Isotherm Posted December 31, 2016 Share Posted December 31, 2016 2 hours ago, bluewave said: Notice how the 0z EPS is already backing off on the strength of the Greenland block and the -PNA forces the SE ridge to return after January 10th. Models have been forecasting too much blocking over the North Atlantic longer range since late November. As we get closer the models correct to weaker blocking there. New run old run I noticed that as well. It coincides with the background conditions. As I said in my post last night, we really need an alteration in the stratospheric regime for a true, protracted -NAO. There's more potential for that in February if we can achieve sufficiently potent wave driving this month. But it will still be difficult with the hostile westerly shear stress. Link to comment Share on other sites More sharing options...
Allsnow Posted December 31, 2016 Share Posted December 31, 2016 Yep above normal comes back 2nd week of January. Wash rinse repeat Link to comment Share on other sites More sharing options...
donsutherland1 Posted December 31, 2016 Share Posted December 31, 2016 Earlier in this thread, Bluewave noted the importance of a PNA+ for January snowstorms. Now that I'm back from Canada, I took a look at the numbers. NYC's 4" or greater January snowstorms (1950-2016): PNA-: 29% (-0.500 or below: 12%); PNA+: 71% (+0.500 or above: 44%) NYC's 6" or greater January snowstorms: (1950-2016): PNA-: 17% (-0.500 or below: 6%); PNA+: 83% (+0.500 or above: 39%) There were 41 4" or greater snowstorms and 18 6" or greater snowstorms in January (1950-2016). The biggest PNA- snowstorm occurred when the AO was -3.806. That storm brought 9.1". All said, while a lighter snowfall (up to a few inches) might be possible over the next 7-10 days, the synoptic pattern argues against a moderate (4" or greater) and especially significant (6" or greater) snowfall for the NYC Metro Area. Link to comment Share on other sites More sharing options...
PB GFI Posted December 31, 2016 Share Posted December 31, 2016 2 hours ago, SnowGoose69 said: That appears to be driven mainly by another cutting system. Even with a -NAO I think that 3-5 day period torches. It just would torch slightly less. Thats all that is and I posted you will split the period in 2 / 4 days ago in here . The NAO is neg for 15 days on both ensembles and you will see the trough back in the east . Look at the 168 500 mb EPS then look at its original 360 from Dec 23. I posted it away .... You will see why you just buy orange height lines and think the pattern just abruptly ends. Link to comment Share on other sites More sharing options...
mimillman Posted December 31, 2016 Share Posted December 31, 2016 25 minutes ago, donsutherland1 said: Earlier in this thread, Bluewave noted the importance of a PNA+ for January snowstorms. Now that I'm back from Canada, I took a look at the numbers. NYC's 4" or greater January snowstorms (1950-2016): PNA-: 29% (-0.500 or below: 12%); PNA+: 71% (+0.500 or above: 44%) NYC's 6" or greater January snowstorms: (1950-2016): PNA-: 17% (-0.500 or below: 6%); PNA+: 83% (+0.500 or above: 39%) There were 41 4" or greater snowstorms and 18 6" or greater snowstorms in January (1950-2016). The biggest PNA- snowstorm occurred when the AO was -3.806. That storm brought 9.1". All said, while a lighter snowfall (up to a few inches) might be possible over the next 7-10 days, the synoptic pattern argues against a moderate (4" or greater) and especially significant (6" or greater) snowfall for the NYC Metro Area. This is great analysis, thank you. Do you have a way you perform this type of analysis quickly, or is it all just manual? Link to comment Share on other sites More sharing options...
donsutherland1 Posted December 31, 2016 Share Posted December 31, 2016 6 minutes ago, mimillman said: This is great analysis, thank you. Do you have a way you perform this type of analysis quickly, or is it all just manual? I use a list of NYC's 4" and larger snowstorms to run the data against the teleconnections that I export into Excel from NCEP's ascii file. One can find those values by clicking on any of the teleconnection indices (http://www.cpc.noaa.gov/products/precip/CWlink/daily_ao_index/teleconnections.shtml) and then selecting the daily values from January 1950. NWS lists New York City's 6" or greater snowstorms can be found here: http://www.weather.gov/media/okx/Climate/CentralPark/sixplussnow.pdf Link to comment Share on other sites More sharing options...
mimillman Posted December 31, 2016 Share Posted December 31, 2016 15 minutes ago, donsutherland1 said: I use a list of NYC's 4" and larger snowstorms to run the data against the teleconnections that I export into Excel from NCEP's ascii file. One can find those values by clicking on any of the teleconnection indices (http://www.cpc.noaa.gov/products/precip/CWlink/daily_ao_index/teleconnections.shtml) and then selecting the daily values from January 1950. NWS lists New York City's 6" or greater snowstorms can be found here: http://www.weather.gov/media/okx/Climate/CentralPark/sixplussnow.pdf This is exactly what I was looking for. Thank you! Link to comment Share on other sites More sharing options...
mikemost Posted December 31, 2016 Share Posted December 31, 2016 10 minutes ago, UlsterCountySnowZ said: GFS OTS GGEM scraper with 3-5" Much different progressions at H5 though. Good news is that all the players are still there. Link to comment Share on other sites More sharing options...
White Gorilla Posted December 31, 2016 Share Posted December 31, 2016 With such a progressive pattern, my guess is that a big snow event that verifies will only be picked up within 72 hours. Anything beyond are mere darts, as is usually the case, but even lower confidence than usual on any one solution given the current teleconnections . Sent from my iPad using Tapatalk Link to comment Share on other sites More sharing options...
bluewave Posted December 31, 2016 Share Posted December 31, 2016 2 hours ago, donsutherland1 said: Earlier in this thread, Bluewave noted the importance of a PNA+ for January snowstorms. Now that I'm back from Canada, I took a look at the numbers. NYC's 4" or greater January snowstorms (1950-2016): PNA-: 29% (-0.500 or below: 12%); PNA+: 71% (+0.500 or above: 44%) NYC's 6" or greater January snowstorms: (1950-2016): PNA-: 17% (-0.500 or below: 6%); PNA+: 83% (+0.500 or above: 39%) There were 41 4" or greater snowstorms and 18 6" or greater snowstorms in January (1950-2016). The biggest PNA- snowstorm occurred when the AO was -3.806. That storm brought 9.1". All said, while a lighter snowfall (up to a few inches) might be possible over the next 7-10 days, the synoptic pattern argues against a moderate (4" or greater) and especially significant (6" or greater) snowfall for the NYC Metro Area. Don, great work compiling all those stats. It will be interesting to see if the EPS weeklies are correct about a shift to a more +PNA regime near or after January 20th. Link to comment Share on other sites More sharing options...
EastonSN+ Posted December 31, 2016 Share Posted December 31, 2016 Just learning here. We are loosing -epo which is bad but potentially gaining a positive pna which is good? Link to comment Share on other sites More sharing options...
UlsterCountySnowZ Posted December 31, 2016 Share Posted December 31, 2016 Euro no go for next week Link to comment Share on other sites More sharing options...
WeatherFeen2000 Posted December 31, 2016 Share Posted December 31, 2016 Euro looked better that's all we can hope for right now Link to comment Share on other sites More sharing options...
mimillman Posted December 31, 2016 Share Posted December 31, 2016 8 minutes ago, UlsterCountySnowZ said: Euro no go for next week It's a huge improvement from 00z. Link to comment Share on other sites More sharing options...
UlsterCountySnowZ Posted December 31, 2016 Share Posted December 31, 2016 25 minutes ago, mimillman said: It's a huge improvement from 00z. I know... not comparing runs this far out just informing everyone what it showed, it's still ots, with late development Link to comment Share on other sites More sharing options...
mikemost Posted December 31, 2016 Share Posted December 31, 2016 I believe the main issue the models are having is in regards to difficulty reconciling timing. There is also uncertainty as to how much energy will be available with the shortwaves, as well as possible PV enhancement. This is fairly typical this far out. Especially when you're dealing with the sparse data collection area of western Canada. That's why we're seeing drastic differences in each run, ensembles included. Same story as most of you know... Key thing to take from it is that the pieces to the puzzle keep showing up run to run, they're just put together a different way each time at this juncture. Link to comment Share on other sites More sharing options...
Rtd208 Posted December 31, 2016 Share Posted December 31, 2016 6 minutes ago, mikemost said: I believe the main issue the models are having is in regards to difficulty reconciling timing. There is also uncertainty as to how much energy will be available with the shortwaves, as well as possible PV enhancement. This is fairly typical this far out. Especially when you're dealing with the sparse data collection area of western Canada. That's why we're seeing drastic differences in each run, ensembles included. Same story as most of you know... Key thing to take from it is that the pieces to the puzzle keep showing up run to run, they're just put together a different way each time at this juncture. Good post..we have seen all of this with previous storms. Honestly, I would rather be where we are at this stage and have the storm come back in our favor as we get closer rather then the storm fall apart which has been the theme this year. Link to comment Share on other sites More sharing options...
PB GFI Posted December 31, 2016 Share Posted December 31, 2016 Watch wave 1 first .By 132 / 138 the best VVs come right through the area and into - 12 air. Dont look at precip grids as the end all be all . Upward motion will show you where the best max is coming through . Take 1 at time Link to comment Share on other sites More sharing options...
donsutherland1 Posted December 31, 2016 Share Posted December 31, 2016 4 hours ago, bluewave said: Don, great work compiling all those stats. It will be interesting to see if the EPS weeklies are correct about a shift to a more +PNA regime near or after January 20th. I agree. I'm concerned that they might be rushing it a little bit, but we'll see what happens. Link to comment Share on other sites More sharing options...
mimillman Posted December 31, 2016 Share Posted December 31, 2016 Positive changes on the18z GFS as well. Perhaps we could slowly reel this one in. I believe that a near miss is far more likely than a complete whiff out to sea. Link to comment Share on other sites More sharing options...
UlsterCountySnowZ Posted December 31, 2016 Share Posted December 31, 2016 GFS slightly improved but OTS Link to comment Share on other sites More sharing options...
winterwx21 Posted December 31, 2016 Share Posted December 31, 2016 18z GFS has 2 threats. Thursday night into Friday, and then late in the weekend. Plenty of time for one of them to trend in our favor. Link to comment Share on other sites More sharing options...
White Gorilla Posted January 1, 2017 Share Posted January 1, 2017 I am really glad we have potentials to track Sent from my iPad using Tapatalk Link to comment Share on other sites More sharing options...
EasternLI Posted January 1, 2017 Share Posted January 1, 2017 Trends seem favorable for the Fri deal, at least on the GFS. Something to watch at least. 00z was a better look, doesn't quite get there. Happy new year. Link to comment Share on other sites More sharing options...
dmillz25 Posted January 1, 2017 Author Share Posted January 1, 2017 Snowing here Link to comment Share on other sites More sharing options...
MJO812 Posted January 1, 2017 Share Posted January 1, 2017 Euro looks good for wave 1. 2-4 inches for the area. Link to comment Share on other sites More sharing options...
Animal Posted January 1, 2017 Share Posted January 1, 2017 5 hours ago, Snow88 said: Euro looks good for wave 1. 2-4 inches for the area. Morning afd from mt holly nws is calling for a non event. Fish storm/non event. Link to comment Share on other sites More sharing options...
PB GFI Posted January 1, 2017 Share Posted January 1, 2017 Happy New Year. Wanted to touch on a few things . As I suspected the 6Z GEFS mutes the SE ridge on day 11 12 13 . The WPO AO NAO are still neg out to the 13th and those features are the reason theres not ridge just ballooning up the EC The Euro maintains its error pattern by just jumping the trough in the west. The corrections are too numerous to post I am still a fan of wave 1 and have ignored the GFS operational for now The Euro/Canadian see it . The difference at 500 over the last 2 days have been impressive Last nights Euro VVs all the way into E Canada , so I think that has more room to come W. Wave 2 is too far to look at . Link to comment Share on other sites More sharing options...
bluewave Posted January 1, 2017 Share Posted January 1, 2017 4 minutes ago, PB GFI said: Happy New Year. Wanted to touch on a few things . As I suspected the 6Z GEFS mutes the SE ridge on day 11 12 13 . The WPO AO NAO are still neg out to the 13th and those features are the reason theres not ridge just ballooning up the EC The Euro maintains its error pattern by just jumping the trough in the west. The corrections are too numerous to post I am still a fan of wave 1 and have ignored the GFS operational for now The Euro/Canadian see it . The difference at 500 over the last 2 days have been impressive Last nights Euro VVs all the way into E Canada , so I think that has more room to come W. Wave 2 is too far to look at . Happy New Year to you also. The most impressive feature on the map this week is the very strong -EPO drop. But the ensembles continue the theme of not much help from the AO as a piece of the stubborn vortex remains there. Any blocking on the Atlantic side looks east based. After a mild start to the month, temps cool off for several days before they recover near of after day 10 closer to normal or maybe above. Link to comment Share on other sites More sharing options...
PB GFI Posted January 1, 2017 Share Posted January 1, 2017 16 minutes ago, bluewave said: Happy New Year to you also. The most impressive feature on the map this week is the very strong -EPO drop. But the ensembles continue the theme of not much help from the AO as a piece of the stubborn vortex remains there. Any blocking on the Atlantic side looks east based. After a mild start to the month, temps cool off for several days before they recover near of after day 10 closer to normal or maybe above. Happy New Year Chris , Day 11 12 13 are BN at 2M on the GEFS and the ridge is gone . It should be . Day 10 Euro is N with another HP pushing back thru the UMW. I am not even sure that day 10 ridge is even there , but its gone 11 thru 13 on the GFS. Link to comment Share on other sites More sharing options...
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