tornadotony Posted March 11, 2012 Share Posted March 11, 2012 I don't normally post for anything this far out, and specifics will not be provided in this post. But the GFS and the Euro have both been consistent in bringing a powerhouse jet ashore sometime a bit after St. Patrick's Day. How it evolves changes from run to run, but there have been two constants in this equation. 1) Very powerful jet. 2) Wide open Gulf, extremely warm/humid central/eastern United States, with that airmass locked in place in the previous days. It's too early to even highlight regions that might be threatened. It could be anywhere from the southern plains to the lower Lakes or even the upper Midwest. But combining the two above constants does not typically end all that well, and this time frame bears very close watching through the week and next weekend. Link to comment Share on other sites More sharing options...
Indystorm Posted March 12, 2012 Share Posted March 12, 2012 Yes, the days around astronomical spring could really pack a wallop for some places according to current model patterns. Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 GFS has two strong systems, for different regions of the country, actually is close to merging them into one massive trough... Link to comment Share on other sites More sharing options...
beneficii Posted March 12, 2012 Share Posted March 12, 2012 GFS has two strong systems, for different regions of the country, actually is close to merging them into one massive trough... If you don't mind me asking, Could you show maps of this? Link to comment Share on other sites More sharing options...
turtlehurricane Posted March 12, 2012 Share Posted March 12, 2012 My gut is saying the same thing, a series of severe weather outbreaks seems unavoidable sometime later this month. Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 If you don't mind me asking, Could you show maps of this? First system is the upper level low centered in SW Saskatchewan and the second comes out of that vigorous mid/upper level jet streak into Southern CA, and you can see how they are close to merging together into one beast of a trough (the 528 dm heights are connected between both jet streaks, previously, there was a ridge between the two systems). In that case, the second, more powerful jet streak would possibly lead to a powerful shortwave impulse ejecting out from underneath the trough sometime between 174 and 216 hrs, inducing rapid, potentially intense surface cyclogenesis, beneath a broad-based and likely somewhat negatively tilted trough, which would spell big trouble in all likelihood for somebody. Both systems have huge warm sectors to work with. Link to comment Share on other sites More sharing options...
beneficii Posted March 12, 2012 Share Posted March 12, 2012 First system is the upper level low centered in SW Saskatchewan and the second comes out of that vigorous mid/upper level jet streak into Southern CA, and you can see how they are close to merging together into one beast of a trough (the 528 dm heights are connected between both jet streaks, previously, there was a ridge between the two systems). In that case, the second, more powerful jet streak would possibly lead to a powerful shortwave impulse ejecting out from underneath the trough sometime between 174 and 216 hrs, inducing rapid, potentially intense surface cyclogenesis, beneath a broad-based and likely somewhat negatively tilted trough, which would spell big trouble in all likelihood for somebody. Both systems have huge warm sectors to work with. Thank you for posting that. Now I was also looking at the Euro, and it seems to show only a single system during that time frame, but it doesn't really eject at all, and ends up being cut off at 216 hr. Now, as I understand it, the Euro sometimes has problems modeling the ejection of a shortwave onto the Plains. Is that correct, and may the Euro's depiction of the low getting cut off be therefore in error? Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 The Euro develops some kind of insane blocking that prevents the trough from ejecting fully, it has a closed off 582 dm ridge across the NE at 240, which seems pretty unrealistic, even with the extent of this torch. I mean, 570 dm heights into Hudson's Bay in March? Come on... If that first wave comes in like the GFS progs, it will likely suppress the ridge somewhat and allow the second upper/mid level trough to eject more fully, and, as I mentioned, it is close to merging the two storm systems together. Link to comment Share on other sites More sharing options...
beneficii Posted March 12, 2012 Share Posted March 12, 2012 The Euro develops some kind of insane blocking that prevents the trough from ejecting fully, it has a closed off 582 dm ridge across the NE at 240, which seems pretty unrealistic, even with the extent of this torch. I mean, 570 dm heights into Hudson's Bay in March? Come on... If that first wave comes in like the GFS progs, it will likely suppress the ridge somewhat and allow the second upper/mid level trough to eject more fully, and, as I mentioned, it is close to merging the two storm systems together. You're right. That would be one heck of a torch. Heck, it was considered notable down here during last summer in Memphis when the 500 hPa heights got up to 592 dm over us, as they did on a number of occasions. 582 dm and 588 dm heights were the minimum rule over us, making for an absolutely baking summer. I'm guessing the reason the Euro has a tendency to hold back the shortwave is because it tends to build up too strong of blocking. I suppose it remains to be seen exactly where this unified trough would set up. If it's large and broad, though, then it would likely affect a large area of the country. Link to comment Share on other sites More sharing options...
brettjrob Posted March 12, 2012 Share Posted March 12, 2012 As we've been discussing over in Central/Western for a few days now, the stage being set over the course of this next week is rather extraordinary for mid-March. Ignoring the potential for big fireworks once the trough ejects, it's noteworthy enough just to look at the surface dew points and SBCAPE progged over much of the central U.S. each afternoon this coming week (starting Tuesday). I can't remember ever seeing a sloshing dryline with high instability hanging out over the Plains and upper Midwest day-after-day prior to late April... until now. Like Tony said, extended, broad eastern CONUS ridging that draws in unseasonably-rich low-level moisture this early in the season is a huge red flag all on its own. In all likelihood, the only way to "avoid" a high-impact event over the next 7-14 days will be for the omega block solutions to verify, preventing the longwave trough from ever translating past the Great Basin prior to lifting/shearing out. Link to comment Share on other sites More sharing options...
tornadotony Posted March 12, 2012 Author Share Posted March 12, 2012 As we've been discussing over in Central/Western for a few days now, the stage being set over the course of this next week is rather extraordinary for mid-March. Ignoring the potential for big fireworks once the trough ejects, it's noteworthy enough just to look at the surface dew points and SBCAPE progged over much of the central U.S. each afternoon this coming week (starting Tuesday). I can't remember ever seeing a sloshing dryline with high instability hanging out over the Plains and upper Midwest day-after-day prior to late April... until now. Like Tony said, extended, broad eastern CONUS ridging that draws in unseasonably-rich low-level moisture this early in the season is a huge red flag all on its own. In all likelihood, the only way to "avoid" a high-impact event over the next 7-14 days will be for the omega block solutions to verify, preventing the longwave trough from ever translating past the Great Basin prior to lifting/shearing out. It really is extraordinary. We never really had a winter, and now we're entering a May-type pattern. Link to comment Share on other sites More sharing options...
OceanStWx Posted March 12, 2012 Share Posted March 12, 2012 It really is extraordinary. We never really had a winter, and now we're entering a May-type pattern. Looks like our thoughts of starting the season quickly could be coming to fruition (March 2nd outbreak not withstanding). Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 00z run of the GFS is very similar to 18z through 144. Not even the main system yet, and look at this LLJ and SLP/sfc winds: Link to comment Share on other sites More sharing options...
Hoosier Posted March 12, 2012 Share Posted March 12, 2012 If you took the dates off some of the progs you'd swear you were in April or May. Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 As for the later system, 00z went south, ends up closing the low, but it still ejects and you still get an ugly setup across the Plains/Ozarks on the 19th/20th/21st, and this is with the 582 dm line into Ontario and a closed off 585 ridge in the NE... This concerns me significantly, as we still are seeing a volatile setup even with the omega blocking solution in place... Link to comment Share on other sites More sharing options...
beneficii Posted March 12, 2012 Share Posted March 12, 2012 Wow, that's showing potential severe going into the Northern Plains and Upper Mississippi Valley! To have that occur this early in the season is simply mesmerizing. Link to comment Share on other sites More sharing options...
beneficii Posted March 12, 2012 Share Posted March 12, 2012 As for the later system, 00z went south, ends up cutting off the low, but it still ejects and you still get an ugly setup across the Plains/Ozarks on the 20th/21st, and this is with the 582 dm line into Ontario... In other words, we're still gonna wanna take it with a grain of salt. Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 In other words, we're still gonna wanna take it with a grain of salt. Yes, of course, given we're 8-10 days out, but I think my concern just went up a bit seeing a potentially significant setup with the trough ejecting even with Euro-like blocking in place. (I.E. I'm looking for trends in one direction or the other for this system at this point). Right now I'll focus on that lead wave, which looks to be a possible setup in itself, if the upper support arrives in time to help erode the cap. Link to comment Share on other sites More sharing options...
brettjrob Posted March 12, 2012 Share Posted March 12, 2012 The 00z GFS looks extremely impressive for Monday 3/19... no other way to put it. Simply a textbook early spring dryline setup for central and western portions of NE/KS/OK/TX. No reason to get into details given the timeframe and wild swings in the evolution of this trough, but the main takeaway is that the GFS has moved back toward ejecting it in a timely manner. Link to comment Share on other sites More sharing options...
PatrickSumner Posted March 12, 2012 Share Posted March 12, 2012 Anything for the Ohio Valley/Great Lakes region in the next few weeks??? Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 Anything for the Ohio Valley/Great Lakes region in the next few weeks??? You don't need to post multiple question marks But, yes, I think there is a definite possibility. And...yeah, what brett just mentioned looks ominous (keep in mind Brett that this ridging on this run is even more impressive than the Euro, more blocking and still a dangerous looking situation), it is not often you see that much CAPE show up on the GFS 192 hrs out...wow... Link to comment Share on other sites More sharing options...
brettjrob Posted March 12, 2012 Share Posted March 12, 2012 You don't need to post multiple question marks But, yes, I think there is a definite possibility. And...yeah, what brett just mentioned looks ominous (keep in mind Brett that this ridging on this run is even more impressive than the Euro, more blocking and still a dangerous looking situation), it is not often you see that much CAPE show up on the GFS 192 hrs out...wow... Exactly... one would assume that a less extreme Omega pattern would lead to less meridional flow and slightly better moisture. Eagerly awaiting the Euro, though it's going to be harder to stay awake that long from here on out! Link to comment Share on other sites More sharing options...
beneficii Posted March 12, 2012 Share Posted March 12, 2012 Anything for the Ohio Valley/Great Lakes region in the next few weeks??? It's still too early to know what the evolution of this storm is going to be, so what we've talked about being shown on St. Patrick's Day and beyond has potential for pretty much anywhere between the Appalachians and the Rocky Mountains. As we get closer, we should start being able to pin down specific regions most likely to be affected. Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 Exactly... one would assume that a less extreme Omega pattern would lead to less meridional flow and slightly better moisture. Eagerly awaiting the Euro, though it's going to be harder to stay awake that long from here on out! There's very minimal capping as well. Allow me to add to my previous post, it is exceedingly rare to see that much CAPE show up on the GFS at 192 hrs in a relatively uncapped warm sector... And even with all these systems, the Gulf remains virtually untouched. Link to comment Share on other sites More sharing options...
beneficii Posted March 12, 2012 Share Posted March 12, 2012 There's very minimal capping as well. Allow me to add to my previous post, it is exceedingly rare to see that much CAPE show up on the GFS at 192 hrs in a relatively uncapped warm sector... And even with all these systems, the Gulf remains virtually untouched. That last point certainly supports the idea of multiple rounds in the latter half of the month. Oh boy, now we're back into the watching and waiting game. By the time we get to the event, I wouldn't have been thinking about anything but models and potential. Link to comment Share on other sites More sharing options...
Stebo Posted March 12, 2012 Share Posted March 12, 2012 I don't normally post for anything this far out, and specifics will not be provided in this post. But the GFS and the Euro have both been consistent in bringing a powerhouse jet ashore sometime a bit after St. Patrick's Day. How it evolves changes from run to run, but there have been two constants in this equation. 1) Very powerful jet. 2) Wide open Gulf, extremely warm/humid central/eastern United States, with that airmass locked in place in the previous days. It's too early to even highlight regions that might be threatened. It could be anywhere from the southern plains to the lower Lakes or even the upper Midwest. But combining the two above constants does not typically end all that well, and this time frame bears very close watching through the week and next weekend. Honestly I can not remember a time period of extended above normal temps/moisture flowing northward for so many days in advance of this trough. I mean some of the instability numbers that the GFS is putting out before this would be exceptional for severe weather this time of the year and mind you it is the GFS which has a tendency to grossly underdo instability in the early season. A closer to reality image would be the NAM, an example of the potential amount of instability for the region later this week is as follows: If someone posted this without a date I would say Late May or Early June. To have 3000 J/kg of CAPE this far north this time of year is absolutely extraordinary, and one would imagine as you go on further in time closer to this system next weekend these numbers would have the potential to go up even higher given the continual flow out of the gulf plus the upper-level cooling advancing in with the trough. Like you say it is hard to pinpoint an area right now but to see the stuff we are seeing in the models looking ahead one would certainly be concerned about a significant outbreak within the 5-10 day range, maybe a couple outbreaks. Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 Honestly I can not remember a time period of extended above normal temps/moisture flowing northward for so many days in advance of this trough. I mean some of the instability numbers that the GFS is putting out before this would be exceptional for severe weather this time of the year and mind you it is the GFS which has a tendency to grossly underdo instability in the early season. A closer to reality image would be the NAM, an example of the potential amount of instability for the region later this week is as follows: If someone posted this without a date I would say Late May or Early June. To have 3000 J/kg of CAPE this far north this time of year is absolutely extraordinary, and one would imagine as you go on further in time closer to this system next weekend these numbers would have the potential to go up even higher given the continual flow out of the gulf plus the upper-level cooling advancing in with the trough. Like you say it is hard to pinpoint an area right now but to see the stuff we are seeing in the models looking ahead one would certainly be concerned about a significant outbreak within the 5-10 day range, maybe a couple outbreaks. Great post. Reminds me a bit of April 9th/10th last year thermodynamically, except three weeks earlier... Link to comment Share on other sites More sharing options...
Stebo Posted March 12, 2012 Share Posted March 12, 2012 Great post. Reminds me a bit of April 9th/10th last year thermodynamically... Yeah I am using that map more as an instability reference more than anything. Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 Euro at 168: Link to comment Share on other sites More sharing options...
andyhb Posted March 12, 2012 Share Posted March 12, 2012 Wow, the 00z GGEM is pretty interesting, not sure about you guys, but that looks like a multi-day significant severe weather threat if I've ever seen one: Day 1: Day 2: Day 3: 12z Day 4: Day 4: Link to comment Share on other sites More sharing options...
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