Wonderdog Posted January 2, 2022 Share Posted January 2, 2022 7 minutes ago, BristowWx said: Sadness Maybe it'll be mostly rain:)) Link to comment Share on other sites More sharing options...
Bob Chill Posted January 2, 2022 Share Posted January 2, 2022 38 minutes ago, CAPE said: GFS has locked in on the big storm idea for 4 straight runs now, e incrementally better. Gotta go with it. Impressed that the GFS was the best (by far) handling H5 in the mid range. I got dragged in when the first few runs hit showing h5 closing off just east of the MS River in the deep south. That's part of our textbook here with southern stream shortwaves. Too soon = rain. Too late = furries or cirrus. Just right? Gfs is perfection, basically 9 3 1 Link to comment Share on other sites More sharing options...
jayyy Posted January 2, 2022 Share Posted January 2, 2022 Hmmm, perhaps I should stay at my brother’s house in Ellicott City another night instead of heading back up to my house in Carroll County. I am off until Tuesday anyway! Looks like a better spot to be for this one (first time I’ve said this in several years) excited for you all in the southern half of the CWA! 1 Link to comment Share on other sites More sharing options...
SnowenOutThere Posted January 2, 2022 Share Posted January 2, 2022 With my homemade python program which takes in the EURO, GFS, CMC and ICON input then weights each differently (EURO then CMC then GFS then ICON), it spit out a raw output of 6.93 not factoring in melt or anything. Fed the program 7, 15, 5, 0 for amounts so glad to see the output is somewhat realistic. 7 Link to comment Share on other sites More sharing options...
jayyy Posted January 2, 2022 Share Posted January 2, 2022 1 minute ago, Bob Chill said: Impressed that the GFS was the best (by far) handling H5 in the mid range. I got dragged in when the first few runs hit showing h5 closing off just east of the MS River in the deep south. That's part of our textbook here with southern stream shortwaves. Too soon = rain. Too late = furries or cirrus. Just right? Gfs is perfection, basically So good to see you here my friend. Gfs truly is a thing of a beauty, and it’s been pretty damn consistent the past few days. Link to comment Share on other sites More sharing options...
IronTy Posted January 2, 2022 Share Posted January 2, 2022 6 minutes ago, WxMan1 said: The 'warm ground' theory has been debunked numerous times, most notably out west (CO front range, temps in the 70s one day, blizzard the next), but even here in the mid Atlantic as well. Especially along the coast (see Norfolk with the March 1980 snowstorm). Your point about the rates is spot on. Best case scenario I see is we crash to 32 with ripping fat flakes. There is certainly some instability, or very weak stability, to work with within the dendritic growth zone. Can you point to a reference on the warm ground debunking? Not arguing, I'm genuinely interested in reading more on it. My experience is the warm ground makes a 1" layer of slush but on top of that it's all snow. 3 Link to comment Share on other sites More sharing options...
batmanbrad Posted January 2, 2022 Share Posted January 2, 2022 32 minutes ago, Scraff said: My first snowfall map I’ve ever attempted. Don’t be too harsh… Is that the same Sharpie that was used during Hurricane Dorian's Sharpiegate? 1 2 Link to comment Share on other sites More sharing options...
Maestrobjwa Posted January 2, 2022 Share Posted January 2, 2022 2 minutes ago, batmanbrad said: Is that the same Sharpie that was used during Hurricane Dorian's Sharpiegate? So THAT'S where it went! Link to comment Share on other sites More sharing options...
peribonca Posted January 2, 2022 Share Posted January 2, 2022 So what are people thinking in terms of wasted precipitation? Do we have white rain for a few hours 1am-3am then start sticking? Link to comment Share on other sites More sharing options...
baltosquid Posted January 2, 2022 Share Posted January 2, 2022 Mesmerizing to watch this trend. Just give it a bit more, and juice that shield.... 1 Link to comment Share on other sites More sharing options...
Bob Chill Posted January 2, 2022 Share Posted January 2, 2022 12 minutes ago, IronTy said: Can you point to a reference on the warm ground debunking? Not arguing, I'm genuinely interested in reading more on it. My experience is the warm ground makes a 1" layer of slush but on top of that it's all snow. Most of the long timers here debunked it through experience. All the doubt and hand wringing leading in then "shock and awe" that it stuck. IME, it usually comes down to the start. We all know the ground won't be frozen at all so how does it still pile up? Gotta get a quick start. Miller A's are good at that because the front side WAA snow usually comes in hot and heavy. It has to, otherwise the Pacman starts eating and never stops. If the front piece comes in in pulses and lulls...that's trouble. I've lost half of a storms qpf to melt/nonstick away too many times. 1"/hr rates at night will stick no problem above freezing. Gotta get the blanket down to maximize the cold side of the storm. March 2013 is a great example of how you get screwed even when qpf is good enough. 4 Link to comment Share on other sites More sharing options...
LeesburgWx Posted January 2, 2022 Share Posted January 2, 2022 1 minute ago, baltosquid said: Mesmerizing to watch this trend. Just give it a bit more, and juice that shield.... Yeah, that trend is sick. Thanks for posting as this shows it very well. 1 Link to comment Share on other sites More sharing options...
IronTy Posted January 2, 2022 Share Posted January 2, 2022 13 minutes ago, batmanbrad said: Is that the same Sharpie that was used during Hurricane Dorian's Sharpiegate? Bigly northern cutoff Link to comment Share on other sites More sharing options...
Amped Posted January 2, 2022 Share Posted January 2, 2022 Going to be a tough forecast for the NW burbs. They're just beyond the sharp cutoff of a storm trending NW. Probably need warnings up all the way to the MD line based on experience with past storms. 2 Link to comment Share on other sites More sharing options...
WxMan1 Posted January 2, 2022 Share Posted January 2, 2022 23 minutes ago, IronTy said: Can you point to a reference on the warm ground debunking? Not arguing, I'm genuinely interested in reading more on it. My experience is the warm ground makes a 1" layer of slush but on top of that it's all snow. I think the cooling due to conduction, i.e. with cold rain at the outset, does a great deal pretty quickly. We often see road surface temps fall into the 30s pretty quickly. But you're absolutely correct -- that first layer would be slush, and overall, the depth of snow on the roads in this setup would be less than that over non-paved surfaces. Would be a mess to drive on. Like you all have said, it's a "rates" storm. We absolutely need that or it's essentially a non-event. Much like November 11th 1987. When it happens, it's a think of beauty. A pasty wet snowfall -- my favorite -- with clumping aggregate flakes. A low probability event to be sure, but we've got the setup going for us, as well as a consensus among most models now within 24 hrs of the event. 3 1 Link to comment Share on other sites More sharing options...
Amped Posted January 2, 2022 Share Posted January 2, 2022 49 minutes ago, Scraff said: My first snowfall map I’ve ever attempted. Don’t be too harsh… Just go 8-12.". Pretend to have confidence. 1 1 1 Link to comment Share on other sites More sharing options...
IronTy Posted January 2, 2022 Share Posted January 2, 2022 2 minutes ago, Bob Chill said: Most of the long timers here debunked it through experience. All the doubt and hand wringing leading in then "shock and awe" that it stuck. IME, it usually comes down to the start. We all know the ground won't be frozen at all so how does it still pile up? Gotta get a quick start. Miller A's are good at that because the front side WAA snow usually comes in hot and heavy. It has to, otherwise the Pacman starts eating and never stops. If the front piece comes in in pulses and lulls...that's trouble. I've lost half of a storms qpf to melt/nonstick away too many times. 1"/hr rates at night will stick no problem above freezing. Gotta get the blanket down to maximize the cold side of the storm. March 2013 is a great example of how you get screwed even when qpf is good enough. Good point, I agree on the pulsing. It's gotta push during the onset to build up a slush layer. If it comes and goes it ends up as an inch or two of slush. This is what happened during last winter's storm for us. Even during snowmageddon we had a solid inch of slush underneath. Link to comment Share on other sites More sharing options...
Bob Chill Posted January 2, 2022 Share Posted January 2, 2022 8 minutes ago, peribonca said: So what are people thinking in terms of wasted precipitation? Do we have white rain for a few hours 1am-3am then start sticking? Nowcast for that stuff. Need the wall of yellows to roll right overhead with no light green lulls or worse... holes... If the waa is juicy, we avoid relying on a 6 hour windowor less of "rates" to cover everything. The best accum snow will obviously be during the CCB portion. If your ground is still mostly brown by that time, big snows become hard to impossible. If there's 2-4" of gloppy potatoes on the ground when the CCB sets up... oh boy.... hehe The tricky part is nobody can honestly say they know how the front side breaks and until that's figured out, the cold side amounts are nothing more than wild guesses 1 Link to comment Share on other sites More sharing options...
IronTy Posted January 2, 2022 Share Posted January 2, 2022 1 minute ago, WxMan1 said: I think the cooling due to conduction, i.e. with cold rain at the onset, does a great deal pretty quickly. We often see road surface temps fall into the 30s pretty quickly. But you're absolutely correct -- that first layer would be slush, and overall, the depth of snow on the roads in this setup would be less than that over non-paved surfaces. Would be a mess to drive on. Like you all have said, it's a "rates" storm. We absolutely need that or it's essentially a non-event. Much like November 11th 1987. When it happens, it's a think of beauty. A low probability event to be sure, but we've got the setup going for us, as well as a consensus among most models now within 24 hrs of the event. Mind blown, I've never thought of conduction which is pretty embarrassing as an engineer. A cold rain right at 33F or somewhere close should take all the heat out of the soil. Then it's just losses due to snow hitting wet ground, not necessarily warm ground though. 3 1 Link to comment Share on other sites More sharing options...
BTRWx's Thanks Giving Posted January 2, 2022 Share Posted January 2, 2022 The early precipitation falling overnight helps. Link to comment Share on other sites More sharing options...
IronTy Posted January 2, 2022 Share Posted January 2, 2022 1 minute ago, BTRWx's Thanks Giving said: The early precipitation falling overnight helps. Also a good point. At this point the sun angle is so high and rising we should expect it to melt anything short of steel. Eta, that's a joke BTW. 5 Link to comment Share on other sites More sharing options...
LeesburgWx Posted January 2, 2022 Share Posted January 2, 2022 Who is doing pbp for the euro when it starts? Link to comment Share on other sites More sharing options...
VA Mad Man Posted January 2, 2022 Share Posted January 2, 2022 Winter Weather Advisory just issued - 2-4 inches. Very conservative??? Link to comment Share on other sites More sharing options...
stormtracker Posted January 2, 2022 Share Posted January 2, 2022 Lol dc metro under weather advisory. Charles county s and e upgraded to warning. Ok 1 Link to comment Share on other sites More sharing options...
BTRWx's Thanks Giving Posted January 2, 2022 Share Posted January 2, 2022 2 minutes ago, LeesburgWx said: Who is doing pbp for the euro when it starts? Everyone who knows how. lol 1 Link to comment Share on other sites More sharing options...
snowmagnet Posted January 2, 2022 Share Posted January 2, 2022 Just got a WAA for Fairfax for 2-4”. It seems to be too conservative based on the latest information. Is that because they depend on the NAM? Link to comment Share on other sites More sharing options...
baltosquid Posted January 2, 2022 Share Posted January 2, 2022 Another cool way to watch the trend... look at the last few HRRR runs. Check out the cold pressing more and more and the distance between the yellows and the freezing line shrinking in the south. 1 Link to comment Share on other sites More sharing options...
Bob Chill Posted January 2, 2022 Share Posted January 2, 2022 Just now, stormtracker said: Lol dc metro under weather advisory. Charles county s and e upgraded to warning. Ok DC itself could end up with a wide range of outcomes based on tiny distances. You're in the best general area of DC so that's good. Foggy bottom or navy yard weenies may not be stoked bros after the storm is done. Link to comment Share on other sites More sharing options...
WVsnowlover Posted January 2, 2022 Share Posted January 2, 2022 2 minutes ago, snowmagnet said: Just got a WAA for Fairfax for 2-4”. It seems to be too conservative based on the latest information. Is that because they depend on the NAM? Makes more sense for them to be conservative here and upgrade this evening if the trend holds/continues rather than go all in now and have it bust. Link to comment Share on other sites More sharing options...
Yeoman Posted January 2, 2022 Share Posted January 2, 2022 4 minutes ago, stormtracker said: Lol dc metro under weather advisory. Charles county s and e upgraded to warning. Ok I'd wait for Sue Palka to weigh in 1 Link to comment Share on other sites More sharing options...
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