EasternLI Posted January 24, 2011 Share Posted January 24, 2011 Here's the sounding for Riverhead LI...Hr 60 on 18Z GFS... Link to comment Share on other sites More sharing options...
TheTrials Posted January 24, 2011 Share Posted January 24, 2011 large and powerful deform. band does not mean that every ensemble member shows as much as the OP. IMO 0.5+ that falls as snow on the backside could be considered large and strong given the situation. Almost every member shows this Exactly. Not sure what the poster is looking for, but the low resolution ensembles are not going to spit out 2 inches liquid. Link to comment Share on other sites More sharing options...
RowanBrandon Posted January 24, 2011 Share Posted January 24, 2011 Is the clown map out yet for the 18z GFS? Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 24, 2011 Share Posted January 24, 2011 Somone was talking about the 2002 xmas storm earlier today. #3 analogue from our friends at CIPS http://www.eas.slu.e...fhr=072&flg=new lol some wild analogs in there-- 1/12/87 is #1.... a nice surprise snow 12/26/02 is #3... much discussed 3/16/99 is #8.... another nice snow 2/12/2006 is #14...... seems out of place, delivered 27" to NYC (although the CCB might be the reason for that.) IMO 12/5/2003 should be in there also. Link to comment Share on other sites More sharing options...
Ridingtime Posted January 24, 2011 Share Posted January 24, 2011 What time is this thing bombing Wednesday and will the weather before it effect flights? Could use some help here cause I've got a overseas flight Wednesday at 6pm Link to comment Share on other sites More sharing options...
Kaner587 Posted January 24, 2011 Share Posted January 24, 2011 Exactly. Not sure what the poster is looking for, but the low resolution ensembles are not going to spit out 2 inches liquid. I think it is more semantics than anything else, but as long as were stating what we'd consider "large" and "powerful" it is clear that most members have this signal. Link to comment Share on other sites More sharing options...
unknown Posted January 24, 2011 Share Posted January 24, 2011 JMA Link to comment Share on other sites More sharing options...
eduggs Posted January 24, 2011 Share Posted January 24, 2011 large and powerful deform. band does not mean that every ensemble member shows as much as the OP. IMO 0.5+ that falls as snow on the backside could be considered large and strong given the situation. Almost every member shows this Snowfall on the western or northwestern side of a mid-level low does not equal a powerful deformation band. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 24, 2011 Share Posted January 24, 2011 One meteorological point in reference to questions about saturating the column: in general, precipitation is driven by supersaturation, i.e., when saturated parcels of air at the surface and lower levels of the atmosphere are subjected to momentum transport into the middle and even upper levels of the atmosphere ("vertical velocities" produced, typically from temperature/pressure gradients resulting from "colliding" low and high pressure systems), which are much colder and and when the saturated parcels cool, those parcels become "supersaturated" i.e., they temporarily hold more moisture (water vapor in air) than is thermodynamically favored (much like sweet tea can hold far more sugar in solution than thermodynamics would indicate - the sugar is supersaturated, but eevntually will come out of solution as sugar crystals, given the right impetus) and once supersaturation relief is initiated (often by seed nucleates in the atmosphere), these parcels can almost instantaneously convert the supersaturated portion of the water vapor into snow crystals via vapor deposition. Therefore, if all of the column becomes saturated, that means the column is moisture laden to the extent that it won't take much transport of saturated parcels of air upwards at almost any level to lead to snow growth - it's a measure of the "potential energy" available for snow growth. I'll admit my meteorology might be a little shaky, but my understanding of supersaturation-driven nucleation and crystallization phenomena is pretty advanced, as I do a lot of that work for a living in Pharma and the same processes we use for crystallizing organic molecules from solvents via supersaturation should apply to crystallizing snowflakes from air via supersaturation. Hope this helps a little. On another note, if Wednesday starts out relatively tranquil and rainy in the I-95 corridor and then we see a 6-hour period of hellacious snows as depicted and that period is anywhere around the afternoon rush hour, it's going to be an absolute disaster, like Jan 1987 was, when all the snow hit after everyone was safely ensconced at work. That's a case where either you get out early or stay late and let the idiots all get stuck. It's interesting you mention Jan 1987 as that seems to be the top analog listed on CIPS. You also described 2/11/2010 right there as we went from light rain to heavy snow and high winds during the early afternoon and evening. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 24, 2011 Share Posted January 24, 2011 Exactly. Not sure what the poster is looking for, but the low resolution ensembles are not going to spit out 2 inches liquid. The ensemble mean also tends to be a bit SE of the OP. Link to comment Share on other sites More sharing options...
Kaner587 Posted January 24, 2011 Share Posted January 24, 2011 What time is this thing bombing Wednesday and will the weather before it effect flights? Could use some help here cause I've got a overseas flight Wednesday at 6pm that is definitely in the timeframe with which it may start getting bad. Also if you're leaving from JFK as opposed to say EWR that may give you some extra time to get out because there will be a rain snow line progressing east. Obviously these details are too difficult to pin down completely at this juncture but I'd def keep an eye on it because it'll be close. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 24, 2011 Share Posted January 24, 2011 that is definitely in the timeframe with which it may start getting bad. Also if you're leaving from JFK as opposed to say EWR that may give you some extra time to get out because there will be a rain snow line progressing east. Obviously these details are too difficult to pin down completely at this juncture but I'd def keep an eye on it because it'll be close. Based on those maps it looks like its going to switch to snow somewhere around midnight. Link to comment Share on other sites More sharing options...
Ridingtime Posted January 24, 2011 Share Posted January 24, 2011 that is definitely in the timeframe with which it may start getting bad. Also if you're leaving from JFK as opposed to say EWR that may give you some extra time to get out because there will be a rain snow line progressing east. Obviously these details are too difficult to pin down completely at this juncture but I'd def keep an eye on it because it'll be close. Yah, that's my thinking too. It will be JFK too, so maybe it will work out. Crazy thing is a huge part of me wants it to not work out. I'd hate to take off right before a massive snow storm hits. Link to comment Share on other sites More sharing options...
Kaner587 Posted January 24, 2011 Share Posted January 24, 2011 Snowfall on the western or northwestern side of a mid-level low does not equal a powerful deformation band. like I said...semantics. Large signal for backside snows totaling 5in or more Link to comment Share on other sites More sharing options...
eduggs Posted January 24, 2011 Share Posted January 24, 2011 Exactly. Not sure what the poster is looking for, but the low resolution ensembles are not going to spit out 2 inches liquid. I think you overreached, because you are looking for encouraging signs for a big snowstorm, instead of objectively evaluating the information. The 18z GEFS backed off slightly from 12z and does not show evidence of high QPF. The operational GFS is probably overdone with QPF from 54-60hrs. QPF was excessive over a short duration despite a nearly identical track to 12z. I happen to think QPF in excess of 1" is a good likelihood. But I don't think the GEFS is currently a strong supporter of this idea. Euro, Euro ensembles, UKMET, and GGEM moreso. Link to comment Share on other sites More sharing options...
sn0w Posted January 24, 2011 Share Posted January 24, 2011 JMA How is this temp wise...I can never read the temps on the JMA for some reason. Link to comment Share on other sites More sharing options...
tcutter Posted January 24, 2011 Share Posted January 24, 2011 JMA is that all snow for pa/nj and north?? Link to comment Share on other sites More sharing options...
MJO812 Posted January 24, 2011 Share Posted January 24, 2011 is that all snow for pa/nj and north?? It's cold enough at all levels. Link to comment Share on other sites More sharing options...
ag3 Posted January 24, 2011 Share Posted January 24, 2011 You can't tell on those Jma maps because it's previous 24 hours of precip and current upper air levels. We can't see in between those hours to see when the levels cool. Link to comment Share on other sites More sharing options...
Noreaster07 Posted January 24, 2011 Share Posted January 24, 2011 Link to comment Share on other sites More sharing options...
Thunder Road Posted January 24, 2011 Share Posted January 24, 2011 so is it actually better if we see a two-part storm? it seems like the NAM led the trend in this development Link to comment Share on other sites More sharing options...
yhbrooklyn Posted January 24, 2011 Share Posted January 24, 2011 Sign me up for that. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 24, 2011 Share Posted January 24, 2011 Sign me up for that. Sign on the dotted line ............. lol tell me about it-- thats the first time Ive ever seen a "nose" of heavy snow extend southward like that to put this part of Long Island in the foot plus range. Granted we know which run it is lol. Link to comment Share on other sites More sharing options...
Noreaster07 Posted January 24, 2011 Share Posted January 24, 2011 when ratios are encorporated it is slightly less than the 10:1 Link to comment Share on other sites More sharing options...
whiteoutwx1796 Posted January 24, 2011 Share Posted January 24, 2011 Who was it that compared this to Xmas 2002. I think it was ALEX, and I'm really liking that analog right about now. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 24, 2011 Share Posted January 24, 2011 Thanks noreaster-- what ratio and/or algorithm is that using? Northern Nassau is still in the foot plus range, and Im down from foot plus to 10" Link to comment Share on other sites More sharing options...
ace0927 Posted January 24, 2011 Share Posted January 24, 2011 Who was it that compared this to Xmas 2002. I think it was ALEX, and I'm really liking that analog right about now. i did, 4 days ago....since then many have. Link to comment Share on other sites More sharing options...
Kaner587 Posted January 24, 2011 Share Posted January 24, 2011 Sign me up for that. forget about that clown map verifying, even half of that would be welcomed by everyone. EVERY model, literally every model suggests back end relatively strong deform band snows. I think unless something major changes, 4in+ is a good bet for most of the area with the potential of as much as 8, unless the Goofus is right. Even the warmest model (GGEM) gets us some good back end snows. I think, as tombo and many others have stated, this has huge bust potential, but based on how conservative upton is being right now, it actually has huge bust potential in both directions. Link to comment Share on other sites More sharing options...
Manny Posted January 24, 2011 Share Posted January 24, 2011 The two-part scenario might help us out, with the first part being a nuisance of rain and mix, and then just waiting for the low to bomb and develop that CCB over our heads, as the column cools down. Pretty simple. lol If only... Link to comment Share on other sites More sharing options...
tombo82685 Posted January 25, 2011 Share Posted January 25, 2011 so is it actually better if we see a two-part storm? it seems like the NAM led the trend in this development Ryan, imho yes it is. If this was all together as one solid piece. The front end part may limit the backend snows do to how much rain would of fallen already. The ground would be pretty wet and would take a while for the snow to accumulate. Link to comment Share on other sites More sharing options...
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