Chris L Posted January 30, 2012 Share Posted January 30, 2012 Like I said a few days ago that ridge sagging to the east is not favorable for any time of winter storm around here. Its not like the ridge is positioned to the east -- that would be fine -- if it had a better S-N component to its axis. But it actually de-amplifies eastward and that is no good. Nevertheless the signals beginning at the end of this coming week are huge...and the GFS ensemble mean is screaming for both a +PNA ridge extending into Yukon and a pronounced Greenland Block. Start your engines ECMWF has a better look with regards to blocking, correct, John? Link to comment Share on other sites More sharing options...
Chris L Posted January 30, 2012 Share Posted January 30, 2012 It's not really east based by definition. An east based -NAO would have the ridge axis and area of positive height anomalies farther north. The ridge axis extends into the Davis Straight and there are +18 to +24dm above normal height anomalies over Greenland...not the Northwest Atlantic. The positive height anomalies extend all the way over the Pole. It may not be a cutoff block like we've seen the past two years...but don't really expect that, ever. Those are incredibly rare. But it's the 18z GFS height anomalies anyway. I think everyone's skewed by having a cutoff block, which we saw clearly in December 2010. but like you said, rare as Frank Sinatra's voice. Link to comment Share on other sites More sharing options...
TheTrials Posted January 30, 2012 Share Posted January 30, 2012 I think everyone's skewed by having a cutoff block, which we saw clearly in December 2010. but like you said, rare as Frank Sinatra's voice. no, I am perfectly aware of how hard it is to get them over the strait or to be pinched off over greenland, but this one is most assuredly focused to the east Link to comment Share on other sites More sharing options...
redbanknjandbigbasslakepa Posted January 30, 2012 Share Posted January 30, 2012 Yeah Trials is taking a cutoff monster block like last Dec/Jan and thinking every Greenland block has to look like that. That one was a rare animal, we don't need something that anomalous. What we are seeing on some of the computer guidance after day 7 will do just fine. Link to comment Share on other sites More sharing options...
TheTrials Posted January 30, 2012 Share Posted January 30, 2012 Yeah Trials is taking a cutoff monster block like last Dec/Jan and thinking every Greenland block has to look like that. That one was a rare animal, we don't need something that anomalous. What we are seeing on some of the computer guidance after day 7 will do just fine. No, but keep mis-quoting me. It doesnt need to be cut off or 570 dm, but you def. at least want the highest heights over the island, which they are not. Its all I am saying. A block like the one shown is going to probably push storms to the south and east and you can see the blue areas of the maps showing negative 500mb heights being pushed in that direction, thats what I am saying. Link to comment Share on other sites More sharing options...
TheTrials Posted January 30, 2012 Share Posted January 30, 2012 its also impt to note I am not speaking in terms of the measurement of the NAO in terms of its classical definition as the difference between the pressures over the azores and iceland . I am speaking of blocking and its positioning. East based blocking and an east based nao can be and are often different animals. Link to comment Share on other sites More sharing options...
tmagan Posted January 30, 2012 Share Posted January 30, 2012 should be an automatic month ban anytime someone brings up 96. Its a 100 year storm. Historic, but not a one-in-a-hundred. Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 30, 2012 Share Posted January 30, 2012 Like I said a few days ago that ridge sagging to the east is not favorable for any time of winter storm around here. Its not like the ridge is positioned to the east -- that would be fine -- if it had a better S-N component to its axis. But it actually de-amplifies eastward and that is no good. Nevertheless the signals beginning at the end of this coming week are huge...and the GFS ensemble mean is screaming for both a +PNA ridge extending into Yukon and a pronounced Greenland Block. Start your engines I would put those keys back into the draw, the pattern upcoming can still very easily disapoint if the PNA ridge does not get as strong as modeled or it slips east leaving the vortex over AK. Link to comment Share on other sites More sharing options...
earthlight Posted January 30, 2012 Share Posted January 30, 2012 I would put those keys back into the draw, the pattern upcoming can still very easily disapoint if the PNA ridge does not get as strong as modeled or it slips east leaving the vortex over AK. Sure. The medium range still offers many possibilities. But the MJO and developments in the arctic are giving us major help this time. Link to comment Share on other sites More sharing options...
TheTrials Posted January 30, 2012 Share Posted January 30, 2012 Here is a good illustration. Check out the deep ridge over the atlantic but most def. east of greenland (where i drew the red x). This is an east based block. I am not talking about the nao measurement, i am speaking of the height fields in their relation to greenland. In this scenario, you have a pv trapped to the s and w of greenand which is supressing the flow (see the flat looking line over the easter conus and see the arrow comng out of the pv to the south and west). Because the ridge is east of island, the pv cant move up and out, and you won't get anything to come up the coast. Now, if you move the core of those heights west over the island where i drew the circle, the pv moves up and east (see the arrow coming out of the top right of the pv) and you would get the heights on the east coast to rebound and a storm could come up (see the arrow over the gulf pointed towards us). A great example of how this hurts us in January 2007. We had this exact kind of look and what looked like a promissing time period was basically a waste of a lot of cold air. Link to comment Share on other sites More sharing options...
TheTrials Posted January 30, 2012 Share Posted January 30, 2012 and yes, i realize the ensemble mean does look a little better than this map, but the CORE of the anomolies has a tough time getting to a position where I could say, wow, thats gonna absolutely work for us. Link to comment Share on other sites More sharing options...
uncle W Posted January 30, 2012 Share Posted January 30, 2012 with the AO below-4 chances are great for the biggest snow or coldest temperature a head of us...First up is another mild week...Some years with mild temperatures in early February saw a snowstorm later in the month or in March... 2/5/1890...68 degrees...March had 17" of snow... 2/2/1967...58 degrees...15" of snow 2/6-7/1967 2/3/1983...59 degrees...18" of snow 2/11-12/1983 2/1/1989...67 degrees...3" of snow 3/6/1989 2/5/1991...70 degrees...8" of snow 2/26/1991 2/3/2006...62 degrees...26" of snow 2/11-12/2006 2/6/2008...68 degrees...3" 2/12 and 6" 2/22... Link to comment Share on other sites More sharing options...
TheTrials Posted January 30, 2012 Share Posted January 30, 2012 can't believe this is going to break up, at least per the nam Link to comment Share on other sites More sharing options...
SnoSki14 Posted January 30, 2012 Share Posted January 30, 2012 2/11-12/1983 jumps out immediately , were supposed to get to 59-60 this week, pattern really sets up by Feb 8-15. Link to comment Share on other sites More sharing options...
ag3 Posted January 30, 2012 Share Posted January 30, 2012 can't believe this is going to break up, at least per the nam Hrrr brings it intact through our area around 6z. But as a rain snow mix. http://rapidrefresh.noaa.gov/hrrrconus/displayMap.cgi?keys=hrrr:&runtime=2012012922&plot_type=cref_t3sfc&fcst=08&time_inc=60&num_times=16&model=hrrr&ptitle=HRRR%20Model%20Fields%20-%20Experimental&maxFcstLen=15&fcstStrLen=-1&domain=t3&adtfn=1&wjet=1 Link to comment Share on other sites More sharing options...
ORH_wxman Posted January 30, 2012 Share Posted January 30, 2012 Here is a good illustration. Check out the deep ridge over the atlantic but most def. east of greenland (where i drew the red x). This is an east based block. I am not talking about the nao measurement, i am speaking of the height fields in their relation to greenland. In this scenario, you have a pv trapped to the s and w of greenand which is supressing the flow (see the flat looking line over the easter conus and see the arrow comng out of the pv to the south and west). Because the ridge is east of island, the pv cant move up and out, and you won't get anything to come up the coast. Now, if you move the core of those heights west over the island where i drew the circle, the pv moves up and east (see the arrow coming out of the top right of the pv) and you would get the heights on the east coast to rebound and a storm could come up (see the arrow over the gulf pointed towards us). A great example of how this hurts us in January 2007. We had this exact kind of look and what looked like a promissing time period was basically a waste of a lot of cold air. That ridge axis actually bends back into the Davis straight but its weakened by the time its in that location...the problem isn't being east based on that map, its being too far south...more of a N ATL ridge and not a big Greenland ridge...it gets into Greenland but only the northern part of it. East based blocks usually promote further north storms than west based blocks...not the other way around. A north ATL ridge is a common pattern for big cold outbreaks in the east but it is generally poor for huge snowstorms. Obviously there are exceptions to these rules...but if you composite the top 20 or 30 cold outbreaks in the past 30 years, the N ATL ridge is staring at us in the face. Link to comment Share on other sites More sharing options...
ag3 Posted January 30, 2012 Share Posted January 30, 2012 Hrrr brings it intact through our area around 6z. But as a rain snow mix. http://rapidrefresh.noaa.gov/hrrrconus/displayMap.cgi?keys=hrrr:&runtime=2012012922&plot_type=cref_t3sfc&fcst=08&time_inc=60&num_times=16&model=hrrr&ptitle=HRRR%20Model%20Fields%20-%20Experimental&maxFcstLen=15&fcstStrLen=-1&domain=t3&adtfn=1&wjet=1 Reports in PA are awsome. 45-50mph winds with blinding snow and up to 1" in minutes. Hopefully, band holds and gives someone in our area something. Link to comment Share on other sites More sharing options...
CooL Posted January 30, 2012 Share Posted January 30, 2012 I think the solution of holding the cutoff energy in the sw has come and gone. Our problem is going to be if and when the storm system cuts to out west, when and if it transfers, and how much cold air will we have to work with. Im reviving this thread with the 87hr sref mean, lol. Which doesn't look to be holding anything back Link to comment Share on other sites More sharing options...
TheTrials Posted January 30, 2012 Share Posted January 30, 2012 That ridge axis actually bends back into the Davis straight but its weakened by the time its in that location...the problem isn't being east based on that map, its being too far south...more of a N ATL pridge and not a big Greenland ridge...it gets into Greenland but only the northern part of it. East based blocks usually promote further north storms than west based blocks...not the other way around. A north ATL ridge is a common pattern for big cold outbreaks in the east but it is generally poor for huge snowstorms. Obviously there are exceptions to these rules...but if you composite the top 20 or 30 cold outbreaks in the past 30 years, the N ATL ridge is staring at us in the face. Well it's south and east. It's still not gonna work. The ensembles show your point well.about the heights getting pushed back before getting firmly.over Greenland. Do you have an illustration of what you consider east and good becuase everything ive looked at shows me the west best and or retrograding block brings the goods. Also I guess geographic perspective is impt here given where you are. Link to comment Share on other sites More sharing options...
earthlight Posted January 30, 2012 Share Posted January 30, 2012 Well it's south and east. It's still not gonna work. The ensembles show your point well.about the heights getting pushed back before getting firmly.over Greenland. Do you have an illustration of what you consider east and good becuase everything ive looked at shows me the west best and or retrograding block brings the goods. Also I guess geographic perspective is impt here given where you are. It is not "very east based" as you stated. It is south of Greenland -- and the anomalies extend to Greenland. And most importantly the ridge axis is near Greenland. An east based NAO or block has the most pronounced positive height anomalies over Iceland and the N Atlantic. None of the guidance shows that. Link to comment Share on other sites More sharing options...
TheTrials Posted January 30, 2012 Share Posted January 30, 2012 It is not "very east based" as you stated. It is south of Greenland -- and the anomalies extend to Greenland. And most importantly the ridge axis is near Greenland. An east based NAO or block has the most pronounced positive height anomalies over Iceland and the N Atlantic. None of the guidance shows that. Im using greenland as marker. The ensembles clearly.show the highest heights never getting all the way over Greenland before getting pushed back. It's all fantasy anyway. We have yet to get any blocking east West etc to.verify so let's see it get closer in.time Link to comment Share on other sites More sharing options...
ORH_wxman Posted January 30, 2012 Share Posted January 30, 2012 Well it's south and east. It's still not gonna work. The ensembles show your point well.about the heights getting pushed back before getting firmly.over Greenland. Do you have an illustration of what you consider east and good becuase everything ive looked at shows me the west best and or retrograding block brings the goods. Also I guess geographic perspective is impt here given where you are. PDII in Feb '03 had an east based block with ridging poking back into Greenland leading up to it: Feb 2006 also had east based ridging...not a big block though...but a east based -NAO setting the stage for that system...but that system def had to work a bit to become what it did...NAO isn't the only factor, but its a huge help...so its hard to isolate the variables. January 1961 as well Link to comment Share on other sites More sharing options...
Isotherm Posted January 30, 2012 Share Posted January 30, 2012 Reports in PA are awsome. 45-50mph winds with blinding snow and up to 1" in minutes. Hopefully, band holds and gives someone in our area something. It's weakening pretty rapidly per latest frames. I wouldn't hold out much hope. Link to comment Share on other sites More sharing options...
ag3 Posted January 30, 2012 Share Posted January 30, 2012 It's weakening pretty rapidly per latest frames. I wouldn't hold out much hope. Yup. Models had it breaking up rapidly past the mountains. Link to comment Share on other sites More sharing options...
TheTrials Posted January 30, 2012 Share Posted January 30, 2012 and will, how do you make those maps? There are a bunch of dates I would like to look at. And looking at those maps, boy did we get lucky on 2/06 and look at those beautiful epo ridges on 1 and 3 Link to comment Share on other sites More sharing options...
psv88 Posted January 30, 2012 Share Posted January 30, 2012 It's weakening pretty rapidly per latest frames. I wouldn't hold out much hope. Its also 40 degrees out. He would be holding out hope for a breezy rain shower at like 4 am...oh what a winter it has been! Link to comment Share on other sites More sharing options...
ag3 Posted January 30, 2012 Share Posted January 30, 2012 Its also 40 degrees out. He would be holding out hope for a breezy rain shower at like 4 am...oh what a winter it has been! I definitely am not. Models had this breaking up and looks like its happening just as they showed. Link to comment Share on other sites More sharing options...
bass28 Posted January 30, 2012 Share Posted January 30, 2012 Its also 40 degrees out. He would be holding out hope for a breezy rain shower at like 4 am...oh what a winter it has been! Im at 33 so itd prob snow over here. Link to comment Share on other sites More sharing options...
psv88 Posted January 30, 2012 Share Posted January 30, 2012 Im at 33 so itd prob snow over here. nice...take some pics for us Link to comment Share on other sites More sharing options...
rgwp96 Posted January 30, 2012 Share Posted January 30, 2012 Its also 40 degrees out. He would be holding out hope for a breezy rain shower at like 4 am...oh what a winter it has been! 28 here but i will see flurries at most Link to comment Share on other sites More sharing options...
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