Burghblizz Posted January 11, 2018 Share Posted January 11, 2018 Quick glance....just looks more progressive and weaker....although maybe a positive trend for less rain. But I wouldn’t be surprised if output is lower Link to comment Share on other sites More sharing options...
blackngoldrules Posted January 11, 2018 Share Posted January 11, 2018 Yeah, just looked at the 12z. That's ugly and wouldn't surprise me if it happened knowing our luck. Westmoreland County would join in on the WSW while we'd end up with an advisory event probably. Sent from my SM-G920P using Tapatalk Link to comment Share on other sites More sharing options...
Rd9108 Posted January 11, 2018 Share Posted January 11, 2018 We may have jumped the gun here. Let's hope the NAM is wrong. Link to comment Share on other sites More sharing options...
MikeB_01 Posted January 11, 2018 Share Posted January 11, 2018 12z Nam is interesting. Not really sure where all the luster from the previous runs went. The 500 vort looks relatively similar from 00z and 06z. Link to comment Share on other sites More sharing options...
Rd9108 Posted January 11, 2018 Share Posted January 11, 2018 6 minutes ago, MikeB_01 said: 12z Nam is interesting. Not really sure where all the luster from the previous runs went. The 500 vort looks relatively similar from 00z and 06z. It doesn't look any different from 6z to my naked eye. Had to be due to the temps/column. Link to comment Share on other sites More sharing options...
MikeB_01 Posted January 11, 2018 Share Posted January 11, 2018 6 hours ago, MAG5035 said: The minimum of accums is likely attributed to the Kuchera algorithm used for that snowfall map. A look at thermals during the heaviest frame of precip in the Pit region (Hr 54) shows a kink in the 850 zero line where it cuts through the middle of PA til near UNV and then cuts westward roughly to Indiana and then turns south towards Morgantown. Pretty much lines up with where the Euro has the 850mb low at the time (right over central PA) Should also note the column is quite marginal all the way up from 850 to 700, with a pretty good chunk of west central PA actually above 0 in between the 700-800mb level while 850 is below zero while cold air undercuts below 850mb. The cross section I made off the Euro illustrates this pretty nicely. I provided a VERY rough guesstimate of locations the cross section refers to as you look left to right. I also looked at the 0z NAM's cross section and it was much colder in those mid levels over western PA and it really had a significant undercutting wedge of lower level cold.. likely attributing to the bigger snow totals it threw out. Far E OHIO------WHEELING-------KPIT-------------- LBE--------------------------------JST----------------------------AOO At any rate, the above description is talking generally about the area where theres a "dry slot". The Kuchera method is simply an equation that plugs in the warmest temp in the column (below 500mb) and puts out a ratio and associated snow number. So it's going to put out lousy numbers where this lingering warm air aloft is near 0ºC. I'm not going to get too math-y with this but I will say you have to convert to K from Celsius for this (0ºC = 273.15K). So say you use a borderline temp of 0ºC or 273.16K and apply to the above equation you get a ratio of 8:1. If you look at the far left of the cross section (Far E OH/Far western PA) and apply the colder max temp of about -5ºC near the 750mb layer your going to come up with a ratio of 15:1. Kuchera method doesn't consider snow growth and lifting processes that truly dictate the real world snow ratios. Honestly I personally think it is a good method to use in colder situations where the thermal column stays pretty stable the whole event but I'd be careful using it for this type of event..especially in this region where we have a complicated but progressively cooling thermal column. It's one of those type events where the ratio can start off bad but get better as cold air establishes. I'd probably just use a straight 10:1 map to get a rough idea on accums. It's a complicated scenario anyways so I wouldn't get too hung up on exact numbers yet but just the fact the models have trended southeast enough to give the region a good shot at decent changeover snowfall with the deform precip band being in a good spot. There's still going to be the issue of mixed precip too before any snow.. potentially for a pretty sizable chunk of the rest of western and eventually central PA. Wow this was a great explanation. Thank you. Any chase you know where to get free thermal profiles like the one that you posted? Link to comment Share on other sites More sharing options...
SteelCity08 Posted January 11, 2018 Share Posted January 11, 2018 4 minutes ago, Rd9108 said: It doesn't look any different from 6z to my naked eye. Had to be due to the temps/column. At least the axis of heavier snow has remained basically the same for the past few runs on the nam. Link to comment Share on other sites More sharing options...
MikeB_01 Posted January 11, 2018 Share Posted January 11, 2018 Just now, SteelCity08 said: At least the axis of heavier snow has remained basically the same for the past few runs on the nam. Agreed, I think we are at least going to get some kind of thump. All of matter of how long it thumps Link to comment Share on other sites More sharing options...
Rd9108 Posted January 11, 2018 Share Posted January 11, 2018 4 minutes ago, MikeB_01 said: Agreed, I think we are at least going to get some kind of thump. All of matter of how long it thumps Case of watching the rain/snow line take it's time getting to us. Link to comment Share on other sites More sharing options...
Rd9108 Posted January 11, 2018 Share Posted January 11, 2018 RGEM Link to comment Share on other sites More sharing options...
Rd9108 Posted January 11, 2018 Share Posted January 11, 2018 6z using 10:1 for comparison. Link to comment Share on other sites More sharing options...
SteelCity08 Posted January 11, 2018 Share Posted January 11, 2018 6 minutes ago, Rd9108 said: RGEM Models def seem to be coming into better agreement on track Link to comment Share on other sites More sharing options...
MikeB_01 Posted January 11, 2018 Share Posted January 11, 2018 7 minutes ago, Rd9108 said: 6z using 10:1 for comparison. Improvement. Just a little more Link to comment Share on other sites More sharing options...
SteelCity08 Posted January 11, 2018 Share Posted January 11, 2018 This may very well end up being a true nowcasting event. 4-6" seems like a pretty safe call after the runs so far but as always it won't take much for that number to go up or down. Link to comment Share on other sites More sharing options...
north pgh Posted January 11, 2018 Author Share Posted January 11, 2018 1 minute ago, SteelCity08 said: This may very well end up being a true nowcasting event. 4-6" seems like a pretty safe call after the runs so far but as always it won't take much for that number to go up or down. I agree. We just need to get the storm here and see what happens. As we know from past events we could be forecast for 2-4 and bumped up as the storm hits or busted down to and inch or 2 after ice. I do like that it has trended to put us in the game. We need the Canadian to come our way next. Link to comment Share on other sites More sharing options...
Burghblizz Posted January 11, 2018 Share Posted January 11, 2018 4 minutes ago, SteelCity08 said: This may very well end up being a true nowcasting event. 4-6" seems like a pretty safe call after the runs so far but as always it won't take much for that number to go up or down. I don’t like the open wave/progressive look on the NAM as far as anything that is more than 4-6”. But it looks like there are multiple waves, so with an early changeover it still could be nice. Link to comment Share on other sites More sharing options...
KPITSnow Posted January 11, 2018 Share Posted January 11, 2018 Gfs...again not impressive. It figures we will likely get teased then end up with another crap 2-4 event. Link to comment Share on other sites More sharing options...
SteelCity08 Posted January 11, 2018 Share Posted January 11, 2018 2 minutes ago, north pgh said: I agree. We just need to get the storm here and see what happens. As we know from past events we could be forecast for 2-4 and bumped up as the storm hits or busted down to and inch or 2 after ice. I do like that it has trended to put us in the game. We need the Canadian to come our way next. I'd much rather go to battle with temps at this point over a east, west, north or south shift. Solely because it's a change from the norm lol. Link to comment Share on other sites More sharing options...
Rd9108 Posted January 11, 2018 Share Posted January 11, 2018 5 minutes ago, Burghblizz said: I don’t like the open wave/progressive look on the NAM as far as anything that is more than 4-6”. But it looks like there are multiple waves, so with an early changeover it still could be nice. Almost seemed to fast. Reminded me of frontal passage and less of an organized storm. Link to comment Share on other sites More sharing options...
SteelCity08 Posted January 11, 2018 Share Posted January 11, 2018 Pittsburgh is great at three things... Sports, drinking, and 2-4" snows. Link to comment Share on other sites More sharing options...
MikeB_01 Posted January 11, 2018 Share Posted January 11, 2018 8 minutes ago, KPITSnow said: Gfs...again not impressive. It figures we will likely get teased then end up with another crap 2-4 event. Again, not sure for the reason in the changes on snow totals. 500 vort looks similar. Models are still trying to figure this one out. Lots of players and variability. Lets focus on the ensembles and hope for a fast transition to snow. I would take a 6 in storm considering its been a couple of years since we've seen anything close. Link to comment Share on other sites More sharing options...
MikeB_01 Posted January 11, 2018 Share Posted January 11, 2018 GEM continues to push ever so slightly SE. Still got time. variability will occur. We are still in the game Link to comment Share on other sites More sharing options...
RitualOfTheTrout Posted January 11, 2018 Share Posted January 11, 2018 3 minutes ago, MikeB_01 said: Again, not sure for the reason in the changes on snow totals. 500 vort looks similar. Models are still trying to figure this one out. Lots of players and variability. Lets focus on the ensembles and hope for a fast transition to snow. I would take a 6 in storm considering its been a couple of years since we've seen anything close. I think a lot of it has to do with temperatures, this situation is not going to play out well for snow map algorithms. Slight changes of a degree or 2 C at any point in the column will make a big difference. Also doesn't help that it's doesn't really start getting it's act together until well north of here. Would love to see that deepening happen just a bit sooner, of course to soon and we get wet rather than white. That being said best totals look to be NW of the city. I'm honestly not expecting much more than 2-4 right now, but I am in NW Westmoreland, so I'm anticipating taking longer to change over to snow. Link to comment Share on other sites More sharing options...
blackngoldrules Posted January 11, 2018 Share Posted January 11, 2018 So, this may be yet another WSW that doesn't end up materializing into a warning. Another case of getting our hopes up and then pulling the rug out from underneath us. I'll go back to being pessimistic since that's when the models started looking better for us. Sent from my SM-G920P using Tapatalk Link to comment Share on other sites More sharing options...
KPITSnow Posted January 11, 2018 Share Posted January 11, 2018 The GEM snow map is posted in the upstate NY thread. The gradient goes right through us with 6-7 inches in beaver county and the northern panhandle, but only 2-4 in AGC. I guarantee that will happen. Link to comment Share on other sites More sharing options...
Rd9108 Posted January 11, 2018 Share Posted January 11, 2018 11 minutes ago, blackngoldrules said: So, this may be yet another WSW that doesn't end up materializing into a warning. Another case of getting our hopes up and then pulling the rug out from underneath us. I'll go back to being pessimistic since that's when the models started looking better for us. Sent from my SM-G920P using Tapatalk Can I join you. I feel like this will be a 2-4 slopfest. If we somehow get 6-8 I would be shocked. Link to comment Share on other sites More sharing options...
KPITSnow Posted January 11, 2018 Share Posted January 11, 2018 1 minute ago, Rd9108 said: Can I join you. I feel like this will be a 2-4 slopfest. If we somehow get 6-8 I would be shocked. I will say that 2-4 AFTER the slop is better than our typical 2-4, then slop, then melt everything. Link to comment Share on other sites More sharing options...
Rd9108 Posted January 11, 2018 Share Posted January 11, 2018 Ukie looks good. Don't feel like posting the different frames. Let's see what the euro does. Link to comment Share on other sites More sharing options...
Rd9108 Posted January 11, 2018 Share Posted January 11, 2018 I lied the low looks west. Oh well on to the next one. Link to comment Share on other sites More sharing options...
Mailman Posted January 11, 2018 Share Posted January 11, 2018 I see the 0z Euro had a big storm for next week. Link to comment Share on other sites More sharing options...
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