Hoosier Posted March 16, 2013 Share Posted March 16, 2013 Don S hit the nail on the head...can't wait to see what he thinks about April. Here's a hint that he dropped in the medium range thread in the main forum: In terms of North American weather, it wouldn't surprise me to see April start cold courtesy of the blocking and then see a shift toward notably warmer conditions as the spring progresses and neutral ENSO conditions (biased a little on the warm side) prevail. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted March 16, 2013 Share Posted March 16, 2013 Just out of curiosity, I did a little bit of digging to find out how frequent subfreezing highs are at Toronto, since with this current pattern extended for a while we might be looking at the possibility of seeing some this year. Turns out that they've actually occurred less frequently than I thought. Since 1960, they've only occurred 24 times, giving them a ~45% chance of happening in any given year. However, many months had consecutive days of subfreezing highs, and they only occurred in 13 of the past 53 years. 4/7/2009 4/7/2007, 4/6/2007, 4/7/2007 4/4/2003, 4/6/2003, 4/7/2003, 4/8/2003 4/8/1997 4/4/1996 4/9/1985 4/4/1982, 4/5/1982, 4/6/1982, 4/7/1982 4/8/1979 4/8/1977 4/4/1975, 4/6/1975 4/8/1974 4/6/1972, 4/7/1972, 4/8/1972 4/1/1965 Also, more of a coincidence than anything, but all of these dates except for two of them happened in the April 4 - 8 range. lol, for a sec I thought you were talking about March and the head scratching was about to begin. Relative paucity of subfreezing April days doesn't surprise me though. Stretch in 2003 coincides with the ice storm Link to comment Share on other sites More sharing options...
OntarioWX Posted March 16, 2013 Share Posted March 16, 2013 lol, for a sec I thought you were talking about March and the head scratching was about to begin. Relative paucity of subfreezing April days doesn't surprise me though. Stretch in 2003 coincides with the ice storm Shoot, I forgot to mention April in the original post. Has Toronto ever gone a March without a high below 0C? Link to comment Share on other sites More sharing options...
snowstormcanuck Posted March 16, 2013 Share Posted March 16, 2013 Shoot, I forgot to mention April in the original post. Has Toronto ever gone a March without a high below 0C? Off the top of my head I would have said that's never happened. Surprisingly, it's happened a few times (1943, 1946, and most recently in 2010). And some close calls: March 2000 and 1945 had just one. March 1957, 1958, 2012: two. March 1938 and 1977: three. Link to comment Share on other sites More sharing options...
Chicago WX Posted March 16, 2013 Share Posted March 16, 2013 Actually...compared to normal, the real cold will be east of here... 12z Euro ensemble mean 850 temperature departure maps for days 1-5 and 6-10. Link to comment Share on other sites More sharing options...
SpartyOn Posted March 17, 2013 Share Posted March 17, 2013 From the main forum. Historic dip in the AO causing extreme warming over the N Pole. Just incredible. GaWX Per the 0Z 3/16 GEFS, the AO is forecasted to dip to near -5 or lower 3/19-23 (yes, 5 days of sub ~-5) with a low ~-5.5 within 3/20-2!! This is even lower than prior runs! How unprecedented is this? Well, going back to 1950, when daily AO records start, there has not been a single day near or lower than -5 between 3/11 and 11/16, inclusive! Actually, there have been sub -5 days in March only in 1970 and that was seven days in early March (3/4-10). How crazy is this? The 0Z 3/16 and earlier Euro runs have had a 1064 mb sfc high and 566 dm 500 mb hts. centered over the N pole on 3/19! Considering how anomalous is this AO dip, the major S showing for parts of the SE US on 3/22 on the 0Z 3/16 Euro is not far-fetched at all. Weatherguy701 In the context of the atmospheric anomalies. The severe -AO would create above normal temperatures in the arctic, perhaps reaching record territory along the west coast of Greenland. Last year at this time the AO was weakly positive and the polar vortex was on the other side of the hemisphere and confined to Siberia and parts of Europe. Creating record warm temperatures during the winter and spring of 2012 in North America. A similar negative AO event occured in 2010 which eventually led to the warmest year on record, ranking close to 1998 and 2005 in terms of global temperatures. Link to comment Share on other sites More sharing options...
MidwestChaser Posted March 17, 2013 Share Posted March 17, 2013 So, what does that mean for the Plains severe season? Link to comment Share on other sites More sharing options...
wxdudemike Posted March 17, 2013 Share Posted March 17, 2013 So, what does that mean for the Plains severe season? I know for the OV it means cold rain Link to comment Share on other sites More sharing options...
DAFF Posted March 17, 2013 Share Posted March 17, 2013 Wow some incredible weather about to unfold... Link to comment Share on other sites More sharing options...
Chicago WX Posted March 17, 2013 Share Posted March 17, 2013 Impressive. Link to comment Share on other sites More sharing options...
SpartyOn Posted March 17, 2013 Share Posted March 17, 2013 Impressive. 3:16 AO index.gif Thats a save worthy image there. Add the NH global plot showing the Arctic/N pole heights and toasty temps in there too. Wow. Link to comment Share on other sites More sharing options...
MidwestChaser Posted March 17, 2013 Share Posted March 17, 2013 Wow some incredible weather about to unfold... Meaning what? Link to comment Share on other sites More sharing options...
Chicago WX Posted March 17, 2013 Share Posted March 17, 2013 Thats a save worthy image there. Add the NH global plot showing the Arctic/N pole heights and toasty temps in there too. Wow. Pretty cool really. After the record warm March last year, a potential record low daily AO reading with this one...since 1950 anyway. Link to comment Share on other sites More sharing options...
SpartyOn Posted March 17, 2013 Share Posted March 17, 2013 Meaning what? An atmospheric log jam. Link to comment Share on other sites More sharing options...
hm8 Posted March 17, 2013 Author Share Posted March 17, 2013 Reminder that the AO index there is measured in standard deviations from the 1979-2000 mean....so models are forcasting a 5.5-6 sigma event. Which is absurd. Link to comment Share on other sites More sharing options...
Chinook Posted March 17, 2013 Share Posted March 17, 2013 Thats a save worthy image there. Add the NH global plot showing the Arctic/N pole heights and toasty temps in there too. Wow. I've been following this for years, and the CPC indices just don't go to +6 or -6. This AO of -5.8 is insane. Link to comment Share on other sites More sharing options...
MidwestChaser Posted March 17, 2013 Share Posted March 17, 2013 An atmospheric log jam. So how is that "incredible weather"? Link to comment Share on other sites More sharing options...
OHweather Posted March 17, 2013 Share Posted March 17, 2013 So how is that "incredible weather"? It may not be incredible from a sensible weather stand point for a lot of this sub-forum...however it is cool to watch something occur in the atmosphere that doesn't really ever occur this time of year. Also, the -AO will likely contribute to a sizable snowstorm over the interior Mid-Atlantic and New England...and potentially some decent lake effect snow in the lake belts Tuesday-Thursday as well...it will also have something to do with you needing to wear a jacket outside for at least the next week. I guess it depends on where you live and what you want to get out of the weather...obviously this -AO will put severe season on hold for the foreseeable future, although things appear ready to begin relaxing near the end of March. Link to comment Share on other sites More sharing options...
Stebo Posted March 17, 2013 Share Posted March 17, 2013 It may not be incredible from a sensible weather stand point for a lot of this sub-forum...however it is cool to watch something occur in the atmosphere that doesn't really ever occur this time of year. Also, the -AO will likely contribute to a sizable snowstorm over the interior Mid-Atlantic and New England...and potentially some decent lake effect snow in the lake belts Tuesday-Thursday as well...it will also have something to do with you needing to wear a jacket outside for at least the next week. I guess it depends on where you live and what you want to get out of the weather...obviously this -AO will put severe season on hold for the foreseeable future, although things appear ready to begin relaxing near the end of March. One thing I would imagine however is when the pattern does flip eventually it could flip in a huge way. Link to comment Share on other sites More sharing options...
OHweather Posted March 17, 2013 Share Posted March 17, 2013 One thing I would imagine however is when the pattern does flip eventually it could flip in a huge way. Yeah...and there will probably be a nice stout baroclinic zone to play with too for any storms when/if that occurs. Link to comment Share on other sites More sharing options...
cyclone77 Posted March 17, 2013 Share Posted March 17, 2013 One thing I would imagine however is when the pattern does flip eventually it could flip in a huge way. Yeah, you'd think after such a long streak of cold that when it flips it's gonna be dramatic. That seems to be how it usually works whether it's for one extreme or the other in any season. Link to comment Share on other sites More sharing options...
wisconsinwx Posted March 17, 2013 Share Posted March 17, 2013 One thing I would imagine however is when the pattern does flip eventually it could flip in a huge way. Yep, but remember how long it took last year's crazy warm pattern to flip in its currently huge way. Nothing can be ruled out for certain, and that includes a persistently cold year. Link to comment Share on other sites More sharing options...
TimChgo9 Posted March 17, 2013 Share Posted March 17, 2013 I am kind of banking on an active severe season based on what I have read so far. We will see how it pans out, but my gut feeling is that things may get serious come April/May. Link to comment Share on other sites More sharing options...
Stebo Posted March 17, 2013 Share Posted March 17, 2013 Yep, but remember how long it took last year's crazy warm pattern to flip in its currently huge way. Nothing can be ruled out for certain, and that includes a persistently cold year. No nothing is certain but one would have to imagine the -AO/-NAO regime would break down eventually especially at its current magnitude. Link to comment Share on other sites More sharing options...
Powerball Posted March 17, 2013 Share Posted March 17, 2013 I just want something BIG locally (weather-wise) to come out of this crap. No more salt on the wound. Link to comment Share on other sites More sharing options...
DAFF Posted March 17, 2013 Share Posted March 17, 2013 With this type of set up wouldn't there be a very sharp temperature gradient from 30-80 causing a clash along the front. Just a thought towards severe weather south of us. Link to comment Share on other sites More sharing options...
hm8 Posted March 17, 2013 Author Share Posted March 17, 2013 I just want something BIG locally (weather-wise) to come out of this crap. No more salt on the wound. Future headline: Biggest Stratus Deck in History Hangs over Michigan Link to comment Share on other sites More sharing options...
nwburbschaser Posted March 17, 2013 Share Posted March 17, 2013 Obviously the long term forecasts of the teleconnections are still fantasy land, but at least the 00z GFS has a +AO, weakly -NAO, +EPO, -PNA around the beginning of April. My understanding is that would be a signal for warmer temps around here, but that doesn't mean much at this range. Link to comment Share on other sites More sharing options...
andyhb Posted March 17, 2013 Share Posted March 17, 2013 Obviously the long term forecasts of the teleconnections are still fantasy land, but at least the 00z GFS has a +AO, weakly -NAO, +EPO, -PNA around the beginning of April. My understanding is that would be a signal for warmer temps around here, but that doesn't mean much at this range. A lot of those would be a nice signal for a more active severe period. Link to comment Share on other sites More sharing options...
wisconsinwx Posted March 17, 2013 Share Posted March 17, 2013 Future headline: Biggest Stratus Deck in History Hangs over Michigan It really gets to me that the stratus has been hanging on so long on many nights this winter (the opposite qualm that Powerball has with stratus hanging on during the day, limiting sun and high temps). Link to comment Share on other sites More sharing options...
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