last night. WAA aloft ended up being so strong that even the counties in the north that we're supposed to still 6+ of snow at the beginning of yesterday ended up not seeing anywhere near that. Now let me add the disclaimer that this event should drop some nice snow up front for everyone. With that said, obviously my concern is more robust warming aloft than even the NAM has modeled... especially at 700mb considering how far west the low feature is. You get that sneaky thin area up somewhere between 700-800mb of above 0ºC air and suddenly your pinging away. So def something to keep in consideration.
  4. It's a pretty weak low pressure system overall that's trying to press up into what will be a much better positioned high pressure this go around. I don't think it's really fighting anything, it's actually more focused with a singular significant press of overrunning precip vs the Euro or the ||GFS which seems to have two separate surges of heavier precip. Euro op looked somewhat stronger with the high pressure so that likely had a hand in kind of focusing on the southern tier more. The surface "low" you see west of the mountains is part of the overall low pressure area but the colder denser air draining down via the high pressure in place gives it that two low look. This is an A with a pretty weak surface low. Classic overrunning look.
  5. Pretty close. MDT is getting 14.1 Kuchera on 1.36" QPF.. so basically a 10.4 to 1 avg snow ratio.
  6. That's a classic 18z NAM job if i've ever seen one lol. 10"+ roughly southeast half of PA on the 10:1, and Kuchera coming out to be pretty close to the 10:1 in that stripe. DC and surrounding has 2-4" of sleet.
  7. 0z Euro and Euro ensemble check out for Thursday's event. Mostly all snow for everyone in here. Also while I"m at it might as well throw on the 0z WPC guidance blend. That only goes out to 72hr, so probably more snow to be had in the Sus Valley. 0z Euro ensemble 0z WPC guidance (50th percentile snowfall)
  8. Starting to notice the ice on the trees some now. P-type is mainly freezing rain with temp floating 32ish. Do have a fairly stiff SSE breeze now, which may help mix temps up a degree or two (KAOO at 34ºF). The wind probably won't help matters on the ridges though, where the bigger ice accumulations likely will be.
  9. The || GFS does as well. Both are mostly snow with a bit of late mix in the LSV on regular GFS while the Para-GFS never gets mix line above the mason-dixon.
  10. Pretty much all guidance except the NAM (until 0z tonight) have been showing good front snows with varying degrees of mixing later in the event (Euro pretty much an all snow event back in our area). The new 0z NAM now joining the party with the bigger front end thump. So def not a fluke or anything, but a little early to be including accums like that in the grid forecasts considering how rapidly this current one went sideways the last few days.
  11. Might as well put up a pic of the “ice board”. A little over a half inch of ice encased sleet. Ice accrual on trees isn’t too notable yet.
  12. Pinging away here as well. Pretty much all sleet falling moderately.
  13. 0z NAM def coming in colder vs 18 and 12z with the mixing portion of the Thursday storm. Very intense front end thump of snow as well.
  14. Screaming southerly winds showing on velocity near the 850mb level, >60knots showing up. Basically the reason why this has WAA aloft and associated mixed precip driving further and further north has been so robust. With the lowest 0.5º tilt you can make out the general wind direction near the radar site as well, which is out of the ESE. That easterly component at the surface is going to keep temps from going much of anywhere.
  15. Hopefully we can stay more sleet for a good bit of this event. Looking at the dual pol products on the radar with the higher tilts it looks like the mixing layer is still pretty high up.. roughly about the 4,000ft level (up closer to the 850mb level). So that gives a good bit of time for droplets to refreeze thru the colder 925mb level to the surface.
  16. Ugh. At least on the bright side being caught up in the traffic behind the wreck is always better than being caught in the actual wreck itself.
  17. Looks like a pretty heavy area of precip about ready to get to your neck of the woods within the next 30 min.
  18. On a lighter note, CTP point and click FTW apparently with the 6-12" 48+ hrs out just thru Thursday daytime. Boy if only... lol.
  19. 29ºF and moderate mixed precip. Call it maybe a 60/40 sleet to freezing rain blend with a little bit of glazed-in sleet accumulation on untreated stuff already. Tonight's gonna suck.
  20. Yea it's def attainable in the warning area. The main consequences of the models trending NW the last several runs are aloft, with much more robust warming at the 850mb and 925mb level, especially looking at today's runs. Surface CAD is still about the same which will maintain freezing rain, and I know it's above freezing in some spots right now but dew points are mostly in the 20s and this is coming overnight as well. I'm hoping more sleet is able to nose down and knock freezing rain down some here. This is my point and click for tonight, then 12ºF for a low tomorrow night, ugh.
  21. The positives I see for Thursday are a better positioned high pressure to the north and the fact that this is coming pretty quickly on the heels of tonight's system...which about the only thing that's gonna be good for other than ice tonight is finally moving the gradient some as we do have some half decent cold that will come in behind. That aforementioned high actually builds overhead before shifting north of us as this next system approached. So I think we can at least get widespread front end snow if this stronger high holds in. That's part of what sunk us with the current one, which I've mentioned a couple times. Problems I see are that the overall mean trough axis is still going to be similarly positioned to where it is now (a bit too far west for my liking) and that's going to present the opportunity for this to track like the current system, potentially sending the surface low up the west side of the apps to an eventual transfer to the coast. Southern tier is pretty vulnerable to mixing in this setup IMO. Looking at mid-level features, even the Euro is a bit left of my liking with the 850mb low (roughly taking that overhead). The GFS and || GFS had a more focused 850mb low that went west and drew a stronger southerly flow and more mix. The stronger surface high to the north is extremely important for front end snow and maybe getting this low pressure under us, although I"m somewhat pessimistic of that happening without at least some surface low reflection carrying up west of the Apps up to at least the Ohio River. Probably don't want this to slow down at all either. The faster on the heels of the current system, the better chance it has at staying under us.
  22. Can't help but marvel at the craziness of this weather event down in Texas. San Antonio socked in with heavy snow and FOURTEEN DEGREES. Brownsville, TX sitting colder than MDT right now at 32ºF and reporting light snow. The Brownsville NWS was saying in their discussion their ASOS sites aren't even equipped with freezing rain sensors bc well, guess that stuff never happens down there lol.
  23. New 0z HREF showing support for upgrading that swath of watches to what would likely be an ice storm warning. This is the accrual algorithm. 24 hr snowfall:
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