Isotherm Posted December 2, 2014 Share Posted December 2, 2014 This is somewhat correct. However, I don't think the amount of recovery of stratospheric PV some of model forecasts are now showing, were anticipated for mid-December. There was assumption that this disruption will resume in mid to late December, once this NW Asian low leaves. But so far I see no renewed significant warming event through 10-15 days on models. If this trend continues through this Friday, I think this will push the favorable cold and snow period back further, until we see another major disruption of stratospheric PV. This process often to several weeks to occur again and then impact us. The PDO and ENSO are doing as what we hoped so far. Some more uncertainty now with the MJO progression. But if a strong stratospheric PV persists on top of all that, it will continue be a problem for us. Do you have verification statistics for stratospheric forecasts at the D10+ range? I would believe they're even less reliable than tropospheric long-term model guidance. Speaking of the much discussed NW Asian low, this feature will be dislodged by D 4-5, and a mid level ridge will take its place, setting the stage for a conducive 500mb pattern for the resumption of strong vertical wave propagation into the stratosphere for the entire D5-D15 period. So if tropospheric forecasts are correct, I would anticipate another strong assault on the stratospheric vortex in approximately 10-15 days. Current: D5: D10 (looks similar through D 15): Link to comment Share on other sites More sharing options...
PB GFI Posted December 2, 2014 Share Posted December 2, 2014 The departures for the 10 - 11 -12 -on the 12z EURO are COLD The first 7 days are N at best . So next week is no longer warm . Just like this week is no longer warm . The best case for warmth is for after this period , but for how long . We will see. Link to comment Share on other sites More sharing options...
danstorm Posted December 2, 2014 Share Posted December 2, 2014 The departures for the 10 - 11 -12 -on the 12z EURO are COLD The first 7 days are N at best . So next week is no longer warm . Just like this week is no longer warm . The best case for warmth is for after this period , but for how long . We will see. Yeah, but you can't say that's a good pattern overall D8-10. The entirety of NA is flooded with warm PAC air and that looks to continue beyond D10. Link to comment Share on other sites More sharing options...
PB GFI Posted December 2, 2014 Share Posted December 2, 2014 Yeah, but you can't say that's a good pattern overall D8-10. The entirety of NA is flooded with warm PAC air and that looks to continue beyond D10. Better amplitude on today`s Euro MJO and the UKIE has been rock steady . The PAC air should intrude but could be short lived and certainly muted . Link to comment Share on other sites More sharing options...
Weathergun Posted December 2, 2014 Share Posted December 2, 2014 Do you have verification statistics for stratospheric forecasts at the D10+ range? I would believe they're even less reliable than tropospheric long-term model guidance. Speaking of the much discussed NW Asian low, this feature will be dislodged by D 4-5, and a mid level ridge will take its place, setting the stage for a conducive 500mb pattern for the resumption of strong vertical wave propagation into the stratosphere for the entire D5-D15 period. So if tropospheric forecasts are correct, I would anticipate another strong assault on the stratospheric vortex in approximately 10-15 days. Current: D5: D10 (looks similar through D 15): WSI tweet this image out. For the 0z Euro Ensemble at 360hr. It show 10mb temps cooling: Link to comment Share on other sites More sharing options...
Isotherm Posted December 2, 2014 Share Posted December 2, 2014 WSI tweet this image out. For the 0z Euro Ensemble at 360hr. It show 10mb temps cooling: WSI tweet this image out. For the 0z Euro Ensemble at 360hr. It show 10mb temps cooling: If that verifies, it would definitely be concerning. Again, I'm not sure of the accuracy of longer term stratospheric guidance (I doubt very good). Do you remember if the ensembles detected the recent 10mb warm spike at 360hrs from back in early/mid November? Link to comment Share on other sites More sharing options...
Weathergun Posted December 2, 2014 Share Posted December 2, 2014 If that verifies, it would definitely be concerning. Again, I'm not sure of the accuracy of longer term stratospheric guidance (I doubt very good). Do you remember if the ensembles detected the recent 10mb warm spike at 360hrs from back in early/mid November? This is from Nov 17th: Link to comment Share on other sites More sharing options...
Isotherm Posted December 2, 2014 Share Posted December 2, 2014 This is from Nov 17th: It appears it slightly missed the timing as 10mb temperatures have cooled rapidly over the past few days, but overall, a generally pretty good forecast. Should be interesting to see how things progress particularly after the NW Asian mid level pattern reverses in several days. Again, I wonder if there are any stats out there on its verification; going to check into that. Edit: I found tropospheric verification but not stratospheric: http://www.ecmwf.int/en/forecasts/charts/catalogue?f[0]=im_field_chart_type_2%3A606 Link to comment Share on other sites More sharing options...
earthlight Posted December 2, 2014 Author Share Posted December 2, 2014 It appears it slightly missed the timing as 10mb temperatures have cooled rapidly over the past few days, but overall, a generally pretty good forecast. Should be interesting to see how things progress particularly after the NW Asian mid level pattern reverses in several days. Again, I wonder if there are any stats out there on its verification; going to check into that. Edit: I found tropospheric verification but not stratospheric: http://www.ecmwf.int/en/forecasts/charts/catalogue?f[0]=im_field_chart_type_2%3A606 This website lets you view the last few days of forecasts back to the 22nd of November. Interestingly enough, if you went back even further you'd see that the Euro specifically was pretty poor in forecasting the split of the vortex. It really backed off on that, in the end. But for a while it was splitting the vortex at many levels and causing a major disruption. http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/ I agree that cooling in the stratosphere over the region of Eurasia would be concerning, if it does come to pass, over the next week or so. Link to comment Share on other sites More sharing options...
SnowGoose69 Posted December 2, 2014 Share Posted December 2, 2014 Someone just posted this Link to comment Share on other sites More sharing options...
PB GFI Posted December 2, 2014 Share Posted December 2, 2014 Someone just posted this And after this week of N , this is where we are in 7 to 10 days at the surface while we are in 4- 5 and should be above . The pos PNA has cut this warmth short . Guys are looking at 500 and not looking at the surface . The torch is muted . Is 10 -15 is warm ? PROB I can buy that but this should have been a 10 to 15 day period of above and I think it`s 5 - 7 max . Again if it`s snow people want I will concede , it will not happen on the coastal plain . But we will not be that far above by the time we flip out of this . Link to comment Share on other sites More sharing options...
Allsnow Posted December 3, 2014 Share Posted December 3, 2014 Post day 10 on the euro ens not bad! That goa low/trof is eroding and a Caspian sea ridge pops which usually promotes cross polar flow into Canada to get that cold again. Link to comment Share on other sites More sharing options...
REDMK6GLI Posted December 3, 2014 Share Posted December 3, 2014 Post day 10 on the euro end not bad! That goa low/trof is eroding and a Caspian sea ridge pops which usually promotes cross polar flow into Canada to get that cold again. Makes sense given the MJO moving into a more favorable phase around that time period. Also watching the stratospheric warming to see if it can do some dirty work in disturbing the PV enough to get to split and possible kick start or NAO to tank. D 10 would take us to the 13th so it may fit nicely to where the pattern is expected to change/step down save for a few days of lag maybe Link to comment Share on other sites More sharing options...
Thundersnow12 Posted December 3, 2014 Share Posted December 3, 2014 More amplified look today...but the Euro isn't as bullish Link to comment Share on other sites More sharing options...
Weathergun Posted December 3, 2014 Share Posted December 3, 2014 This website has MJO in phases with ENSO background. Phase 5 is pretty warm in Eastern US. Phase 6 somewhat cooler. Phase 7 in in El Nino December is very warm for much the CONUS. It dosn't get that cold again until phase 1: http://www.meteonetwork.it/models/mjo/ Link to comment Share on other sites More sharing options...
Dsnowx53 Posted December 3, 2014 Share Posted December 3, 2014 And we are in phase 6 next week and getting closer to phase 7. That probably explains the PNA spike, as well as the fact that Canada is actually pretty cold. Not a shock that the Euro has two winter events next week, though we still have work to do to get them to be snow for the coast. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted December 3, 2014 Share Posted December 3, 2014 We also have to be wary of the short sample size of strictly +ENSO and MJO phases. But those composites do seem to make some sort of sense. Link to comment Share on other sites More sharing options...
SnowGoose69 Posted December 3, 2014 Share Posted December 3, 2014 In essence there are NO MJO phases that are good in December in an El Nino, remarkable 02 and 09 were as good as they were, even with blocking Link to comment Share on other sites More sharing options...
jm1220 Posted December 3, 2014 Share Posted December 3, 2014 In essence there are NO MJO phases that are good in December in an El Nino, remarkable 02 and 09 were as good as they were, even with blocking We get our El Nino-year chances when we start seeing the parades of storms coming east from California, tapping into Gulf moisture and hopefully running north into a cold dome here without being suppressed. That was the ticket for most of our big 02-03 and 09-10 storms, and that usually happens later in the season, such as Feb 1983, the Feb 2010 storms, and PDII. Link to comment Share on other sites More sharing options...
SnoSki14 Posted December 3, 2014 Share Posted December 3, 2014 Why are El Ninos usually back loaded I never understood that. Why is mid December often so different from mid January in an El Niño? Does it have to do with the wavelengths. Link to comment Share on other sites More sharing options...
Weathergun Posted December 3, 2014 Share Posted December 3, 2014 In essence there are NO MJO phases that are good in December in an El Nino, remarkable 02 and 09 were as good as they were, even with blocking Yeah, for example phase 8 500mb composite looks alot less favorable for winter storms over Eastern US than a neutral ENSO or La Nina. No blocking, and more heights along over Eastern US, Link to comment Share on other sites More sharing options...
bluewave Posted December 3, 2014 Share Posted December 3, 2014 We also have to be wary of the short sample size of strictly +ENSO and MJO phases. But those composites do seem to make some sort of sense. The other possibility is that the El Nino conditions are the dominant factor and the MJO phase is just playing a background role. Notice how the November pattern matched the Nino 3.4 chart. It also matched MJO Nino 6 but we weren't in that phase in November. The present December pattern just looks like the typical El Nino composite rather than any specific MJO phase. Link to comment Share on other sites More sharing options...
SnowGoose69 Posted December 4, 2014 Share Posted December 4, 2014 The other possibility is that the El Nino conditions are the dominant factor and the MJO phase is just playing a background role. Notice how the November pattern matched the Nino 3.4 chart. It also matched MJO Nino 6 but we weren't in that phase in November. The present December pattern just looks like the typical El Nino composite rather than any specific MJO phase. All in all it sums up why trying to make winter forecasts is crazy hard. We have seen many end up correct but many end up wrong too. El Ninos and La Ninas I find are the toughest because you never quite know how they will behave, not all strong versions or weak versions ever behave the same each time. 2010-2011 didn't act at all like a La Nina to make matters even harder. One concern I had going into this winter was the atmospheric memory, El Ninos following a long period dominated by La Ninas or a strong La Niña can act La Niña like and vice versa, that may have been what caused the 2010-2011 winter to behave Niño like and partly why 95-96 may have also acted somewhat like an El Niño. The concern I had was we could end up mostly positive on the AO and NAO if that memory took hold. Link to comment Share on other sites More sharing options...
Allsnow Posted December 4, 2014 Share Posted December 4, 2014 Check out h5 for dec 03 compared to this December so far...very close. Complete flip by January 04. HM had been talking about this on twitter Link to comment Share on other sites More sharing options...
SnowGoose69 Posted December 4, 2014 Share Posted December 4, 2014 Check out h5 for dec 03 compared to this December so far...very close. Complete flip by January 04. HM had been talking about this on twitter Yeah I mentioned awhile back how December 03 is the poster boy for miserable pattern that produced a bunch of snow, it got ugly though in February on but that was a neutral or weak weak niño if I remember right Link to comment Share on other sites More sharing options...
Radders Posted December 4, 2014 Share Posted December 4, 2014 Check out h5 for dec 03 compared to this December so far...very close. Complete flip by January 04. HM had been talking about this on twitter I remember there was a major snowstorm on the east coast around Dec 5th 2003 that lasted over two days... Was that a thread the needle? I recall that after the storm, the it warmed up to the 50s and the snow melted pretty rapidly... Link to comment Share on other sites More sharing options...
SnowGoose69 Posted December 4, 2014 Share Posted December 4, 2014 I remember there was a major snowstorm on the east coast around Dec 5th 2003 that lasted over two days... Was that a thread the needle? I recall that after the storm, the it warmed up to the 50s and the snow melted pretty rapidly... No I think the NAO was negative but we got lucky in that the overrunning round which was not really anticipated to be snow or even happen for that matter produced 6-10 inches of snow. The main low itself on Saturday was largely a disappointment for many, I think I got 9 Friday and 4 Saturday. It was similar to the late January 2011 event in that the lead overrunning was totally missed by the models. Link to comment Share on other sites More sharing options...
Stormlover74 Posted December 4, 2014 Share Posted December 4, 2014 I remember there was a major snowstorm on the east coast around Dec 5th 2003 that lasted over two days... Was that a thread the needle? I recall that after the storm, the it warmed up to the 50s and the snow melted pretty rapidly... The first 10 days were mostly cold but I do remember initially it was supposed to be rain. It did warm up briefly around the 10th but torched the last 10 days of the month Link to comment Share on other sites More sharing options...
Allsnow Posted December 4, 2014 Share Posted December 4, 2014 yes, we got lucky in a crappy pattern overall in december 03. February 04 sucked, but march 04 was real snowy... it was pretty neutral overall to very weak nino Link to comment Share on other sites More sharing options...
SnowGoose69 Posted December 4, 2014 Share Posted December 4, 2014 yes, we got lucky in a crappy pattern overall in december 03. February 04 sucked, but march 04 was real snowy... it was pretty neutral overall to very weak nino The 2nd storm was really odd, it was about as Niña like a storm you could have in a very non La Niña like pattern. And we sort of overachieved in that event too much like the first. Link to comment Share on other sites More sharing options...
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