usedtobe Posted November 20, 2012 Share Posted November 20, 2012 Here's my latest article with stats on ENSO climo, seasonal snowfall when ONI is positive, # of big snowstorms (a big thanks to Matt), AO average during D-F. http://www.washingto....html#pagebreak Link to comment Share on other sites More sharing options...
ORH_wxman Posted November 20, 2012 Share Posted November 20, 2012 Nice article Wes. The weaker El Ninos tend to be more northern stream dominated...I'm sure that is a big reason why they don't perform blockbuster seasons there, even when the AO is negative. The STJ this year has been doing pretty well the past 3 or 4 weeks, so we'll have to see if that continues or dies out as winter goes on. If it stays active, that would probably give a higher chance for DC to get a good storm...provided the blocking is in place too of course. Link to comment Share on other sites More sharing options...
Bob Chill Posted November 20, 2012 Share Posted November 20, 2012 Great stuff Wes! If you overlay snow cover data (and assume that the ao won't suck like 06-07) then 76-77, 77-78, and 04-05 fit nicely. 04-05 wasn't in my top 10 with my snow cover post because I focused on Eurasia. It's #9 overall w/ NH snowcover data. Your data definitely is just another indication that this winter might be "normal" in the snow dept. Link to comment Share on other sites More sharing options...
usedtobe Posted November 20, 2012 Author Share Posted November 20, 2012 Nice article Wes. The weaker El Ninos tend to be more northern stream dominated...I'm sure that is a big reason why they don't perform blockbuster seasons there, even when the AO is negative. The STJ this year has been doing pretty well the past 3 or 4 weeks, so we'll have to see if that continues or dies out as winter goes on. If it stays active, that would probably give a higher chance for DC to get a good storm...provided the blocking is in place too of course. I made an error about the positive AO weak ones. Most storms just go into the plains or Great Lakes and then die by the time they get to the dc area. I almost put the statement about the subtropical jet into the ninos that produced lower than normal snowfall with a negative AO as a couple of years that was true but when the AO was weakly negative like 1997-1998 in a strong nino, there was lots of southern stream and a great storm track but no cold air. To include all that would have made a long article too long. We need the southern stream and a negative AO to both pan out. 1995-1996 has always interested me because despite having a strong northern stream they dug far enough south at times in the eastern u.s. that they became southern stream systems. If you look at the seasonal 500 mb anomaly pattern it looked nothing like a nina. Link to comment Share on other sites More sharing options...
RodneyS Posted November 20, 2012 Share Posted November 20, 2012 Here's my latest article with stats on ENSO climo, seasonal snowfall when ONI is positive, # of big snowstorms (a big thanks to Matt), AO average during D-F. http://www.washingto....html#pagebreak Very informative, as always. I note that you include 1958-59 as a weak El Nino year, but not 1969-70. This table -- http://ggweather.com/enso/oni.htm -- shows the opposite. Snowfall at DCA during the former year was 4.9 inches, whereas it was 14.0 inches during the latter year. Link to comment Share on other sites More sharing options...
ORH_wxman Posted November 20, 2012 Share Posted November 20, 2012 I made an error about the positive AO weak ones. Most storms just go into the plains or Great Lakes and then die by the time they get to the dc area. I almost put the statement about the subtropical jet into the ninos that produced lower than normal snowfall with a negative AO as a couple of years that was true but when the AO was weakly negative like 1997-1998 in a strong nino, there was lots of southern stream and a great storm track but no cold air. To include all that would have made a long article too long. We need the southern stream and a negative AO to both pan out. 1995-1996 has always interested me because despite having a strong northern stream they dug far enough south at times in the eastern u.s. that they became southern stream systems. If you look at the seasonal 500 mb anomaly pattern it looked nothing like a nina. 1995-1996 was interesting in that during January, the KU happened with a big split flow in the polar jet...and the southern branch was far enough south to act as a pseudo STJ and produce the great miller A storm we saw on 1/6 through 1/8. Then in February 1996, we got an actual STJ going a bit...enough that it helped jump start systems like 2/16/96 and 2/2/96. The northern stream was still digging far south which helped...but having a bit of STJ energy to focus the baroclinicity almost certainly helped those systems form further south. Weird winter that was...you are definitely right that it looked nothing like a La Nina. Link to comment Share on other sites More sharing options...
Deck Pic Posted November 20, 2012 Share Posted November 20, 2012 nicely done Link to comment Share on other sites More sharing options...
usedtobe Posted November 20, 2012 Author Share Posted November 20, 2012 Very informative, as always. I note that you include 1958-59 as a weak El Nino year, but not 1969-70. This table -- http://ggweather.com/enso/oni.htm -- shows the opposite. Snowfall at DCA during the former year was 4.9 inches, whereas it was 14.0 inches during the latter year. Looks like I should have included both according to CPC. Somehow when picking of the years I missed 1969-1970. http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtm I don't think that changes the conclusions much though it may be the reason our El Nino averages were a little different. Actually that would give me 14 weaker nino events and would change the top end of the 70% grouping to from 12.5 to 14. Link to comment Share on other sites More sharing options...
Ian Posted November 20, 2012 Share Posted November 20, 2012 nice read. btw, i have every snow event since records began in a sheet if anyone wants it. one of those things i created then did nothing with.. not sure why since it took forever. Link to comment Share on other sites More sharing options...
usedtobe Posted November 20, 2012 Author Share Posted November 20, 2012 nicely done Matt, the dates you gave for the 5.5 inch events helped quite bit. Link to comment Share on other sites More sharing options...
Deck Pic Posted November 20, 2012 Share Posted November 20, 2012 Matt, the dates you gave for the 5.5 inch events helped quite bit. no problem....now we just need a 5.5" event this winter to add to it Link to comment Share on other sites More sharing options...
usedtobe Posted November 20, 2012 Author Share Posted November 20, 2012 nice read. btw, i have every snow event since records began in a sheet if anyone wants it. one of those things i created then did nothing with.. not sure why since it took forever. I think I've used them before for a post on the chances of having snow fall during the week of xmas. You should do a post on that as we approach the date especially if it looks like there is a chance of snow. The Roundy stuff suggests not but the mjo forecasts are not good enough to really draw any firm conclusion about that far in advance. Link to comment Share on other sites More sharing options...
Fozz Posted November 20, 2012 Share Posted November 20, 2012 I like some of those years, esp. for northern MD. Nice write up as usual. Link to comment Share on other sites More sharing options...
RodneyS Posted November 21, 2012 Share Posted November 21, 2012 http://www.cpc.ncep..../ensoyears.shtm The link doesn't work for me. Link to comment Share on other sites More sharing options...
usedtobe Posted November 21, 2012 Author Share Posted November 21, 2012 The link doesn't work for me. http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml Link to comment Share on other sites More sharing options...
RodneyS Posted November 21, 2012 Share Posted November 21, 2012 http://www.cpc.ncep....ensoyears.shtml Thanks. That's the same table that is on the webpage that I posted, except centered differently. I just e-mailed the author of that webpage to inquire why he does not count 1958-59 as a Nino event. Link to comment Share on other sites More sharing options...
RodneyS Posted November 21, 2012 Share Posted November 21, 2012 Thanks. That's the same table that is on the webpage that I posted, except centered differently. I just e-mailed the author of that webpage to inquire why he does not count 1958-59 as a Nino event. The author, Jan Null, has already gotten back to me and acknowledges that 1958-59 should be classified as a Nino event. So, the new count (since 1949-50) is 21 Nino events, 22 Nina events, and 20 neutral events. Link to comment Share on other sites More sharing options...
usedtobe Posted November 21, 2012 Author Share Posted November 21, 2012 The author, Jan Null, has already gotten back to me and acknowledges that 1958-59 should be classified as a Nino event. So, the new count (since 1949-50) is 21 Nino events, 22 Nina events, and 20 neutral events. Good, at least you and I looking at it got the list updated and corrected. Link to comment Share on other sites More sharing options...
mitchnick Posted November 21, 2012 Share Posted November 21, 2012 The author, Jan Null, has already gotten back to me and acknowledges that 1958-59 should be classified as a Nino event. So, the new count (since 1949-50) is 21 Nino events, 22 Nina events, and 20 neutral events. that was one cr@ppy winter....makes sense since I was born in 58' Link to comment Share on other sites More sharing options...
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