A-L-E-X Posted March 1, 2011 Share Posted March 1, 2011 1916-17 was a moderate La Niña with a very cold regime; 1917-1918 was a weak Niña with brutal cold. I think that many long-range forecasters envisioned the turnaround in pattern, however...I said that December would be the coldest month and February the mildest, with the trough shifting into the west and the AO/NAO becoming more positive. I didn't think the blocking would hold out as long in January, that was unprecedented for a strong La Niña and perhaps related to the low geomagnetic flux that Isotherm had highlighted in his forecast. We're definitely seeing the 1989/1955 pattern where the cold anomalies moved into the west for February after the winter had started colder east. March will be a wild card, but all signs are that the back of the blocking has been broken...the vortex over Baffin Island and the Canadian Archipelago doesn't want to disappear. We've seen some great -NAO blocks in weak La Niñas like 95-96 and 66-67, but of course these winters followed El Niño. There may be a lag effect in terms of stratosphere temperatures and developments of the polar vortex. We'll have to do some more research on la ninas after la ninas-- but this is pretty much uncharted territory and the solar influence might be the wild card. It looks like the sun is trying to come out of its malaise. I agree that 1966-67 and 1995-96 were so great because they were weak la ninas that came after el ninos. It makes me wonder how much longer the blocking would have held on for had this la nina stayed weak. We probably would have broken the 1995-96 snowfall record with ease. Link to comment Share on other sites More sharing options...
A-L-E-X Posted March 1, 2011 Share Posted March 1, 2011 Yup, but unlikely we see a repeat anytime soon in this -PDO phase. Oh yes, I agree with this-- I think next winter will be quite -PDO. BTW I don't have the NAO numbers off hand for late Feb and early Mar, but I remember seeing the AO was forecast to be quite positive, +4 or so. Link to comment Share on other sites More sharing options...
A-L-E-X Posted March 1, 2011 Share Posted March 1, 2011 Can't say I agree here. If we have a weaker La Nina event next winter, the prospects of a -NAO increase quite a bit. My theory regarding the solar-NAO connection worked out well this year, so if we remain on the low side w/ geomagnetic activity, another highly blocked winter is possible. If we see a rapid increase in solar activity, paritcularly the aa index, then +NAO/AO probability rises (assuming another La Nina). With that being said, there are no guarantees either way, since a ramp-up in sunspot activity could induce a SSW event(s), but whether they propagate downward and impact the NAO modality is anyone's guess. I'd personally feel much more comfortable w/ -NAO prospects in a low solar env rather than a high one. This winter we're finally seeing the effects of the power house nina on the global regime. Also, even w/ the strong nina, we're not seeing a raging positive NAO (which we'd probably see if not for the low geomag environment). The solar influence is definitely the wild card. We're on a fine line regarding ramp up of solar activity, as it may encourage the development of an el nino, but it would also discourage strong blocking. Link to comment Share on other sites More sharing options...
wxmx Posted April 1, 2011 Share Posted April 1, 2011 Noice! 1 Apr 2011 1015.08 1002.35 74.55 19.23 20.06 Link to comment Share on other sites More sharing options...
Ed Lizard Posted April 1, 2011 Share Posted April 1, 2011 Noice! 1 Apr 2011 1015.08 1002.35 74.55 19.23 20.06 And Kush was making fun of the AccuMap targetting Venezuela. Link to comment Share on other sites More sharing options...
nzucker Posted April 1, 2011 Share Posted April 1, 2011 The last six days have had double-digit SOI numbers, with most of the days above +20...perhaps a resurgence of Niña? Link to comment Share on other sites More sharing options...
wxmx Posted April 1, 2011 Share Posted April 1, 2011 The last six days have had double-digit SOI numbers, with most of the days above +20...perhaps a resurgence of Niña? It has to do with the Aussie low near Darwin that is being talked about in the Aussie cyclone thread. But still, that is a consequence of having a very Niña pattern that isn't breaking down soon. If it can hold up until the end of spring, odds are that a new and improved Niña might build up towards Fall/Winter. Link to comment Share on other sites More sharing options...
gil888 Posted April 1, 2011 Share Posted April 1, 2011 Noice! 1 Apr 2011 1015.08 1002.35 74.55 19.23 20.06 I think that should be 47, not 74-- the changes weren't large enough to support such a high number -- yesterday's values was only in the 30s. Either way, the SOI has come on strong again. Link to comment Share on other sites More sharing options...
nzucker Posted April 1, 2011 Share Posted April 1, 2011 It has to do with the Aussie low near Darwin that is being talked about in the Aussie cyclone thread. But still, that is a consequence of having a very Niña pattern that isn't breaking down soon. If it can hold up until the end of spring, odds are that a new and improved Niña might build up towards Fall/Winter. Do you think the Niña stays weak this summer and then redevelops towards moderate/strong next fall? I'm obviously no expert, but that's my expectation. Link to comment Share on other sites More sharing options...
wxmx Posted April 1, 2011 Share Posted April 1, 2011 Do you think the Niña stays weak this summer and then redevelops towards moderate/strong next fall? I'm obviously no expert, but that's my expectation. I expect a La Niña for fall, not sure about the strenght, but I think it will trend towards cooler wrt Spring/Summer. Also, I don't think it will get in Niño territory in the weeklies, but neutral positive is probable. Disclaimer is that anything can happen, but the various factors that govern ENSO plus some research tells me that El Niño is unlikely for next winter. Link to comment Share on other sites More sharing options...
tacoman25 Posted April 1, 2011 Share Posted April 1, 2011 I expect a La Niña for fall, not sure about the strenght, but I think it will trend towards cooler wrt Spring/Summer. Also, I don't think it will get in Niño territory in the weeklies, but neutral positive is probable. Disclaimer is that anything can happen, but the various factors that govern ENSO plus some research tells me that El Niño is unlikely for next winter. Agreed. Weak Nina is most likely, imo. Similar to what happened in 2008-09, but maybe a bit stronger. FWIW, only 3 of 13 mod/strong Ninas have been followed by a Nino. Only one first year mod/strong Nina has been followed by a Nino (1964-65), and that one peaked exceptionally early in the fall. Link to comment Share on other sites More sharing options...
NC_hailstorm Posted May 7, 2011 Share Posted May 7, 2011 Starting to see some cracks.Overall the average has been lowering over the last couple weeks,might get below 19 on the 90 day average soon. 5 May 2011 -2.59 6 May 2011 -10.63 7 May 2011 -3.35 Link to comment Share on other sites More sharing options...
NC_hailstorm Posted May 13, 2011 Share Posted May 13, 2011 The La Nina is getting a good kick in the pants lately.90 day average down to 17.73 now. 8 May 2011 -13.16 9 May 2011 -17.06 10 May 2011 -14.92 11 May 2011 -9.48 12 May 2011 -20.13 13 May 2011 -10.55 Link to comment Share on other sites More sharing options...
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