Poimen Posted January 25, 2011 Share Posted January 25, 2011 So why would this not show on a model? I'm just trying to understand if this is usually what happens without that High, then why would a model still show snow? Are you referring to the GFS showing snow for us with this next storm? If so, here's what I mean. Check out the 192 hour panel: The high is retreating as the next northern stream system kicks it out. Our southern storm is going to have to be timed absolutely perfectly (if this is indeed the set-up) to give us any snow. If the timing is not right, it's more than likely either going to move inland ahead of the northern system, or if it is slower it will more than likely get suppressed or squashed by the northern system. Link to comment Share on other sites More sharing options...
tpsteffe Posted January 25, 2011 Share Posted January 25, 2011 What we need to look for 7-10 days out in this pattern is a wave moving along the Gulf and high pressure building in too late. If the trend of storms being delayed holds, the high pressure should be able to work in in concert with or just ahead of the system. Without blocking, high pressure won't hold for too long, so we'll need the good timing. Good thing is, there seems to be an endless supply of highs dropping out of Canada. Hopefully, they don't continuously drop out too far west...that is a possibility. Yep, been saying this for a few days now. It's a very fine line for us in the southeast without blocking as we need almost perfect timing between a shortwave and high pressure building into the region. As we can see with the storm unfolding today, without the timing between the two many people are left out of the wintry weather. The lack of blocking + west-based -NAO is concerning, but it's not impossible to see a winter storm without the two. An impressive +PNA looks to stay intact through at least the first week of February which is a plus (there are questions as to where it will go after this time), so we will just have to wait and see if we can get that timing between a high and low nailed down. Link to comment Share on other sites More sharing options...
UNCCmetgrad Posted January 25, 2011 Share Posted January 25, 2011 you know what's funny? DT is back to woofing this up on his fb page. He shows today's GFS and basically says, "you see, I told you so." I find this funny because he was just trashing the GFS a couple days ago, citing things like there's no blocking so this(current storm) has to be an Apps runner,etc etc. Well, what has changed? There's still no blocking with the upcoming storm and yet Dave is tooting his own horn and using his favorite whipping boy (the GFS) to do so. I like DT but sometimes I have a hard time following his inconsistent reasoning. Anyway, with regards to this next storm-it looks to me like it's either going to be suppression city or an inland/apps runner. As others have said, unless we can get that next high to anchor over the NE we'll probably end up with a non-wintry event in the SE. He is probably woofing more for the mid-atlantic and northeast than down here. Just because you have no blocking doesn't mean you will get an inland runner every time, just more times than now. The difference with the storm on the 204hr GFS and this upcoming storm is that by 204hrs the polar vortex over Canada has pulled to the southeast and strengthened. This would cause the storm track to shift south east to a more favorable position. However the problem with the transient highs would still be there with really nothing keeping them from moving out to sea. Link to comment Share on other sites More sharing options...
SnowNiner Posted January 25, 2011 Share Posted January 25, 2011 He is probably woofing more for the mid-atlantic and northeast than down here. Just because you have no blocking doesn't mean you will get an inland runner every time, just more times than now. The difference with the storm on the 204hr GFS and this upcoming storm is that by 204hrs the polar vortex over Canada has pulled to the southeast and strengthened. This would cause the storm track to shift south east to a more favorable position. However the problem with the transient highs would still be there with really nothing keeping them from moving out to sea. Question: would the polar vortex supply cold air to the south to feed the storm, or is the HIGH the part of the supply line? In my mind I'm trying to separate the two but I have a feeling they're connected. In other words do we really need the HIGH in next week's situation? Link to comment Share on other sites More sharing options...
Poimen Posted January 25, 2011 Share Posted January 25, 2011 King Euro looks down right ugly at 144 hours. I have no idea how the rest of the run will turn out, but this does not look positive for the SE crew. Link to comment Share on other sites More sharing options...
WeatherNC Posted January 25, 2011 Share Posted January 25, 2011 King Euro looks down right ugly at 144 hours. I have no idea how the rest of the run will turn out, but this does not look positive for the SE crew. Large PV setting up shop at 192 in SE Canada, >1040mb high coming into the northern plains, and 50-50 displaced south, looks pretty good... At 216 <512dm heights are along the NC/VA boarder, major cold blast, with the high >1035 over the lower MS valley. Overall a good setup, and despite the lack of high latitude blocking, which appears more important for HKY SN's compared to RDU per Allan's climo study, the +PNA is the strongest we have seen this winter, and we have cross polar flow at 168 on this run. All we need now is a trigger... Link to comment Share on other sites More sharing options...
Cold Rain Posted January 25, 2011 Share Posted January 25, 2011 Yep, been saying this for a few days now. It's a very fine line for us in the southeast without blocking as we need almost perfect timing between a shortwave and high pressure building into the region. As we can see with the storm unfolding today, without the timing between the two many people are left out of the wintry weather. The lack of blocking + west-based -NAO is concerning, but it's not impossible to see a winter storm without the two. An impressive +PNA looks to stay intact through at least the first week of February which is a plus (there are questions as to where it will go after this time), so we will just have to wait and see if we can get that timing between a high and low nailed down. Yeah, the PNA looks good. If I had to choose, I'd probably take the -NAO over the +PNA, but I don't see any sign of it returning anytime soon. LOL at the 216 Euro, by the way. Yet another 9 day out Arctic blast on the Euro. Link to comment Share on other sites More sharing options...
Cold Rain Posted January 25, 2011 Share Posted January 25, 2011 Large PV setting up shop at 192 in SE Canada, >1040mb high coming into the northern plains, and 50-50 displaced south, looks pretty good... At 216 <512dm heights are along the NC/VA boarder, major cold blast, with the high >1035 over the lower MS valley. Overall a good setup, and despite the lack of high latitude blocking, which appears more important for HKY SN's compared to RDU per Allan's climo study, the +PNA is the strongest we have seen this winter, and we have cross polar flow at 168 on this run. All we need now is a trigger... What we have here is a nice Lakes Cutter. Helps to drag down the cold. Usually seems like cold and dry conditions follow in these kinds of situations, but there has indeed been a lot of energy in the flow this year. Maybe, just maybe, we'll get our trigger. Link to comment Share on other sites More sharing options...
WeatherNC Posted January 25, 2011 Share Posted January 25, 2011 Yeah, the PNA looks good. If I had to choose, I'd probably take the -NAO over the +PNA, but I don't see any sign of it returning anytime soon. LOL at the 216 Euro, by the way. Yet another 9 day out Arctic blast on the Euro. Coldest air of the season if, big if, the EC has a handle on the pattern over Canada for the next 7 days. Cross polar flow via a +PNA is more important here than a -NAO, climo speaking. From Allan's site... The 500mb pattern most common in these 20 events is one where there is pronounced ridging over and above Alaska and also in western North America leading to cross-polar flow and a +PNA configuration, but unlike Hickory, the -NAO signature is very diffuse and much less than what is shown in the Hickory data. This could indicate the ideal pattern for big RDU snows is a strong +PNA configuration and a transitional NAO pattern where the value is around neutral. A very strong positive anomaly over Alaska creating cross-polar flow. The -NAO feature is very diffuse if non-existent, and obviously this could just be a few events with positive NAO's balancing out a general negative NAO but the event is none the less interesting and shows that for Raleigh to get big snows, the NAO does NOT have to be raging negative. Link to comment Share on other sites More sharing options...
rduwx Posted January 25, 2011 Share Posted January 25, 2011 Coldest air of the season if, big if, the EC has a handle on the pattern over Canada for the next 7 days. Cross polar flow via a +PNA is more important here than a -NAO, climo speaking. From Allan's site... Nice find WeatherNC! I've read this before on Allan's site but failed to recognize it in the recent Euro runs. Link to comment Share on other sites More sharing options...
griteater Posted January 25, 2011 Share Posted January 25, 2011 Gotta love the -23C at 850 here at hr216, with rapid warming to -4C at hr240...guess that fits the pattern without the Atlantic blocking. Link to comment Share on other sites More sharing options...
Cold Rain Posted January 25, 2011 Share Posted January 25, 2011 Coldest air of the season if, big if, the EC has a handle on the pattern over Canada for the next 7 days. Cross polar flow via a +PNA is more important here than a -NAO, climo speaking. Ok you've convinced me. I want a +PNA. But if this doesn't produce, I'm changing my preference back to a -NAO! Link to comment Share on other sites More sharing options...
SnowNiner Posted January 25, 2011 Share Posted January 25, 2011 Yeah, whatever works!! You mets just let us know what looks good on the long range, honking the horns, beating the drums, and we'll come running! Whether it's +PNA / - NAO, etc cross polar flow, NBA, NRA, LBC, just don't keep it on the DL. Kapeesh? Link to comment Share on other sites More sharing options...
UNCCmetgrad Posted January 25, 2011 Share Posted January 25, 2011 Question: would the polar vortex supply cold air to the south to feed the storm, or is the HIGH the part of the supply line? In my mind I'm trying to separate the two but I have a feeling they're connected. In other words do we really need the HIGH in next week's situation? The polar vortex serves as the source of the cold air. As you can see there are some very cold air over southeast Canada associated with it. However there is really nothing to feed this air south as the high has moved off the northeast coast. Without this we need the low to track perfectly for us to remain cold enough for snow. So technically we don't have to have a high over the eastern lakes or northeast next week, but it would greatly widen our room for error if we did. As it is on the GFS this looks like more of a setup for the mountains and then the mid-atlantic north as the low bombs off the coast of North Carolina and draws in the cold air from the northwest but this is way too far off to get into details. I think the EURO is actually showing an APPS runner for about this time period so who knows. Heck, models didn't seem to nail down the track of the current storm until today. Just know that there is potential for next week. Link to comment Share on other sites More sharing options...
Weather Czar Posted January 25, 2011 Share Posted January 25, 2011 Won't the vortex act as blocking? With the position of the vortex on the gfs I see no way this could go west of the apps. Link to comment Share on other sites More sharing options...
UNCCmetgrad Posted January 25, 2011 Share Posted January 25, 2011 Won't the vortex act as blocking? With the position of the vortex on the gfs I see no way this could go west of the apps. Not with the 500mb depiction on the GFS. The eastern US trough doesn't really amplify until it gets to the Mississippi River which would be too far east for an APPS runner. Link to comment Share on other sites More sharing options...
Poimen Posted January 25, 2011 Share Posted January 25, 2011 Large PV setting up shop at 192 in SE Canada, >1040mb high coming into the northern plains, and 50-50 displaced south, looks pretty good... At 216 <512dm heights are along the NC/VA boarder, major cold blast, with the high >1035 over the lower MS valley. Overall a good setup, and despite the lack of high latitude blocking, which appears more important for HKY SN's compared to RDU per Allan's climo study, the +PNA is the strongest we have seen this winter, and we have cross polar flow at 168 on this run. All we need now is a trigger... I agree, the rest of the run indicates a generally good set-up for us as you mentioned, but as for the storm in question on this thread the Euro is not so good for us. The Euro is much faster with the evolution of the system. At 144 it has the low in north TX, Sneaking out ahead of the northern stream, while the GFS at the same time has the developing low back near the 4 corners. The difference has huge consequences out in time, as the Euro takes it through the OH Valley on day 7, while the GFS still has it in west TX at that time. I don't know if the Euro is right, but I wouldn't bet against it. Link to comment Share on other sites More sharing options...
burrel2 Posted January 25, 2011 Share Posted January 25, 2011 For entertainment purposes. The 18z DGEX is showing a major winter storm for the deep south at the end of it's run. http://www.meteo.psu...z/dgexloop.html Link to comment Share on other sites More sharing options...
strongwxnc Posted January 26, 2011 Share Posted January 26, 2011 Great question and follow up post.. Very nice! [quote name='UNCCmetgrad' timestamp='1295986190' post='360410' The polar vortex serves as the source of the cold air. As you can see there are some very cold air over southeast Canada associated with it. However there is really nothing to feed this air south as the high has moved off the northeast coast. Without this we need the low to track perfectly for us to remain cold enough for snow. So technically we don't have to have a high over the eastern lakes or northeast next week, but it would greatly widen our room for error if we did. As it is on the GFS this looks like more of a setup for the mountains and then the mid-atlantic north as the low bombs off the coast of North Carolina and draws in the cold air from the northwest but this is way too far off to get into details. I think the EURO is actually showing an APPS runner for about this time period so who knows. Heck, models didn't seem to nail down the track of the current storm until today. Just know that there is potential for next week. Link to comment Share on other sites More sharing options...
oconeexman Posted January 26, 2011 Share Posted January 26, 2011 For entertainment purposes. The 18z DGEX is showing a major winter storm for the deep at the end of it's run. http://www.meteo.psu...z/dgexloop.html Sure is burrel! The Euro actually showed it as an I85 special a couple days ago now has went to the apps runner, in the mean time the GFS has had it and kept it for 3 days now. Will definitely be one to watch imo..we need perfect timing like someone said earlier with the PNA ridge as I put no faith in a high pressure wedge anymore. They seem to be far and few between and poorly modeled, kind of like todays event. Crazy to say but the DGEX isn't much worse than any other model in mid range right now. Link to comment Share on other sites More sharing options...
superjames1992 Posted January 26, 2011 Share Posted January 26, 2011 If there's one thing I've learned about the pattern this season, it's that the cold shot will NOT be nearly as strong or severe as progged. It will probably come in a more moderated fashion, but cold in its own right. Link to comment Share on other sites More sharing options...
Northern Foothills Snowman Posted January 26, 2011 Share Posted January 26, 2011 Link to comment Share on other sites More sharing options...
Northern Foothills Snowman Posted January 26, 2011 Share Posted January 26, 2011 Link to comment Share on other sites More sharing options...
Northern Foothills Snowman Posted January 26, 2011 Share Posted January 26, 2011 I know I posted the maps backwards but just wanted to show it's should stay cold for a while. Link to comment Share on other sites More sharing options...
BullCityWx Posted January 26, 2011 Share Posted January 26, 2011 That's reaaaaaaally far south in Texas for ice/snow accumulations. Link to comment Share on other sites More sharing options...
triadwx Posted January 26, 2011 Share Posted January 26, 2011 Looks like the cold is here to stay.. Link to comment Share on other sites More sharing options...
DCMetroWinston Posted January 26, 2011 Share Posted January 26, 2011 No one should believe that it will be anywhere as cold as the models depict. They have consistently teased barbaric cold this winter multiple times, but it never happened. this time wont be different, though it will probably be moderately cold. Link to comment Share on other sites More sharing options...
FoothillsNC Posted January 26, 2011 Share Posted January 26, 2011 the Latest Op. Run of the Euro has the main of the cold west of the Apps through day 10. Around day 6 and 7 theres some damming and a southern feature (weak) comes into the Southeast, and the bigger cold blast is west of the Apps over the Plains. It has some -16 in Texas if I recall, and sw flow in the Southeast, which could be overrunning later on. But I wouldn't take the Euro too seriously in this changing pattern, its having trouble. Link to comment Share on other sites More sharing options...
SnowNiner Posted January 26, 2011 Share Posted January 26, 2011 the Latest Op. Run of the Euro has the main of the cold west of the Apps through day 10. Around day 6 and 7 theres some damming and a southern feature (weak) comes into the Southeast, and the bigger cold blast is west of the Apps over the Plains. It has some -16 in Texas if I recall, and sw flow in the Southeast, which could be overrunning later on. But I wouldn't take the Euro too seriously in this changing pattern, its having trouble. Yes, I think the EURO handled this last storm pretty poorly IMO. And it continues to honk big cold that never quite comes to fruition. Though is seems the most reliable in some situations, I'm starting to think it has something to do with seeing -NAO conditions well like it did in Dec/Jan. I don't know, but this last storm was a swing and a miss in the medium range. I'm pulling for the GFS forecast as of this time!! I reserve the right to switch at any given moment. Link to comment Share on other sites More sharing options...
POWERSTROKE Posted January 26, 2011 Share Posted January 26, 2011 All mets are talking about how the cold is coming back next week. On tv last night all the locals showed warming up until tuesday then cold comes back, JB had a big hype on how cold it will be until at least mid february. So I don't think the cold is leaving but without moisture blocking we get nothing but cold rain just like now. 36degrees and cold rain Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.