Chrisrotary12 Posted December 19, 2012 Share Posted December 19, 2012 Since we are in a boring (but active) time during the winter I am trying to better understand some of the atmospheric phenomena that impact our New England winters. I have read and I understand this paper: http://www.weatheranswer.com/public/NORLUN2.pdf I am curious to see if some of you guys have some other thoughts or forecasting tricks? Maybe some good memories that I could look at and perform my own case study. Thanks in advance. Link to comment Share on other sites More sharing options...
Tropopause_Fold Posted December 19, 2012 Share Posted December 19, 2012 One thing I think happens a bit is we tend to call a lot of inverted surface troughs a norlun and that's a bit deceiving. They are a lot of fun though, IMO. A synoptic scale event playing itself out on the mesoscale level. They can be prolific producers if you have the right ingredients in place. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 19, 2012 Share Posted December 19, 2012 One thing I think happens a bit is we tend to call a lot of inverted surface troughs a norlun and that's a bit deceiving. They are a lot of fun though, IMO. A synoptic scale event playing itself out on the mesoscale level. They can be prolific producers if you have the right ingredients in place. Yeah and they'll always have a narrow area that just gets destroyed in a 6hr time. Models struggle with these convective snows. Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 19, 2012 Share Posted December 19, 2012 You could look in depth at the most recent Jan 11 events in CT. There is a wealth of data available. Link to comment Share on other sites More sharing options...
ORH_wxman Posted December 19, 2012 Share Posted December 19, 2012 A norlun trough IS an inverted trough but it has a higher set of instability parameters than just a generic inverted trough...and yeah, usually there's a nice narrow area that gets smoked. Link to comment Share on other sites More sharing options...
eekuasepinniW Posted December 19, 2012 Share Posted December 19, 2012 Yeah and they'll always have a narrow area that just gets destroyed in a 6hr time. Models struggle with these convective snows. There was an awesome one here in 2007/2008 that dumped about 13" IIRC. It was crazy fluffy. Link to comment Share on other sites More sharing options...
Chrisrotary12 Posted December 19, 2012 Author Share Posted December 19, 2012 A norlun trough IS an inverted trough but it has a higher set of instability parameters than just a generic inverted trough...and yeah, usually there's a nice narrow area that gets smoked. It's an inverted trough that has all the parameters of a WINDEX event right? Link to comment Share on other sites More sharing options...
CoastalWx Posted December 19, 2012 Share Posted December 19, 2012 I don't know if there are any tricks to forecasting these. Usually, models will show some sort of an inverted trough....it's not something you can try to take a stab at....if conditions warrant, models will show it. They are very mesoscale and models may not always have the exact placement down, so a 20 mile shift means a 10" dump in 3hrs that originally looked like it could be over NE MA is now in BOS and you have huge bust potential. NORLUNs are one of those deals where a model like the NAM may spit out 6" of snow and you end up with 12". Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 19, 2012 Share Posted December 19, 2012 Matt Noyes had a great blog piece just prior to the SW CT biggie on Jan 7 th 2011 http://www.mattnoyes.net/new_england_weather/2011/01/exactly-what-is-a-norlun-trough-and-how-do-you-forecast-weather-associated-with-it.html Link to comment Share on other sites More sharing options...
CoastalWx Posted December 19, 2012 Share Posted December 19, 2012 I don't think the instability parameters were there (perhaps very localized it was), but SE NH had a great inv trough last winter. Early March I believe. Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 19, 2012 Share Posted December 19, 2012 Wait Nor. lun , hey Scooter you related to Mr Nor? Link to comment Share on other sites More sharing options...
CoastalWx Posted December 19, 2012 Share Posted December 19, 2012 Wait Nor. lun , hey Scooter you related to Mr Nor? Ha...no, but pretty strange to have someone with my last name as part of this feature. Part of the reason I like these. Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 19, 2012 Share Posted December 19, 2012 Ha...no, but pretty strange to have someone with my last name as part of this feature. Part of the reason I like these. That's cool, wonder how much Phil weenied out in Feb 19 th 1993 super Norlun on the Cape, 30 inch reports. What was he then like 11? Probably still has the crayon maps he made. Link to comment Share on other sites More sharing options...
dendrite Posted December 19, 2012 Share Posted December 19, 2012 There was an awesome one here in 2007/2008 that dumped about 13" IIRC. It was crazy fluffy. 12/19-20/07 dropped 14.0" here...almost the 5 year anni. Link to comment Share on other sites More sharing options...
ORH_wxman Posted December 19, 2012 Share Posted December 19, 2012 12/19-20/07 dropped 14.0" here...almost the 5 year anni. That was a decent event...fairly widespread actually...but it had some very intense squall-like bands embedded in the lighter snows. BOS had over 7" and some of the northern towns up near the NH border had close to 10" IIRC. Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 19, 2012 Share Posted December 19, 2012 Nice norlun in Maine right now Link to comment Share on other sites More sharing options...
Zeus Posted December 19, 2012 Share Posted December 19, 2012 Some quick facts on Norluns, from me: They are magical They make it snow in my backyard I like them The GFS signals them too often People also call something a Norlun too often when it's still directly associated with a low You don't understand Norluns like I understand Norluns Link to comment Share on other sites More sharing options...
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