ORH_wxman Posted July 16, 2015 Share Posted July 16, 2015 I would argue a strictly PNA driven pattern without EPO would not allow for the transient block to set up, Jan 27th storm. Many here as seen in this thread previously refused to believe transient blocking was as effective as Neg NAO. Well you def want at least some -EPO influence, i do agree on that (I'm not trying to argue -EPOs are bad)...otherwise you also risk warmer storms, even if they take seemingly good tracks. It probably wouldn't matter away from the coast, but for places like BOS and esp the south shore/south coast, the extra cold source is more optimal. The EPO was pretty weak for the Jan 26-27 blizzard. We did get that little transient block north of Greenland/Iceland late in the game on that pattern, which proabbly minorly helped with stalling the storm...but a majority of the "Stall" was due to the capture of the sfc low with the obscenely deepening 500mb trough/closed low. Link to comment Share on other sites More sharing options...
CoastalWx Posted July 16, 2015 Share Posted July 16, 2015 PNA ridge was skewed a bit east over the N Rockies...that is pretty much dead perfect for eastern New England. A Boston-optimized pattern....it sticks the trough far enough east so that you are either getting buried or scrapers/late bloomers/whiffs...no cutters in that pattern. And yeah, notice how the blocking up north is more in the WPO region...it's still a negative EPO but only mildly to moderately. And note that beautiful Aleutian low and what likely was just enough NATL ridging. I can believe this was done in a +NAO regime. Link to comment Share on other sites More sharing options...
ORH_wxman Posted July 16, 2015 Share Posted July 16, 2015 And note that beautiful Aleutian low and what likely was just enough NATL ridging. I can believe this was done in a +NAO regime. Different year, but pattern look a bit familiar? 10 day snow blitz in Jan 2005. Obviously the AO was more negative in '05, but the big N ATL ridge, the PNA, and the lower heights from Baffin Island into the NE were similar. The NAO here was technically negative since we got higher heights into Greenland....but the CONUS pattern is eerily similar. Link to comment Share on other sites More sharing options...
CoastalWx Posted July 16, 2015 Share Posted July 16, 2015 Different year, but pattern look a bit familiar? 10 day snow blitz in Jan 2005. Obviously the AO was more negative in '05, but the big N ATL ridge, the PNA, and the lower heights from Baffin Island into the NE were similar. The NAO here was technically negative since we got higher heights into Greenland....but the CONUS pattern is eerily similar. Yeah awesome. I think we know where our sweet spot is out west regarding ridge placement. Link to comment Share on other sites More sharing options...
Ginx snewx Posted July 16, 2015 Share Posted July 16, 2015 2005 analog showed up 11 times in a 5 day period for the Jan storm 6-14 days out. Link to comment Share on other sites More sharing options...
Ginx snewx Posted July 16, 2015 Share Posted July 16, 2015 Will post the composite for just the day of the blizzard Link to comment Share on other sites More sharing options...
nzucker Posted July 16, 2015 Share Posted July 16, 2015 PNA ridge was skewed a bit east over the N Rockies...that is pretty much dead perfect for eastern New England. A Boston-optimized pattern....it sticks the trough far enough east so that you are either getting buried or scrapers/late bloomers/whiffs...no cutters in that pattern. And yeah, notice how the blocking up north is more in the WPO region...it's still a negative EPO but only mildly to moderately. Definitely can see why BOS had its snowiest winter ever whereas farther south had solidly above average snowfall without approaching records. We had 55" in Dobbs Ferry, which is about 150% of climo whereas much of SNE had nearly 300% of normal. The PNA ridge being further east definitely explains the propensity for the late bloomers and coastal scrapers that create this distribution of snowfall anomalies.Just as the 500mb maps are similar to Jan 2005, so is the placement of snowfall anomalies. In my area, LI got buried in 04-05 with parts of the North Shore seeing almost 80" snowfall, about 275% of climo. Southern Westchester had 50", or around 140% of normal snow. The late January blizzard and March equinox storms hit LI very hard with lesser amounts to the west. Similar winter in many ways, although 14-15 was far colder with a much better February. 04-05 let up in February after a great January whereas 14-15 had an unmemorable January and huge February. Also, the EPO was much more negative last winter than in '05, which was a PNA driven pattern, accounting for the differences in cold. Link to comment Share on other sites More sharing options...
ORH_wxman Posted July 16, 2015 Share Posted July 16, 2015 Will post the composite for just the day of the blizzard Jan 26: Jan 27: Link to comment Share on other sites More sharing options...
CoastalWx Posted July 16, 2015 Share Posted July 16, 2015 Not gonna happen James. Link to comment Share on other sites More sharing options...
ORH_wxman Posted July 16, 2015 Share Posted July 16, 2015 Definitely can see why BOS had its snowiest winter ever whereas farther south had solidly above average snowfall without approaching records. We had 55" in Dobbs Ferry, which is about 150% of climo whereas much of SNE had nearly 300% of normal. The PNA ridge being further east definitely explains the propensity for the late bloomers and coastal scrapers that create this distribution of snowfall anomalies. Just as the 500mb maps are similar to Jan 2005, so is the placement of snowfall anomalies. In my area, LI got buried in 04-05 with parts of the North Shore seeing almost 80" snowfall, about 275% of climo. Southern Westchester had 50", or around 140% of normal snow. The late January blizzard and March equinox storms hit LI very hard with lesser amounts to the west. Similar winter in many ways, although 14-15 was far colder with a much better February. 04-05 let up in February after a great January whereas 14-15 had an unmemorable January and huge February. Also, the EPO was much more negative last winter than in '05, which was a PNA driven pattern, accounting for the differences in cold. Yes, there were a lot of similarities with the pattern. Some subtle differences of course as you mention, esp up in the arctic...but the CONUS pattern was almost a perfect match. The 2015 pattern also was stagnent for a longer period which of course prolonged the snow blitz in SNE...rather than like 10 days, it was more like 24 days. Contrast that to the great 3 week period in January 2011...esp for CT back through Philly. It was obviously great here too, but better in that corridor....we got the benefit of the Feb 1-2 storm later on when the pattern started flipping, but I am not cincluding that storm in this composite since it was a different type pattern: The 2011 pattern had the trough axis further southwest versus 2015...and of course the western ridge was actually offshore. But despite the ridge being much further west, it was offset some by a -NAO. So we didn't get the cutters anyway. Link to comment Share on other sites More sharing options...
Ginx snewx Posted July 16, 2015 Share Posted July 16, 2015 Jan 26: Jan 27: wood Link to comment Share on other sites More sharing options...
CoastalWx Posted July 16, 2015 Share Posted July 16, 2015 Ray was still disappointed. Link to comment Share on other sites More sharing options...
Ginx snewx Posted July 16, 2015 Share Posted July 16, 2015 4 wave patterns are the best Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.